FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
MOTOR CONTROL DEVICE AND ELECTRIC POWER STEERING DEVICE;
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED AND
EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-3,
MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO 1008310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.
2
[DESCRIPTION]
[Technical Field]
[0001]
The present disclosure relates to a motor control device and an electric power steering
5 device.
[Background Art]
[0002]
An electric power steering device which includes a motor control device that has a
main control unit and an auxiliary control unit is disclosed in Patent Document 1. As
10 such, by adopting a double redundant control system, it is possible to continue motor
control even when an abnormality occurs in one control unit of the control system.
[Citation List]
[Patent Document]
[0003]
15 [Patent Document 1] Published Japanese Translation No. 2021-508635 of the PCT
International Publication
[Summary of Invention]
[PROBLEM TO BE SOLVED BY THE INVNETION]
[0004]
20 Since the main control unit and the auxiliary control unit share a pre-driver in the
motor control device disclosed in Patent Document 1, when an abnormality occurs in the
pre-driver, there is a possibility that the motor is not being adequately controlled.
[0005]
The present disclosure has been made in order to address the problem above, and an
25 object is to provide a motor control device and an electric power steering device by that
3
are more stable against abnormality occurrences.
[MEANS TO SOLVE THE PROBLEM]
[0006]
A motor control device according to an embodiment of the present disclosure includes:
5 a motor drive circuit that outputs a drive current to a motor; a drive current detector that
detects the drive current; a main control unit, and an auxiliary control unit, wherein the
motor drive circuit is driven based on a drive signal that is output from the main control
unit or the auxiliary control unit, the main control unit has a first control signal generator
that generates a first control signal based on a detected current signal that is input from
10 the drive current detector; a first drive signal generator that generates the drive signal
based on the first control signal, and a first switcher that switches an output state of the
drive signal to the motor drive circuit, and the auxiliary control unit has a second control
signal generator that generates a second control signal based on a detected current signal
that is input from the drive current detector; a second drive signal generator that
15 generates the drive signal based on the second control signal, and a second switcher that
switches an output state of the drive signal to the motor drive circuit.
[0007]
An electric power steering device according to an embodiment of the present
disclosure includes the aforementioned motor control device, and the motor which
20 generates an assist torque to assist a steering torque of steering of an operator.
[EFFECTS OF THE INVENTION]
[0008]
According to the present disclosure, it is possible to provide a motor control device
and an electric power steering device that are more stable against abnormality
25 occurrences.
4
[Brief Description of Drawings]
[0009]
[FIG. 1] A block diagram showing an overall configuration of a motor control device
according to a first embodiment.
5 [FIG. 2] A block diagram showing an overall configuration of the motor control device
according to a second embodiment.
[FIG. 3] A block diagram showing an overall configuration of the motor control device
according to a third embodiment.
[FIG. 4] A block diagram showing an overall configuration of the motor control device
10 according to a fourth embodiment.
[FIG. 5] A block diagram showing an overall configuration of the motor control device
according to a fifth embodiment.
[FIG. 6] A block diagram showing an overall configuration of the motor control device
according to a seventh embodiment.
15 [Description of Embodiments]
[0010]
Hereinafter, configurations of the present disclosure are explained with reference to the
drawings. The scope of the present disclosure is not limited to the embodiments below,
and may be changed so long as the embodiments do not depart from the technical scope
20 of the present disclosure.
[0011]
First Embodiment
As shown in FIG. 1, a motor control device 100 according to a first embodiment
includes a main control unit A1, an auxiliary control unit A2, a motor drive circuit 5, a
25 current detection unit 7, and a current input I/F 8. In the present description, “I/F”
5
stands for “interface”.
The motor control device 100 is configured as a double redundant control system that
includes a first control system (main control unit A1) and a second control system
(auxiliary control unit A2). The motor control device 100 is an example of a part of an
5 electric power steering device mounted on an automobile. The motor control device
100 controls the motor 6 that is included by the electric power steering device. The
motor 6 is connected to a steering system not shown on the drawings.
[0012]
As shown in FIG. 1, the main control unit A1 includes a first microcomputer 1a, a first
10 pre-driver 2a, a first signal cut off switch 3a and a first switch control unit 4a. The
auxiliary control unit A2 includes a second microcomputer 1b, a second pre-driver 2b, a
second signal cut off switch 3b and a second switch control unit 4b. The first
microcomputer 1a corresponds to a first control signal generator, and the second
microcomputer 1b corresponds to a second control signal generator. The first pre-driver
15 2a corresponds to a first drive signal generator, and the second pre-driver 2b corresponds
to a second drive signal generator.
[0013]
The motor drive circuit 5 includes six switching transistors Q1 to Q6, and three shunt
resistors R1 to R3. Switching transistors Q1 to Q6 are types of switching elements. A
20 switching element other than a switching transistor may be used. The motor drive
circuit 5 is configured to drive the motor 6 by having the plurality of switching
transistors Q1 to Q6 switch between supply and cut off of a drive current to the motor 6.
[0014]
The motor 6 includes three input terminals (U phase input terminal, V phase input
25 terminal, and a W phase input terminal). The motor drive circuit 5 inputs three phase
6
drive currents (U phase drive current, V phase drive current, and W phase drive current)
into each of the input terminals of the motor 6. As such, the motor 6 is driven. In
other words, the motor 6 in the present embodiment is a three phase direct current
electric motor.
5 [0015]
The motor 6 is a generating source of an assist torque to assist steering of an operator
operating an automobile. In other words, the motor 6 conducts assistance so as to allow
for steering using a smaller steering torque when the operator is steering the automobile.
[0016]
10 The first microcomputer 1a generates six gate control signals based on a control
program that is stored in advance. The first microcomputer 1a is an integrally formed
chip, having a memory unit which stores the control program, a calculation unit that
executes calculations, and the like based on the control program. The first
microcomputer 1a includes at least six output terminals, and at least three input terminals.
15 It is possible to change a number of input terminals and the number of output terminals in
the various components as necessary. Output terminals or input terminals that are not
connected to any components may exist.
[0017]
The six output terminals that are included in the first microcomputer 1a are connected
20 to the first pre-driver 2a. The first microcomputer 1a outputs the six gate control signals
to the first pre-driver 2a via the six output terminals. The three input terminals that are
included in the first microcomputer 1a are connected to the current input I/F 8. Current
detection signals that correspond to three phases (U phase, V phase, and W phase) are
input to the first microcomputer 1a from the current input I/F 8 via the three input
25 terminals.
7
[0018]
The six gate control signals mentioned above correspond to the six switching
transistors Q1 to Q6 in the motor drive circuit 5. Hereinafter, a control signal
corresponding to the switching transistor Q1 is referred to as “gate control signal S1”, a
5 control signal corresponding to the switching transistor Q2 is referred to as “gate control
signal S2”, a control signal corresponding to the switching transistor Q3 is referred to as
“gate control signal S3”, a control signal corresponding to the switching transistor Q4 is
referred to as “gate control signal S4”, a control signal corresponding to the switching
transistor Q5 is referred to as “gate control signal S5”, and a control signal corresponding
10 to the switching transistor Q6 is referred to as “gate control signal S6”.
[0019]
The first pre-driver 2a is a gate driver that generates six gate signals Sg1 to Sg6 based
on the six gate control signals S1 to S6. The first pre-driver 2a may be a single IC
(Integrated Circuit). Voltages of the gate control signals S1 to S6 that the first
15 microcomputer 1a generates are not enough to operate the switching transistors Q1 to Q6.
As such, the first pre-driver 2a generates the gate signals Sg1 to Sg6 that have enough
voltages to operate the switching transistors Q1 to Q6, based on the gate control signals
S1 to S6. Each of the gate signals Sg1 to Sg6 corresponds to each of the gate control
signals S1 to S6.
20 [0020]
As shown in FIG. 1, the first pre-driver 2a includes six input terminals and six output
terminals. Each of the six input terminals is connected to each of the six output
terminals in the first microcomputer 1a, and each of the gate control signals S1 to S6 is
received therefrom. Each of the six output terminals is connected to the first signal cut
25 off switch 3a, and a corresponding gate signal Sg1 to Sg6 is output to the first signal cut
8
off switch 3a.
[0021]
The first signal cut off switch 3a includes six on/off switches that correspond to each
of the gate signals Sg1 to Sg6. The first signal cut off switch 3a includes six input
5 terminals and six output terminals that correspond to each on/off switch. The first
signal cut off switch 3a also includes one control input terminal. Each of the six input
terminals in the first signal cut off switch 3a is connected to each of the output terminals
in the first pre-driver 2a, and is input into each of the gate signals Sg1 to Sg6.
[0022]
10 The six output terminals in the first signal cut off switch 3a are connected to the motor
drive circuit 5. The first signal cut off switch 3a outputs the six gate signals Sg1 to Sg6
to the motor drive circuit 5 via the six output terminals. The one control input terminal
in the first signal cut off switch 3a is connected to the first switch control unit 4a. The
first switch control unit 4a inputs a first switching signal to the first signal cut off switch
15 3a via the one control input terminal mentioned above.
[0023]
The first signal cut off switch 3a switches between the on/off states of the six on/off
switches, based on the first switching signal. As such, the first signal cut off switch 3a
is a changeover switch that switches an output state (output/no output) of the gate signals
20 Sg1 to Sg6 from the main control unit A1 to the motor drive circuit 5, based on the first
switching signal.
[0024]
The first switch control unit 4a is a signal generating circuit that generates the first
switching signal of the first signal cut off switch 3a, and includes one output terminal.
25 The first switch control unit 4a outputs the first switching signal to the control input
9
terminal of the first signal cut off switch 3a.
[0025]
The second microcomputer 1b generates the six gate control signals S1 to S6 to control
the motor 6 based on the control program that is stored in advance. The second
5 microcomputer 1b is an integrally formed chip, having a memory unit which stores the
control program, a calculation unit that executes calculations, and the like based on the
control program. The control program of the second microcomputer 1b is the same as
the control program of the first microcomputer 1a. The second microcomputer 1b
includes at least six output terminals, and at least three input terminals.
10 [0026]
The six output terminals that are included in the second microcomputer 1b are
connected to the second pre-driver 2b. The second microcomputer 1b outputs the six
gate control signals S1 to S6 to the second pre-driver 2b via the six output terminals.
The three input terminals that are included in the second microcomputer 1b are connected
15 to the current input I/F 8. The current detection signals that correspond to three phases
(U phase, V phase, and W phase) are input to the second microcomputer 1b from the
current input I/F 8 via the three input terminals.
[0027]
The second pre-driver 2b is a gate driver that generates the six gate signals Sg1 to Sg6
20 based on the six gate control signals S1 to S6. The second pre-driver 2a may be a single
IC (Integrated Circuit). Voltages of the gate control signals S1 to S6 that the second
microcomputer 1b generates are not enough to operate the switching transistors Q1 to Q6.
