JP2023085956A - Vehicle steering system controller - Google Patents

Abstract

A control device for a vehicle steering system capable of suppressing an increase in mechanical load and power consumption at the end of steering. A rotation limiting mechanism is provided at a steering end of a steering wheel. The vehicle steering system control device includes a steering torque control section 400 that generates a first current command value based on a steering torque target value. At the end of steering, the steering torque control unit 400 limits the current command value Iref_a based on the current compensation gain calculation unit 440 that derives the current compensation gain Gi for limiting the current command value Iref_a, and the reaction force. and an output limiter 430 that generates a motor current command value Ih_ref for driving the motor. [Selection drawing] Fig. 7

Description

The present invention relates to a control device for a vehicle steering system.

As one vehicle steering system, a steering mechanism (FFA: Force Feedback Actuator) having a steering wheel operated by a driver and a steering mechanism (RWA: Road Wheel Actuator) for steering wheels are mechanically combined. There is a separate Steer By Wire (SBW) system. In the SBW system, the steering mechanism and the steering mechanism are electrically connected via a control device (ECU: Electronic Control Unit), and the operation of the steering wheel is transmitted to the steering mechanism by an electric signal to steer the steered wheels. , the steering mechanism generates a steering reaction force for giving an appropriate steering feeling to the driver. The steering mechanism generates a steering reaction force with a reaction force actuator having a reaction force motor, and the steering mechanism steers the steered wheels with a steering actuator having a steering motor. The reaction force actuator and the steering wheel are mechanically connected via a column shaft, and the reaction force (torque) generated by the reaction force actuator is transmitted to the driver via the column shaft and the steering wheel (for example, Patent document 1).

In such an SBW system, it is necessary to limit the steering wheel operation by the driver so that the steering angle by the steering mechanism does not exceed the steerable range of the steering mechanism. For example, there is disclosed a technique for limiting the steerable range by increasing the steering reaction force when the steering angle is greater than or equal to the steering angle threshold (for example, Patent Document 2).

Japanese Unexamined Patent Application Publication No. 2020-175770 WO2019/193976

In the SBW system in which the steering mechanism and the steering mechanism are mechanically separated, the control device performs control such that the actual steering torque, which is the actual steering torque, follows the steering torque target value corresponding to the steering angle. I do. In addition, the steering mechanism may be provided with a stopper at the steering end, which is the steering limit of the mechanism. In such a configuration, when the driver performs further steering at the end of the steering (for example, when steering to the right, the driver further steers to the right), a Torsion may result in excessive actual steering torque. At this time, the rotation of the lower end side of the column shaft provided with the stopper is restricted by the stopper. and a steering force acting in the opposite direction to the steering reaction force (steering assist force) is applied by the reaction force motor, and an excessive mechanical load may be applied to the steering mechanism including the stopper. There are cases where the steering mechanism is enlarged in order to secure the strength of the steering mechanism. In addition, an excessive current flows through the reaction motor while rotation is inhibited, which may lead to an increase in power consumption of the reaction motor and the ECU.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a controller for a vehicle steering system capable of suppressing an increase in mechanical load and power consumption at the end of steering. there is

In order to achieve the above object, a control device for a vehicle steering system according to one aspect of the present invention is provided with a rotation limiting mechanism at a steering terminal end of a steering wheel, and a steering reaction force is applied to the steering wheel according to a steering angle of the steering wheel. A control device for a vehicle steering system comprising a reaction force motor for applying force and a steering motor for turning steered wheels according to the steering angle of the steering wheel, wherein the steering reaction force is obtained. a steering torque target value generator that generates a steering torque target value that is a target value of steering torque for the steering torque target value; and a steering torque control unit that generates a first current command value based on the steering torque target value, The steering torque control section includes a current compensation gain calculation section for deriving a current compensation gain for limiting the first current command value at the end of the steering, and a current compensation gain calculation section for limiting the first current command value based on the current compensation gain. and an output limiter that generates a second current command value for driving the reaction force motor.

According to the above configuration, it is possible to reduce the mechanical load applied to the steering mechanism including the rotation limiting mechanism at the steering end. In addition, it is possible to limit the current flowing to the reaction force motor at the end of the steering, and to suppress an increase in the power consumption of the reaction force motor and the ECU that constitutes the control device.

As a preferred aspect of the control device for a steering system for a vehicle, the current compensation gain calculation section determines that the steering end is reached when the actual steering torque, which is the actual steering torque of the steering wheel, becomes equal to or greater than a first torque threshold. It is preferable to determine that the steering end has been missed when the actual steering torque becomes less than a second torque threshold smaller than the first torque threshold after the steering end is determined.

According to the above configuration, it is possible to determine whether or not the steering is at the end by using the actual steering torque, which is the actual steering torque of the steering wheel, as a parameter.

As a desirable aspect of the control device for a steering system for a vehicle, the current compensation gain calculation section is configured to calculate the current compensation gain when the actual steering torque, which is the actual steering torque of the steering wheel, becomes equal to or greater than a first torque threshold and a predetermined first time elapses. , the steering end is determined, and after the steering end is determined, the actual steering torque becomes less than the second torque threshold smaller than the first torque threshold, and when a predetermined second time elapses, the steering end is determined. It is preferable to determine that it has missed.

According to the above configuration, frequent switching of the second current command value can be prevented when the additional steering and the reverse steering are repeated at the steering end.

As a desirable aspect of the control device for a steering system for a vehicle, the current compensation gain calculation section is configured to change the steering end and After determining that the steering end has been reached, it is preferable to determine that the steering end has been missed if the actual steering angle becomes less than a second steering angle threshold that is smaller than the first steering angle threshold.

According to the above configuration, it is possible to determine whether or not the steering end is reached by using the actual steering angle, which is the actual steering angle of the steering wheel, as a parameter.

As a desirable aspect of the control device for a steering system for a vehicle, the current compensation gain calculating section calculates the current compensation gain when the actual steering angle, which is the actual steering angle of the steering wheel, becomes equal to or greater than a first steering angle threshold value and a predetermined first time elapses. After determining that the steering end is reached, the actual steering angle becomes less than the second steering angle threshold smaller than the first steering angle threshold, and a predetermined second time elapses. It is preferable to determine that the steering end has been missed.

According to the above configuration, frequent switching of the second current command value can be prevented when the additional steering and the reverse steering are repeated at the steering end.

