Technical field
[0001]The present invention has a switching function of the automatic steering control mode (steering angle control mode for the parking assist, etc.) and a manual steering control mode (assist control mode) in the steering control of the vehicle, drives the motor by a motor current command value, relates to an electric power steering apparatus for applying an assist force to the steering system of the vehicle, it is corrected in the same direction as the particular direction in which the target steering angle value of the steering angle control of the automatic steering control mode steering torque is applied, the correction vehicle speed amount, an electric power steering device steering torque by varying the on state does not reach the switching threshold, improved steering feeling of the driver in accordance with the steering state.
BACKGROUND
[0002]Steering assist force by the rotation force of the motor to a steering mechanism of a vehicle electric power steering apparatus which provides (assist force) (EPS) is the driving force of the motor by the transmission mechanism such as gears or a belt via reduction gear, a steering shaft or adapted to impart a steering assist force to the rack shaft. Such conventional electric power steering apparatus, in order to accurately generate a torque of the steering assist force, and performs a feedback control of a motor current. The feedback control is the difference between the steering assist command value (current command value) and the motor current detection value to adjust the voltage applied to the motor so as to reduce, adjustment of the voltage applied to the motor, generally a PWM (Pulse Width It is carried out by adjusting the modulation) control duty.
[0003]Explaining shows the general construction of an electric power steering apparatus in FIG. 1, the handle (steering wheel) 1 of column shaft (steering shaft, the steering wheel shaft) 2 is a reduction gear 3, universal joints 4a and 4b, a rack and pinion mechanism 5, via tie rods 6a, the 6b, which is further connected steered wheels 8L, the 8R via the hub unit 7a, 7b. In addition, the column shaft 2, a steering angle sensor 14 and torque sensor 10 for detecting the steering torque Th for detecting a steering angle θr of the steering wheel 1 is provided, the motor 20 is a reduction gear which assists a steering force of the steering wheel 1 3 through is connected to the column shaft 2. The control unit (ECU) 30 for controlling the electric power steering apparatus, the electric power from the battery 13 is supplied, the ignition key signal IG is input through the ignition key 11. Control unit 30 performs the calculation of the current command value of the assist control based on the vehicle speed Vs detected by the steering torque Th and the vehicle speed sensor 12 detected by the torque sensor 10, the voltage subjected to compensation for the current command value controlling the current supplied to the motor 20 by the control command value Vref. Note that the steering angle sensor 14 is a steering angle θr is detected, can also be obtained from a rotation sensor coupled to the motor 20.
[0004]The control unit 30, CAN (Controller Area Network) 40 for exchanging various kinds of information of the vehicle and is connected, the vehicle speed Vs is also possible to receive from CAN40. Further, the control unit 30, communications other than CAN40, an analog / digital signal, even non CAN41 for exchanging radio waves connectable.
[0005]
　Consists of a control unit 30 mainly CPU (including an MPU or MCU), is shown in Figure 2 when showing the general functions performed by the program in the CPU.
[0006]
　To explain the function and operation of the control unit 30 with reference to FIG. 2, the vehicle speed Vs (from or CAN) that detected by the steering torque Th and the vehicle speed sensor 12 detected by the torque sensor 10, a current command value Iref1 is input to the current command value calculation unit 31 for calculating. Current command value calculating section 31 uses the assist map or the like based on the input steering torque Th and the vehicle speed Vs, it calculates a current command value Iref1 is a control target value of the current supplied to the motor 20. The current command value Iref1 is inputted to the current limiting unit 33 via the adder portion 32A, limits the maximum current to current command value Iref3 is input to the subtraction unit 32B at overheat protection condition, the motor current value Im that is fed back deviation Iref4 (= Iref3-Im) is calculated, the deviation Iref4 is input to the PI control unit 35 for improving the characteristics of the steering operation. Voltage control command value Vref which is characteristic improvement by the PI control unit 35 is inputted to a PWM control unit 36, the motor 20 is PWM driven further via the inverter 37 as a drive unit. Current value Im of the motor 20 is detected by a motor current detector 38 and fed back to the subtraction section 32B.