As such, the second pre-driver 2b generates the gate signals Sg1 to Sg6 that have enough
voltages to operate the switching transistors Q1 to Q6, based on the gate control signals
25 S1 to S6.
10
[0028]
The second pre-driver 2b includes six input terminals and six output terminals. Each
of the six input terminals is connected to each of the six output terminals in the second
microcomputer 1b, and each of the gate control signals S1 to S6 is received therefrom.
5 Each of the six output terminals is connected to the second signal cut off switch 3b, and a
corresponding gate signal Sg1 to Sg6 is output to the second signal cut off switch 3b.
[0029]
The second signal cut off switch 3b includes six on/off switches that correspond to
each of the gate signals Sg1 to Sg6. The second signal cut off switch 3b includes six
10 input terminals and six output terminals that correspond to each on/off switch. The
second signal cut off switch 3b also includes one control input terminal. Each of the six
input terminals in the second signal cut off switch 3b is connected to each of the output
terminals in the second pre-driver 2b, and is input into each of the gate signals Sg1 to
Sg6.
15 [0030]
The six output terminals in the second signal cut off switch 3b are connected to the
motor drive circuit 5. The second signal cut off switch 3b outputs the six gate signals
Sg1 to Sg6 to the motor drive circuit 5 via the six output terminals. The one control
input terminal in the second signal cut off switch 3b is connected to the second switch
20 control unit 4b. The second switch control unit 4b inputs a second switching signal to
the second signal cut off switch 3b via the one control input terminal mentioned above.
[0031]
The second signal cut off switch 3b switches between the on/off states of the six on/off
switches, based on the second switching signal. As such, the second signal cut off
25 switch 3b is a changeover switch that switches an output state (output/no output) of the
11
gate signals Sg1 to Sg6 from the auxiliary control unit A2 to the motor drive circuit 5,
based on the second switching signal.
[0032]
The second switch control unit 4b is a signal generating circuit that generates the
5 second switching signal of the second signal cut off switch 3b, and includes one output
terminal. The second switch control unit 4b outputs the second switching signal to the
control input terminal of the second signal cut off switch 3b.
[0033]
Each of the six output terminals in the second signal cut off switch 3b are connected to
10 each of the corresponding output terminals in the first signal cut off switch 3a. In other
words, the main control unit A1 and the auxiliary control unit A2 are connected to the
motor drive circuit 5 so that the gate signals Sg1 to Sg6 are input to the motor drive
circuit 5 from either of the main control unit A1 or the auxiliary control unit A2.
[0034]
15 When the main control unit A1 is operating, the six gate signals Sg1 to Sg6 from the
first signal cut off switch 3a are input to the motor drive circuit 5. When the auxiliary
control unit A2 is operating, the six gate signals Sg1 to Sg6 from the second signal cut
off switch 3b are input to the motor drive circuit 5.
[0035]
20 The motor drive circuit 5 is a three phase inverter that includes three switching legs,
each corresponding to a U phase, a V phase, and a W phase. Hereinafter, a switching
leg corresponding to the U phase is referred to as a “U phase leg”, a switching leg
corresponding to the V phase is referred to as a “V phase leg”, and a switching leg
corresponding to the W phase is referred to as a “W phase leg”. The motor drive circuit
25 5 is controlled based on the six gate signals Sg1 to Sg6 that are input from either of the
12
main control A1 or from the auxiliary control A2. The motor drive circuit 5 converts a
direct current of a predetermined voltage (typically 12V) supplied from a battery 9 of the
automobile to three phases, U phase, V phase, and W phase of an alternating current
power, and outputs the aforementioned to the motor 6.
5 [0036]
The U phase leg includes the switching transistor Q1 that configures an upper arm, the
switching transistor Q2 that configures a lower arm, and the shunt resistor R1.
[0037]
The switching transistor Q1 is an MOS transistor, and includes a gate terminal, a
10 source terminal and a drain terminal. The gate terminal of the switching transistor Q1 is
connected to the output terminal of the first signal cut off switch 3a and the output
terminal of the second signal cut off switch 3b. The gate terminal of the switching
transistor Q1 is input to either of the first signal cut off switch 3a or the second signal cut
off switch 3b from the gate signal Sg1.
15 [0038]
The source terminal of the switching transistor Q1 is connected to the drain terminal of
the switching transistor Q2 and the U phase input terminal of the motor 6. The drain
terminal of the switching transistor Q1 is connected to an external battery 9.
[0039]
20 The switching transistor Q2 is an MOS transistor, and includes a gate terminal, a
source terminal and a drain terminal. The gate terminal of the switching transistor Q2 is
connected to the output terminal of the first signal cut off switch 3a and the output
terminal of the second signal cut off switch 3b. The gate terminal of the switching
transistor Q2 is input to either of the first signal cut off switch 3a or the second signal cut
25 off switch 3b from the gate signal Sg2.
13
[0040]
The source terminal of the switching transistor Q2 is connected to an end of the shunt
resistor R1 and to the current detection unit 7. The drain terminal of the switching
transistor Q2 is connected to the source terminal of the switching transistor Q1 and to the
5 U phase input terminal of the motor 6.
[0041]
The shunt resistor R1 is connected in series to the switching transistor Q1 of the upper
arm and the switching transistor Q2 of the lower arm. An end of the shunt resistor R1 is
connected to the source terminal of the switching transistor Q2 and the current detection
10 unit 7, and another end is connected to the ground (reference potential). A drop in
voltage corresponding to the U phase drive current is generated at the shunt resistor R1.
The current detection unit 7 obtains a U phase detected voltage corresponding to the U
phase drive current, based on the voltage drop at the shunt resistor R1.
[0042]
15 The V phase leg includes the switching transistor Q3 that configures an upper arm, the
switching transistor Q4 that configures a lower arm, and the shunt resistor R2.
[0043]
The switching transistor Q3 is an MOS transistor, and includes a gate terminal, a
source terminal and a drain terminal. The gate terminal of the switching transistor Q3 is
20 connected to the output terminal of the first signal cut off switch 3a and the output
terminal of the second signal cut off switch 3b. The gate terminal of the switching
transistor Q3 is input to either of the first signal cut off switch 3a or the second signal cut
off switch 3b from the gate signal Sg3.
[0044]
25 The source terminal of the switching transistor Q3 is connected to the drain terminal of
14
the switching transistor Q4 and the U phase input terminal of the motor 6. The drain
terminal of the switching transistor Q3 is connected to the external battery 9.
[0045]
The switching transistor Q4 is an MOS transistor, and includes a gate terminal, a
5 source terminal and a drain terminal. The gate terminal of the switching transistor Q4 is
connected to the output terminal of the first signal cut off switch 3a and the output
terminal of the second signal cut off switch 3b. The gate terminal of the switching
transistor Q4 is input to either of the first signal cut off switch 3a or the second signal cut
off switch 3b from the gate signal Sg4.
10 [0046]
The source terminal of the switching transistor Q4 is connected to an end of the shunt
resistor R2 and to the current detection unit 7. The drain terminal of the switching
transistor Q4 is connected to the source terminal of the switching transistor Q3 and to the
V phase input terminal of the motor 6.
15 [0047]
The shunt resistor R2 is connected in series to the switching transistor Q3 of the upper
arm and the switching transistor Q4 of the lower arm. An end of the shunt resistor R2 is
connected to the source terminal of the switching transistor Q4 and the current detection
unit 7, and another end is connected to the ground (reference potential). A drop in
20 voltage corresponding to the V phase drive current is generated at the shunt resistor R2.
The current detection unit 7 obtains a V phase detected voltage corresponding to the V
phase drive current, based on the voltage drop at the shunt resistor R2.
[0048]
The W phase leg includes the switching transistor Q5 that configures an upper arm, the
25 switching transistor Q6 that configures a lower arm, and the shunt resistor R3.
15
[0049]
The switching transistor Q5 is an MOS transistor, and includes a gate terminal, a
source terminal and a drain terminal. The gate terminal of the switching transistor Q5 is
connected to the output terminal of the first signal cut off switch 3a and the output
5 terminal of the second signal cut off switch 3b. The gate signal Sg5 is input to the gate
terminal of the switching transistor Q5 from the first signal cut off switch 3a or the
second signal cut off switch 3b.
[0050]
The source terminal of the switching transistor Q5 is connected to the drain terminal of
10 the switching transistor Q6 and the W phase input terminal of the motor 6. The drain
terminal of the switching transistor Q5 is connected to the external battery 9.
[0051]
The switching transistor Q6 is an MOS transistor, and includes a gate terminal, a
source terminal and a drain terminal. The gate terminal of the switching transistor Q6 is
15 connected to the output terminal of the first signal cut off switch 3a and the output
terminal of the second signal cut off switch 3b. The gate signal Sg6 is input to the gate
terminal of the switching transistor Q6 from the first signal cut off switch 3a or the
second signal cut off switch 3b.
[0052]
20 The source terminal of the switching transistor Q6 is connected to an end of the shunt
resistor R3 and to the current detection unit 7. The drain terminal of the switching
transistor Q6 is connected to the source terminal of the switching transistor Q5 and to the
W phase input terminal of the motor 6.
[0053]
25 The shunt resistor R3 is connected in series to the switching transistor Q5 of the upper
16
arm and the switching transistor Q6 of the lower arm. An end of the shunt resistor R3 is
connected to the source terminal of the switching transistor Q6 and the current detection
unit 7, and another end is connected to the ground (reference potential). A drop in
voltage corresponding to the W phase drive current is generated at the shunt resistor R3.
5 The current detection unit 7 obtains a W phase detected voltage corresponding to the W
phase drive current, based on the voltage drop at the shunt resistor R3.
[0054]
The current detection unit 7 detects the U phase drive current, the V phase drive
current, and the W phase drive current based on a U phase detection voltage, a V phase
10 detection voltage, and a W phase detection voltage. Drive currents of various phases
detected by the current detection unit 7 in the present description are collectively referred
to as “detected currents”. The current detection unit 7 includes three input terminals
and three output terminals. Each of the three input terminals of the current detection
unit 7 are connected to ends of the shunt resistors R1 to R3, and each of the U phase
15 detected voltage, the V phase detected voltage, and the W phase detected voltage is input
thereto. Each of the three output terminals in the current detection unit 7 are connected
to the current input I/F 8.
[0055]
The current input I/F 8 is provided between the current detection unit 7 and the
20 microcomputers 1a, 1b, and includes three input terminals and three output terminals.
The three input terminals in the current input I/F 8 are connected to the three output
terminals of the current detection unit 7. The detected currents related to the U phase
drive current, the V phase drive current, and the W phase drive current from the current
detection unit 7 are input to each of the three input terminals of the current input I/F 8.