As a desirable aspect of the control device for a steering system for a vehicle, the current compensation gain calculation section is configured such that the actual steering torque, which is the actual steering torque of the steering wheel, becomes equal to or greater than a first torque threshold, and the actual steering angle of the steering wheel. When the actual steering angle is greater than or equal to the first steering angle threshold, it is determined that the steering is terminated, and after determining that the steering is terminated, the actual steering torque is a second torque threshold smaller than the first torque threshold. or when the actual steering angle becomes less than a second steering angle threshold which is smaller than the first steering angle threshold, it is preferable to determine that the steering end has been missed.

According to the above configuration, it is possible to determine whether or not the steering end is reached by using the actual steering torque, which is the actual steering torque of the steering wheel, and the actual steering angle, which is the actual steering angle of the steering wheel, as parameters.

As a desirable aspect of the control device for a steering system for a vehicle, the current compensation gain calculation section is configured such that the actual steering torque, which is the actual steering torque of the steering wheel, becomes equal to or greater than a first torque threshold, and the actual steering angle of the steering wheel. becomes equal to or greater than the first steering angle threshold and a predetermined first time elapses, it is determined that the steering end is reached, and after determining that the steering end is reached, the actual steering torque becomes greater than the first torque threshold or when the actual steering angle becomes less than a second steering angle threshold which is smaller than the first steering angle threshold and a predetermined second time elapses, the steering end is missed. It is preferable to determine that

According to the above configuration, frequent switching of the second current command value can be prevented when the additional steering and the reverse steering are repeated at the steering end.

As a desirable aspect of the control device for a steering system for a vehicle, the current compensation gain calculation unit is configured such that the actual steering angle, which is the actual steering angle of the steering wheel, is equal to or greater than a first steering angle threshold, and the actual steering angle of the steering wheel is When the actual steering angular velocity, which is the angular velocity, becomes equal to or less than the first steering angular velocity threshold, it is determined that the steering is terminated, and after determining that the steering is terminated, the actual steering angle is smaller than the first steering angle threshold. It is preferable to determine that the steering end has been missed when the actual steering angular velocity becomes less than the steering angle threshold or when the actual steering angular velocity becomes greater than a second steering angular velocity which is larger than the first steering angular velocity threshold.

According to the above configuration, it is possible to determine whether or not the steering is at the end by using the actual steering angle, which is the actual steering angle of the steering wheel, and the actual steering angular velocity, which is the actual steering angular velocity of the steering wheel, as parameters.

As a desirable aspect of the control device for a steering system for a vehicle, the current compensation gain calculation unit is configured such that the actual steering angle, which is the actual steering angle of the steering wheel, is equal to or greater than a first steering angle threshold, and the actual steering angle of the steering wheel is When the actual steering angular velocity, which is the angular velocity, becomes equal to or less than the first steering angular velocity threshold and a predetermined first time elapses, the steering end is determined, and after the steering end is determined, the actual steering angle becomes the first steering angle. When the actual steering angular velocity becomes less than a second steering angle threshold which is smaller than the threshold, or when the actual steering angular velocity becomes greater than a second steering angular velocity which is larger than the first steering angular velocity threshold and a predetermined second time elapses, the It is preferable to determine that the steering end has been missed.

According to the above configuration, frequent switching of the second current command value can be prevented when the additional steering and the reverse steering are repeated at the steering end.

As a desirable aspect of the control device for a steering system for a vehicle, the current compensation gain calculation section changes the current compensation gain from a first gain to a second gain smaller than the first gain when the steering end is determined. It is preferable that the current compensation gain is changed from the second gain to the first gain when it is determined that the steering end has been missed.

According to the above configuration, it is possible to change the second current command value by determining whether or not the steering end is reached.

As a desirable aspect of the control device for a steering system for a vehicle, the current compensation gain calculation section changes the current compensation gain from a first gain to a second gain smaller than the first gain when the steering end is determined. Monotonically decreasing at a predetermined first time rate of change, and when it is determined that the steering end has been missed, the current compensation gain is monotonically increased from the second gain to the first gain at a predetermined second time rate of change. is preferred.

According to the above configuration, it is possible to moderate the change in the second current command value when the current compensation gain is switched between the first gain and the second gain.

As a preferred aspect of the controller for a vehicle steering system, it is preferable that the output limiter generates the second current command value by multiplying the first current command value by the current compensation gain.

According to the above configuration, the second current command value can be generated by limiting the first current command value by the current compensation gain.

As a preferred aspect of the control device for a vehicle steering system, it is preferable that the output limiter limits a lower limit value of the second current command value.

According to the above configuration, it is possible to suppress a rapid change in the second current command value at the steering end.

As a desirable aspect of the control device for a vehicle steering system, the output limiter may set a third current command value obtained by multiplying the first current command value by the current compensating gain and a predetermined current command lower limit value. a comparison unit for comparison, wherein the comparison unit outputs the third current command value as the second current command value when the third current command value is greater than the lower limit value of the current command value; When the three current command values are equal to or less than the current command value lower limit value, it is preferable to output the current command value lower limit value as the second current command value.

According to the above configuration, when the third current command value is equal to or less than the current command value lower limit value, the second current command value is limited to the current command value lower limit value.

As a preferred aspect of the control device for a vehicle steering system, it is preferable that the output limiter limits an upper limit value and a lower limit value of the second current command value.

According to the above configuration, unnecessary fluctuations in the second current command value due to noise or the like can be suppressed.

As a preferred aspect of the control device for a vehicle steering system, the output limiting section includes a first comparing section that compares the first current command value with a predetermined current command upper limit value, and the output of the first comparing section. and a second comparison unit that compares a third current command value that is a value and a predetermined current command value lower limit value, wherein the first comparison unit determines that the first current command value is equal to or less than the current command value upper limit value , the second comparison unit outputs the first current command value, outputs the current command upper limit value when the first current command value is greater than the current command lower limit value, and outputting the third current command value as the second current command value when the third current command value is greater than the current command value lower limit value, wherein the third current command value is equal to the current command value lower limit value It is preferable that the lower limit value of the current command value is output as the second current command value when the current command value is equal to or below.

According to the above configuration, when the first current command value is greater than the current command value lower limit value, the third current command value is limited to the current command value upper limit value. Further, when the third current command value is equal to or less than the current command value lower limit value, the second current command value is limited to the current command value lower limit value.

As a desirable aspect of the controller for a vehicle steering system, the output limiter includes a current command value upper limit value generator that generates the current command value upper limit value, and the current command value upper limit value generator includes a current command value upper limit value generator that It is preferable that the current command value upper limit value is monotonously increased from the current command value lower limit value to a predetermined current command value maximum value as the compensation gain increases.

According to the above configuration, it is possible to set the upper limit of the current command value according to the current compensation gain.