[0007]
　Further, the motor 20 is connected a rotation sensor 21 such as a resolver is, the actual steering angle θs is detected. The addition unit 32A are subject to compensation signal CM from the compensator 34 performs compensation system based by the addition of the compensation signal CM, it is adapted to improve the convergence and inertial characteristics. Compensation unit 34, the self-aligning torque (SAT) 343 and the inertia 342 are added in the addition unit 344, further astringency 341 are added in the addition unit 345 to the addition result, compensation signal CM the addition result of the adder 345 It is set to.
[0008]
　In such an electric power steering apparatus, in recent years an automatic steering control mode (steering angle control mode for the parking assist, etc.) and a manual steering control mode (assist control mode), the vehicle appeared to have a switching function of these control modes and come Te, when implementing the automatic steering, held independently steering angle control and the assist control, configuration of switching these outputs are common. The steering angle control, and position and speed control is used with excellent performance in responsiveness and disturbance suppression properties, and a position control P (proportional) control, speed control PI (proportional integral) control, etc. .
[0009]
　And a function of steering angle control mode and the assist control mode, when a general electric power steering system for FIG 3 will be described with a function of switching the steering control mode, the resolver for the motor 150 for detecting a motor rotation angle θs rotation sensor 151 is connected equal, the motor 150 is driven and controlled via the vehicle-side ECU130 and EPS side ECU 140. Vehicle ECU130, the button indicating the driver's intention, based on the switch, the switching instructor 131 for outputting a switching instruction SW of the steering angle control mode or the assist control mode, the camera (image) and signals such as a laser radar It has and a target steering angle generating section 132 for generating a target steering angle θt based on. Further, the actual steering angle θr detected by the steering angle sensor 14 provided on the column shaft (steering shaft, the handle shaft) is input to the steering angle control unit 200 in the EPS side ECU140 via ECU 130.
[0010]
　Switching instructor 131, signals identifying entering the steering angle control mode, for example, buttons, switches provided the intention of the driver to the peripheral dashboard or steering wheel, or a signal of a vehicle state due parking mode provided in the shift outputs switching command SW based inputs switching instruction SW in the switching unit 142 in the EPS side ECU 140. Further, the target steering angle generating unit 132, a camera (image), the steering angle of the laser generates a target steering angle θt by a known technique based on data such as radar, the EPS side ECU140 the generated target steering angle θt inputted to the control unit 200.
[0011]
　EPS side ECU140 includes an assist control unit 141 for outputting an assist control command value Itref calculated based on the steering torque Th and the vehicle speed Vs, the target steering angle [theta] t, the steering angle control on the basis of the actual steering angle θr and the motor angular velocity ωr a steering angle control command value steering angle control unit 200 which calculates and outputs the Imref for a switching unit 142 for switching the assist control command value Itref and the steering angle control command value Imref by switching command SW, from the switching unit 142 a current control / drive unit 143 which drives and controls the motor 150 based on the motor current command value Iref (= Itref or Imref), determine the motor speed based on the motor rotation angle θs from the rotation sensor 151, motor speed and the gear ratio It has and a motor angular velocity calculation unit 144 for calculating an actual steering angular speed ωr with. Motor angular velocity calculation unit 144 includes a low pass filter (LPF) for cutting off high frequency noise in the subsequent stage of the operation of the differential equivalent.
[0012]
　Steering angle control unit 200, as shown in FIG. 4, the position control unit 210 for outputting a steering angular velocity command value ωc as to follow the actual steering angle θr to the target steering angle [theta] t, Jitsukaji angular velocity steering angular velocity command value ωc It is composed of a speed control unit 220 for outputting a steering angle control command value Imref so as to follow the .omega.r. Further, the switching unit 142, based on the switching instruction SW from switching instructor 131 on the vehicle side ECU 130, the assist control mode by the assist control unit 141 (manual steering control), the steering angle control mode by the steering angle control section 200 ( position / velocity control mode) and switches the outputs assist control command value Itref the assist control, the steering angle control to output the steering angle control command value Imref.