25 [0056]
17
The current input I/F 8 generates a U phase conversion current signal, a V phase
conversion current signal, and a W phase conversion current signal that correspond to
each of the detected currents of the U phase drive current, the V phase drive current and
the W phase drive current. The aforementioned signals that are generated by the current
5 input I/F 8 in the present description are collectively referred to as the “current detection
signal”. In other words, the current input I/F 8 is an interface circuit that generates the
current detection signal, which is a digital signal, based off of the detected current that is
detected by the current detection unit 7, which is an analog value.
The three output terminals in the current input I/F 8 are connected to each of the three
10 input terminals in each of the microcomputers 1a and 1b. The current input I/F 8
outputs the U phase conversion current signal, the V phase conversion current signal, and
the W phase conversion current signal to the microcomputers 1a and 1b via the three
output terminals.
[0057]
15 Although not shown in FIG. 1, a power supply circuit to conduct voltage conversion is
connected to the battery 9. The main control unit A1, the auxiliary control unit A2, the
current detection unit 7, and the current input I/F 8 operate by a power supply voltage
(for example, 5V) supplied by the above power supply circuit.
[0058]
20 The first signal cut off switch 3a and the first switch control unit 4a configure a first
switcher 100b, and the second signal cut off switch 3b and the second switch control unit
4b configure a second switcher 100c. The current detection unit 7 and the current input
I/F 8 configure a drive current detector 100a.
[0059]
25 Next, an operation of a motor control device 100 and an electric power steering device
18
according to the first embodiment having the aforementioned configuration is explained.
[0060]
The first microcomputer 1a calculates target values (target current values) of the U
phase drive current, the V phase drive current, and the W phase drive current that flow to
5 the motor 6, in the main control unit A1. The current detection unit 7 detects the U
phase drive current, the V phase drive current, and the W phase drive current that actually
flow to the motor 6 as the detected currents, and outputs the detected currents to the first
microcomputer 1a via the current input I/F 8. The first microcomputer 1a generates the
control signals S1 to S6 so that the aforementioned target currents and the detected
10 currents match, and outputs the generated control signals to the first pre-driver 2a.
[0061]
The first pre-driver 2a generates the gate signals Sg1 to Sg6 based on the
aforementioned gate control signals S1 to S6, and outputs the generated gate signals to
the motor drive circuit 5 via the first signal cut off switch 3a. By supplying the U phase
15 drive current, the V phase drive current, and the W phase drive current to the motor 6
based on the gate signals Sg1 to Sg6, the motor drive circuit 5 rotationally drives the
motor 6.
[0062]
The second microcomputer 1b calculates target values (target current values) of the U
20 phase drive current, the V phase drive current, and the W phase drive current that flow to
the motor 6, in the auxiliary control unit A2. The current detection unit 7 detects the U
phase drive current, the V phase drive current, and the W phase drive current that actually
flow to the motor 6 as the detected currents, and outputs the detected currents to the
second microcomputer 1b via the current input I/F 8. The second microcomputer 1b
25 generates the control signals S1 to S6 so that the aforementioned target currents and the
19
detected currents match, and outputs the generated control signals to the second
pre-driver 2b.
[0063]
The second pre-driver 2b generates the gate signals Sg1 to Sg6 based on the
5 aforementioned gate control signals S1 to S6, and outputs the generated gate signals to
the motor drive circuit 5 via the second signal cut off switch 3b. By supplying the U
phase drive current, the V phase drive current, and the W phase drive current to the motor
6 based on the aforementioned gate signals Sg1 to Sg6, the motor drive circuit 5
rotationally drives the motor 6.
10 [0064]
The first signal cut off switch 3a in the main control unit A1 controls the output state
(output/no output) of the gate signals Sg1 to Sg6 by the first switching signal that is input
from the first switch control unit 4a. The second signal cut off switch 3b in the
auxiliary control unit A2 controls the output state (output/no output) of the gate signals
15 Sg1 to Sg6 by the second switching signal that is input from the second switch control
unit 4b.
[0065]
When the second signal cut off switch 3b in the auxiliary control unit A2 outputs the
gate signals Sg1 to Sg6 to the motor drive circuit 5, the first signal cut off switch 3a in
20 the main control unit A1 cuts off output of the gate signals Sg1 to Sg6 to the motor drive
circuit 5, and makes it to where control of the motor 6 by the auxiliary control unit A2 is
not hindered.
[0066]
On the other hand, when the first signal cut off switch 3a in the main control unit A1
25 outputs the gate signals Sg1 to Sg6 to the motor drive circuit 5, the second signal cut off
20
switch 3b in the auxiliary control A2 cuts off output of the gate signals Sg1 to Sg6 to the
motor drive circuit 5, and makes it to where control of the motor 6 by the main control
unit A1 is not hindered.
[0067]
5 In other words, the motor drive circuit 5 rotationally drives to the motor 6 by
generating a U phase drive current, a V phase drive current, and a W phase drive current
based on the gate signals Sg1 to Sg6 that are input from either one of the main control
unit A1 or the auxiliary control unit A2.
[0068]
10 As explained above, the motor control device 100 according to the first embodiment
includes a motor drive circuit 5 that outputs a drive current to the motor 6, the drive
current detector 100a which detects the drive current, the main control unit A1, and the
auxiliary control unit A2. The motor drive circuit 5 is driven by a drive signal (gate
signals Sg1 to Sg6) that is output from the main control unit A1 or the auxiliary control
15 unit A2. The main control unit A1 has a first control signal generator (the first
microcomputer 1a) that generates a first control signal (the gate control signals S1 to S6)
based on the current detection signal (the U phase conversion current signal, the V phase
conversion current signal, and the W phase conversion current signal) that is input from
the drive current detector 100a, a first drive signal generator (the first pre-driver 2a) that
20 generates the drive signal based on the first control signal, and the first switcher 100b
that switches the output state of the drive signal to the motor drive circuit 5. The
auxiliary control unit A2 has a second control signal generator (the second
microcomputer 1b) that generates the second control signal (the gate control signals S1 to
S6) based on the current detection signal (the U phase conversion current signal, the V
25 phase conversion current signal, and the W phase conversion current signal) that is input
21
from the drive current detector 100a, a second drive signal generator (the second
pre-driver 2b) that generates the drive signal based on the second control signal, and the
second switcher 100c that switches the output state of the drive signal to the motor drive
circuit 5.
5 [0069]
From the above motor control device 100, a drive signal generator and a switcher are
provided for each of control units A1 and A2. Therefore, even if an abnormality occurs
in one of the drive signal generators provided in either of the control units A1 or A2, it is
possible to continue control to the motor 6 by using the other drive signal generator. As
10 such, it is possible to provide the motor control device 100 that is more stable against
abnormality occurrence. After deliberate consideration, the inventors have concluded
that pre-driver malfunctions especially occupy a large percentage of abnormalities, in
terms of abnormality occurrence in the motor control device. Therefore, when the
pre-driver is used as the drive control signal generator, the configuration of the motor
15 control device 100 in the present embodiment demonstrates excellent results. It is
therefore possible to meet the C standards of the automotive safety level (ASIL:
Automotive Safety Integrity Level).
[0070]
According to the first embodiment, the first pre-driver 2a, the first signal cut off switch
20 3a, and the first switch control unit 4a are provided in the main control unit A1. The
second pre-driver 2b, the second signal cut off switch 3b, and the second switch control
unit 4b are provided in the auxiliary control unit A2. According to such configuration,
when the main control unit A1 is driving the motor 6, the second signal cut off switch 3b
is used to cut off output from the auxiliary control unit A2. Therefore, it is possible to
25 prevent the drive of the motor 6 from being interfered with by the main control unit A1.
22
It is also possible to prevent voltage shortage of the drive signal and delay occurrences
that result from wrapping around of the main control unit A1 by the output from the
auxiliary control unit A2. Similarly, when the auxiliary control unit A2 drives the motor
6, the first signal cut off switch 3a is used to cut off output from the main control unit A1.
5 Therefore, it is possible to prevent having the drive of the motor 6 by the auxiliary
control unit A2 be interfered with. It is also possible to prevent voltage shortage of the
drive signal and delay occurrences that result from wrapping around of the auxiliary
control unit A2 by the output from the main control unit A1.
[0071]
10 Second Embodiment
Next, the motor control device 100 and an electric power steering device according to
a second embodiment are explained. Since fundamental configurations of the motor
control device 100 and the electric power steering device are similar to those of the first
embodiment, explanations that follow mainly focus on differing aspects. Components
15 having similar functions as components explained in the first embodiment have the same
names and reference symbols affixed thereto, with detailed explanations being omitted in
the explanations below.
[0072]
As shown in FIG. 2, the motor control device 100 according to the second embodiment
20 includes a main control unit B1 and an auxiliary control unit B2. The main control unit
B1 includes a first microcomputer 1a2 instead of the first microcomputer 1a of the first
embodiment, and includes a first switch control unit 4a2 instead of the first switch
control unit 4a of the first embodiment. The auxiliary control unit B2 includes a second
microcomputer 1b2 instead of the second microcomputer 1b of the first embodiment, and
25 includes a second switch control unit 4b2 instead of the second switch control unit 4b of
23
the first embodiment.
[0073]
Compared to the main control unit A1 of the first embodiment, a first microcomputer
monitoring unit 10a is added to the main control unit B1. Compared to the auxiliary
5 control unit A2 of the first embodiment, a second microcomputer monitoring unit 10b is
added to the auxiliary control unit B2.
[0074]
In addition to the six output terminals and the three input terminals in the first
microcomputer 1a of the first embodiment, the first microcomputer 1a2 includes two
10 output terminals and one input terminal. One of the two output terminals in the first
microcomputer 1a2 is connected to the first microcomputer monitoring unit 10a. The
first microcomputer 1a2 outputs a signal (a first operation state signal) that shows an
operation state of the first microcomputer 1a2 to the first microcomputer monitoring unit
10a via the one output terminal.
15 [0075]
The other of the two output terminals in the first microcomputer 1a2 is connected to
the first switch control unit 4a2. The first microcomputer 1a2 outputs a first output
command signal to the first switch control unit 4a2 via the other output terminal. The
first output command signal is a signal that outputs the first switching signal which sets
20 the first signal cut off switch 3a to a conductive state, to the first switch control unit 4a2.
[0076]
The one input terminal in the first microcomputer 1a2 is connected to the second
microcomputer monitoring unit 10b. A second abnormality signal is input from the
second microcomputer monitoring unit 10b to the first microcomputer 1a2 via the one
25 input terminal. The first microcomputer 1a2 recognizes an abnormality of the second
24
microcomputer 1b2 based on the second abnormality signal.
[0077]
In addition to the six output terminals and the three input terminals in the second
microcomputer 1b of the first embodiment, the second microcomputer 1b2 includes two
5 output terminals and one input terminal. One of the two output terminals in the second
microcomputer 1b2 is connected to the second microcomputer monitoring unit 10b.
The second microcomputer 1b2 outputs a signal (a second operation state signal) that
shows an operation state of the second microcomputer 1b2 to the second microcomputer
monitoring unit 10b via the one output terminal.