According to the present invention, it is possible to provide a control device for a vehicle steering system capable of suppressing an increase in mechanical load and power consumption at the end of steering.

FIG. 1 is a configuration diagram showing an example of an overview of an SBW system that includes a control device according to the present disclosure. FIG. 2 is a schematic diagram showing a configuration example of a torque sensor. FIG. 3 is a schematic diagram showing the hardware configuration of the ECU. FIG. 4 is a diagram showing an example of a basic control block configuration of a control device according to the present disclosure. FIG. 5 is a region diagram for explaining steering directions in the present disclosure. FIG. 6A is a conceptual diagram showing the change over time of the steering wheel angle θ1 when the steering wheel is turned further right from the center position at a constant speed in the control block configuration shown in FIG. 4 . FIG. 6B is a conceptual diagram showing the change over time of the column angle θ2 when the steering wheel is turned further right from the center position at a constant speed in the control block configuration shown in FIG. 4 . FIG. 6C is a conceptual diagram showing temporal changes in the steering torque target value Th_ref when the steering wheel is turned further right from the center position at a constant speed in the control block configuration shown in FIG. FIG. 6D is a conceptual diagram showing temporal changes in the actual steering torque Th_act when the steering wheel is further turned right from the center position at a constant speed in the control block configuration shown in FIG. FIG. 6E is a conceptual diagram showing temporal changes in the torque difference ΔTh between the steering torque target value Th_ref and the actual steering torque Th_act when the steering wheel is further turned right from the center position at a constant speed in the control block configuration shown in FIG. 4 . is. FIG. 6F is a conceptual diagram showing temporal changes in the motor current command value Ih_ref when the steering wheel is turned further right from the center position at a constant speed in the control block configuration shown in FIG. 7 is a block diagram showing a configuration example of a steering torque control unit according to the first embodiment; FIG. FIG. 8 is a block diagram showing a configuration example of a current compensation gain calculator according to the first embodiment. FIG. 9 is a conceptual diagram showing a specific operation example of the current compensation gain calculator according to the first embodiment. FIG. 10 is a conceptual diagram showing a first modified example of a specific operation example of the current compensation gain calculator according to the first embodiment. FIG. 11 is a conceptual diagram showing a second modification of the specific operation example of the current compensation gain calculator according to the first embodiment. FIG. 12 is a block diagram showing a configuration example of a steering torque control section according to the second embodiment. FIG. 13 is a block diagram showing a configuration example of a current compensation gain calculator according to the second embodiment. FIG. 14 is a conceptual diagram showing a specific operation example of the current compensation gain calculator according to the second embodiment. FIG. 15 is a block diagram showing a configuration example of a steering torque control section according to the third embodiment. FIG. 16 is a block diagram showing a configuration example of a current compensation gain calculator according to the third embodiment. 17A is a conceptual diagram showing a specific operation example of a current compensation gain calculator according to the third embodiment; FIG. 17B is a conceptual diagram showing a first modified example of a specific operation example of the current compensation gain calculator according to the third embodiment; FIG. 17C is a conceptual diagram showing a second modified example of the specific operation example of the current compensation gain calculator according to the third embodiment; FIG. 17D is a conceptual diagram showing a third modified example of the specific operation example of the current compensation gain calculator according to the third embodiment; FIG. FIG. 18 is a block diagram showing a configuration example of a steering torque control section according to the fourth embodiment. FIG. 19 is a block diagram showing a configuration example of a current compensation gain calculator according to the fourth embodiment. 20A is a conceptual diagram showing a specific operation example of a current compensation gain calculator according to the fourth embodiment; FIG. 20B is a conceptual diagram showing a first modified example of a specific operation example of the current compensation gain calculator according to the fourth embodiment; FIG. FIG. 20C is a conceptual diagram showing a second modified example of the specific operation example of the current compensation gain calculator according to the fourth embodiment; FIG. 20D is a conceptual diagram showing a third modified example of the specific operation example of the current compensation gain calculator according to the fourth embodiment. 21 is a block diagram illustrating a configuration example of an output limiter according to the fifth embodiment; FIG. 22 is a block diagram illustrating a configuration example of an output limiter according to the sixth embodiment; FIG. FIG. 23 is a block diagram showing an example of the internal configuration of a current command value upper limit value generator according to the sixth embodiment. FIG. 24 is a diagram showing an example of input/output characteristics of a current command value upper limit generator according to the sixth embodiment.

EMBODIMENT OF THE INVENTION Hereinafter, it demonstrates in detail, referring drawings for the form (henceforth embodiment) for implementing invention. In addition, the present invention is not limited by the following embodiments. In addition, components in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those that fall within a so-called equivalent range. Furthermore, the constituent elements disclosed in the following embodiments can be combined as appropriate.

FIG. 1 is a configuration diagram showing an example of an overview of an SBW system that includes a control device according to the present disclosure. The vehicle includes a reaction force device 30 that constitutes a steering mechanism having a steering wheel operated by a driver, a steering device 40 that constitutes a steering mechanism that steers the steered wheels, and a control device 50 that controls both devices.

The SBW system does not have an intermediate shaft that is mechanically coupled to the column shaft (steering shaft, handle shaft) 2, which is provided in a general electric power steering device. Specifically, the steering angle θh output from the reaction force device 30 is transmitted as an electrical signal.

The reaction force device 30 includes a reaction force motor 31 and a deceleration mechanism 32 that reduces the rotational speed of the reaction force motor 31 . The reaction force device 30 transmits the motion state of the vehicle transmitted from the steered wheels 5L, 5R to the driver as a steering reaction force. A reaction force motor 31 applies a steering reaction force to the steering wheel 1 via a speed reduction mechanism 32 .

The reaction force device 30 further includes a steering angle sensor 33 and a torque sensor 34 . A steering angle sensor 33 detects a steering angle θh of the steering wheel 1 . A torque sensor 34 detects a steering torque Th of the steering wheel 1 . Hereinafter, the steering angle θh detected by the steering angle sensor 33 is also referred to as "actual steering angle θh_act", and the steering torque Th detected by the torque sensor 34 is also referred to as "actual steering torque Th_act".

FIG. 2 is a schematic diagram showing a configuration example of a torque sensor. As shown in FIG. 2, the torque sensor 34 includes an upper angle sensor 34A and a lower angle sensor 34B arranged across a torsion bar 2A interposed on the column shaft 2, and a torque calculator 36. As shown in FIG. The upper angle sensor 34A is arranged on the steering wheel 1 side of the column shaft 2 and detects the steering wheel angle θ1. The lower angle sensor 34B is arranged on the speed reduction mechanism 32 side of the column shaft 2 and detects the column angle θ2.

