Description:Complete Specification:
The following specification describes and ascertains the nature of this
invention and the manner in which it is to be performed
2
Field of the invention
[0001] The present disclosure relates to activation of a vehicle’s ECUs(electric control
units) in a network to perform a task and more specifically, to a system and a method
to selectively activate at least one control unit from plurality 5 of control units of a
vehicle.
[0002] Background of the invention
10 [0003] Many Electronic Control Units (ECUs) are used to control the engine/
transmission / brake loads in the vehicle, in the form of Battery Control Units (BCU),
Vehicle Control Unit (VCU), Anti-lock Braking System (ABS), Cluster Control Unit
(CCU), Engine Management System (EMS), Steering control systems, Transmission
Control Unit (TCU) in combustion-based vehicles and electric vehicles (fuel cell
15 vehicles). The ECU reads all the necessary operating data required for controlling and
regulating the engine/ transmission / brake loads/ electric motor, etc., using sensors,
switches as well as data from the bus systems. Minimizing energy consumption has
become a major need for any new product design, including industrial and automotive
systems that use the CAN bus. One way to reduce system energy consumption is to
20 shut down elements not being used to perform a task in a cluster of ECUs.
[0004] In order to activate an ECU amongst a cluster of ECU connected over a
network, a wake up (activation) signal is sent to the ECU cluster by a host control
25 module through a communication means which can a digital line capable of
transmitting signals. All ECU modules wake up when this signal is sent, and they
check with the host control module that which ECU has to be activated. The prior
knowledge in the field suggests that currently, all control units will wake up in case if
3
a wakeup signal is sent for activation of only a specific ECU(s). For instance, in order
to activate an infotainment unit by a VCU, the VCU sends wakeup (activation) signal
via single line which activates all control unit including Infotainment.
[0005] The prior art US6484082B1 proposes a network management 5 approach for use
in a vehicle to control activation of electronic control units (ECUs) networked together
throughout the vehicle. The ECUs are grouped together by function into virtual
networks, with each virtual network including those ECUs used in carrying out a
particular control task, such as controlling power windows or automatic headlights.
10 The virtual networks are activated using a messaging protocol that specifies which
virtual network is being activated. Periodic messages specifying the virtual network
are also used to maintain it active. This permits the ECUs to be maintained in a low
power quiescent state when the control functions are not needed, while allowing only
those needed for a particular control task to be awakened and maintained in an
15 activated state to carry out their associated control task. An ECU can activate one of
the virtual networks by transmitting a wake-up signal followed by a message
identifying the virtual network. Each of the ECUs receive this message and, if it is a
member of the virtual network being initialized, maintains itself in an active state to
carry out the control task associated with the virtual network. The other ECUs return
20 to the quiescent state. Using this approach, an ECU is able to activate only the
necessary ECUs for a particular control task without having to know which or how
many ECUs are involved in performing the task
[0006] The present disclosure proposes a wake-up module for an ECU. The disclosure
25 proposes to create a set of patterns and assign the said pattern to a particular ECU.
Each of the ECU will have the proposed wake-up receiver module that will receive a
signal with a specific pattern, the wake-up receiver module will compute an average
4
output of the pre-defined signal pattern. When this average output falls within a
threshold range unique to the ECU to be activated, the said ECU will be activated.
Brief description of the accompanying 5 drawings
[0007] Preferred exemplary embodiments of the present invention will hereinafter be
described in conjunction with the appended drawings:
[0008] Figure 1 depicts a system to selectively activate a control unit from plurality of
control units of a vehicle.
10 [0009] Figure 2 depicts the components of a wake up module to selectively activate a
control unit from plurality of control units of a vehicle.
[0010] Figure 3 depicts a flowchart of the method to selectively activate a control unit
from plurality of control units of a vehicle.
15 [0011] Detailed description of the drawings
[0012] The present invention will now be described by way of example, with reference
to accompanying drawings. Throughout all the figures, same or corresponding
elements may generally be indicated by same reference numerals. These depicted
20 embodiments are to be understood as illustrative of the invention and not as
limiting in any way. It should also be understood that the figures are not necessarily
to scale and that the embodiments are sometimes illustrated by graphic symbols,
phantom lines, diagrammatic representations and fragmentary views. In
predetermined instances, details which are not necessary for an understanding of
25 the present invention, or which render other details difficult to perceive may have
been omitted.
[0013] The advantages of the present invention will be apparent with this detailed
description, wherein, the best method known to the applicant to implement the
5
invention has also been described. It is however to be noted that numerous alternate
embodiments of the present invention are possible and the disclosure of one of
them is not to be construed as limiting the others.
[0014] The electric control units (ECUs) in a vehicle operate in different 5 power states
which include an active state, where the ECU is fully powered, a standby/sleep
state, where the ECU is only partially operational and a shut-down state, where the
power consumption of ECU is minimum. Typically, ECUs use wake-up modules
to switch between the power states. These wake up modules comprise a wake-up
10 trigger detection circuitry that monitors certain triggers in order to indicate that the
ECU is to be activated. Once the trigger is detected, the wake-up module generates
signals to activate various circuits inside the ECU.