10 [0078]
The other of the two output terminals in the second microcomputer 1b2 is connected to
the second switch control unit 4b2. The second microcomputer 1b2 outputs a second
output command signal to the second switch control unit 4b2 via the other output
terminal. The second output command signal is a signal that outputs the second
15 switching signal which sets the second signal cut off switch 3b to a conductive state, to
the second switch control unit 4b2.
[0079]
The one input terminal in the second microcomputer 1b2 is connected to the first
microcomputer monitoring unit 10a. A first abnormality signal is input from the first
20 microcomputer monitoring unit 10a to the second microcomputer 1b2 via the one input
terminal. The second microcomputer 1b2 recognizes an abnormality of the first
microcomputer 1a2 based on the first abnormality signal.
[0080]
The first microcomputer monitoring unit 10a includes one input terminal and one
25 output terminal. The input terminal of the first microcomputer monitoring unit 10a is
25
connected to the one output terminal in the first microcomputer 1a2. The output
terminal of the first microcomputer monitoring unit 10a is connected to the first switch
control unit 4a2 and the second microcomputer 1b2.
[0081]
5 The first microcomputer monitoring unit 10a monitors the operation state of the first
microcomputer 1a2 based on the first operation state signal that is input from the first
microcomputer 1a2. When the first microcomputer monitoring unit 10a determines that
the operation state of first microcomputer 1a2 is abnormal, the first microcomputer
monitoring unit 10a outputs the first abnormality signal which shows the abnormality, to
10 the first switch control unit 4a2 and the second microcomputer 1b2.
[0082]
In FIG. 2, the first microcomputer monitoring unit 10a is illustrated as a component
that is separate from the first microcomputer 1a2. The first microcomputer monitoring
unit 10a however, may be the same configuration component as the first microcomputer
15 1a2. In other words, the first microcomputer monitoring unit 10a may be a functional
component realized by a control program stored in advance in the first microcomputer
1a2.
[0083]
The second microcomputer monitoring unit 10b includes one input terminal and one
20 output terminal. The input terminal of the second microcomputer monitoring unit 10b
is connected to the second microcomputer 1b2. The output terminal of the second
microcomputer monitoring unit 10b is connected to the second switch control unit 4b2
and the first microcomputer 1a2.
[0084]
25 The second microcomputer monitoring unit 10b monitors the operation state of the
26
second microcomputer 1b2 based on the second operation state signal that is input from
the second microcomputer 1b2. When the second microcomputer monitoring unit 10b
determines that the operation state of second microcomputer 1b2 is abnormal, the second
microcomputer monitoring unit 10b outputs the second abnormality signal which shows
5 the abnormality, to the second switch control unit 4b2 and the first microcomputer 1a2.
[0085]
In FIG. 2, the second microcomputer monitoring unit 10b is illustrated as a component
that is separate from the second microcomputer 1b2. The second microcomputer
monitoring unit 10b however, may be the same internal configuration component as the
10 second microcomputer 1b2. In other words, the second microcomputer monitoring unit
10b may be a functional component realized by a control program stored in advance in
the second microcomputer 1b2.
[0086]
The first switch control unit 4a2 includes two input terminals, and one output terminal.
15 One of the two input terminals of the first switch control unit 4a2 is connected to the first
microcomputer monitoring unit 10a. The other of the two input terminals of the first
switch control unit 4a2 is connected to the first microcomputer 1a2. The output
terminal of the first switch control unit 4a2 is connected to the control input terminal in
the first signal cut off switch 3a.
20 [0087]
The first switch control unit 4a2 generates the first switching signal based on the first
abnormality signal that is input from the first microcomputer monitoring unit 10a and a
first command signal that is input from the first microcomputer 1a2, and outputs the first
switching signal to the first signal cut off switch 3a.
25 [0088]
27
The second switch control unit 4b2 includes two input terminals, and one output
terminal. One input terminal of the second switch control unit 4b2 is connected to the
second microcomputer monitoring unit 10b. The other input terminal of the second
switch control unit 4b2 is connected to the second microcomputer 1b2. The one output
5 terminal of the second switch control unit 4b2 is connected to the control input terminal
in the second signal cut off switch 3b.
[0089]
The second switch control unit 4b2 generates the second switching signal based on the
second abnormality signal that is input from the second microcomputer monitoring unit
10 10b and a second command signal that is input from the second microcomputer 1b2, and
outputs the second switching signal to the second signal cut off switch 3b.
[0090]
When the first microcomputer monitoring unit 10a in the main control unit B1 of the
motor control device 100 and the electric power steering device according to the second
15 embodiment detects an abnormality of the first microcomputer 1a2, the first
microcomputer monitoring unit 10a outputs the first abnormality signal to the first switch
control unit 4a2 and the second microcomputer 1b2.
[0091]
As a result, the first switch control unit 4a2 in the main control unit B1 outputs the first
20 switching signal, which makes the gate control signals S1 to S6 into no output, to the first
signal cut off switch 3a, and output of the gate signals Sg1 to Sg6 to the motor drive
circuit 5 is cut off.
[0092]
At such time, the second microcomputer 1b2 outputs the second command signal that
25 commands the output of the gate signals Sg1 to Sg6 of the motor drive circuit 5 to the
28
second switch control unit 4b2. The second switch control unit 4b2 outputs the second
switching signal to the second signal cut off switch 3b, so as to have the gate signals Sg1
to Sg6 that are input from the second pre-driver 2b be output to the motor drive circuit 5.
As a result, the gate signals Sg1 to Sg6 are output to the motor drive circuit 5 from the
5 auxiliary control unit B2, instead of the main control unit B1.
[0093]
On the other hand, when the second microcomputer monitoring unit 10b detects an
abnormality of the second microcomputer 1b2, the second microcomputer monitoring
unit 10b outputs the second abnormality signal to the second switch control unit 4b2 and
10 the first microcomputer 1a2. The second switch control unit 4b2 then outputs the
second switching signal, which makes the gate control signals S1 to S6 into no output, to
the second signal cut off switch 3b, and output of the gate signals Sg1 to Sg6 to the motor
drive circuit 5 is cut off.
[0094]
15 At such time, first microcomputer 1a2 outputs the first command signal that
commands the output of the gate signals Sg1 to Sg6 of the motor drive circuit 5 to the
first switch control unit 4a2. The first switch control unit 4a2 outputs the first switching
signal to the first signal cut off switch 3a, so as to have the gate signals Sg1 to Sg6 that
are input from the first pre-driver 2a be output to the motor drive circuit 5. As a result,
20 the gate signals Sg1 to Sg6 are output to the motor drive circuit 5 from the main control
unit B1, instead of the auxiliary control unit B2.
[0095]
As explained above, the motor control device 100 according to the second embodiment
further includes a first control signal generator monitoring unit (the first microcomputer
25 monitoring unit 10a) that monitors an operation state of the first control signal generator
29
(the first microcomputer 1a2), and outputs the first abnormality signal to the first
switcher 100b and the second control signal generator (the second microcomputer 1b2)
when the first control signal generator monitoring unit determines that an abnormality is
occurring in the first control signal generator, and further includes a second control signal
5 generator monitoring unit (second microcomputer monitoring unit 10b) that monitors an
operation state of the second control signal generator, and outputs the second abnormality
signal to the second switcher 100c and the first control signal generator when the second
control signal generator monitoring unit determines that an abnormality is occurring in
the second control signal generator. The drive signal (gate signals Sg1 to Sg6) is output
10 to the motor drive circuit 5 from the control unit having no abnormality out of the main
control unit B1 and the auxiliary control unit B2.
[0096]
With the above configuration, the drive signal from the control unit having no
abnormality out of the main control unit B1 and the auxiliary control unit B2 is output to
15 the motor drive circuit 5. Therefore, it is possible to further increase stability against
abnormality occurrences.
[0097]
Third Embodiment
Next, the motor control device 100 and an electric power steering device according to
20 a third embodiment are explained. Since fundamental configurations of the motor
control device 100 and the electric power steering device are similar to those of the first
embodiment, explanations that follow mainly focus on differing aspects. Components
having similar functions as components explained in the first embodiment have the same
names and reference symbols affixed thereto, with detailed explanations being omitted in
25 the explanations below.
30
[0098]
As shown in FIG. 3, the motor control device 100 according to the third embodiment
includes a main control unit C1 and an auxiliary control unit C2. The main control unit
C1 includes a first microcomputer 1a3 instead of the first microcomputer 1a of the first
5 embodiment, includes a first pre-driver 2a3 instead of the first pre-driver 2a of the first
embodiment, and includes a first switch control unit 4a3 instead of the first switch
control unit 4a of the first embodiment. The auxiliary control unit C2 includes a second
microcomputer 1b3 instead of the second microcomputer 1b of the first embodiment,
includes a second pre-driver 2b3 instead of the second pre-driver 2b of the first
10 embodiment, and includes a second switch control unit 4b3 instead of the second switch
control unit 4b of the first embodiment.
[0099]
Compared to the main control unit A1 of the first embodiment, a first power supply
11a, a first power supply monitoring unit 12a, and a first pre-driver monitoring unit 13a
15 (first drive signal generator monitoring unit) are added to the main control unit C1.
Compared to the auxiliary control unit A2 of the first embodiment, a second power
supply 11b, a second power supply monitoring unit 12b, and a second pre-driver
monitoring unit 13b (second drive signal generator monitoring unit) are added to the
auxiliary control unit C2.
20 [0100]
The first power supply 11a corresponds to the power supply circuit mentioned in the
first embodiment. The first power supply 11a includes one input terminal and one
output terminal. The input terminal of the first power supply 11a is connected to a
positive electrode of the battery 9, and the output terminal of the first power supply 11a is
25 at least connected to the first power supply monitoring unit 12a, the first microcomputer
31
1a3, and the first pre-driver 2a3. The first power supply 11a supplies a first operation
power to at least the first power supply monitoring unit 12a, the first microcomputer 1a3,
and the first pre-driver 2a3. The first power supply 11a may supply power to the other
components as well.
5 [0101]
The first power supply monitoring unit 12a includes one input terminal and one output
terminal. The input terminal of the first power supply monitoring unit 12a is connected
to the first power supply 11a, and the output terminal of the first power supply
monitoring unit 12a is connected to the first switch control unit 4a3 and the second
10 microcomputer 1b3.
[0102]
The first power supply monitoring unit 12a monitors an operation state of the first
power supply 11a based on the first operation power that is input from the first power
supply 11a. The first power supply monitoring unit 12a outputs a first power supply
15 abnormality signal to the first switch control unit 4a3 and the second microcomputer 1b3,
when the first power supply monitoring unit 12a determines that an error is occurring in
the first power supply 11a.