When the driver steers the steering wheel 1, the torsion bar 2A is twisted, and a torsion angle Δθ is formed between the steering wheel angle θ1 detected by the upper angle sensor 34A and the column angle θ2 detected by the lower angle sensor 34B. occurs (Δθ=θ1−θ2). The torque calculator 34C calculates the actual steering torque Th_act according to the torsion angle Δθ. The configuration of the torque sensor 34 is not limited to the mode shown in FIG.

In addition, in the present disclosure, a stopper (rotation limiting mechanism) 35 is provided on the lower end side of the column shaft 2 to physically set the steering end, which is the steerable limit. That is, the magnitude (absolute value) of the steering angle θh is limited by the stopper 35 .

The steering device 40 includes a steering motor 41, a reduction mechanism 42 that reduces the rotational speed of the steering motor 41, and a pinion rack mechanism 44 that converts the rotational motion of the steering motor 41 into linear motion. The steering device 40 drives the steering motor 41 according to the steering angle θh, applies the driving force to the pinion rack mechanism 44 via the reduction mechanism 42, and passes through the tie rods 3a and 3b to the steered wheels 5L. , 5R. An angle sensor 43 is arranged near the pinion rack mechanism 44 to detect the turning angle θt of the steerable wheels 5L and 5R. Instead of the steering angle θt of the steered wheels 5L and 5R, for example, the motor angle of the steering motor 41 or the position of the rack may be detected and the detected value may be used. Hereinafter, the turning angle θt detected by the angle sensor 43 is also referred to as "actual turning angle θt_act". In addition, the steering device 40 is not limited to the aspect described above, and may be, for example, an aspect having a structure such as a ball screw type or an electronically controlled hydraulic system.

In order to cooperatively control the reaction force device 30 and the steering device 40, the control device 50 controls the vehicle speed Vs detected by the vehicle speed sensor 10 in addition to information such as the steering angle θh and the steering angle θt output from both devices. Based on the above, a voltage control command value Vref1 for driving and controlling the reaction force motor 31 and a voltage control command value Vref2 for driving and controlling the steering motor 41 are generated.

The control device 50 is supplied with power from the battery 12 and receives an ignition key signal through the ignition key 11 . Further, the controller 50 is connected to a CAN (Controller Area Network) 20 for exchanging various types of vehicle information, and the vehicle speed Vs can also be received from the CAN 20 . Further, the control device 50 can be connected to a non-CAN 21 that exchanges communication other than the CAN 20, analog/digital signals, radio waves, and the like.

Specifically, the control device 50 is, for example, an ECU (Electronic Control Unit) mounted on a vehicle. The ECU is mainly composed of a CPU (including MCU, MPU, etc.). FIG. 3 is a schematic diagram showing the hardware configuration of the ECU. Coordinated control of the reaction force device 30 and the steering device 40 is mainly executed by a program inside the CPU of the ECU.

FIG. 4 is a diagram showing an example of a basic control block configuration of a control device according to the present disclosure. 4, the reaction force device 30 includes a PWM (Pulse Width Modulation) control section 37, an inverter 38, and a motor current detector 39 in addition to the reaction force motor 31 and the configuration described above. Further, the steering device 40 includes a PWM control section 47, an inverter 48, and a motor current detector 49 in addition to the steering motor 41 and the above-described configuration. The control device 50 implements control blocks of a reaction force control system 60 that controls the reaction force device 30 and a steering control system 70 that controls the steering device 40 . The reaction force control system 60 and the steering control system 70 cooperate to control the reaction force device 30 and the steering device 40 .

A part or all of the constituent elements of the control device 50 may be realized by hardware. In order to store data, programs, etc., the control device 50 may include, for example, a RAM (random access memory), a ROM (read only memory), etc., as shown in FIG. Alternatively, the control device 50 may include the PWM control section 37, the inverter 38, the motor current detector 39, the PWM control section 47, the inverter 48, and the motor current detector 49. FIG.

As shown in FIG. 4, the control device 50 includes, as control blocks, a steering torque target value generator 200, a steering torque controller 400, a current controller 500, a steering angle target value generator 600, and a steering angle controller. 700 and a current control unit 800 . The steering torque target value generator 200 , the steering torque controller 400 , and the current controller 500 are control blocks that make up the reaction force control system 60 . A steering angle target value generator 600 , a steering angle controller 700 , and a current controller 800 are control blocks that constitute a steering control system 70 .

The reaction force control system 60 performs control such that the actual steering torque Th_act detected by the torque sensor 34 follows the steering torque target value Th_ref, which is the steering torque target value of the reaction force device 30 .

A steering torque target value generation unit 200 generates a steering torque target value Th_ref.

The steering torque control unit 400 generates a motor current command value Ih_ref, which is the control target value of the current supplied to the reaction force motor 31 . In the present disclosure, the steering torque control unit 400 calculates the motor current command value Ih_ref such that the deviation Th_err between the steering torque target value Th_ref and the actual steering torque Th_act approaches zero. Alternatively, the steering torque control unit 400 may be configured to receive the torsion angle Δθ of the torsion bar 2A and calculate the motor current command value Ih_ref that causes the torsion angle Δθ to approach zero.

The current control unit 500 controls the current of the reaction force motor 31 . The current control unit 500 detects the deviation Ih_err between the motor current command value Ih_ref output from the steering torque control unit 400 and the actual current value (motor current value) Ih_act of the reaction force motor 31 detected by the motor current detector 39. A voltage control command value Vh_ref that approaches zero is calculated.

In the reaction force device 30, the reaction force motor 31 is driven and controlled via the PWM control section 37 and the inverter 38 based on the voltage control command value Vh_ref.

The steering control system 70 performs control such that the actual steering angle θt_act detected by the angle sensor 43 follows the steering angle target value θt_ref.

A steering angle target value generator 600 generates a steering angle target value θt_ref based on the steering angle θh.

The steering angle control unit 700 generates a motor current command value It_ref, which is a control target value of the current supplied to the steering motor 41 . The steering angle control unit 700 calculates a motor current command value It_ref that causes the deviation θt_err between the steering angle target value θt_ref and the actual steering angle θt_act to approach zero.

The current control section 800 controls the current of the steering motor 41 . The current control unit 800 controls the deviation It_err between the motor current command value It_ref output from the steering angle control unit 700 and the actual current value (motor current value) It_act of the steering motor 41 detected by the motor current detector 49 . A voltage control command value Vt_ref that approaches zero is calculated.