[0013]
　The electric power steering apparatus having such a function, conventionally by controlling the actuator (motor) based on the relationship between the steering angle and the moving distance of the previously stored vehicle, automatically back parking or parallel parking It is made as to do. Then, the conventional steering control apparatus, the actual steering angle to match a target steering angle is set according to the vehicle, calculates a motor current command value, and realize automatic steering control. For example patent automatic steering apparatus shown in No. 4,057,955 (Patent Document 1), when the steering angle control of the switching of the torque assist control, by changing in accordance with the fade transition time to the assist torque amount, control switching and to reduce the discomfort of the time.
CITATION
Patent Document
[0014]
Patent Document 1: Patent No. 4057955 Patent Publication
Patent Document 2: JP 2015-93569 JP
Summary of the Invention
Problems that the Invention is to Solve
[0015]
　The automatic steering control in the electric power steering device for automatic steering to follow the actual steering angle to the target steering angle, stop automatic control if it is determined that the driver steers the steering wheel, the assist control of the manual steering control it is desirable that switched to smoothly. Even steering angle control in the case where the driver does not reach the threshold value for determining that the steering, it is desirable to continue the steering angle control without discomfort the steering operation of the driver. Also, if the driver even steering angle control in does not reach the threshold value for determining that the steering, it is desirable to continue the free control discomfort the steering operation of the driver.
[0016]
　The automatic steering control performs control such that the actual steering angle relative to the target steering angle matches, when the driver added steering torque to the steering mechanism, the actual steering angle moves away from the target steering angle . Therefore, the automatic steering control such that the actual steering angle coincides with the target steering angle so as to oppose against the steering torque, the steering torque and outputs a reverse direction of the motor current command value.
[0017]
　On the other hand, the assist control to output to assisting the steering torque, the steering torque and outputs the same direction of the motor current command value. Therefore, when switching to the manual steering control from the automatic steering control when the steering torque is applied, because each output is reverse, as the driver from being applied steering torque temporarily by the automatic steering control after assisting in the reverse direction is made, the steering torque, switches gradually manual steering control by the fading. In other words, ultimately resulting in the assist steering torque in the same direction it is performed. This is, as the driver, become a sensation that caught on when switched to manual steering control from the automatic steering control, a sense of discomfort. Further, in the steering at the threshold value or less not switch to the assist control is to attempt to match the target steering angle output from the steering angle control is against the driver's steering, the driver can not freely steered.
[0018]
　Further, Japanese Patent 2015-93569 (Patent Document 2), and the steering angle deviation, combined physical value of the deviation of the target steering torque and the steering torque, and mixed while changing the ratio according to the steering intervention, after mixing steering control apparatus is disclosed that reflected to the target value of the steering intervention of the driver so as to reduce the deviation. Although Patent Document 2 reflects the steering intervention of the driver to a target value, and sets a weight to assist deviation and tracking deviation, so to match the unit are mixed according to the weights, the control system becomes complicated and will. Furthermore, since it is not a configuration in consideration of dynamic steering of the driver, it is difficult to set the dynamic steering characteristics.
[0019]
　The present invention has been made in view of the above described circumstances, an object of the present invention, when the driver is steering the steering wheel during the automatic steering control, can be switched smoothly steered with a simple structure, the driver It is to provide a high-performance electric power steering apparatus that does not give a sense of discomfort to.
Means for Solving the Problems
[0020]
　The present invention includes a manual steering control for driving the motor by a first motor current command value calculated on the basis of at least steering torque, by the steering angle control unit, is calculated so as to follow the actual steering angle to the target steering angle and it relates to an electric power steering apparatus having an automatic steering control and the function of switching the driving of the motor by a second motor current command value, the object of the present invention, with respect to the steering torque, in accordance with the steering state and the vehicle speed performs arithmetic processing, and the target steering angle correction unit that outputs a target steering angle correction value, the target steering angle is corrected by the target steering angle correction value, enter the corrected corrected target steering angle to the steering angle control unit It is accomplished by comprising a correction output unit that.
