WO2020100411A1 - Vehicle steering device - Google Patents

Abstract

[Problem] To provide a vehicle steering device that can easily attain a steering torque equivalent to a steering angle or the like independently of the condition of a road surface and changes in mechanical characteristics of a steering system due to aging. Also, to return a steering wheel to a position near the center position after hands are off the steering wheel. [Solution] This vehicle steering device for carrying out assist control for a steering system comprises a target steering torque generation unit for generating a target steering torque, a conversion unit for converting the target steering torque into a target torsion angle, and a torsion angle control unit for calculating a motor current command value such that the torsion angle follows the target torsion angle, wherein the target steering torque generation unit is equipped with a steering wheel return compensation unit for calculating, on the basis of a steering torque and first angular velocity information, a first torque signal for compensating return of a steering wheel, outputs the first torque signal as a target steering torque, and controls driving of a motor on the basis of the motor current command value.

Description

Steering device for vehicle

The present invention relates to a high-performance vehicle steering system that realizes a desired steering torque based on the torsion angle of a torsion bar or the like, is not affected by the state of the road surface, and is not affected by changes in mechanical system characteristics over time.

An electric power steering device (EPS), which is one of vehicle steering devices, applies an assist force (steering assist force) to a steering system of a vehicle by a rotational force of a motor, and uses electric power supplied from an inverter. The drive force of the controlled motor is applied as an assist force to the steering shaft or the rack shaft by the transmission mechanism including the speed reduction mechanism. Such a conventional electric power steering device performs feedback control of the motor current in order to accurately generate the assist force. The feedback control adjusts the motor applied voltage so that the difference between the steering assist command value (current command value) and the detected motor current value becomes small. The motor applied voltage is generally adjusted by PWM (pulse width). Modulation) control duty is adjusted.

The general structure of the electric power steering apparatus will be described with reference to FIG. 1. The column shaft (steering shaft, handle shaft) 2 of the steering wheel 1 includes a speed reduction mechanism 3, universal joints 4a and 4b, a pinion rack mechanism 5, a tie rod 6a, 6b, and further connected to steering wheels 8L, 8R via hub units 7a, 7b. Further, the column shaft 2 having a torsion bar is provided with a torque sensor 10 for detecting a steering torque Ts of the steering wheel 1 and a steering angle sensor 14 for detecting a steering angle θh, and a motor for assisting the steering force of the steering wheel 1 is provided. 20 is connected to the column shaft 2 via the reduction mechanism 3. Electric power is supplied from the battery 13 to the control unit (ECU) 30 that controls the electric power steering device, and an ignition key signal is input via the ignition key 11. The control unit 30 calculates the current command value of the assist (steering assistance) command based on the steering torque Ts detected by the torque sensor 10 and the vehicle speed Vs detected by the vehicle speed sensor 12, and compensates for the current command value. The current supplied to the EPS motor 20 is controlled by the applied voltage control command value Vref.

A CAN (Controller Area Network) 40 that exchanges various vehicle information is connected to the control unit 30, and the vehicle speed Vs can also be received from the CAN 40. The control unit 30 can also be connected to a non-CAN 41 other than the CAN 40 that exchanges communication, analog / digital signals, radio waves, and the like.

The control unit 30 is mainly composed of a CPU (including MCU, MPU, etc.), and a general function executed by a program inside the CPU is shown in FIG.

The function and operation of the control unit 30 will be described with reference to FIG. 2. The steering torque Ts detected by the torque sensor 10 and the vehicle speed Vs detected by the vehicle speed sensor 12 (or from the CAN 40) are the current command value calculation unit. 31 is input. The current command value calculation unit 31 calculates the current command value Iref1 which is the control target value of the current supplied to the motor 20, using the assist map and the like based on the input steering torque Ts and vehicle speed Vs. The current command value Iref1 is input to the current limiting unit 33 via the addition unit 32A, the current command value Irefm in which the maximum current is limited is input to the subtraction unit 32B, and the deviation I (= from the fed back motor current value Im Irefm-Im) is calculated, and the deviation I is input to the PI (proportional integral) control unit 35 for improving the characteristic of the steering operation. The voltage control command value Vref whose characteristics have been improved by the PI control unit 35 is input to the PWM control unit 36, and the motor 20 is PWM-driven via the inverter 37 as a drive unit. The current value Im of the motor 20 is detected by the motor current detector 38 and fed back to the subtraction unit 32B.

The compensating signal CM from the compensating signal generating unit 34 is added to the adding unit 32A, and the characteristic of the steering system system is compensated by adding the compensating signal CM to improve the convergence and the inertia characteristic. .. The compensation signal generation unit 34 adds the self-aligning torque (SAT) 343 and the inertia 342 by the addition unit 344, further adds the convergence 341 to the addition result by the addition unit 345, and compensates the addition result by the addition unit 345. It is a signal CM.

As described above, in the assist control in the conventional electric power steering device, the steering torque applied by the driver's manual input is detected by the torque sensor as the torsion torque of the torsion bar, and the assist current corresponding to the torque is mainly detected. Is controlling the motor current. However, when the control is performed by this method, the steering torque may be different depending on the steering angle due to the difference in the road surface state (for example, inclination). Steering torque may also be affected by variations in motor output characteristics over time.

In order to solve such a problem, for example, an electric power steering device as disclosed in Japanese Patent No. 5208894 (Patent Document 1) has been proposed. In the electric power steering device of Patent Document 1, in order to provide an appropriate steering torque based on the tactile characteristics of the driver, the steering angle or the steering torque is determined based on the relationship between the steering angle or the steering torque and the response amount. The target value of the steering torque is set based on the relationship (steering reaction force characteristic map).

Patent No. 5208894

However, in the electric power steering apparatus of Patent Document 1, the steering reaction force characteristic map must be obtained in advance, and the control is performed based on the deviation between the target value of the steering torque and the detected steering torque. Therefore, the influence on the steering torque may remain.

On the other hand, in the assist control by the electric power steering device, if the steering wheel is released from the turned state, the steering wheel may stop halfway without returning to the on-center, which may result in poor fit. A solution is also desired.

The present invention has been made under the circumstances as described above, and an object of the present invention is not affected by the condition of the road surface, is not affected by the change in the mechanical characteristics of the steering system due to aging, and is effective for the steering angle and the like. It is an object of the present invention to provide a vehicle steering system capable of easily achieving an equivalent steering torque. Further, it is also an object to be able to return the handle after releasing it to the vicinity of the center.