In the steering device 40, the driving of the steering motor 41 is controlled via the PWM control section 47 and the inverter 48 based on the voltage control command value Vt_ref.

In this embodiment, the steering torque control unit 400, the current control unit 500, the steering angle target value generation unit 600, the steering angle control unit 700, and the current control unit 800 are each controlled by the reaction force control system 60 or the steering control system. Any configuration that can realize each control in 70 is acceptable, and the configuration of each control block does not limit the configuration.

Here, the steering direction in the present disclosure will be described. FIG. 5 is a region diagram for explaining steering directions in the present disclosure. In FIG. 5, the horizontal axis indicates the steering angle, and the vertical axis indicates the steering angular velocity.

In region A ((θh, ωh)=(+,+)) shown in FIG. 5, the steering wheel 1 is turned rightward (θh>0) and further turned rightward (ωh> 0). In region B ((θh, ωh)=(+,−)) shown in FIG. 5, the steering wheel 1 is turned rightward (θh>0) and then turned leftward (ωh<0 ) (hereinafter also referred to as “left-turn-back steering”). In region C ((θh, ωh)=(-,-)) shown in FIG. 5, the steering wheel 1 is turned leftward (θh<0) and further turned leftward (ωh< 0). In region D ((θh, ωh)=(−,+)) shown in FIG. 5, the steering wheel 1 is turned leftward (θh<0) and then turned rightward (ωh>0 ) (hereinafter also referred to as “right-turn-back steering”). Further, in FIG. 5, on the steering angle θh axis (ωh=0), it is shown that the steering wheel 1 is neither further turned nor turned back ((θh, ωh)=(θh, 0)), and the steering angular velocity On the ωh axis (θh=0), the steering wheel 1 is at the center position ((θh, ωh)=(0, ωh)).

6A to 6F are conceptual diagrams showing temporal changes in each parameter when the steering wheel is turned further right from the center position at a constant speed in the control block configuration shown in FIG. FIG. 6A shows the change over time of the steering wheel angle θ1. FIG. 6B shows the time change of the column angle θ2. FIG. 6C shows temporal changes in the steering torque target value Th_ref. FIG. 6D shows temporal changes in the actual steering torque Th_act. FIG. 6E shows temporal changes in the torque difference ΔTh between the steering torque target value Th_ref and the actual steering torque Th_act. FIG. 6F shows temporal changes in the motor current command value Ih_ref. FIGS. 6A to 6F show an example in which the steering wheel 1 is turned further to the right from the center position at a constant speed, and the steering is limited by the stopper 35 at time t_st. Here, as shown in FIG. 6B, θ2_end at which the column angle θ2 is limited is set as the steering end position.

In the period up to time t_st, the actual steering torque Th_act follows the steering torque target value Th_ref with a substantially constant torque difference ΔT (see FIG. 6E). At this time, the torque difference ΔT (=Th_ref−Th_act) becomes a positive value. Also, the motor current command value Ih_ref is a positive value.

When the column angle θ2 reaches the steering end position θ2_end at time t_st and the steering wheel 1 is further steered, the torsion angle Δθ (=θ1−θ2_end) of the torsion bar 2A increases, and the torque sensor 34 outputs actual steering. Torque Th_act increases (see FIG. 6D). As a result, the actual steering torque Th_act deviates from the steering torque target value Th_ref, and the torque difference ΔTh between the steering torque target value Th_ref and the actual steering torque Th_act changes from a positive value to a negative value (see FIG. 6E).

At this time, the amount of change over time (ΔIh_ref) of the motor current command value Ih_ref turns to a negative value (see FIG. 6F), and when the motor current command value Ih_ref becomes a negative value after time t_re, the steering reaction counteracts the further right steering. The force is lost, and conversely, the reaction force motor 31 provides a steering force (steering assist force) that assists the steering by turning further to the right.

In this manner, in the control block configuration shown in FIG. 4 , when further steering is continued at the end of steering, a steering force (steering assist force) for assisting further steering is applied by the reaction force motor 31 . As a result, an excessive mechanical load may be applied to the steering mechanism including the stopper 35 provided at the steering end. In addition, in a state in which the rotation of the lower end of the column shaft 2 (the column angle θ2) is blocked by the stopper 35, an excessive current flows through the reaction force motor 31, causing the reaction force motor 31 and the ECU constituting the control device 50 to flow. power consumption may increase.

A specific configuration and operation for suppressing an increase in mechanical load and power consumption at the end of steering will be described below.

(Embodiment 1)
7 is a block diagram showing a configuration example of a steering torque control unit according to the first embodiment; FIG. As shown in FIG. 7 , the steering torque control section 400 according to this embodiment includes a subtraction section 410 , a PID control section 420 , an output limit section 430 and a current compensation gain calculation section 440 .

The steering torque control unit 400 receives the steering torque target value Th_ref output from the steering torque target value generation unit 200 and the actual steering torque Th_act detected by the torque sensor 34 .

Subtraction unit 410 calculates deviation Th_err between steering torque target value Th_ref and actual steering torque Th_act. PID control unit 420 performs PID control so that deviation Th_err between steering torque target value Th_ref, which is the calculation result of subtraction unit 410, and actual steering torque Th_act approaches zero, and outputs current command value Iref_a. In the present disclosure, the current command value Iref_a corresponds to "first current command value".

The actual steering torque Th_act is input to the current compensation gain calculator 440 . A current compensation gain calculator 440 derives a current compensation gain Gi for suppressing an increase in mechanical load and power consumption at the end of steering based on the actual steering torque Th_act.

The output limiter 430 is a component that limits the output of the current command value Iref_a output from the PID controller 420 based on the current compensation gain Gi derived by the current compensation gain calculator 440 . In this embodiment, the output limiter 430 is, for example, a multiplier. Output limiter 430 multiplies current command value Iref_a output from PID controller 420 by current compensation gain Gi derived by current compensation gain calculator 440 to calculate motor current command value Ih_ref. As a result, a motor current command value Ih_ref that suppresses an increase in mechanical load and power consumption at the end of steering is obtained. In the present disclosure, the motor current command value Ih_ref corresponds to "second current command value".

FIG. 8 is a block diagram showing a configuration example of a current compensation gain calculator according to the first embodiment. Current compensation gain calculation section 440 includes first determination section 450 , second determination section 460 , and gain control section 470 .

First determination unit 450 derives first steering end determination flag value Fr1 based on actual steering torque Th_act.