[0021]
　The above object of the present invention, the target steering angle correction unit includes a phase compensation unit for phase lead compensation or the phase-lag compensation on the basis of the steering torque to the steering state, the first compensation steering torque from the phase compensation unit enter a, which has a dead zone in the first region compensation steering torque is small, according to the vehicle speed, outputting a second compensation steering torque increases in the same direction as the method of increasing the first compensation steering torque a dead band gain section that, the upper and lower limit value of the second compensation steering torque limit in accordance with the vehicle speed, by being constituted by a limiter for outputting the corrected target steering angle, or the dead zone gain section by the second phase compensating section is provided at the subsequent stage, or the target steering angle correction unit, and inputs the steering torque, and has a dead zone in the region wherein the steering torque is small Depending on the vehicle speed, the a dead band gain section for outputting a first compensation steering torque increases in the same direction as the method of increasing the steering torque, the phase advance based on the first compensation steering torque to the steering state compensation or a phase compensator for phase lag compensation, and limited in accordance with the lower limit value to the vehicle speed on the second compensation steering torque from the phase compensation unit, it is composed of a limiter for outputting the corrected target steering angle by, or by the second phase compensating section is provided in front of the dead band gain unit, or output gain of the dead band gain section, by becoming smaller as the vehicle speed becomes higher, or the limit of the limiter value, by becoming smaller as the vehicle speed becomes higher, or the dead zone, by a variable according to the vehicle speed, or the Steering state, by at back handle additional turning or switching, or the determination of the return additional turning and switching, the relationship between the actual steering angle and the motor angular speed, or the relationship between the actual steering angle and the steering angular velocity, or the relation between the steering torque and the steering speed, or the relationship of the steering speed and the target steering angle and the actual steering angle deviation, or the target steering angle and the target steering angle change rate and deviation of the steering angular velocity of the and we have got to do on the basis of the relationship between the deviation of the steering angle
The invention's effect
[0022]
　According to the electric power steering apparatus of the present invention, the parking assist, but during the automatic steering control of the automatic traveling such as performing steering angle control of the steering wheel, when the steering torque is applied by the driver, joined the target steering angle is the steering torque direction and corrected in the same direction, with out the steering angle control to match the target steering angle is variable and accordingly the correction amount vehicle speed and steering state. Thus, when controlling added together at a certain ratio to each other the output of the assist control by the steering angle control and the steering torque of the target steering angle correction, to match the direction of the output of the automatic steering control and the manual steering control can be, it becomes difficult to interfere control output of each other, it is possible to reduce the uncomfortable feeling to the driver that occur when switching. Further, it is possible to improve the steering feeling in a state where the steering torque has not reached the switching threshold, leading to improved safety for the driver.
[0023]
　Further, in the present invention, since the sudden target steering angle is controlled to facilitate, nor uneasy feeling to the driver even in automatic operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024]
Is a block diagram showing an outline of FIG. 1 the electric power steering system.
Is a block diagram showing a configuration example of a control system of FIG. 2 the electric power steering apparatus.
3 is a block diagram showing an example of the automatic steering control mode and a manual steering control mode electric power steering apparatus having switching functions.
It is a block diagram showing a configuration example of FIG. 4 steering angle control unit.
Is a block diagram showing a configuration example of FIG. 5 the present invention.
6 is a block diagram showing a configuration example of a target steering angle correction unit (first embodiment) of the present invention.
7 is a characteristic diagram showing a characteristic example of the dead band gain section.
8 is a characteristic diagram showing a characteristic example of the limiter.
9 is a characteristic diagram for explaining the phase compensation.
FIG. 10 is a diagram showing a determination of the steering state (additional turning / switchback).
11 is a block diagram showing a configuration example of a steering angle control unit.
It is a block diagram showing a configuration example of FIG. 12 rate limiter.
It is a characteristic diagram showing a characteristic example of FIG. 13 rate limit value.
14 is a flowchart showing an example of the overall operation of the present invention.
It is a flowchart showing an operation example of FIG. 15 target steering angle correction unit.
16 is a block diagram showing a configuration example of a target steering angle correction unit (second embodiment) of the present invention.
Another configuration example of the target steering angle correction unit in FIG. 17 the present invention (third embodiment, fourth embodiment) is a block diagram showing the.
DESCRIPTION OF THE INVENTION
[0025]
　In the present invention, when applied steering torque from the driver, the target steering angle is corrected to join a direction the same direction as the steering torque, to implement the steering angle control to match the target steering angle. In addition, by varying the correction amount of the correction unit in accordance with the vehicle speed, it is possible to appropriately set the correction amount in accordance with a change in vehicle characteristics by the vehicle speed. The inclination of the correction amount for the torque (gain) is configured to set smaller as the vehicle speed increases, the correction amount of the correction unit is limited by smaller limit value as the vehicle speed increases so that it will not be excessively corrected .