The present invention relates to a steering device for a vehicle, which includes at least a torsion bar having an arbitrary spring constant and a sensor for detecting a torsion angle of the torsion bar, and which assist-controls a steering system by driving and controlling a motor. The object of the above is to provide a target steering torque generator that generates a target steering torque, a converter that converts the target steering torque into a target twist angle, and a motor current that causes the twist angle to follow the target twist angle. And a steering wheel return compensating section for calculating a first torque signal for compensating the steering wheel returning based on the steering torque and the first angular velocity information. It is achieved by outputting the first torque signal as the target steering torque and controlling the drive of the motor based on the motor current command value.

Further, the above object of the present invention is that the steering wheel return compensator uses a torque sensitive gain map to obtain a torque sensitive gain based on the magnitude of the steering torque, and a speed sensitive gain map. A speed sensitive gain unit that obtains a speed sensitive gain based on the magnitude of the first angular velocity information, and calculates the first torque signal from the torque sensitive gain, the speed sensitive gain, and the sign of the first angular velocity information. Or the torque-sensitive gain map has a characteristic that the torque-sensitive gain decreases as the steering torque increases, or the speed-sensitive gain map includes the first angular velocity information. Is from zero to a predetermined value, the velocity sensitive gain increases as the magnitude of the first angular velocity information increases, and when the magnitude of the first angular velocity information exceeds the predetermined value, the The steering wheel return compensating unit further includes a limiting unit that limits the upper and lower limit values of the first torque signal by having a characteristic that the velocity sensitive gain decreases as the magnitude of the first angular velocity information increases. Alternatively, the target steering torque generation unit uses the basic map to obtain the second torque signal from the steering angle and the vehicle speed, and the damper gain map that is a vehicle speed response to obtain the second angular velocity information. The present invention further includes a damper calculation unit that obtains a third torque signal based on the steering state and the steering angle, and a hysteresis correction unit that obtains a fourth torque signal by performing hysteresis correction using the steering state and the steering angle. By calculating the target steering torque from at least one of the three torque signal and the fourth torque signal and the first torque signal, or the characteristics of the basic map and the hysteresis correction unit are vehicle speed responsiveness. Alternatively, the target steering torque generation unit further includes a phase compensating unit that performs phase compensation in a front stage or a rear stage of the basic map unit, and the steering wheel is provided via the basic map unit and the phase compensating unit. This is achieved more effectively by obtaining the second torque signal from the angle and the vehicle speed.

According to the vehicle steering apparatus of the present invention, the twist angle follows the target twist angle by controlling the target twist angle obtained based on the target steering torque generated by the target steering torque generation unit. Thus, a desired steering torque can be realized, and an appropriate steering torque based on the driver's feeling of steering can be applied.

Furthermore, by compensating for the handle return by the handle return compensator, the handle can be returned to the vicinity of the center when the handle is turned off and then released.

It is a block diagram which shows the outline of an electric power steering device. It is a block diagram showing an example of composition in a control unit (ECU) of an electric power steering device. It is a structural diagram showing an installation example of an EPS steering system and various sensors. It is a block diagram which shows the structural example (1st Embodiment) of this invention. FIG. 3 is a block diagram showing a configuration example (first embodiment) of a target steering torque generation unit. It is a diagram which shows the characteristic example of a basic map. It is a diagram which shows the characteristic example of a damper gain map. It is a diagram which shows the characteristic example of a hysteresis correction part. It is a block diagram showing an example of composition of a handle return compensation part. It is a diagram which shows the characteristic example of a torque sensitive gain map. It is a diagram which shows the characteristic example of a speed sensitive gain map. It is a diagram showing an example of setting the upper and lower limit values in the limiting unit. It is a block diagram showing an example of composition of a twist angle control part. 5 is a flowchart showing an operation example (first embodiment) of the present invention. 6 is a flowchart showing an operation example (first embodiment) of a target steering torque generation unit. It is a flow chart which shows an example of operation of a twist angle control part. 6 is a graph showing an example of a time response of a steering angle and a steering torque when there is no steering wheel return compensation in a simulation showing an effect of a steering wheel return compensation unit. 6 is a graph showing an example of a time response of a steering angle and a steering torque when steering wheel return compensation is performed in a simulation showing an effect of a steering wheel return compensation unit. It is a block diagram which shows the structural example (2nd Embodiment) of a target steering torque production | generation part. It is a block diagram which shows the structural example (3rd Embodiment) of this invention. It is a block diagram which shows the example of insertion of a phase compensation part. It is a block diagram which shows the outline of an SBW system. It is a block diagram which shows the structural example (4th Embodiment) of this invention. It is a block diagram which shows the structural example of a target turning angle production | generation part. It is a block diagram which shows the structural example of a steering angle control part. It is a flowchart which shows the operation example (4th Embodiment) of this invention.

The present invention is a steering apparatus for a vehicle for realizing an equivalent steering torque with respect to a steering angle or the like without being affected by the state of the road surface, and a torsion angle of a torsion bar or the like is set to a value corresponding to the steering angle or the like. The desired steering torque is realized by controlling so as to follow.

Embodiments of the present invention will be described below with reference to the drawings.

First, an example of installation of various sensors that detect information related to an electric power steering device that is one of the vehicle steering systems according to the present invention will be described. FIG. 3 is a diagram showing an installation example of the EPS steering system and various sensors, and the column shaft 2 is provided with a torsion bar 2A. Road surface reaction force Fr and road surface information μ act on the steered wheels 8L and 8R. An upper angle sensor is provided on the handle side of the column shaft 2 with the torsion bar 2A interposed therebetween, and a lower angle sensor is provided on the steering wheel side of the column shaft 2 with the torsion bar 2A interposed therebetween. Detects the steering wheel angle θ ₁ , and the lower angle sensor detects the column angle θ ₂ . The steering angle θh is detected by a steering angle sensor provided above the column shaft 2, and the twist angle Δθ and the torsion bar torque of the torsion bar are calculated from the deviations of the steering wheel angle θ ₁ and the column angle θ _{2 according to} the following formulas 1 and 2. Tt can be calculated. Note that Kt is the spring constant of the torsion bar 2A.

The torsion bar torque Tt can also be detected by using a torque sensor disclosed in JP 2008-216172 A, for example. In the present embodiment, the torsion bar torque Tt is also treated as the steering torque Ts.

Next, a configuration example of the present invention will be described.

FIG. 4 is a block diagram showing a configuration example (first embodiment) of the present invention, in which steering of a driver's steering wheel is assist-controlled by a motor in the EPS steering system / vehicle system 100. In addition to the steering angle θh, the target steering torque generation unit 200 that outputs the target steering torque Tref includes the vehicle speed Vs, the steering torque Ts, and the right-turn or left-turn steering state output from the right-turn / left-turn determination unit 500. STs is input. The target steering torque Tref is converted into a target twist angle Δθref by the conversion unit 400, and the target twist angle Δθref is input to the twist angle control unit 300 together with the twist angle Δθ of the torsion bar 2A and the motor angular velocity ωm. The twist angle control unit 300 calculates a motor current command value Imc such that the twist angle Δθ becomes the target twist angle Δθref, and the motor of the EPS is driven by the motor current command value Imc.