[0103]
The first pre-driver monitoring unit 13a includes one input terminal and one output
20 terminal. The input terminal of the first pre-driver monitoring unit 13a is connected to
the first pre-driver 2a3, and the output terminal of the first pre-driver monitoring unit 13a
is connected to the first switch control unit 4a3 and the second microcomputer 1b3.
[0104]
The first pre-driver monitoring unit 13a monitors the operation state of the first
25 pre-driver 2a3 based on a first pre-driver state signal that is output from the first
32
pre-driver 2a3. The first pre-driver monitoring unit 13a outputs a first drive
abnormality signal to the first switch control unit 4a3 and the second microcomputer 1b3,
when the first pre-driver monitoring unit 13a determines that an error is occurring in the
first pre-driver 2a3.
5 [0105]
Just as with the first power supply 11a, the second power supply 11b corresponds to a
power supply circuit. The second power supply 11b includes one input terminal and
one output terminal. The input terminal of the second power supply 11b is connected to
a positive electrode of the battery 9, and the output terminal of the second power supply
10 11b is at least connected to the second power supply monitoring unit 12b, the second
microcomputer 1b3, and the second pre-driver 2b3. The second power supply 11b
supplies a second operation power to at least the second power supply monitoring unit
12b, the second microcomputer 1b3, and the second pre-driver 2b3. The second power
supply 11b may supply power to the other components as well.
15 [0106]
The second power supply monitoring unit 12b includes one input terminal and one
output terminal. The input terminal of the second power supply monitoring unit 12b is
connected to the second power supply 11b, and the output terminal of the second power
supply monitoring unit 12b is connected to the second switch control unit 4b3 and the
20 first microcomputer 1a3.
[0107]
The second power supply monitoring unit 12b monitors an operation state of the
second power supply 11b based on the second operation power that is input from the
second power supply 11b. The second power supply monitoring unit 12b outputs a
25 second power supply abnormality signal to the second switch control unit 4b3 and the
33
first microcomputer 1a3, when the second power supply monitoring unit 12b determines
that an error is occurring in the second power supply 11b.
[0108]
The second pre-driver monitoring unit 13b includes one input terminal and one output
5 terminal. The input terminal of the second pre-driver monitoring unit 13b is connected
to the second pre-driver 2b3, and the output terminal of the second pre-driver monitoring
unit 13b is connected to the second switch control unit 4b3 and the first microcomputer
1a3.
[0109]
10 The second pre-driver monitoring unit 13b monitors the operation state of the second
pre-driver 2b3 based on a second pre-driver state signal that is output from the second
pre-driver 2b3. The second pre-driver monitoring unit 13b outputs the second power
supply abnormality signal to the second switch control unit 4b3 and the first
microcomputer 1a3, when the second pre-driver monitoring unit 13b determines that an
15 error is occurring in the second pre-driver 2b3.
[0110]
In addition to the six output terminals and the three input terminals in the first
microcomputer 1a of the first embodiment, the first microcomputer 1a3 includes one
output terminal, four input terminals, and a first current input I/F monitoring unit 14a.
20 [0111]
The output terminal of the first microcomputer 1a3 is connected to the first switch
control unit 4a3 and the second microcomputer 1b3. The first microcomputer 1a3
outputs a first current input I/F abnormality signal that is generated by the first current
input I/F monitoring unit 14a to the first switch control unit 4a3 and the second
25 microcomputer 1b3 via the output terminal.
34
[0112]
An input terminal of the first microcomputer 1a3 is connected to the first power supply
11a. The first operation power from the first power supply 11a is input to the first
microcomputer 1a3 via the aforementioned input terminal. The first microcomputer 1a3
5 operates based on the first operation power.
[0113]
An input terminal of the first microcomputer 1a3 is connected to the second power
supply monitoring unit 12b. A second power supply abnormality signal is input to the
first microcomputer 1a3 via the aforementioned input terminal.
10 An input terminal of the first microcomputer 1a3 is connected to the second pre-driver
monitoring unit 13b. A second drive abnormality signal is input to the first
microcomputer 1a3 via the aforementioned input terminal.
An input terminal of the first microcomputer 1a3 is connected to the second
microcomputer 1b3. A second current input I/F abnormality signal is input to the first
15 microcomputer 1a3 via the aforementioned input terminal.
[0114]
The first current input I/F monitoring unit 14a is a functional component that is
provided within the first microcomputer 1a3. The first current input I/F monitoring unit
14a monitors an operation state of the current input I/F 8 based on the U phase
20 conversion current signal, the V phase conversion current signal, and the W phase
conversion current signal that are input to the first microcomputer 1a3 from the current
input I/F 8. When first current input I/F monitoring unit 14a determines that an
abnormality occurred in the current input I/F 8, the first current input I/F monitoring unit
14a outputs the first current input I/F abnormality signal which shows the abnormality to
25 the first switch control unit 4a3 and the second microcomputer 1b3.
35
[0115]
On the other hand, in addition to the six output terminals and the three input terminals
in the second microcomputer 1b of the second embodiment, the second microcomputer
1b3 includes one output terminal, four input terminals, and the second current input I/F
5 monitoring unit 14b.
[0116]
The output terminal of the second microcomputer 1b3 is connected to the second
switch control unit 4b3and the first microcomputer 1a3. The second microcomputer
1b3 outputs the second current input I/F abnormality signal that is generated by the
10 second current input I/F monitoring unit 14b to the second switch control unit 4b3 and
the first microcomputer 1a3 via the aforementioned output terminal.
[0117]
An input terminal of the second microcomputer 1b3 is connected to the second power
supply 11b. A second operation power from the second power supply 11b is input to the
15 second microcomputer 1b3 via the aforementioned input terminal. The second
microcomputer 1b3 operates based on the second operation power.
[0118]
An input terminal of the second microcomputer 1b3 is connected to the first power
supply monitoring unit 12a. The first power supply abnormality signal is input to the
20 second microcomputer 1b3 via the aforementioned input terminal.
An input terminal of the second microcomputer 1b3 is connected to the first pre-driver
monitoring unit 13a. The first drive abnormality signal is input to the second
microcomputer 1b3 via the aforementioned input terminal.
An input terminal of the second microcomputer 1b3 is connected to the first
25 microcomputer 1a3. The first current input I/F abnormality signal is input to the second
36
microcomputer 1b3 via the aforementioned input terminal.
[0119]
The second current input I/F monitoring unit 14b is a functional component that is
provided within the second microcomputer 1b3. The second current input I/F
5 monitoring unit 14b monitors the operation state of the current input I/F 8 based on the U
phase conversion current signal, the V phase conversion current signal, and the W phase
conversion current signal that are input to the second microcomputer 1b3 from the
current input I/F 8. When the second current input I/F monitoring unit 14b determines
that an abnormality occurred in the current input I/F 8, the second current input I/F
10 monitoring unit 14b outputs the second current input I/F abnormality signal which shows
the abnormality to the second switch control unit 4b3 and the first microcomputer 1a3.
[0120]
In addition to the six input terminals and the six output terminals in the first pre-driver
2a of the first embodiment, the first pre-driver 2a3 includes one output terminal and two
15 input terminals. The one output terminal of the first pre-driver 2a3 is connected to the
first pre-driver monitoring unit 13a. The first pre-driver 2a3 outputs the first pre-driver
state signal which shows the operation state of the first pre-driver 2a3 to the first
pre-driver monitoring unit 13a via the one output terminal.
[0121]
20 An input terminal of the first pre-driver 2a3 is connected to a positive electrode of the
battery 9, and a voltage (positive voltage) is input to the positive electrode. An input
terminal of the first pre-driver 2a3 is connected to the first power supply 11a, and the first
operation power is input thereto.
[0122]
25 Along with generating the gate signal Sg1 to Sg6 based on the gate control signal S1 to
37
S6, the first pre-driver 2a3 includes a function of generating the positive voltage, and of
generating the first pre-driver state signal based on the first operation power.
[0123]
In addition to the six input terminals and the six output terminals in the second
5 pre-driver 2b of first embodiment, the second pre-driver 2b3 includes one output terminal
and two input terminals. The one output terminal of the second pre-driver 2b3 is
connected to the second pre-driver monitoring unit 13b, and outputs the second
pre-driver state signal which shows the operation state of the second pre-driver 2b3 to the
second pre-driver monitoring unit 13b.
10 [0124]
One input terminal of the second pre-driver 2b3 is connected to the positive electrode
of the battery 9, and a voltage (positive voltage) is input to the positive electrode. The
other input terminal of the second pre-driver 2b3 is connected to the second power
supply 11b, and a second operation power is input thereto.
15 [0125]
Along with generating the gate signal Sg1 to Sg6 from the gate control signal S1 to S6,
the second pre-driver 2b3 includes a function of generating the positive voltage, and of
generating the second pre-driver state signal based on the second operation power.
[0126]
20 The first switch control unit 4a3 includes three input terminals and one output
terminal.
An input terminal of the first switch control unit 4a3 is connected to the first power
supply monitoring unit 12a, and the first power supply abnormality signal is input
thereto.
25 An input terminal of the first switch control unit 4a3 is connected to the first pre-driver
38
monitoring unit 13a, and the first drive abnormality signal is input thereto.
An input terminal of the first switch control unit 4a3 is connected to the first
microcomputer 1a3, and the first current input I/F abnormality signal that is output from
the first current input I/F monitoring unit 14a is input thereto.
5 [0127]
The first switch control unit 4a3 generates the first switching signal based on the first
power supply abnormality signal, the first drive abnormality signal and the first current
input I/F abnormality signal, and outputs the first switching signal to the first signal cut
off switch 3a. In other words, when any one of the first power supply abnormality
10 signal, the first drive abnormality signal, or the first current input I/F abnormality signal
is input, the first switch control unit 4a3 cuts off output of the gate signal Sg1 to Sg6
from the first signal cut off switch 3a to the motor drive circuit 5.
[0128]
The second switch control unit 4b3 includes three input terminals and one output
15 terminal.
An input terminal of the second switch control unit 4b3 is connected to the second
power supply monitoring unit 12b, and the second power supply abnormality signal is
input thereto.
An input terminal of the second switch control unit 4b3 is connected to the second
20 pre-driver monitoring unit 13b, and the second drive abnormality signal is input thereto.
An input terminal of the second switch control unit 4b3 is connected to the second
microcomputer 1b3, and the second current input I/F abnormality signal that is output
from the second current input I/F monitoring unit 14b is input thereto.
[0129]
25 The second switch control unit 4b3 generates the second switching signal based on the
39
second power supply abnormality signal, the second drive abnormality signal and the
second current input I/F abnormality signal, and outputs the second switching signal to
the second signal cut off switch 3b. In other words, when any one of the second power
supply abnormality signal, the second drive abnormality signal, or the second current
5 input I/F abnormality signal is input, the second switch control unit 4b3 cuts off output of
the gate signal Sg1 to Sg6 from the second signal cut off switch 3b to the motor drive
circuit 5.