[0026]
　In the present invention, in addition to this, the phase compensation portion is provided on either or both of the front and rear of the gain portion having a dead zone, it changes the characteristics of the phase compensation when the steer-back time handle switching characteristics of a phase compensator. Accordingly, the driver if you are steered within the steering angle control is not canceled, it is possible to deflect the vehicle in a range of the correction amount limit value. Limiter is provided to prevent excessive vehicle deflection by the driver during automatic operation. Further, when switched to the assist control from the steering angle control is also a steering angle control of the target steering angle correction, for controlling are summed at a certain ratio to each other and an output of the assist control by the steering torque, the steering angular control and can match the direction of the output of the assist control, the control output of each other is hardly interfere, it is possible to reduce the uncomfortable feeling to the driver that occur when switching.
[0027]
　Further, by switching when the additional turning time failback the characteristics of the phase compensator, since born difference in the correction amount when the return time additional turning and switching, it is possible to vary the hysteresis of the steering torque. By changing the phase compensation characteristic, it is possible to adjust the dynamic steering characteristics. For example, when the phase lag at the time of additional turning, since the steering torque increases in the steer for correction lags behind the change in the steering torque, it is possible to widen the hysteresis, a large phase delay of the phase compensation unit case, the correction amount by the steering torque is delayed, the steering torque is greater than when the phase lag is small. If for example, to increase the hysteresis by the phase lag than that at the time of cuts back the phase characteristic during turning-increasing, compared to when not switching the characteristics of the phase compensator, a wide hysteresis width when steering It can be provided to become. By attaching a hysteresis, it is adjusted steering feel, the torque change due to a change in external disturbance and the steering angle control quantity from the road surface, there is an advantage that does not excessively react.
[0028]
　Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0029]
　5 shows in correspondence with embodiments of the present invention in FIG. 3, with respect to the steering torque Th from the torque sensor 154, according to the steering state ST and the vehicle speed Vs from the steer / steer-back determination unit 160 performs arithmetic processing, includes a target steering angle correction unit 230 outputs a target steering angle correction value θha determined, the target steering angle θt is a target steering angle correction value θha from the target steering angle correction unit 230 adding unit 145 is corrected are added. Corrected by an adder 145 are corrected target steering angle θto is inputted to the steering angle control unit 200, steering angle control unit 200 inputs the actual steering angle θr and the motor angular velocity omega, outputs the calculated motor current command value Imref .
[0030]
　Target steering angle correction unit 230 is as shown in FIG. 6 (first embodiment), a phase compensation unit 231 to the phase lead compensation or the phase-lag compensation on the basis of the steering torque Th of the steering state ST, the phase compensator 231 dead band of type a compensation steering torque Th1, which has a dead band DB in domain compensation steering torque Th1 is small as shown in FIG. 7, and outputs the compensated steering torque Th2 that increases in the same direction as the method of increasing the compensation steering torque Th1 a gain unit 232, and a limiter 233 outputs a target steering angle correction value θha limits the upper limit value of the compensation steering torque Th2.
[0031]
　The dead band gain section 232 and the vehicle speed Vs is input, as shown in FIG. 7 (A), has a constant dead band DB, compensation steering torque Th2 is output which changes linearly, the output gain (slope) is It becomes smaller as the vehicle speed Vs is high. That is, the dead zone gain unit 232, the compensation steering torque Th2 as the vehicle speed Vs is high is small, and is output with a dead band DB. In FIG. 7 (A) is a dead zone DB is constant, the output gain (slope) is an example in which a linear, as shown in FIG. 7 (B), even by varying the deadband DB according to the vehicle speed Vs good. In other words, it is greater as as the vehicle speed Vs is high dead zone DB also DB1 → DB2 → DB3. Further, the output gain in Fig. 7 (A) and (B) is increased linearly, or may be an increase of non-linear as shown in FIG. 7 (C). Although FIG. 7 (C) in the dead zone in accordance with the vehicle speed Vs (DB4 ~ DB6) is variable, it may be constant.