The right-turn / left-turn determination unit 500 determines whether the steering is right-turn or left-turn based on the motor angular velocity ωm, and outputs the determination result as the steering state STs. That is, when the motor angular velocity ωm has a positive value, it is determined to be “right cut”, and when the motor angular velocity ωm has a negative value, it is determined to be “left cut”. Instead of the motor angular velocity ωm, an angular velocity calculated by performing a velocity calculation on the steering angle θh, the steering wheel angle θ ₁ or the column angle θ ₂ may be used.

FIG. 5 shows a configuration example of the target steering torque generation unit 200. The target steering torque generation unit 200 includes a basic map unit 210, a differentiation unit 220, a damper gain unit 230, a hysteresis correction unit 240, a steering wheel return compensation unit 250, and a multiplication. The steering angle θh is input to the basic map unit 210, the differentiation unit 220, the hysteresis correction unit 240, and the steering wheel return compensation unit 250, and output from the right-turn / left-turn determination unit 500. The steering state STs is input to the hysteresis correction unit 240, the steering torque Ts is input to the steering wheel return compensation unit 250, and the vehicle speed Vs is input to the basic map unit 210 and the damper gain unit 230.

The basic map unit 210 has a basic map and outputs a torque signal (second torque signal) Tref_a with the vehicle speed Vs as a parameter using the basic map. The basic map is adjusted by tuning. For example, as shown in FIG. 6A, the torque signal Tref_a increases as the magnitude (absolute value) | θh | of the steering angle θh increases, and the vehicle speed Vs increases. Is increasing as is increased. Note that, in FIG. 6A, the sign unit 211 outputs the sign (+1, −1) of the steering angle θh to the multiplication unit 212, and the magnitude of the steering angle θh indicates the magnitude of the torque signal Tref_a from the map. The torque signal Tref_a is calculated by multiplying the calculated value by the sign of the steering angle θh. However, as shown in FIG. 6B, a map may be formed according to the positive and negative steering angles θh. Of course, in this case, the mode of change may be changed depending on whether the steering angle θh is positive or negative. Further, although the basic map shown in FIG. 6 is sensitive to vehicle speed, it may not be sensitive to vehicle speed.

The differentiator 220 differentiates the steering angle θh to calculate the steering angular velocity ωh that is the angular velocity information (second angular velocity information), and the steering angular velocity ωh is input to the multiplier 270.

The damper gain unit 230 outputs a damper gain D _G by which the steering angular velocity ωh is multiplied. The multiplication result of the steering angular velocity ωh and the damper gain D _{G in} the multiplication unit 270 is input to the addition unit 272 as a torque signal (third torque signal) Tref_b. The damper gain D _G is obtained according to the vehicle speed Vs using the vehicle speed sensitive damper gain map included in the damper gain unit 230. The damper gain map has a characteristic of gradually increasing as the vehicle speed Vs increases, as shown in FIG. 7, for example. The damper gain map may be variable according to the steering angle θh. The damper gain unit 230 and the multiplication unit 270 form a damper calculation unit.

The hysteresis correction unit 240 calculates the torque signal (fourth torque signal) Tref_c according to the following Expression 3 based on the steering angle θh and the steering state STs. In the following Expression 3, x = θh, y = Tref_c, a> 1, c> 0, and A _hys is a hysteresis width.

When switching from right-turn steering to left-turn steering and from left-turn steering to right-turn steering, the following equation 4 is substituted into “b” of equation 3 after switching based on the value of the final coordinate (x1, y1). Thereby, the continuity before and after the switching is maintained.

The above formula 4 can be derived by substituting x1 for x and y1 for y _R and y _L in the above formula 3.

An arbitrary positive number larger than 1 can be used as “a”. For example, when the Napier number “e” is used, the expressions 3 and 4 become the following expressions 5 and 6, respectively.

Hysteresis correction when A _hys = 1 [Nm] and c = 0.3 are set in the equations 5 and 6, starting from 0 [deg] and steering +50 [deg] and -50 [deg]. An example diagram of the generated torque signal Tref_c is shown in FIG. That is, the torque signal Tref_c from the hysteresis correction unit 240 has hysteresis characteristics such as 0 origin → L1 (thin line) → L2 (broken line) → L3 (thick line).

It should be _noted that the coefficient A _hys that represents the output width of the hysteresis characteristic and the coefficient c that represents roundness may be variable according to the vehicle speed Vs and / or the steering angle θh.

The steering wheel return compensator 250 calculates a torque signal (first torque signal) Tref_d for compensating the steering wheel return. When the handle is released from the turned state, the handle may stop halfway without returning to the on-center, so the torque signal Tref_d for returning the handle to near the center is calculated.

FIG. 9 shows a configuration example of the handle return compensation unit 250. The handle return compensation unit 250 includes a differentiating unit 251, absolute value units 252 and 253, a torque sensitive gain unit 254, a speed sensitive gain unit 255, a coding unit 256, multiplying units 260 and 261, a limiting unit 257, a filter unit 258, and a sign reversing unit. The unit 259 is provided.

Like the differentiating part 220, the differentiating part 251 differentiates the steering angle θh to calculate the steering angular speed ωh1 which is the angular speed information (first angular speed information). The differentiating unit 220 may be shared and the differentiating unit 251 may be omitted.

The absolute value units 252 and 253 output the magnitude (absolute value) of the input data. The absolute value unit 252 outputs the absolute value of the steering torque Ts, and the absolute value unit 253 outputs the absolute value of the steering angular velocity ωh1. ..

The torque sensitive gain unit 254 obtains the torque sensitive gain Gt according to the absolute value of the steering torque Ts using the torque sensitive gain map. The torque sensitive gain map has a characteristic that the torque sensitive gain Gt gradually decreases as the absolute value of the steering torque Ts increases, as shown in FIG. 10, for example.

The speed sensitive gain unit 255 obtains the speed sensitive gain Gv according to the absolute value of the steering angular speed ωh1 using the speed sensitive gain map. For example, as shown in FIG. 11, the speed-sensitive gain map shows that the speed-sensitive gain Gv increases rapidly as the absolute value of the steering angular speed ωh1 increases in the range of the absolute value of the steering angular speed ωh1 from 0 to a predetermined value ω0. In the range in which the steering angular velocity ωh1 increases, the steering angle velocity ωh1 gradually decreases as the absolute value of the steering angular velocity ωh1 increases.