[0130]
The first current input I/F monitoring unit 14a corresponds to a first detector
10 monitoring unit, and the second current input I/F monitoring unit 14b corresponds to a
second detector monitoring unit. The first current input I/F abnormality signal output
by the first current input I/F monitoring unit 14a corresponds to a first current detection
abnormality signal. The second current input I/F abnormality signal output by the
second current input I/F monitoring unit 14b corresponds to a second current detection
15 abnormality signal.
[0131]
In the motor control device 100 and an electric power steering device according to the
third embodiment, the first switch control unit 4a3 outputs the first switching signal to
the first signal cut off switch 3a when an abnormality occurs in any one of the first power
20 supply 11a, the first pre-driver 2a3, or the current input I/F 8. As such, output of the
gate signals Sg1 to Sg6 from the first signal cut off switch 3a to the motor drive circuit 5
is cut off.
[0132]
On the other hand, the second switch control unit 4b3 outputs the second switching
25 signal to the second signal cut off switch 3b when an abnormality occurs in any one of
40
the second power supply 11b, the second pre-driver 2b3, or the current input I/F 8. As
such, output of the gate signals Sg1 to Sg6 from the second signal cut off switch 3b to the
motor drive circuit 5 is cut off.
[0133]
5 As explained above, the motor control device 100 according to the present
embodiment further includes a first drive signal generator monitoring unit (first
pre-driver monitoring unit 13a) that monitors an operation state of the first drive signal
generator (first pre-driver 2a3), and outputs the first drive abnormality signal to the first
switcher 100b and the second control signal generator (the second microcomputer 1b3)
10 when the first drive signal generator monitoring unit determines that an abnormality is
occurring in the first drive signal generator, and further includes a second drive signal
generator monitoring unit (second pre-driver monitoring unit 13b) that monitors an
operation state of the second drive signal generator (second pre-driver 2b3), and outputs
the second drive abnormality signal to the second switcher 100c and the first control
15 signal generator when the second drive signal generator monitoring unit determines that
an abnormality is occurring in the second drive signal generator. The drive signal is
output to the motor drive circuit 5 from the control unit having no abnormality out of the
main control unit C1 and the auxiliary control unit C2. With such configuration, by
monitoring the operation state of the first drive signal generator and of the second drive
20 signal generator, it is possible to further increase stability against abnormality
occurrences in the aforementioned drive signal generators.
[0134]
The motor control device 100 according to the present embodiment further includes
the first power supply 11a that supplies operation power to the first control signal
25 generator (the first microcomputer 1a3) and the first drive signal generator (the first
41
pre-driver 2a3), the second power supply 11b that supplies operation power to the second
control signal generator (the second microcomputer 1b3) and the second drive signal
generator (the second pre-driver 2b3), the first power supply monitoring unit 12a that
monitors the operation state of the first power supply 11a, and outputs the first power
5 supply abnormality signal to the first switcher 100b and the second control signal
generator when the first power supply monitoring unit 12a determines that an
abnormality is occurring in the first power supply 11a, and the second power supply
monitoring unit 12b that monitors the operation state of the second power supply 11b,
and outputs the second power supply abnormality signal to the second switcher 100c and
10 the first control signal generator when the second power supply monitoring unit 12b
determines that an abnormality is occurring in the second power supply 11b. The drive
signal is output to the motor drive circuit 5 from the control unit having no abnormality
out of the main control unit C1 and the auxiliary control unit C2. With such
configuration, by monitoring the operation state of the first power supply 11a and the
15 second power supply 11b, it is possible to further increase stability of power supplies 11a
and 11b against abnormality occurrences.
[0135]
The motor control device 100 according to the present embodiment further includes
the first detector monitoring unit (the first current input I/F monitoring unit 14a) that is
20 provided in the main control unit C1, that monitors the operation state of the drive
current detector 100a, and that outputs the first current detection abnormality signal to
the first switcher 100b and the second control signal generator when the first detector
monitoring unit determines that an abnormality is occurring in the drive current detector
100a, and the second detector monitoring unit (second current input I/F monitoring unit
25 14b) that is provided in the auxiliary control unit C2, that monitors the operation state of
42
the drive current detector 100a, and that outputs the second current detection abnormality
signal to the second switcher 100c and the first control signal generator when the second
detector monitoring unit determines that an abnormality is occurring in the drive current
detector 100a.
5 [0136]
In addition to the effects explained in the configuration of the second embodiment, it is
possible to increase abnormality detection rate in the main unit control C1 and the
auxiliary control unit C2 with the aforementioned configuration of the third embodiment.
According to the third embodiment, it is also possible to detect abnormality occurrence in
10 the current input I/F 8. Therefore, it is possible to realize more accurate switching of
the control unit, and it is possible to further increase stability against abnormality
occurrences.
[0137]
Fourth Embodiment
15 Next, the motor control device 100 and an electric power steering device according to
a fourth embodiment are explained. Since fundamental configurations of the motor
control device 100 and the electric power steering device are similar to those of the third
embodiment, explanations that follow mainly focus on differing aspects. Components
having similar functions as components explained in the third embodiment have the same
20 names and reference symbols affixed thereto, with detailed explanations being omitted in
the explanations below.
[0138]
As shown in FIG. 4, the motor control device 100 according to the fourth embodiment
includes a main control unit D1 and an auxiliary control unit D2. The main control unit
25 D1 includes a first microcomputer 1a4 instead of the first microcomputer 1a3 of the third
43
embodiment. The auxiliary control unit D2 includes a second microcomputer 1b4
instead of the second microcomputer 1b3 of the third embodiment.
[0139]
Compared to the first microcomputer 1a3 of the third embodiment, the first
5 microcomputer 1a4 has an additional input terminal. The aforementioned input
terminal is connected to the second switch control unit 4b3. The first microcomputer
1a4 recognizes an operation state of the second switch control unit 4b3 based on the
second switching signal that is input from the second switch control unit 4b3.
[0140]
10 Compared to the second microcomputer 1b3 of the third embodiment, the second
microcomputer 1b4 has an additional input terminal. The aforementioned input
terminal is connected to the first switch control unit 4a3. The second microcomputer
1b4 recognizes an operation state of the first switch control unit 4a3 based on the first
switching signal that is input from the first switch control unit 4a3.
15 [0141]
In the third embodiment, when an abnormality of the first power supply 11a is
inadvertently determined by the second microcomputer 1b3 for example, there is
possibility that the gate signals Sg1 to Sg6 are input to the motor drive circuit 5 from
both the main control unit C1 and the auxiliary control unit C2.
20 [0142]
In response to such problem, in the first microcomputer 1a4 of the fourth embodiment,
the second switching signal is input from the second switch control unit 4b3. As such,
in a state where the auxiliary control unit D2 outputs the gate signals Sg1 to Sg6 to the
motor drive circuit 5, the main control unit D1 does not output the gate signals Sg1 to
25 Sg6 to the motor drive circuit 5.
44
[0143]
In the second microcomputer 1b4, the first switching signal is input from the first
switch control unit 4a3. As such, in a state where the main control unit D1 outputs the
gate signals Sg1 to Sg6 to the motor drive circuit 5, the auxiliary control unit D2 does not
5 output the gate signals Sg1 to Sg6 to the motor drive circuit 5.
[0144]
As explained above, the main control unit D1 outputs a drive signal (the gate signals
Sg1 to Sg6) to the motor drive circuit 5 via the first switcher 100b only when the second
switcher 100c does not output the drive signal to the motor drive circuit 5, and the
10 auxiliary control unit D2 outputs the drive signal to the motor drive circuit 5 via the
second switcher 100c only when the first switcher 100b does not output the drive signal
the motor drive circuit 5. From such configuration, it is possible to avoid having the
gate signals Sg1 to Sg6 be outputted to the motor drive circuit 5 from both the main
control unit D1 and the auxiliary control unit D2.
15 [0145]
Fifth Embodiment
Next, the motor control device 100 and an electric power steering device according to
a fifth embodiment are explained. Since fundamental configurations of the motor
control device 100 and the electric power steering device are similar to those of the first
20 embodiment, explanations that follow mainly focus on differing aspects. Components
having similar functions as components explained in the first embodiment have the same
names and reference symbols affixed thereto, with detailed explanations being omitted in
the explanations below.
[0146]
25 As shown in FIG. 5, the motor control device 100 according to the fifth embodiment
45
includes the main control unit A1 and an auxiliary control unit E2. The auxiliary
control unit E2 includes a second microcomputer 1b5 instead of the second
microcomputer 1b of the first embodiment.
[0147]
5 Compared to the motor control device 100 of the first embodiment, the motor control
device 100 according to the fifth embodiment has a motor terminal state detection unit 15.
The motor terminal state detection unit 15 includes three input terminals and one output
terminal.
Each input terminal of the motor terminal state detection unit 15 is connected to each
10 of a U phase switching leg, a V phase switching leg, and a W phase switching leg. The
output terminal of the motor terminal state detection unit 15 is connected to the second
microcomputer 1b5.
[0148]
The motor terminal state detection unit 15 detects a state (motor terminal state) of
15 three input terminals of the motor 6, in other words, the U phase input terminal, the V
phase input terminal, and the W phase input terminal, and outputs the motor terminal
state to the second microcomputer 1b5 as a motor terminal state detection signal.
The second microcomputer 1b5 conducts the operation below in a state where the
supply of the gate signal Sg1 to Sg6 from the main control unit A1 to the motor drive
20 circuit 5 is cut off, and the supply of the gate signal Sg1 to Sg6 from the auxiliary control
unit E2 to the motor drive circuit 5 is being conducted. In other words, the gate control
signals S1 to S6 which render all the switching transistors Q1 to Q6 that configure the
motor drive circuit 5 to the OFF state (no transmission state), in other words, the gate
control signals S1 to S6 that sequentially transmit to the switching transistors Q1 to Q6
25 individually, are output to the individually the second pre-driver 2b.
46
[0149]
By referencing the motor terminal state detection signal that is input from the motor
terminal state detection unit 15 in the aforementioned state, the second microcomputer
1b5 diagnoses failure of the auxiliary control unit E2, in other words, failures of the
5 second pre-driver 2b, the second signal cut off switch 3b, and the second switch control
unit 4b.
[0150]
For example, in a state where the gate control signals S1 to S6 which render all of the
switching transistors Q1 to Q6 in the OFF state (no transmission state) are output to the
10 second pre-driver 2b by the second microcomputer 1b5, a case where the motor terminal
state detection signal shows that any one of the switching transistors Q1 to Q6 is in the
ON state (transmission state) is considered. In such case, the second microcomputer
1b5 determines that a failure is occurring in any one of the second pre-driver 2b, the
second signal cut off switch 3b, or the second switch control unit 4b.