[0032]
　Further, the vehicle speed Vs to the limiter 233 is input, the limit value as the vehicle speed Vs becomes higher as shown in FIG. 8 has become smaller properties. That is, in the limiter 233, the vehicle speed Vs is limited to upper and lower limit values ​​at a higher smaller limit value.
[0033]
　By switching in a steering state ST during the additional turning time failback the characteristics of the phase compensation unit 231, since born difference in the correction amount when the return time additional turning and switching, can vary the hysteresis of the steering torque Th to become. 9 for no phase compensation (solid characteristic B), in the case where the phase delay compensation (dashed characteristic C), shows the characteristics when the phase lead (characteristics D of dashed lines), the phase compensator 231 If the phase lag is large, the correction amount is delayed with respect to change in the steering torque Th, the steering torque is greater than when the phase lag is small. During automatic steering, the driver torque increases in steering, to try to return the handle to the target steering angle [theta] t, the relationship of the steering angle θ and the steering torque Th is as characteristic A in FIG. Taking logic for correcting the target steering angle θt in accordance with the torque, it is possible to change the relationship between the steering angle θ and the steering torque Th as characteristic B. Since in the case of phase lead correction enters early, would be characteristic D, the correction is delayed in the case of phase delay, so that the characteristics C.
[0034]
　Steering state ST supplied to the phase compensating unit 231 is determined by the additional turning / steer-back determination unit 160. Steer / steer-back determining unit 160 as shown in FIG. 10 for example, determines that additional turning the case where the sign of the steering angle θ and the motor angular velocity ω match, failback the case of different codes and determination to there. Or a combination of steer / steer-back decision following signals, but if the additional turning the sign either case match, switching back and determining when a mismatch. The relationship between the actual steering angle and the motor angular velocity, or the relationship between the actual steering angle and the steering angular velocity, or determined by the steering torque and the steering angular velocity determines a steering angular speed, before the correction by the deviation between the target steering angle and the actual steering angle, and the deviation of the change rate and the steering angular velocity of the target steering angle before correction, and the like determined before the correction by the deviation between the target steering angle and the steering angle.
[0035]
　Target steering angle correction unit 230 in the corrected target steering angle correction value? Ha is , is inputted to the adder 145 as a correction output unit, corrects the target steering angle θto which corrects the target steering angle [theta] t by an adder 145 (= θt + θha) There is input to the steering angle control unit 200, a steering angle control section 200 calculates and outputs a motor current command value Imref.
[0036]
　11 shows a configuration example of a steering angle control unit 200, smoothing when corrected target steering angle θt0 is rapidly changed from the addition section 145, that is smoothly varying as within a predetermined time change rate correction target steering angle θt0 the rate limiter 211 to the input, the target steering angle θta that has passed through the LPF212 to eliminate disturbances of the radio frequency is input added to the subtraction unit 213A. Actual steering angle θr is subtracted input to the subtracting unit 213A, an angle deviation between the smoothed target steering angle θta is gain Kpp multiplied by proportional gain (Kpp) section 214, added to the subtraction unit 213B as the motor speed command value ωe It is input. The subtraction unit 213B motor angular velocity ω from the motor angular velocity calculating unit 144 is subtracted input, the calculated speed deviation Df is gain Kvi multiplied by the integral gain (Kvi) portion 216B via the integrating unit 216A adds the input to the subtraction unit 213C with the speed deviation Df is input subtracted subtraction unit 213C is gain Kvp multiplied by proportional gain (Kvp) unit 216C. Motor current command value Ib is a subtraction result of the subtraction unit 213C is outputted as the motor current command value Imref via a limiter 217 for limiting the upper and lower limit values.