The sign unit 256 outputs the sign (+1, -1) of the steering angular velocity ωh1.

The limiting unit 257 limits the upper and lower limit values of the torque signal Tref_d0 calculated by multiplying the torque sensitive gain Gt, the speed sensitive gain Gv, and the sign of the steering angular velocity ωh1, and outputs the torque signal Tref_d1. By limiting the upper and lower limit values of the torque signal Tref_d0, the output of abnormal values is suppressed. As shown in FIG. 12, the upper limit value and the lower limit value for the torque signal are set in advance, and when the input torque signal Tref_d0 is the upper limit value or more, the upper limit value is set, and when the input torque signal Tref_d0 is the lower limit value or less, the lower limit value is set otherwise. In the case of, the torque signal Tref_d0 is output as the torque signal Tref_d1.

The filter unit 258 reduces the high-frequency noise component included in the torque signal Tref_d1 by the filtering process using the low-pass filter (LPF), and outputs it as the torque signal Tref_d2.

The sign inversion unit 259 inverts the sign of the torque signal Tref_d2 and outputs it as the torque signal Tref_d.

The characteristics of the torque sensitive gain map and the speed sensitive gain map are not limited to the curved characteristics shown in FIGS. 10 and 11, and may be linear characteristics or may be defined by a function. Further, the limiting unit 257 can be omitted when the torque signal does not become an abnormal value, or when the output of the abnormal value is suppressed by other means, and when the high frequency noise is not superimposed on the torque signal or by other means. The filter unit 258 can be omitted when reducing high frequency noise.

The torque signals Tref_d, Tref_c, Tref_b, and Tref_a obtained as described above are sequentially added by the adders 273, 272, and 271, and the final addition result is output as the target steering torque Tref.

The steering angular velocities ωh and ωh1 calculated by the differentiating units 220 and 251 are obtained by a differential calculation with respect to the steering angle θh, but even if the LPF process is appropriately performed to reduce the influence of noise in the high range. Good (with respect to the steering angular velocity ωh1 calculated by the differentiating unit 251, the LPF process does not have to be performed if the high-frequency noise reduction can be handled by the filter unit 258). Further, the differential calculation and the LPF processing may be performed using a high pass filter (HPF) and a gain. Further, the steering angular velocities ωh and ωh1 are calculated not by the steering angle θh but by performing a differential calculation and LPF processing on the steering wheel angle θ ₁ detected by the upper angle sensor or the column angle θ ₂ detected by the lower angle sensor. You may. Instead of the steering angular velocities ωh and ωh1, the motor angular velocity ωm may be used as the angular velocity information, and in this case, the differentiating units 220 and 251 are unnecessary.

The conversion unit 400 has a characteristic of −1 / Kt in which the sign of the reciprocal of the spring constant Kt of the torsion bar 2A is inverted, and converts the target steering torque Tref into the target twist angle Δθref.

The twist angle control unit 300 calculates the motor current command value Imc based on the target twist angle Δθref, the twist angle Δθ, and the motor angular velocity ωm. FIG. 13 is a block diagram showing a configuration example of the torsion angle control unit 300. The torsion angle control unit 300 includes a torsion angle feedback (FB) compensation unit 310, a torsion angular velocity calculation unit 320, a velocity control unit 330, and a stabilization compensation unit. 340, an output limiting unit 350, a subtracting unit 361, and an adding unit 362 are provided. The target twist angle Δθref output from the converting unit 400 is input to the subtracting unit 361, and the twist angle Δθ is input to the subtracting unit 361. The motor angular velocity ωm is input to the stabilization compensator 340.

The torsion angle FB compensation unit 310 multiplies the target torsion angle Δθref and the deviation Δθ ₀ of the torsion angle Δθ calculated by the subtraction unit 361 by a compensation value C _FB (transfer function), and the target torsion angle Δθref is twisted by the torsion angle Δθ. Outputs a target torsional angular velocity ωref that follows. The compensation value C _FB may be a simple gain Kpp or a commonly used compensation value such as a PI control compensation value. The target twist angular velocity ωref is input to the velocity control unit 330. The twist angle FB compensator 310 and the speed controller 330 allow the twist angle Δθ to follow the target twist angle Δθref to realize a desired steering torque.

The torsional angular velocity calculation unit 320 calculates the torsional angular velocity ωt by performing a differential calculation on the torsional angle Δθ, and the torsional angular velocity ωt is input to the velocity control unit 330. Pseudo-differentiation using HPF and gain may be performed as the differential operation. Further, the twist angular velocity ωt may be calculated by other means or other than the twist angle Δθ and input to the velocity control unit 330.

The speed control unit 330 calculates the motor current command value Imca1 by the IP control (proportional PI control) so that the torsional angular velocity ωt follows the target torsional angular velocity ωref. The subtraction unit 333 calculates a difference (ωref−ωt) between the target torsional angular velocity ωref and the torsional angular velocity ωt, the integration unit 331 having a gain Kvi integrates the difference, and the integration result is added and input to the subtraction unit 334. It The torsional angular velocity ωt is also input to the proportional section 332, subjected to proportional processing by the gain Kvp, and subtracted and input to the subtraction section 334. The subtraction result of the subtraction unit 334 is output as the motor current command value Imca1. The speed control unit 330 is not the IP control but the PI control, the P (proportional) control, the PID (proportional integral derivative) control, the PI-D control (differential preceding PID control), the model matching control, the model reference. The motor current command value Imca1 may be calculated by a generally used control method such as control.

The stabilization compensator 340 has a compensation value Cs (transfer function), and calculates the motor current command value Imca2 from the motor angular velocity ωm. If the gains of the torsion angle FB compensator 310 and the speed controller 330 are increased in order to improve the followability and the disturbance characteristics, a controllable oscillation phenomenon in a high range will occur. As a countermeasure against this, a transfer function (Cs) necessary for stabilizing the motor angular velocity ωm is set in the stabilization compensating unit 340. As a result, stabilization of the entire EPS control system can be realized. As the transfer function (Cs) of the stabilization compensating unit 340, for example, a first-order filter represented by the following formula 7 is set, which is set by a pseudo-differential using a first-order HPF structure and a gain.

Here, K _sta is a gain, fc is a center frequency, and fc is set to 150 [Hz], for example. s is a Laplace operator. Note that a secondary filter, a quaternary filter, or the like may be used as the transfer function.

The motor current command value Imca1 from the speed control unit 330 and the motor current command value Imca2 from the stabilization compensating unit 340 are added by the adding unit 362 and output as the motor current command value Imcb.

The output limiter 350 limits the upper and lower limits of the motor current command value Imcb and outputs the motor current command value Imc. Similar to the limiting unit 257 in the steering wheel return compensating unit 250, the upper limit value and the lower limit value for the motor current command value Imcb are set in advance and limited.