[0015] Referring to figure 1, the same depicts a system (10) to selectively activate a
15 control unit from plurality of control units (1,2,3,4,5,6) of a vehicle (not shown).
The person skilled in the art would appreciate that the reference to control units
here is with respect to the electric control units (ECUs) of the vehicle. The
components of the control units (ECU) such as the associated memory,
input/output interfaces, embedded software and communication links generally
20 present in the control units are well known and not being described for the sake of
brevity.
[0016] The said plurality of control units inside the vehicle are connected to a network
(20). In an example the network (20) may include the plurality control units (or
25 electric control units {ECUs}) connected to each other by way of an in-vehicle
network bus . The network bus is capable of sending signals across the network to
all ECUs it connects. In an example, the signal may be transmitted to the network
by one ECU acting as a master ECU for a specific function. In another example,
6
there may be multiple ECUs acting as master ECUs to control the function. The
ECU(s) acting as master ECU may comprise a wake-up transmitting module
(WTM) (1a, 4a, 5a) to transmit a signal pattern. The network may be (but not
limited to) a digital line capable of providing digital wake-up (activation) signals.
It will be appreciated that the illustrated network is just a fragment 5 of a typical onboard
vehicle network and is shown for the purposes of illustrating the construction
and operation of the present invention.
[0017] Each of the said plurality of control units (1,2,3,4,5,6) have a wake-up receiver
10 module (1b, 2b,3b,4b,5b,6b). Said wake-up receiver module is configured to
receive at least one signal with a pre-defined pattern that is transmitted to the
network (20) by a wake-up transmitted (1a, 4a,5a). According to an embodiment,
the wake-up receiver module (WRM) may include the wake-up trigger detection
circuitry, a power supply source , clock and reset controls and microcontrollers to
15 execute a program. The pre-defined pattern of signal may be generated by pulse
width modulation of the voltage or current signal. In an example, a signal pattern
can be Fixed ON time (high state) and variable OFF time (low state). In another
example , the signal pattern can be variable ON/OFF time (high/low) over a fixed
time period.
20 [0018] Referring to Fig 1-2, said wake-up receiver module (1b-6b) comprises an
averaging circuit (7) , a threshold detection circuit(8) and an activation circuit (9).
The averaging circuit (7) gives an average output of the pre-defined pattern of the
at least one activation signal. The averaging circuit (7) calculates an average value
of the input signal. Averaging circuit may be simple RC low pass filter which filter
25 out high frequency/ average out the waveform. A person skilled in the art will
appreciate the averaging circuit may comprise of resistors to provide the necessary
impedance and voltage division and capacitors arranged in series or parallel to
resistors to store and release electric charge or to form low-pass filters or
7
integrators. It may further comprise operational amplifiers, feedback components,
switches and multiplexers.
[0019] The threshold detection circuit (8) compares the average output with a
threshold output range, wherein, said threshold output range is 5 unique to the said
at least one control unit (1) to be activated. A person skilled in the art will
appreciate that the threshold detection circuit may comprise of comparator to
compare the input signal voltage with a reference voltage to give a logical high or
low (ON or OFF) to determine whether the input signal is above or below the
10 threshold. The threshold detection may further comprise components such as
hysteresis to prevent oscillations or rapid switching when the input signal hovers
near the threshold range. In an embodiment, the output from the threshold
detection circuit may pass through a filter circuit (11) to a steady state.
15 [0020] The wake-up receiver module further comprises an activation circuit (9) to
activate the at least one control unit when the average output is within the range of
threshold output. A person skilled in the art will appreciate that the activation
circuit may comprise of microcontrollers or dedicated logic control to generate
signals based on inputs to activate a desired functionality. It may further comprise
20 of transistors, switches or relays to turn the power supply ON or OFF and other
protection components such as diodes and fuses for protection against voltage
spikes.
[0021] In order to supply power to the wake-up receiver module, a direct battery
25 supply can be derived from, in an example, a Zener diode. In another example,
energy stored in capacitors may be used. The energy from WTM can be stored in
buffer capacitor and stored energy from buffer capacitor can be used for powering
up WRM.
8
[0022] The working of the system as described in Fig 1 and Fig 2 is described further.
It is to be noted that the working described further is strictly exemplary for a better
understanding of the system. In an example, control unit 1 acting as a master
control unit sends the activation signal with wake-up transmitter 5 module (WTM)
1a, wherein, control units (1,2,3,4) have to be woken up with a respective threshold
output range of 1-1.4V,1.5-1.9V, 2-2.4V and 2.5-3 V. The WTM 1a may transmit
the signal patterns whose output when computed by the threshold detection circuits
of the respective wake-up receiver modules (1b,2b,3b,4b) lies within the range of
10 threshold output unique to the respective control units to be activated. Therefore,
in an example, when the average output of a first, a second, a third and a forth
signal is sequentially computed to be 1.3V, 1.7V, 2.1V and 2.6V (respectively, one
at a time) the control unit 1, 2, 3, 4 get activated. The other control units (5,6) do
not respond to the said signal.