15 [0151]
In a state where the gate control signals S1 to S6 that sequentially transmit the
switching transistors Q1 to Q6 individually are output to the second pre-driver 2b by the
second microcomputer 1b5, a case where the second microcomputer 1b5 shows the
transmission state of the switching transistors Q1 to Q6 of the motor terminal state
20 detection signal that differ from the gate control signals S1 to S6 is considered. In such
case, the second microcomputer 1b5 determines that a failure is occurring in any one of
the second pre-driver 2b, the second signal cut off switch 3b, or the second switch control
unit 4b.
[0152]
25 It is not possible to conduct the above failure determination in a state where the main
47
control unit A1 or the auxiliary control unit E2 are being controlled. Therefore, the
above determination is conducted in a state where the main control unit A1 and the
auxiliary control unit E2 are both not controlling the motor 6, in other words, in a state
where no assist by the electric power steering device is being conducted on steering
5 operation.
[0153]
As explained above, the motor control device 100 according to the present
embodiment further includes the motor terminal state detection unit 15 that detects a state
of the input terminal of the motor 6 as the motor terminal state. By referencing the
10 motor terminal state (the motor terminal state detection signal output by the motor
terminal state detection unit 15), the second control signal generator (the second
microcomputer 1b5) determines the occurrence of failure in the auxiliary control unit E2.
According to such a configuration, since it is possible for the auxiliary control unit E2 to
diagnose failures, it is possible to further increase reliability of the motor control device
15 100 and electric power steering device.
[0154]
Sixth Embodiment
Next, the motor control device 100 and an electric power steering device according to
a sixth embodiment are explained. Since fundamental configurations of the motor
20 control device 100 and the electric power steering device are similar to those of the first
embodiment, explanations that follow mainly focus on differing aspects. Components
having similar functions as components explained in the first embodiment have the same
names and reference symbols affixed thereto, with detailed explanations being omitted in
the explanations below.
25 [0155]
48
In the motor control device 100 according to the sixth embodiment, computing power
of the second microcomputer 1b is less than computing power of the first microcomputer
1a, out of the first microcomputer 1a and the second microcomputer 1b in the first
embodiment.
5 [0156]
In other words, the motor control device 100 according to the sixth embodiment does
not use two microcomputers (large scale integrated circuit) with the same computing
power, but a large scale integrated circuit as the second microcomputer 1b having less
computing power than the large scale integrated circuit as the first microcomputer 1a is
10 adopted.
[0157]
The auxiliary control unit A2 of the first embodiment only operates when an error
occurs in the main control unit A1. Therefore using the second microcomputer 1b as
the large scale integrated circuit having lower computing power than the first
15 microcomputer 1a is enough for the motor control device 100 to function.
[0158]
According to the configuration of the sixth embodiment, since the second
microcomputer 1b having a lower computing power than the first microcomputer 1a is
used as the large scale integrated circuit, it is possible to make the auxiliary control unit
20 A2 even cheaper. Therefore, according to the sixth embodiment, it is possible to reduce
the cost of the motor control device 100 and electric power steering device.
[0159]
Seventh Embodiment
Next, the motor control device 100 and an electric power steering device according to
25 a seventh embodiment are explained. Since fundamental configurations of the motor
49
control device 100 and the electric power steering device are similar to those of the first
embodiment, explanations that follow mainly focus on differing aspects. Components
having similar functions as components explained in the first embodiment have the same
names and reference symbols affixed thereto, with detailed explanations being omitted in
5 the explanations below.
[0160]
As shown in FIG. 6, the motor control device 100 according to the seventh
embodiment includes a main control unit F1 and an auxiliary control unit F2. The main
control unit F1 includes a first microcomputer 1a6 instead of the first microcomputer 1a
10 of the first embodiment, and a first switch control unit 4a6 instead of the first switch
control unit 4a of the first embodiment. The auxiliary control unit F2 includes a second
microcomputer 1b6 instead of the second microcomputer 1b of the first embodiment, and
a second switch control unit 4a6 instead of the second switch control unit 4a of the first
embodiment.
15 [0161]
Compared to the main control unit A1 of the first embodiment, the main control unit
F1 additionally has a first steering torque input I/F 17a and a first rotation angle input I/F
20a. Compared to the auxiliary control unit A2 of the first embodiment, the auxiliary
control unit F2 additionally has a second steering torque input I/F 17b and a second
20 rotation angle input I/F 20b.
[0162]
As shown in FIG. 6, the electric power steering device according to the seventh
embodiment includes a steering torque detection unit 16 and a rotation angle detection
unit 19.
25 [0163]
50
The steering torque detection unit 16 is connected to the first steering torque input I/F
17a and the second steering torque input I/F 17b. The steering torque detection unit 16
detects a torque of steering of an automobile operator as a steering torque, and outputs a
detection torque signal that shows the steering torque to the first steering torque input I/F
5 17a and the second steering torque input I/F 17b.
[0164]
The first steering torque input I/F 17a includes one input terminal and one output
terminal. The input terminal of the first steering torque input I/F 17a is connected to the
steering torque detection unit 16, and the output terminal of the first steering torque input
10 I/F 17a is connected to the first microcomputer 1a6. The first steering torque input I/F
17a converts a detected torque signal that is input from the steering torque detection unit
16 to a first torque conversion signal suitable for input to the first microcomputer 1a6,
and outputs the detected torque signal to the first microcomputer 1a6.
[0165]
15 The second steering torque input I/F 17b includes one input terminal and one output
terminal. The input terminal of the second steering torque input I/F 17b is connected to
the steering torque detection unit 16, and the output terminal of the second steering
torque input I/F 17b is connected to the second microcomputer 1b6. The second
steering torque input I/F 17b converts a detected torque signal that is input from the
20 steering torque detection unit 16 to a second torque conversion signal suitable for input to
the second microcomputer 1b6, and outputs the detected torque signal to the second
microcomputer 1b6.
[0166]
The rotation angle detection unit 19 includes an output terminal that is connected to
25 the first rotation angle input I/F 20a and to the second rotation angle input I/F 20b. The
51
rotation angle detection unit 19 detects a rotation angle of the motor 6, and outputs a
rotation angle detection signal that shows the rotation angle to the first rotation angle
input I/F 20a and the second rotation angle input I/F 20b.
[0167]
5 The first rotation angle input I/F 20a includes one input terminal and one output
terminal. The input terminal of the first rotation angle input I/F 20a is connected to the
rotation angle detection unit 19, and the output terminal of the first rotation angle input
I/F 20a is connected to the first microcomputer 1a6. The first rotation angle input I/F
20a converts the rotation angle detection signal that is input from the rotation angle
10 detection unit 19 to a first rotation conversion signal suitable for input to the first
microcomputer 1a6 and outputs the first rotation conversion signal to the first
microcomputer 1a6.
[0168]
The second rotation angle input I/F 20b includes one input terminal and one output
15 terminal. The input terminal of the second rotation angle input I/F 20b is connected to
the rotation angle detection unit 19, and the output terminal of the second rotation angle
input I/F 20b is connected to the second microcomputer 1b6. The second rotation angle
input I/F 20b converts the rotation angle detection signal that is input from the rotation
angle detection unit 19 to a second rotation conversion signal suitable for input to the
20 second microcomputer 1b6 and outputs the second rotation conversion signal to the
second microcomputer 1b6.
[0169]
In addition to the six output terminals and the three output terminals in the first
microcomputer 1a of the first embodiment, the first microcomputer 1a6 includes five
25 input terminals, two output terminals, a first steering torque input I/F monitoring unit 18a,
52
and a first rotation angle input I/F monitoring unit 21a.
[0170]
An input terminal of the first microcomputer 1a6 is connected to the first steering
torque input I/F 17a, and the first torque conversion signal from the first steering torque
5 input I/F 17a is input thereto.
An input terminal of the first microcomputer 1a6 is connected to the first rotation
angle input I/F 20a, and the first rotation conversion signal from the first rotation angle
input I/F 20a is input thereto.
[0171]
10 An input terminal of the first microcomputer 1a6 is connected to the second steering
torque input I/F monitoring unit 18b, and a second steering torque input I/F abnormality
signal from the second steering torque input I/F monitoring unit 18b is input thereto.
An input terminal of the first microcomputer 1a6 is connected to the second rotation
angle input I/F monitoring unit 21b, and a second rotation angle input I/F abnormality
15 signal from the second rotation angle input I/F monitoring unit 21b is input thereto.
An input terminal of the first microcomputer 1a6 is connected to the second switch
control unit 4b6, and the second switching signal from the second switch control unit 4b6
is input thereto.
[0172]
20 An output terminal of the first microcomputer 1a6 is connected to the first switch
control unit 4a6 and to the second microcomputer 1b6, and outputs a first steering torque
input I/F abnormality signal that is output from the first steering torque input I/F
monitoring unit 18a to the first switch control unit 4a6 and to the second microcomputer
1b6.
25 [0173]
53
An output terminal of the first microcomputer 1a6 is connected to the first switch
control unit 4a6 and to the second microcomputer 1b6, and outputs a first rotation angle
input I/F abnormality signal that is output from the first rotation angle input I/F
monitoring unit 21a to the first switch control unit 4a6 and to the second microcomputer
5 1b6.
[0174]
The first steering torque input I/F monitoring unit 18a is a functional component that is
provided within the first microcomputer 1a6. The first steering torque input I/F
monitoring unit 18a includes one input terminal and one output terminal. The first
10 steering torque input I/F monitoring unit 18a monitors an operation state of the first
steering torque input I/F 17a based on the first torque conversion signal that is input from
the first steering torque input I/F 17a. When the first steering torque input I/F
monitoring unit 18a determines that an abnormality occurred at the first steering torque
input I/F 17a, the first steering torque input I/F monitoring unit 18a outputs the first
15 steering torque input I/F abnormality signal which shows the abnormality to the first
switch control unit 4a6 and to the second microcomputer 1b6.
[0175]
The first rotation angle input I/F monitoring unit 21a is a functional component that is
provided within the first microcomputer 1a6. The first rotation angle input I/F
20 monitoring unit 21a includes one input terminal and one output terminal. The first
rotation angle input I/F monitoring unit 21a monitors the operation state of the first
rotation angle input I/F 20a based on the first rotation conversion signal that is input from
the first rotation angle input I/F 20a. When the first rotation angle input I/F monitoring
unit 21a determines an abnormality of the first rotation angle input I/F 20a, the first
25 rotation angle input I/F monitoring unit 21a outputs the first rotation angle input I/F
54
abnormality signal which shows the abnormality to the first switch control unit 4a6 and
the second microcomputer 1b6.
[0176]
In addition to the six output terminals and the three input terminals in the second
5 microcomputer 1b of the first embodiment, the second microcomputer 1b6 includes five
input terminals, two output terminals, the second steering torque input I/F monitoring
unit 18b, and the second rotation angle input I/F monitoring unit 21b.
[0177]
An input terminal of the second microcomputer 1b6 is connected to the output terminal
10 of the second steering torque input I/F 17b, and the second torque conversion signal is
input from the second steering torque input I/F 17b.