Note that if the EPS control system is stable, the stabilization compensator may be omitted. The output limiting unit can also be omitted.

With such a configuration, an operation example of this embodiment will be described with reference to the flowcharts of FIGS. 14 to 16.

When the operation is started, the right-turn / left-turn determination unit 500 inputs the motor angular velocity ωm, determines whether the steering is right-turn or left-turn based on the sign of the motor angular velocity ωm, and sets the determination result as the steering state STs. It is output to the target steering torque generation unit 200 (step S10).

The target steering torque generator 200 inputs the steering angle θh, the steering torque Ts, and the vehicle speed Vs together with the steering state STs, and generates the target steering torque Tref (step S20). An operation example of the target steering torque generation unit 200 will be described with reference to the flowchart in FIG.

The steering angle θh input to the target steering torque generation unit 200 is input to the basic map unit 210, the differentiation unit 220, the hysteresis correction unit 240 and the steering wheel return compensation unit 250, the steering state STs is input to the hysteresis correction unit 240, and the steering torque Ts is input to the steering wheel Ts. The vehicle speed Vs is input to the return compensating unit 250 and to the basic map unit 210 and the damper gain unit 230 (step S21).

The basic map unit 210 uses the basic map shown in FIG. 6A or 6B to generate a torque signal Tref_a corresponding to the steering angle θh and the vehicle speed Vs and outputs it to the addition unit 271 (step S22). ).

The differentiating unit 220 differentiates the steering angle θh and outputs the steering angular velocity ωh (step S23), and the damper gain unit 230 outputs the damper gain D _G according to the vehicle speed Vs using the damper gain map shown in FIG. 7 (step S23). S24), the multiplication unit 270 multiplies the steering angular velocity ωh and the damper gain D _G to calculate the torque signal Tref_b, and outputs the torque signal Tref_b to the addition unit 272 (step S25).

The hysteresis correction unit 240 performs the hysteresis correction by switching the calculation according to Formula 5 and Formula 6 according to the steering state STs with respect to the steering angle θh (step S26), generates the torque signal Tref_c, and adds it to the addition unit 273. Output (step S27). Note that the hysteresis widths A _hys , c, x1, and y1 in _Equations 5 and 6 are set and held in advance, but b and b ′ are calculated in advance from Equation 6 and b and b ′ are used instead of x1 and y1. May be held.

The steering wheel return compensation unit 250 inputs the input steering torque Ts and steering angle θh to the absolute unit 252 and the differentiation unit 251, respectively, and the differentiation unit 251 differentiates the steering angle θh to calculate the steering angular velocity ωh1 (step S28). ), And the steering angular velocity ωh1 is input to the absolute value unit 253 and the encoding unit 256. The absolute value unit 252 calculates the absolute value of the steering torque Ts and outputs it to the torque sensitive gain unit 254, and the absolute value unit 253 calculates the absolute value of the steering angular velocity ωh1 and outputs it to the speed sensitive gain unit 255 (step S29). ). The torque sensitive gain unit 254 determines the torque sensitive gain Gt according to the absolute value of the steering torque Ts by using the torque sensitive gain map having the characteristics shown in FIG. 10 (step S30). The speed sensitive gain unit 255 determines the speed sensitive gain Gv according to the absolute value of the steering angular speed ωh1 by using the speed sensitive gain map having the characteristics shown in FIG. 11 (step S31). The torque sensitive gain Gt and the speed sensitive gain Gv are multiplied by the multiplication unit 260 (step S32), and the multiplication result is multiplied by the sign of the steering angular velocity ωh1 obtained by the encoding unit 256 in the multiplication unit 261 (step S33). The torque signal Tref_d0 is output. The torque signal Tref_d0 is input to the limiting unit 257, and the limiting unit 257 limits the upper and lower limit values of the torque signal Tref_d0 by the preset upper limit value and lower limit value, and outputs the torque signal Tref_d1 to the filter unit 258 (step S34). .. The filter unit 258 performs a filtering process on the torque signal Tref_d1 and outputs it as the torque signal Tref_d2 to the sign inverting unit 259 (step S35). The sign inversion unit 259 outputs the torque signal Tref_d, which is the inversion of the sign of the torque signal Tref_d2, to the addition unit 273 (step S36).

Then, the addition unit 273 adds the torque signals Tref_c and Tref_d, the addition unit 272 adds the torque signal Tref_b to the addition result, and the addition unit 271 adds the torque signal Tref_a to the addition result. The steering torque Tref is calculated (step S37).

The target steering torque Tref generated by the target steering torque generation unit 200 is input to the conversion unit 400 and converted into the target twist angle Δθref by the conversion unit 400 (step S40). The target twist angle Δθref is input to the twist angle control unit 300.

The torsion angle control unit 300 inputs the torsion angle Δθ and the motor angular velocity ωm together with the target torsion angle Δθref, and calculates the motor current command value Imc (step S50). An operation example of the torsion angle control unit 300 will be described with reference to the flowchart of FIG.

The target twist angle Δθref input to the twist angle control unit 300 is input to the subtraction unit 361, the twist angle Δθ is input to the subtraction unit 361 and the twist angular velocity calculation unit 320, and the motor angular velocity ωm is input to the stabilization compensation unit 340 (step S51).

The subtraction unit 361 calculates the deviation Δθ ₀ by subtracting the twist angle Δθ from the target twist angle Δθref (step S52). Deviation [Delta] [theta] ₀ is input to the helix angle FB compensation unit 310, the twist angle FB compensation unit 310 compensates the deviation [Delta] [theta] ₀ is multiplied by the compensation value _{C FB} on the deviation [Delta] [theta] ₀ (step S53), the target torsion angular velocity ωref Is output to the speed control unit 330.

The torsional angular velocity calculation unit 320, which has received the torsional angle Δθ, calculates the torsional angular velocity ωt by a differential calculation with respect to the torsion angle Δθ (step S54), and outputs it to the velocity control unit 330.

In the speed control unit 330, the difference between the target torsional angular velocity ωref and the torsional angular velocity ωt is calculated by the subtracting unit 333, and the difference is integrated (Kvi / s) by the integrating unit 331 and added to the subtracting unit 334 (step S55). ). Further, the twisting angular velocity ωt is proportionally processed (Kvp) by the proportional portion 332, the proportional result is subtracted and input to the subtracting portion 334 (step S55), and the motor current command value Imca1 which is the subtracting result of the subtracting portion 334 is output and added. It is input to the unit 362.