15
[0023] Referring to Fig 3 and Fig 1, the Fig 3 depicts a flowchart of the method to
selectively activate a control unit from plurality of control units of a vehicle. The
method (100) described herein is implemented by the system (10) described in
20 Figure 1 above. The method (100) to selectively activate at least one control unit
from plurality of control units of a vehicle is implemented by the system (10)
where each of said plurality of control units (1—6) comprise a wake-up-receiver
module (WRM) (1b-6b). The first step (101) of the method (100) includes
receiving by the WRM (See Fig 1), at least one activation signal with a pre-defined
25 pattern. The at least one signal is transmitted to a network that connects said
plurality of control units. The further step (102) is obtaining the average output of
the pre-defined pattern of the at least one activation signal by an averaging circuit.
This is followed by step (103) of selecting said at least one control unit by a
threshold detection circuit when the average output falls within a threshold output
9
range, said threshold output range unique to the said at least one control unit to be
activated. The final step (104) is activating the at least one control unit by an
activation circuit when the average output falls within the threshold output range.
In the method step (100) generation of the pre-defined pattern of the at least one
signal is through pulse width modulation of the signal with a fixed 5 ON time and a
variable OFF time. The signal with the pre-defined pattern is transmitted by a
wake-up transmitter module (WTM) where this pre-defined pattern is unique to
said at least one control unit to be activated.
[0024] The disclosure advantageously minimizes power loss and leads to a more
10 efficient ECU wake-up system. , Claims:WE CLAIM:
1. A wake-up-receiver module (WRM) to selectively activate at least one control
unit from plurality of control units of a vehicle, each of said plurality of control units
comprising said wake-up module,
10
said wake-up module configured to receive at least one signal with a pre-defined
pattern, the at least one signal transmitted to a network that connects said plurality of
control units,
15 said wake up module comprising:
-an averaging circuit that gives an average output of the pre-defined pattern of the at
least one activation signal;
-a threshold detection circuit that compares the average output with a threshold output
range, wherein, said at least one control unit is selected when the average output falls
20 within the threshold output range,
said threshold output range unique to the said at least one control unit to be activated;
and
-an activation circuit to activate the at least one control unit when the average output
is within the range of threshold output.
25
2. The WRM as Claimed in Claim 1, wherein, the pre-defined pattern of the at
least one signal is generated through pulse width modulation of the signal with either-
-a fixed ON time and a variable OFF time, or
11
- a variable ON time and a fixed OFF time, or
- a variable ON time and a variable OFF time over a fixed time period.
3. The WRM as claimed in Claim 1, wherein the pre-defined pattern of the at
least one signal is generated through pulse width modulation 5 is a voltage unit.
4. The WRM as claimed in Claim 1, wherein the pre-defined pattern of the at
least one signal is generated through pulse width modulation is a current unit.
10
5. The WRM as claimed in Claim 1, wherein, at least one of said plurality of
control unit comprise a wake-up transmitter module (WTM) to transmit the signal with
the pre-defined pattern, said pre-defined pattern unique to said at least one control unit
to be activated.
15
6. The WRM as claimed in Claim 1, wherein, an energy from WTM is stored in a
buffer capacitor and the energy so stored in the buffer capacitor is used to power the
WRM.
20
7. A method to selectively activate at least one control unit from plurality of
control units of a vehicle, each of said plurality of control units comprising a wakeup-
receiver module (WRM),
25 the method comprising the steps of :
- receiving by the WRM, at least one activation signal with a pre-defined pattern, the
at least one signal transmitted to a network that connects said plurality of control units,
12
characterized in the method,
-obtaining the average output of the pre-defined pattern of the at least one activation
signal 5 by an averaging circuit;
- selecting said at least one control unit by a threshold detection circuit when the
average output falls within a threshold output range, said threshold output range
unique to the said at least one control unit to be activated; and
10
- activating the at least one control unit by an activation circuit when the average output
falls within the threshold output range.
8. The method as Claimed in Claim 7, wherein, generating the pre-defined pattern
15 of the at least one signal through pulse width modulation of the signal with either:
- a fixed ON time and a variable OFF time, or
-a variable ON time and a fixed OFF time, or
-a variable ON and time and a variable OFF time over a fixed time period.
20
9. The method as Claimed in Claim 7, wherein, transmitting the signal with the
pre-defined pattern by a wake-up transmitter module (WTM), said pre-defined pattern
unique to said at least one control unit to be activated.
25 10. The method as claimed in Claim 7, wherein, storing an energy from WTM in a
buffer capacitor and using the energy so stored in the buffer capacitor to power the
WRM.