An input terminal of the second microcomputer 1b6 is connected to the second rotation
angle input I/F 20b, and the second rotation conversion signal is input from the second
rotation angle input I/F 20b.
15 [0178]
An input terminal of the second microcomputer 1b6 is connected to the first steering
torque input I/F monitoring unit 18a in the first microcomputer 1a6, and the first steering
torque input I/F abnormality signal is input from the first steering torque input I/F
monitoring unit 18a.
20 An input terminal of the second microcomputer 1b6 is connected to the first rotation
angle input I/F monitoring unit 21a in the first microcomputer 1a6, and the first rotation
angle input I/F abnormality signal is input from the first rotation angle input I/F
monitoring unit 21a.
An input terminal of the second microcomputer 1b6 is connected to the first switch
25 control unit 4a6 in the first microcomputer 1a6, and the first switching signal is input
55
from the first switch control unit 4a6.
[0179]
An output terminal of the second microcomputer 1b6 is connected to the second switch
control unit 4b6 and the first microcomputer 1a6, and outputs the second steering torque
5 input I/F abnormality signal that is output from the second steering torque input I/F
monitoring unit 18b to the second switch control unit 4b6 and the first microcomputer
1a6.
[0180]
An output terminal of the of the second microcomputer 1b6 is connected to the second
10 switch control unit 4b6 and the first microcomputer 1a6, and outputs the second rotation
angle input I/F abnormality signal that is output from the second rotation angle input I/F
monitoring unit 21b to the second switch control unit 4b6 and the first microcomputer
1a6.
[0181]
15 The second steering torque input I/F monitoring unit 18b is a functional component
that is provided within the second microcomputer 1b6. The second steering torque
input I/F monitoring unit 18b includes one input terminal and one output terminal. The
second steering torque input I/F monitoring unit 18b monitors an operation state of the
second steering torque input I/F 17b based on the second torque conversion signal that is
20 input from the second steering torque input I/F 17b. When the second steering torque
input I/F monitoring unit 18b determines that an abnormality occurred at the second
steering torque input I/F 17b, the second steering torque input I/F monitoring unit 18b
outputs the second steering torque input I/F abnormality signal which shows the
abnormality, to the second switch control unit 4b6 and the first microcomputer 1a6.
25 [0182]
56
The second rotation angle input I/F monitoring unit 21b is a functional component that
is provided within the second microcomputer 1b6. The second rotation angle input I/F
monitoring unit 21b includes one input terminal and one output terminal. The second
rotation angle input I/F monitoring unit 21b monitors an operation state of the second
5 rotation angle input I/F 20b based on the second rotation conversion signal that is input
from the second rotation angle input I/F 20b. When the second rotation angle input I/F
monitoring unit 21b determines that an abnormality occurred at the second rotation angle
input I/F 20b, the second rotation angle input I/F monitoring unit 21b outputs the second
rotation angle input I/F abnormality signal which shows the abnormality, to the second
10 switch control unit 4b6 and the first microcomputer 1a6.
[0183]
Next, an operation of a motor control device 100 and an electric power steering device
according to the seventh embodiment is explained.
[0184]
15 The first microcomputer 1a6 generates the gate control signal S1 to S6 based on the
first torque conversion signal that is input from the first steering torque input I/F 17a, the
U phase conversion current signal, the V phase conversion current signal, and the W
phase conversion current signal that are generated by the current input I/F 8, and the first
rotation conversion signal that is input from the first rotation angle input I/F 20a in the
20 main control unit F1.
[0185]
In other words, the first microcomputer 1a6 in the main control unit F1 feedback
controls the motor 6 based on the steering torque that is detected by the steering torque
detection unit 16, a U phase drive current, a V phase drive current and a W phase drive
25 current that are detected by the current detection unit 7, and a rotation angle detected by
57
the rotation angle detection unit 19

WE CLAIM
[Claim 1]
A motor control device comprising:
a motor drive circuit that outputs a drive current to a motor;
5 a drive current detector that detects the drive current;
a main control unit, and
an auxiliary control unit, wherein
the motor drive circuit is driven based on a drive signal that is output from the main
control unit or the auxiliary control unit,
10 the main control unit has
a first control signal generator that generates a first control signal based on a
detected current signal that is input from the drive current detector;
a first drive signal generator that generates the drive signal based on the first control
signal, and
15 a first switcher that switches an output state of the drive signal to the motor drive
circuit, and
the auxiliary control unit has
a second control signal generator that generates a second control signal based on a
detected current signal that is input from the drive current detector;
20 a second drive signal generator that generates the drive signal based on the second
control signal, and
a second switcher that switches an output state of the drive signal to the motor drive
circuit.
[Claim 2]
25 The motor control device according to claim 1, wherein
65
the motor drive circuit includes a plurality of switching elements, and the motor is
driven by having each of the switching elements switch between supply and cut off of the
drive current to the motor.
[Claim 3]
5 The motor control device according to claim 1 or claim 2 further comprising:
a first control signal generator monitoring unit that monitors an operation state of the
first control signal generator, and outputs a first abnormality signal to the first switcher
and the second control signal generator when the first control signal generator monitoring
unit determines that an abnormality is occurring in the first control signal generator, and
10 a second control signal generator monitoring unit that monitors an operation state of
the second control signal generator, and outputs a second abnormality signal to the
second switcher and the first control signal generator when the second control signal
generator monitoring unit determines that an abnormality is occurring in the second
control signal generator, wherein
15 the drive signal is output to the motor drive circuit from a control unit having no
abnormality out of the main control unit and the auxiliary control unit.
[Claim 4]
The motor control device according to any one of claims 1 to 3 further comprising:
a first drive signal generator monitoring unit that monitors an operation state of the
20 first drive signal generator, and outputs a first drive abnormality signal to the first
switcher and the second control signal generator when the first drive signal generator
monitoring unit determines that an abnormality is occurring in the first drive signal
generator, and
a second drive signal generator monitoring unit that monitors an operation state of the
25 second drive signal generator, and outputs a second drive abnormality signal to the
66
second switcher and the first control signal generator when the second drive signal
generator monitoring unit determines that an abnormality is occurring in the second drive
signal generator, wherein
the drive signal is output to the motor drive circuit from a control unit having no
5 abnormality out of the main control unit and the auxiliary control unit.
[Claim 5]
The motor control device according to any one of claims 1 to 4 further comprising:
a first power supply that supplies operation power to the first control signal generator
and the first drive signal generator;
10 a second power supply that supplies operation power to the second control signal
generator and the second drive signal generator;
a first power supply monitoring unit that monitors an operation state of the first power
supply, and outputs a first power supply abnormality signal to the first switcher and the
second control signal generator when the first power supply monitoring unit determines
15 that an abnormality is occurring in the first power supply, and
a second power supply monitoring unit that monitors an operation state of the second
power supply, and outputs a second power supply abnormality signal to the second
switcher and the first control signal generator when the second power supply monitoring
unit determines that an abnormality is occurring in the second power supply, wherein
20 the drive signal is output to the motor drive circuit from a control unit having no
abnormality out of the main control unit and the auxiliary control unit.
[Claim 6]
The motor control device according to any one of claims 1 to 5 further comprising:
a first detector monitoring unit that is provided in the main control unit, that monitors
25 an operation state of the drive current detector, and that outputs a first current detection
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abnormality signal to the first switcher and the second control signal generator when the
first detector monitoring unit determines that an abnormality is occurring in the drive
current detector, and
a second detector monitoring unit that is provided in the auxiliary control unit, that
5 monitors an operation state of the drive current detector, and that outputs a second
current detection abnormality signal to the second switcher and the first control signal
generator when the second detector monitoring unit determines that an abnormality is
occurring in the drive current detector.
[Claim 7]
10 The motor control device according to any one of claims 1 to 6, wherein:
the main control unit outputs the drive signal to the motor drive circuit via the first
switcher only when the second switcher does not output the drive signal to the motor
drive circuit, and
the auxiliary control unit outputs the drive signal to the motor drive circuit via the
15 second switcher only when the first switcher does not output the drive signal to the motor
drive circuit.
[Claim 8]
The motor control device according to any one of claims 1 to 7 further comprising:
a motor terminal state detection unit that detects a state of an input terminal of the
20 motor as a motor terminal state, wherein
the second control signal generator determines failure of the auxiliary control unit by
referencing the motor terminal state.
[Claim 9]
The motor control device according to any one of claims 1 to 8, wherein
25 the second control signal generator has a lower computing power than the first control
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signal generator.
[Claim 10]
An electric power steering device comprising:
the motor control device according to any one of claims 1 to 9;
5 the motor which generates an assist torque to assist a steering torque of steering of an
operator.
[Claim 11]
The electric power steering device according to claim 10 further comprising:
a steering torque detection unit which detects the steering torque;
10 a first steering torque input I/F that converts a detected torque signal that is detected by
the steering torque detection unit to a first torque conversion signal, and inputs the first
torque conversion signal to the first control signal generator;
a first steering torque input I/F monitoring unit that determines the presence or absence
of an abnormality occurrence in the first steering torque input I/F;
15 a second steering torque input I/F that converts the detected torque signal that is
detected by the steering torque detection unit to a second torque conversion signal, and
inputs the second torque conversion signal to the second control signal generator, and
a second steering torque input I/F monitoring unit that determines the presence or
absence of an abnormality occurrence in the second steering torque input I/F, wherein
20 the first switcher cuts off output of the drive signal based on the first control signal to
the motor drive circuit, when the first steering torque input I/F monitoring unit
determines that an abnormality occurred in the first steering torque input I/F, and
the second switcher cuts off output of the drive signal based on the second control
signal to the motor drive circuit, when the second steering torque input I/F monitoring
25 unit determines that an abnormality occurred in the second steering torque input I/F.
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[Claim 12]
The electric power steering device according to claim 10 or 11 further comprising:
a rotation angle detection unit that detects the rotation angle of the motor;
a first rotation angle input I/F that converts a detected rotation angle signal detected by
5 the rotation angle detection unit to a first rotation conversion signal, and inputs the first
rotation conversion signal to the first control signal generator;
a first rotation angle input I/F monitoring unit that determines the presence or absence
of an abnormality occurrence in the first rotation angle input I/F;
a second rotation angle input I/F that converts the detected rotation angle signal that is
10 detected by the rotation angle detection unit to a second rotation conversion signal, and
inputs the second rotation conversion signal to the second control signal generator, and
a second rotation angle input I/F monitoring unit that determines the presence or
absence of an abnormality occurrence in the second rotation angle input I/F, wherein
the first switcher cuts off output of the drive signal based on the first control signal to
15 the motor drive circuit, when the first rotation angle input I/F monitoring unit determines
that an abnormality occurred in the first rotation angle input I/F, and
the second switcher cuts off output of the drive signal based on the second control
signal to the motor drive circuit, when the second rotation angle input I/F monitoring unit
determines that an abnormality occurred in the second rotation angle input I/F.