The stabilization compensator 340 performs stabilization compensation on the input motor angular velocity ωm using the transfer function Cs represented by Expression 7 (step S56), and the motor current command value Imca2 from the stabilization compensator 340 is obtained. Is input to the addition unit 362.

The addition unit 362 adds the motor current command values Imca1 and Imca2 (step S57), and the addition result motor current command value Imcb is input to the output limiting unit 350. The output limiter 350 limits the upper and lower limit values of the motor current command value Imcb by the preset upper limit value and lower limit value (step S58), and outputs the motor current command value Imc (step S59).

The motor is driven based on the motor current command value Imc output from the torsion angle control unit 300, and current control is performed (step S60).

Note that the order of data input and calculation in FIGS. 14 to 16 can be changed as appropriate.

The effect of the handle return compensation unit in this embodiment will be described based on the simulation result.

In the simulation, it is assumed that the steering angle θh starts to operate in a state of about 60 deg, and the steering wheel return compensation unit performs steering wheel return compensation with and without steering wheel return compensation part 2 seconds after the operation is started. The time response of the upper angle of the torsion bar), the target steering torque, and the steering torque (torsion bar torque) is simulated.

Fig. 17 shows the simulation result when there is no steering wheel return compensation. 17A shows the time response of the steering angle, and FIG. 17B shows the time response of the target steering torque with a broken line and the time response of the steering torque with a solid line. From FIG. 17 (A), it can be seen that the steering angle is stopped at a position of about 17 deg after being released after 2 seconds from the start of the operation. This state is visually unpleasant to the driver and the vehicle deviates greatly from straight running, which is an unsuitable state in terms of safety.

On the other hand, FIG. 18 shows a simulation result in the case where there is steering wheel return compensation, and FIGS. 18A and 18B correspond to FIGS. 17A and 17B, respectively. From (A), it can be seen that the steering angle is improved to about 2 deg after the part is released. If improvements are made up to this point, it is possible to maintain a state similar to straight running, and the driver does not feel uncomfortable.

The target steering torque generation unit 200 according to the first embodiment includes a basic map unit 210, a damper calculation unit (damper gain unit 230 and multiplication unit 270), a hysteresis correction unit 240, and a steering wheel return compensation unit 250. Only the handle return compensating section 250 may be specialized and only the handle return compensating section 250 may be provided. FIG. 19 shows a configuration example (second embodiment) of the target steering torque generation unit in this case. In the target steering torque generation unit 600, the torque signal Tref_d output from the steering wheel return compensation unit 250 is output as the target steering torque Tref. The target steering torque generation unit may be configured by combining at least one of the basic map unit 210, the damper calculation unit and the hysteresis correction unit 240, and the steering wheel return compensation unit 250.

The motor current command value Imc output from the torsion angle control unit in the first and second embodiments is a current command value calculated based on the steering torque in the conventional EPS (hereinafter referred to as “assist current command value”). ) May be added to, for example, the current command value Iref1 output from the current command value calculation unit 31 shown in FIG. 2 or the current command value Iref2 obtained by adding the compensation signal CM to the current command value Iref1.

FIG. 20 shows a configuration example (third embodiment) in which the above contents are applied to the first embodiment. The assist control unit 700 includes a current command value calculation unit 31, or a current command value calculation unit 31, a compensation signal generation unit 34, and an addition unit 32A. The assist current command value Iac output from the assist control unit 700 (corresponding to the current command value Iref1 or Iref2 in FIG. 2) and the motor current command value Imc output from the torsion angle control unit 300 are added by the addition unit 710. The current command value Ic that is the addition result is input to the current limiting unit 720, the motor is driven based on the current command value Icm in which the maximum current is limited, and the current control is performed.

In the target steering torque generation unit 200 including the basic map unit 210 of the first to third embodiments, the phase compensating unit 280 that performs phase compensation may be inserted in the preceding stage or the subsequent stage of the basic map unit 210. That is, the configuration of the region R surrounded by the broken line in FIG. 5 may be configured as shown in FIG. 21 (A) or (B). In the phase compensating unit 280, when phase lead compensation is set as the phase compensation and, for example, phase lead compensation is performed by a first-order filter with a numerator cutoff frequency of 1.0 Hz and a denominator cutoff frequency of 1.3 Hz, A refreshing feel can be realized. The target steering torque generation unit is not limited to the above configuration as long as it has a configuration based on the steering angle.

1 and 3, the present invention is applied to a column type EPS, but the present invention is not limited to an upstream type such as a column type, but can also be applied to a downstream type EPS such as a rack and pinion. Further, the feedback control based on the target twist angle can be applied to a steer-by-wire (SBW) reaction force device including at least a torsion bar (arbitrary spring constant) and a sensor for detecting a twist angle. An embodiment (fourth embodiment) in which the present invention is applied to an SBW reaction force device including a torsion bar will be described.

First, I will explain the entire SBW system including the SBW reaction device. FIG. 22 is a diagram showing a configuration example of the SBW system in correspondence with the general configuration of the electric power steering device shown in FIG. 1. The same components are designated by the same reference numerals, and detailed description will be omitted.

The SBW system is a system that does not have an intermediate shaft mechanically coupled to the column shaft 2 by a universal joint 4a and transmits the operation of the steering wheel 1 to an steering mechanism including steering wheels 8L, 8R by an electric signal. .. As shown in FIG. 22, the SBW system includes a reaction force device 60 and a drive device 70, and a control unit (ECU) 50 controls both devices. The reaction force device 60 detects the steering angle θh by the steering angle sensor 14, and at the same time transmits the motion state of the vehicle transmitted from the steered wheels 8L, 8R to the driver as reaction force torque. The reaction torque is generated by the reaction force motor 61. Note that some SBW systems do not have a torsion bar in the reaction device, but the SBW system to which the present invention is applied is a type having a torsion bar, and the torque sensor 10 detects the steering torque Ts. To do. Further, the angle sensor 74 detects the motor angle θm of the reaction force motor 61. The drive device 70 drives the drive motor 71 in accordance with the steering of the steering wheel 1 by the driver, applies the drive force to the pinion rack mechanism 5 via the gear 72, and operates it via the tie rods 6a and 6b. Steering wheels 8L and 8R are steered. An angle sensor 73 is arranged in the vicinity of the pinion rack mechanism 5 and detects the steering angle θt of the steered wheels 8L, 8R. In order to control the reaction force device 60 and the drive device 70 in a coordinated manner, the ECU 50, based on the vehicle speed Vs from the vehicle speed sensor 12 and the like, in addition to the information such as the steering angle θh and the turning angle θt output from both devices, A voltage control command value Vref1 for driving and controlling the reaction force motor 61 and a voltage control command value Vref2 for driving and controlling the drive motor 71 are generated.