Specifically, in the present embodiment, the first determination unit 450 is set with a first torque threshold value Tth1 for the absolute value |Th_act| of the actual steering torque Th_act (hereinafter simply referred to as “actual steering torque |Th_act|”). It is The first torque threshold Tth1 is stored, for example, in the ROM of the ECU that constitutes the control device 50 .

When the actual steering torque |Th_act| is less than the first torque threshold value Tth1 (|Th_act|<Tth1), the first determination unit 450 sets the first steering end determination flag value Fr1 to "0" (Fr1=0), When the actual steering torque |Th_act| is greater than or equal to the first torque threshold value Tth1 (Tth1≦|Th_act|), the first steering end determination flag value Fr1 is set to "1" (Fr1=0). The first torque threshold Tth1 can be set to 7 to 10 [Nm], for example.

Second determination unit 460 derives second steering end determination flag value Fr2 based on actual steering torque Th_act.

Specifically, in the present embodiment, the second determination unit 460 is set with a second torque threshold value Tth2 for the actual steering torque |Th_act|. The second torque threshold Tth2 is set to a value smaller than the first torque threshold Tth1 set in the first determination section 450 . The second torque threshold Tth2 is stored, for example, in the ROM of the ECU that constitutes the control device 50 .

When the actual steering torque |Th_act| is less than the second torque threshold value Tth2 (|Th_act|<Tth2), the second determination unit 460 sets the second steering end determination flag value Fr2 to "1" (Fr2=1), When the actual steering torque |Th_act| is greater than or equal to the second torque threshold value Tth2 (Tth2≦|Th_act|), the second steering end determination flag value Fr2 is set to "0" (Fr2=0). The second torque threshold Tth2 can be set to 4 to 5 [Nm], for example.

Gain control section 470 derives current compensation gain Gi based on first steering termination determination flag value Fr1 derived by first determination section 450 and second steering termination determination flag value Fr2 derived by second determination section 460. do.

Specifically, when the first steering termination determination flag value Fr1 derived by the first determination section 450 changes from "0" to "1", the gain control section 470 determines that the steering termination is reached. The compensation gain Gi is transitioned from the first gain (here, "1") to the second gain (here, "0") smaller than the first gain. Further, when the second steering end determination flag value Fr2 derived by the second determination unit 460 changes from "0" to "1", the gain control unit 470 determines that the steering end has been missed. Gi is transitioned from the second gain (here, "0") to the first gain (here, "1").

A specific operation example of the current compensation gain calculator 440 according to the first embodiment will be described in detail below with reference to FIG. FIG. 9 is a conceptual diagram showing a specific operation example of the current compensation gain calculator according to the first embodiment.

In FIG. 9, the actual steering torque |Th_act|, the first steering end determination flag value Fr1, the second steering end determination flag value Fr2, and the current compensation gain Gi when the steering is changed from the additional steering to the return steering at the steering end. It illustrates time change.

When the actual steering torque |Th_act| becomes equal to or greater than the second torque threshold value Tth2 (Tth2≦|Th_act|<Tth1) at time t1 when the additional steering is performed, the second steering end determination flag value Fr2 changes from "1" to "0." ”.

When the actual steering torque |Th_act| becomes equal to or greater than the first torque threshold value Tth1 (Tth1≦|Th_act|) at subsequent time t2, the first steering end determination flag value Fr1 changes from "0" to "1". At this time, the gain control unit 470 determines that the steering wheel position is the steering end, and changes the current compensation gain Gi from "1" to "0". As a result, in the subsequent output limiter 430 (see FIG. 7), the current command value Iref_a output from the PID controller 420 is multiplied by the current compensation gain Gi "0" derived by the current compensation gain calculator 440. and the motor current command value Ih_ref becomes "0".

After time t2, the steering state transitions from additional steering to reverse steering. When the actual steering torque |Th_act| becomes less than the first torque threshold value Tth1 (Tth2≦|Th_act|<Tth1) at time t3 when the return steering is performed, the first steering end determination flag value Fr1 changes from "1" to "0". ”.

When the actual steering torque |Th_act| becomes less than the second torque threshold value Tth2 (|Th_act|<Tth2) at subsequent time t4, the second steering end determination flag value Fr2 changes from "0" to "1". At this time, the gain control unit 470 determines that the steering end has been missed, and changes the current compensation gain Gi from "0" to "1". As a result, in the subsequent output limiter 430 (see FIG. 7), the current command value Iref_a output from the PID controller 420 is multiplied by the current compensation gain Gi "1" derived by the current compensation gain calculator 440. and the current command value Iref_a is output as the motor current command value Ih_ref.

That is, in the present embodiment, the actual steering torque Th_act is used as a parameter, and when the additional steering is performed, the return steering is performed after the actual steering torque |Th_act| After the transition, until the actual steering torque |Th_act| becomes smaller than the second torque threshold Tth2 (|Th_act|<Tth2), which is smaller than the first torque threshold Tth1, the motor current command value is maintained, assuming that the steering wheel position is the end of the steering. Limit Ih_ref to 0[A]. As a result, the mechanical load applied to the steering mechanism including the stopper 35 at the steering end can be reduced. In addition, the current flowing through the reaction force motor 31 at the steering end can be limited, and an increase in the power consumption of the reaction force motor 31 and the ECU that constitutes the control device 50 can be suppressed.

Here, as a comparative example, when there is one torque threshold for the actual steering torque |Th_act|, the motor current command value Ih_ref is 0 [A] when the actual steering torque |Th_act| It may oscillate between the value Iref_a. In the present embodiment, the actual steering torque |Th_act| The motor current command value Ih_ref is limited until the steering wheel position is assumed to be the end of the steering until it becomes less than the second torque threshold Tth2 (|Th_act|<Tth2) which is smaller than the first torque threshold Tth1. As a result, it is possible to prevent the motor current command value Ih_ref from oscillating at the steering end.

FIG. 10 is a conceptual diagram showing a first modified example of a specific operation example of the current compensation gain calculator according to the first embodiment.

In the first modification shown in FIG. 10, the actual steering torque |Th_act| when the additional steering and the reverse steering are repeated at the steering end, the first steering end determination flag value Fr1, and the second steering end determination flag value Fr2. , and changes over time of the current compensation gain Gi.

In the first modification shown in FIG. 10, the gain control unit 470 sets the actual steering torque |Th_act| to the first torque threshold value Tth1 or more (Tth1≦|Th_act|), and the first steering end determination flag value Fr1 is "1". is maintained equal to or greater than the first time threshold value tth1, it is determined that the steering wheel position is at the end of steering, and the current compensation gain Gi is changed from "1" to "0".