[0037]
　Rate limiter 211, the corrected target steering angle θt0 are those that facilitate and outputs when changes rapidly, and is, for example, as shown in FIG. 12 configuration. That is, the corrected target steering angle θt0 is input summing the subtraction unit 211-1, the holding unit (Z -1 in) 211-4 is a subtraction result of the past values of the steering angle θt1 is variation setting unit 211-2 It is input. Variation setting unit 211-2 performs the upper and lower limit processing on the steering angle Shitati1, and outputs the result to adding section 211-3 as variation Shitati2. Adding section 211-3 outputs the addition result of the variation θt2 the past values as a new target steering angle Shitati3. Variation setting unit 211-2 is to restrict the variation does not exceed the set upper limit and lower limit. Process performed in each operation cycle T is input obtains a difference between the (target steering angle) Shitati0 and the target steering angle θt3 the previous calculation cycle, when outside the range of upper and lower limits of the variation setting unit 211-2 It is carried out by repeating adding the difference θt2 which is limited by an upper limit or a lower limit to past values. An example of results obtained by this processing is shown in FIG. 13. And the upper limit is S, even if the step-like input (target steering angle) Shitati0 size 4S, by changing the output Shitati3 stepwise size S, the target steering angle finally output θt3 θt0 to match to. The input when the difference between the (target steering angle) Shitati0 is in the range of upper and lower limits of the variation setting unit 211-2, and outputs the change amount Shitati2 = difference Shitati1, since added to past values, the the resulting output θt3 the input (target steering angle) θt0 is consistent. 13 corresponds to the case of setting the upper limit to more than 4S. These results, also vary rapidly the target steering angle Shitati0, it is possible to change the target steering angle Shitati0 rapidly changing smoothly, preventing current surge (= abrupt steering), the driver It plays the function of reducing the anxiety of automatic operation.
[0038]
　In such a configuration will be described with reference to a flowchart of FIG. 14 the entire operation example.
[0039]
　When the operation of the steering system is started, the torque control by the torque control unit 141 is implemented (step S1), the motor 150 is driven by a current control / drive unit 143 using the motor current command value Itref (step S2). The above operation is repeated until the switching command SW from switching instructor 131 is output (step S3).
[0040]
　Becomes automatic steering control, the switching instructor 131 from switching command SW is output, the steering torque Th is input (step S4), and the steering state ST is determined by the additional turning / steer-back determination unit 160 (step S5), and vehicle speed Vs is input (step S6), and the target steering angle correction value θha is calculated by the target steering angle correction unit 230 (step S10).
[0041]
　Further, the target steering angle target steering angle θt from the generation unit 132 is input (step S20), is corrected by adding the target steering angle correction value θha to the target steering angle θt by an adder 145 (step S21), and is corrected corrected target steering angle θto is inputted to the steering angle control unit 200 (step S22). Further, the actual steering angle θr from the steering angle sensor 152 is input (step S23), the motor angular velocity ω from the motor angular velocity calculating unit 144 is input (step S24), and the motor current command value Imref is generated by the steering angle control unit 200 that (step S25). Then, it switched (step S26), drives the motor 150 by the current control / drive unit 143 using the motor current command value Imref from the steering angle control unit 200 switching unit 142 by switching command SW from switching instructor 131 (step S27), and returns to the step S3. Drive control by the motor current instruction value Imref is repeated from switching instructor 131 to switching command SW is changed.
[0042]
　Next, a description example of the operation of the target steering angle correction unit 230 (step S10 in FIG. 14) with reference to the flowchart of FIG. 15.
[0043]
　Phase compensation unit 231, the steering torque Th based on the steering state ST phase lead compensation or the phase lag compensation (step S11), and the compensation steering torque Th1 from the phase compensator 231 is inputted to the dead band gain section 232, the vehicle speed Vs is the gain multiplied based on (step S12). Compensation steering torque Th2 from the dead zone gain unit 232 is input to the limiter 233, the vehicle speed upper limit value of the compensation steering torque Th2 a limit value corresponding to Vs is limited (step S13), and the target steering that is limited to the upper and lower limit values angular correction value θha is output (step S14).
[0044]
　The target steering angle correction unit 230 of FIG. 6, although the gain-multiplied by entering a compensation steering torque Th1 which is phase-compensated deadband gain section 232, the dead band gain section 232 a steering torque Th as shown in FIG. 16 after the gain multiplied by entering it may be phase compensated by the phase compensating unit 231 (second embodiment). Further, as shown in FIG. 17 (A), the first embodiment of the may be provided a second phase compensating section 231A to the subsequent dead band gain section 232 (third embodiment) shown in FIG. In this case, two one of the phase compensation unit 231 and 231A used primarily target correction, can be used the other to noise removal or the like, it is possible to obtain a smoother feeling. Furthermore, as shown in FIG. 17 (B), the second embodiment of the may be provided a second phase compensating section 231B in front of the dead band gain section 232 (fourth embodiment) shown in FIG. 16. Again, used primarily target correction either of the two phase compensation unit 231 and 231B, the other can be used in noise elimination or the like to obtain a smoother feeling.