The configuration of the fourth embodiment in which the present invention is applied to such an SBW system will be described.

FIG. 23 is a block diagram showing the configuration of the fourth embodiment. In the fourth embodiment, the twisting angle Δθ is controlled (hereinafter referred to as “twisting angle control”) and the steering angle θt is controlled (hereinafter referred to as “steering angle control”) to twist the reaction force device. The drive device is controlled by the steering angle control. The drive device may be controlled by another control method.

In the twist angle control, the twist angle Δθ follows the target twist angle Δθref calculated through the target steering torque generation unit 200 and the conversion unit 400 using the steering angle θh and the like by the same configuration and operation as in the first embodiment. Control. The motor angle θm is detected by the angle sensor 74, and the motor angular velocity ωm is calculated by differentiating the motor angle θm by the angular velocity calculator 951. The turning angle θt is detected by the angle sensor 73. Further, although the detailed description is not given as the processing in the EPS steering system / vehicle system 100 in the first embodiment, the current control unit 130 includes the subtraction unit 32B, the PI control unit 35, and the PWM control shown in FIG. With the same configuration and operation as the unit 36 and the inverter 37, based on the motor current command value Imc output from the torsion angle control unit 300 and the current value Imr of the reaction force motor 61 detected by the motor current detector 140, The reaction force motor 61 is driven to control the current.

In the turning angle control, the target turning angle generation unit 910 generates a target turning angle θtref based on the steering angle θh, and the target turning angle θtref is input to the turning angle control unit 920 together with the turning angle θt. The steering angle control unit 920 calculates the motor current command value Imct so that the steering angle θt becomes the target steering angle θtref. Then, based on the motor current command value Imct and the current value Imd of the drive motor 71 detected by the motor current detector 940, the current control unit 930 has the same configuration and operation as the current control unit 130, and the drive motor. 71 is driven to control the current.

FIG. 24 shows a configuration example of the target turning angle generation unit 910. The target turning angle generation unit 910 includes a limiting unit 931, a rate limiting unit 932, and a correcting unit 933.

The limiter 931 limits the upper and lower limit values of the steering angle θh and outputs the steering angle θh1. Similar to the limiting unit 257 in the steering wheel return compensating unit 250 and the output limiting unit 350 in the torsion angle control unit 300, an upper limit value and a lower limit value for the steering angle θh are set in advance and are limited.

The rate limiting unit 932 sets a limit value and limits the amount of change in the steering angle θh1 in order to avoid a sudden change in the steering angle, and outputs the steering angle θh2. For example, when the difference from the steering angle θh1 one sample before is set as the change amount, and the absolute value of the change amount is larger than a predetermined value (limit value), the steering angle is adjusted so that the absolute value of the change amount becomes the limit value. θh1 is added / subtracted and output as the steering angle θh2. When the steering angle θh1 is less than the limit value, the steering angle θh1 is output as the steering angle θh2. Note that instead of setting a limit value for the absolute value of the amount of change, it is also possible to set an upper limit value and a lower limit value for the amount of change to impose a limit. The rate may be limited.

The correction unit 933 corrects the steering angle θh2 and outputs the target turning angle θtref. For example, like the basic map unit 210 in the target steering torque generation unit 200, using a map that defines the characteristics of the target turning angle θtref with respect to the magnitude | θh2 | of the steering angle θh2, the target turning angle θh2 is used. Find the angle θtref. Alternatively, the target turning angle θtref may be obtained simply by multiplying the steering angle θh2 by a predetermined gain.

FIG. 25 shows a configuration example of the steering angle control unit 920. The turning angle control unit 920 has the same configuration as the configuration example of the twist angle control unit 300 shown in FIG. 13 except for the stabilization compensating unit 340 and the adding unit 362, and has a target twist angle Δθref and a twist. The target turning angle θtref and the turning angle θt are input instead of the angle Δθ, and the turning angle feedback (FB) compensation unit 921, the turning angular velocity calculation unit 922, the speed control unit 923, the output limiting unit 926, and the subtraction unit 927. However, the torsion angle FB compensation unit 310, the torsion angular velocity calculation unit 320, the velocity control unit 330, the output limiting unit 350, and the subtraction unit 361 perform the same operation.

With such a configuration, an operation example of the fourth embodiment will be described with reference to the flowchart of FIG.

When the operation is started, the angle sensor 73 detects the steering angle θt, the angle sensor 74 detects the motor angle θm (step S110), the steering angle θt is detected by the steering angle control unit 920, and the motor angle θm is measured by the angular velocity. It is input to each of the calculation units 951.

The angular velocity calculation unit 951 differentiates the motor angle θm to calculate the motor angular velocity ωm, and outputs the motor angular velocity ωm to the right-turn / left-turn determination unit 500 (step S120).

After that, the same operation as steps S10 to S60 shown in FIG. 14 is performed, the reaction force motor 61 is driven, and the current control is performed (steps S130 to S170).

On the other hand, in the turning angle control, the target turning angle generating unit 910 inputs the steering angle θh, and the steering angle θh is input to the limiting unit 931. The limiting unit 931 limits the upper and lower limit values of the steering angle θh by the preset upper limit value and lower limit value (step S180), and outputs the steering angle θh1 to the rate limiting unit 932. The rate limiting unit 932 limits the amount of change in the steering angle θh1 by a preset limit value (step S190), and outputs the steering angle θh2 to the correction unit 933. The correction unit 933 corrects the steering angle θh2 to obtain the target turning angle θtref (step S200), and outputs it to the turning angle control unit 920.

The turning angle control unit 920, which has input the turning angle θt and the target turning angle θtref, calculates the deviation Δθt ₀ by subtracting the turning angle θt from the target turning angle θtref in the subtracting unit 927 (step S210). Deviation Derutashitati ₀ is input to the turning angle FB compensation unit 921, the turning angle FB compensation unit 921 compensates the deviation Derutashitati ₀ by multiplying the compensation value to the deviation Δθt ₀ (step S220), the target turning angular velocity ωtref is output to the speed control unit 923. The steered angular velocity calculation unit 922 inputs the steered angle θt, calculates the steered angular velocity ωtt by a differential calculation with respect to the steered angle θt (step S230), and outputs it to the speed control unit 923. The speed control unit 923 calculates the motor current command value Imcta by the IP control similarly to the speed control unit 330 (step S240) and outputs it to the output limiting unit 926. The output limiter 926 limits the upper and lower limits of the motor current command value Imcta by the preset upper and lower limits (step S250) and outputs the motor current command value Imct (step S260).

The motor current command value Imct is input to the current control unit 930, and the current control unit 930 uses the motor current command value Imct and the current value Imd of the drive motor 71 detected by the motor current detector 940 to drive the motor. 71 is driven and a current control is implemented (step S270).