Specifically, as shown in FIG. 10, at time t6, the first steering termination determination flag value Fr1 becomes "1", and at time t7 after the first time threshold tth1 has elapsed, the current compensation gain Gi is changed from "1" to transition to "0". The first time threshold tth1 can be set to 0.5 to 1.0 [sec], for example.

Further, in the first modification shown in FIG. 10, gain control unit 470 sets actual steering torque |Th_act| to be less than second torque threshold value Tth2 (|Th_act|<Tth2), and second steering end determination flag value Fr2 is 1" is maintained equal to or greater than the second time threshold value tth2, it is determined that the steering end has been missed, and the current compensation gain Gi is changed from "0" to "1".

Specifically, as shown in FIG. 10, the second steering termination determination flag value Fr2 becomes "1" at time t11, and at time t12 after the second time threshold tth2 has elapsed, the current compensation gain Gi is changed from "0" to Transition to "1". The second time threshold tth2 can be set to 0.1 to 0.2 [sec], for example.

As a result, frequent switching of the motor current command value Ih_ref between the current command value Iref_a and 0 [A] can be prevented when the additional steering and the reverse steering are repeated at the steering end.

Note that the first time threshold tth1 and the second time threshold tth2 may be the same value, or may be different values.

FIG. 11 is a conceptual diagram showing a second modification of the specific operation example of the current compensation gain calculator according to the first embodiment.

In the second modified example shown in FIG. 11, as in the first modified example described above, the actual steering torque |Th_act| when the additional steering and the reverse steering are repeated at the steering end, and the first steering end determination flag value It illustrates temporal changes of Fr1, the second steering end determination flag value Fr2, and the current compensation gain Gi.

In the second modification shown in FIG. 11, the gain control unit 470 sets the actual steering torque |Th_act| to the first torque threshold value Tth1 or more (Tth1≦|Th_act|), and the first steering end determination flag value Fr1 is "1". is maintained equal to or greater than the first time threshold value tth1, it is determined that the steering wheel position is at the end of steering, and the current compensation gain Gi is changed from "1" to "0" at a predetermined first time rate of change. , monotonically decreasing to .

Specifically, as shown in FIG. 11, the first steering termination determination flag value Fr1 becomes "1" at time t6, and the current The compensation gain Gi is monotonically decreased from "1" to "0".

Further, in the first modification shown in FIG. 11, gain control unit 470 sets actual steering torque |Th_act| to be less than second torque threshold value Tth2 (|Th_act|<Tth2), and second steering end determination flag value Fr2 is 1" is maintained equal to or greater than the second time threshold value tth2, it is determined that the steering end has been missed, and the current compensation gain Gi is changed from "0" to "1" at a predetermined second time rate of change. monotonically increasing to

Specifically, as shown in FIG. 11, the second steering termination determination flag value Fr2 becomes "1" at time t11, and the current The compensation gain Gi is changed from "0" to "1".

This moderates the change in the motor current command value Ih_ref when the current compensation gain Gi is switched between the first gain (here, "1") and the second gain (here, "0"). can be done.

Note that the first time rate of change and the second time rate of change may have the same value with only the sign reversed, or may have different values. Also, the first time rate of change and the second time rate of change may be fixed values, or may be values that change while the current compensation gain Gi is monotonically decreasing or monotonically increasing.

(Embodiment 2)
FIG. 12 is a block diagram showing a configuration example of a steering torque control section according to the second embodiment. FIG. 13 is a block diagram showing a configuration example of a current compensation gain calculator according to the second embodiment. In addition, the same code|symbol is attached|subjected to the structure which has the same function as Embodiment 1 mentioned above, and description is abbreviate|omitted.

In the first embodiment, the actual steering torque Th_act is used as the parameter for determining that the steering wheel position is at the end of steering. In the present embodiment, however, the actual steering angle θh_act is used as a parameter to determine the end of steering.

In addition to the steering torque target value Th_ref output from the steering torque target value generation unit 200 and the actual steering torque Th_act detected by the torque sensor 34, the steering torque control unit 400a receives the actual steering angle detected by the steering angle sensor 33. θh_act is input.

The actual steering angle θh_act is input to the current compensation gain calculator 440a. Based on the actual steering angle θh_act, the current compensation gain calculator 440a derives a current compensation gain Gi for suppressing increases in mechanical load and power consumption at the end of steering.

First determination unit 450a derives first steering end determination flag value Fr1 based on actual steering angle θh_act.

Specifically, in the present embodiment, the first determination unit 450a stores a first steering angle threshold value θth1 with respect to the absolute value |θh_act| is set. The first steering angle threshold value θth1 is stored in the ROM of the ECU that constitutes the control device 50, for example.

When the actual steering angle |θh_act| is less than the first steering angle threshold value θth1 (|θh_act|<θth1), the first determination unit 450a sets the first steering end determination flag value Fr1 to "0" (Fr1=0). , the first steering end determination flag value Fr1 is set to "1" (Fr1=0) when the actual steering angle |θh_act| is equal to or greater than the first steering angle threshold value θth1 (θth1≦|θh_act|).

Second determination unit 460a derives second steering end determination flag value Fr2 based on actual steering angle θh_act.

Specifically, in the present embodiment, a second steering angle threshold θth2 with respect to the actual steering angle |θh_act| is set in the second determination section 460a. The second steering angle threshold θth2 is set to a value smaller than the first steering angle threshold θth1 set in the first determination section 450a. The second steering angle threshold θth2 is stored in the ROM of the ECU that constitutes the control device 50, for example.

When the actual steering angle |θh_act| is less than the second steering angle threshold value θth2 (|θh_act|<θth2), the second determination unit 460a sets the second steering end determination flag value Fr2 to "1" (Fr2=1). , the second steering end determination flag value Fr2 is set to "0" (Fr2=0) when the actual steering angle |θh_act| is greater than or equal to the second steering angle threshold value θth2 (θth2≦|θh_act|).

A specific operation example of the current compensation gain calculator 440a according to the second embodiment will be described in detail below with reference to FIG. FIG. 14 is a conceptual diagram showing a specific operation example of the current compensation gain calculator according to the second embodiment.

FIG. 14 shows the actual steering angle |θh_act|, the first steering end determination flag value Fr1, the second steering end determination flag value Fr2, and the current compensation gain Gi when the steering is shifted from the additional steering to the return steering at the steering end. It illustrates time change.

When the actual steering angle |θh_act| becomes equal to or greater than the second steering angle threshold value θth2 (θth2≦|θh_act|<θth1) at time t1 when the additional steering is performed, the second steering end determination flag value Fr2 changes from "1" to " 0”.