DESCRIPTION OF SYMBOLS
[0045]
1 handle (steering
wheel) 2 column shaft (steering shaft, the handle
shaft) 10,154 torque sensor
12 vehicle speed sensor
14 steering angle sensor
20, 150 motor
30 control unit
(ECU) 130 vehicle-side
ECU 140 EPS side
ECU 141 assist control unit
142 switching
200 the steering angle control unit
210 position control unit
220 speed controller
230 target steering angle correction unit
231,231A, 231B phase compensation unit
232 dead band gain section
233 limiter

The scope of the claims
[Requested item 1]
A manual steering control for driving the motor by a first motor current command value calculated on the basis of at least steering torque, by the steering angle control unit, the calculated second so as to follow the actual steering angle to the target steering angle the electric power steering apparatus having a function of switching between automatic steering control for driving the motor by the motor current command value,
with respect to the steering torque, performs arithmetic processing in accordance with the steering state and vehicle speed, a target steering angle correction value a target steering angle correction unit that outputs,
the target steering angle is corrected by the target steering angle correction value, a correction output unit that inputs a corrected corrected target steering angle to the steering angle control unit,
by comprising a electric power steering apparatus according to claim.
[Requested item 2]
The target steering angle correction unit,
wherein a phase compensator for phase lead compensation or the phase-lag compensation based on steering torque to the steering state,
and enter the first compensation steering torque from the phase compensation unit, the first and has a dead zone in the domain compensation steering torque is small, according to the vehicle speed, and the dead band gain section for outputting a second compensation steering torque increases in the same direction as the method of increasing the first compensation steering torque,
the the upper and lower limits of the second compensation steering torque limit in accordance with the vehicle speed, the corrected target steering angle and the limiter outputting a,
in the electric power steering apparatus of claim 1 being configured.
[Requested item 3]
The electric power steering apparatus according to claim 2 in which the second phase compensating section is provided downstream of the dead zone gain section.
[Requested item 4]
The target steering angle correction unit,
the steering torque input by the conjunction steering torque has a dead zone in a small area, in accordance with the vehicle speed, the first compensation steering that increases in the same direction as the method of increasing the steering torque a dead band gain section for outputting a torque,
and a phase compensation unit for phase lead compensation or the phase-lag compensation on the basis of the first compensation steering torque to the steering state,
on the second compensation steering torque from the phase compensation unit limit in accordance with the lower limit value to the vehicle speed, the corrected target steering angle and the limiter outputting a,
in the electric power steering apparatus of claim 1 being configured.
[Requested item 5]
The electric power steering apparatus according to claim 4 in which the second phase compensation unit in front of the dead band gain portion.
[Requested item 6]
Output gain of the dead band gain section, the electric power steering device according to any one of smaller claims 2 to 5 in accordance with the vehicle speed becomes higher.
[Requested item 7]
Limit value of the limiter, the electric power steering device according to any one of smaller claims 2 to 5 in accordance with the vehicle speed becomes higher.
[Requested item 8]
The dead zone is an electric power steering device according to any one of claims 2 to 5 which is variable according to the vehicle speed.
[Requested item 9]
The steering state, the electric power steering device according to any one of claims 1 to 8 is returned handle of additional turning or switching.
[Requested item 10]
The determination of the return the additional turning and switching, the relationship between the actual steering angle and the motor angular speed, or the relationship between the actual steering angle and the steering angular velocity, or the relation between the steering torque and the steering speed, or the said steering angular velocity and it performs, based on the relationship between the deviation of the target steering angle and the actual steering angle, or the relationship between the rate of change of the target steering angle and the deviation of the steering angular velocity and the target steering angle and the steering angle deviation the electric power steering apparatus according to claim 9.
[Requested item 11]
The electric power steering apparatus according to any one of claims 1 to 10 wherein the correction output section is an addition unit.