Note that the order of data input and calculation in FIG. 26 can be changed as appropriate. The speed control unit 923 in the turning angle control unit 920 does not use the IP control, but the PI control, the P control, the PID control, and the PI-D, like the speed control unit 330 in the torsion angle control unit 300. Control, etc. are feasible and any control of P, I and D may be used, and the follow-up control by the steering angle control unit 920 and the twist angle control unit 300 is generally used. It may be performed with a control structure. The steered angle control unit 920 is used in a vehicle device as long as it has a control configuration in which the actual angle (here, the steered angle θt) follows the target angle (here, the target steered angle θtref). The control configuration is not limited, and for example, a control configuration used in an industrial positioning device, an industrial robot, or the like may be applied.

In the fourth embodiment, as shown in FIG. 22, one ECU 50 controls the reaction force device 60 and the drive device 70. However, the ECU for the reaction force device 60 and the ECU for the drive device 70 are respectively controlled. It may be provided. In this case, the ECUs exchange data with each other by communication. Further, the SBW system shown in FIG. 22 does not have a mechanical connection between the reaction force device 60 and the drive device 70, but when an abnormality occurs in the system, the column shaft 2 and the steering mechanism are connected to a clutch or the like. The present invention can also be applied to an SBW system that includes a mechanical torque transmission mechanism that mechanically couples with each other. In such an SBW system, when the system is normal, the clutch is turned off to release the mechanical torque transmission, and when the system is abnormal, the clutch is turned on to enable the mechanical torque transmission.

Although the torsion angle control unit 300 in the above-described first to fourth embodiments and the assist control unit 700 in the third embodiment directly calculate the motor current command value Imc and the assist current command value Iac, Before calculating them, the motor torque (target torque) desired to be output may be calculated first, and then the motor current command value and the assist current command value may be calculated. In this case, in order to obtain the motor current command value and the assist current command value from the motor torque, the generally used relationship between the motor current and the motor torque is used.

The diagrams used above are conceptual diagrams for qualitatively explaining the present invention, and are not limited to these. Further, the above-described embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. Further, the mechanism is not limited to the torsion bar as long as the mechanism has an arbitrary spring constant between the handle and the motor or the reaction force motor.

A main object of the present invention is a means for realizing a target steering torque for performing steering wheel return compensation, and means for realizing the followability of the steering torque with respect to the target steering torque is limited to the above-mentioned converter and torsion angle controller. You don't have to.

1 Handle 2 Column shaft (steering shaft, handle shaft)
2A Torsion bar 3 Reduction mechanism 10 Torque sensor 12 Vehicle speed sensor 14 Steering angle sensor 20 Motor 30, 50 Control unit (ECU)
31 current command value computing units 33, 720 current limiting unit 34 compensation signal generating units 38, 140, 940 motor current detector 60 reaction force device 61 reaction force motor 70 drive device 71 drive motor 72 gears 73, 74 angle sensor 100 EPS steering system / vehicle system 130, 930 Current control unit 200, 600 Target steering torque generation unit 210 Basic map unit 230 Damper gain unit 240 Hysteresis correction unit 250 Steering wheel return compensation unit 254 Torque sensitive gain unit 255 Speed sensitive gain unit 257, 931 Limit 280 Phase compensator 300 Torsional angle controller 310 Torsional angle feedback (FB) compensator 320 Torsional angular velocity calculator 330, 923 Speed controller 340 Stabilization compensator 350, 926 Output limiter 400 Convertor 500 Right-cut / left-cut Determining unit 700 Assist control unit 910 Target turning angle generation unit 920 Turning angle control unit 921 Turning angle feedback (FB) compensation unit 922 Turning angular velocity calculation unit 932 Rate limiting unit 933 Correction unit 951 Angular velocity calculation unit

Claims (8)

1. At least a torsion bar having an arbitrary spring constant and a sensor for detecting a torsion angle of the torsion bar are provided, and in a vehicle steering device for assist-controlling a steering system by drivingly controlling a motor,
   A target steering torque generation unit that generates a target steering torque,
   A conversion unit that converts the target steering torque into a target twist angle;
   A twist angle control unit that calculates a motor current command value that causes the twist angle to follow the target twist angle,
   The target steering torque generation unit,
   A steering wheel return compensating unit for calculating a first torque signal for compensating the steering wheel return based on the steering torque and the first angular velocity information, and outputting the first torque signal as the target steering torque;
   A vehicle steering apparatus, characterized in that the motor is drive-controlled based on the motor current command value.
2. The handle return compensation unit,
   A torque sensitive gain section that obtains a torque sensitive gain based on the magnitude of the steering torque using a torque sensitive gain map;
   A velocity-sensitive gain unit that obtains a velocity-sensitive gain based on the magnitude of the first angular velocity information using a velocity-sensitive gain map,
   The vehicle steering apparatus according to claim 1, wherein the first torque signal is calculated from a sign of the torque sensitive gain, the speed sensitive gain, and the first angular velocity information.
3. The vehicle steering apparatus according to claim 2, wherein the torque-sensitive gain map has a characteristic that the torque-sensitive gain decreases as the magnitude of the steering torque increases.
4. In the velocity sensitive gain map, when the magnitude of the first angular velocity information is from zero to a predetermined value, the velocity sensitive gain increases as the magnitude of the first angular velocity information increases, and the first angular velocity information The vehicle steering apparatus according to claim 2, wherein the velocity-sensing gain decreases as the magnitude of the first angular velocity information increases when the magnitude exceeds the predetermined value.
5. The handle return compensation unit,
   The vehicle steering apparatus according to any one of claims 2 to 4, further comprising a limiting unit that limits upper and lower limits of the first torque signal.
6. The target steering torque generation unit,
   A basic map section for obtaining a second torque signal from the steering angle and the vehicle speed using the basic map,
   A damper calculation unit that obtains a third torque signal based on second angular velocity information using a damper gain map that is a vehicle speed response;
   And a hysteresis correction unit that performs a hysteresis correction using the steering state and the steering angle to obtain a fourth torque signal,
   The vehicle according to any one of claims 1 to 5, wherein the target steering torque is calculated from at least one of the second torque signal, the third torque signal, and the fourth torque signal, and the first torque signal. Steering device.
7. The vehicle steering apparatus according to claim 6, wherein the characteristics of the basic map and the hysteresis correction section are vehicle speed responsiveness.
8. The target steering torque generation unit,
   In a stage before or after the basic map unit, a phase compensation unit for performing phase compensation is further provided.
   The vehicle steering apparatus according to claim 6 or 7, wherein the second torque signal is obtained from the steering angle and the vehicle speed via the basic map unit and the phase compensator.
   

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