At subsequent time t2, when the actual steering angle |θh_act| becomes greater than or equal to the first steering angle threshold value θth1 (θth1≦|θh_act|), the first steering end determination flag value Fr1 changes from "0" to "1". At this time, the gain control unit 470 determines that the steering wheel position is the steering end, and changes the current compensation gain Gi from "1" to "0". As a result, in the subsequent output limiter 430 (see FIG. 12), the current command value Iref_a output from the PID controller 420 is multiplied by the current compensation gain Gi "0" derived by the current compensation gain calculator 440a. and the motor current command value Ih_ref becomes "0".

After time t2, the steering state transitions from additional steering to reverse steering. When the actual steering angle |θh_act| becomes less than the first steering angle threshold value θth1 (θth2≦|θh_act|<θth1) at time t3 when the return steering is performed, the first steering end determination flag value Fr1 changes from "1" to " 0”.

When the actual steering angle |θh_act| becomes less than the second steering angle threshold value θth2 (|θh_act|<θth2) at subsequent time t4, the second steering end determination flag value Fr2 changes from "0" to "1". At this time, the gain control unit 470 determines that the steering end has been missed, and changes the current compensation gain Gi from "0" to "1". As a result, in the subsequent output limiter 430 (see FIG. 12), the current command value Iref_a output from the PID controller 420 is multiplied by the current compensation gain Gi "1" derived by the current compensation gain calculator 440a. and the current command value Iref_a is output as the motor current command value Ih_ref.

That is, in the present embodiment, the actual steering angle θh_act is used as a parameter, and when the additional steering is performed, the return steering is performed after the actual steering angle |θh_act| , until the actual steering angle |θh_act| becomes less than the second steering angle threshold θth2 (|θh_act|<θth2), which is smaller than the first steering angle threshold θth1, the steering wheel position is assumed to be the steering end, and the motor The current command value Ih_ref is limited to 0 [A]. As a result, the mechanical load applied to the steering mechanism including the stopper 35 at the steering end can be reduced. In addition, the current flowing through the reaction force motor 31 at the steering end can be limited, and an increase in the power consumption of the reaction force motor 31 and the ECU that constitutes the control device 50 can be suppressed.

Although omitted in the present embodiment, as a specific operation example of the current compensation gain calculation unit according to the second embodiment, the same operation as the first modification of the first embodiment or the second modification of the first embodiment is performed. It is good also as an aspect.

That is, for example, the gain control unit 470 determines that the actual steering angle |θh_act| is greater than or equal to the first steering angle threshold value θth1 (θth1≦|θh_act|), and the first steering end determination flag value Fr1 is maintained at “1”. When the period is equal to or longer than the first time threshold tth1, it is determined that the steering wheel position is at the end of steering, the current compensation gain Gi is changed from "1" to "0", and the actual steering angle |θh_act| 2 When the steering angle is less than the threshold θth2 (|θh_act|<θth2) and the period during which the second steering end determination flag value Fr2 is maintained at “1” is equal to or greater than the second time threshold tth2, the steering end is missed. It may be determined that the current compensation gain Gi is changed from "0" to "1".

Further, for example, the gain control unit 470 maintains the first steering end determination flag value Fr1 at "1" when the actual steering angle |θh_act| When the period is equal to or greater than the first time threshold tth1, it is determined that the steering wheel position is at the end of steering, and the current compensation gain Gi is monotonously decreased from "1" to "0" at a predetermined first time rate of change. , the actual steering angle |θh_act| becomes less than the second steering angle threshold θth2 (|θh_act|<θth2), and the period during which the second steering end determination flag value Fr2 maintains "1" is equal to or greater than the second time threshold tth2. In this case, it may be determined that the steering end has been missed, and the current compensation gain Gi may be monotonously increased from "0" to "1" at a predetermined second time change rate.

(Embodiment 3)
FIG. 15 is a block diagram showing a configuration example of a steering torque control section according to the third embodiment. FIG. 16 is a block diagram showing a configuration example of a current compensation gain calculator according to the third embodiment. In addition, the same code|symbol is attached|subjected to the structure which has the same function as each embodiment mentioned above, and description is abbreviate|omitted.

In the third embodiment, a configuration will be described in which the actual steering torque Th_act and the actual steering angle θh_act are used as parameters for determining that the steering wheel position is the end of steering.

In the steering torque control unit 400b, similarly to the second embodiment, the steering torque target value Th_ref output from the steering torque target value generation unit 200, the actual steering torque Th_act detected by the torque sensor 34, and the steering angle sensor 33 A detected actual steering angle θh_act is input.

The actual steering torque Th_act and the actual steering angle θh_act are input to the current compensation gain calculator 440b. Based on the actual steering torque Th_act and the actual steering angle θh_act, the current compensation gain calculator 440b derives a current compensation gain Gi for suppressing increases in mechanical load and power consumption at the end of steering.

The first determination unit 450b derives a first steering end determination flag value Fr1 based on the actual steering torque Th_act and the actual steering angle θh_act.

Specifically, in the present embodiment, a first torque threshold value Tth1 for the actual steering torque |Th_act| and a first steering angle threshold value θth1 for the actual steering angle |θh_act| are set in the first determination unit 450b. . The first torque threshold value Tth1 and the first steering angle threshold value θth1 are stored, for example, in the ROM of the ECU that constitutes the control device 50 .

is less than the first torque threshold value Tth1 (|Th_act|<Tth1), or the actual steering angle |θh_act| is less than the first steering angle threshold value θth1 (|θh_act |<θth1), the first steering end determination flag value Fr1 is set to "0" (Fr1=0), the actual steering torque |Th_act| is equal to or greater than the first torque threshold Tth1 (Tth1≦|Th_act|), and When the actual steering angle |θh_act| is greater than or equal to the first steering angle threshold value θth1 (θth1≦|θh_act|), the first steering end determination flag value Fr1 is set to "1" (Fr1=0).

Second determination unit 460b derives second steering end determination flag value Fr2 based on actual steering torque Th_act and actual steering angle θh_act.

Specifically, in the present embodiment, a second torque threshold Tth2 for the actual steering torque |Th_act| and a second steering angle threshold θth2 for the actual steering angle |θh_act| are set in the second determination unit 460b. . The second torque threshold Tth2 is set to a value smaller than the first torque threshold Tth1 set in the first determination section 450b. The second steering angle threshold θth2 is set to a value smaller than the first steering angle threshold θth1 set in the first determination section 450b. The second torque threshold Tth2 and the second steering angle threshold θth2 are stored, for example, in the ROM of the ECU that constitutes the control device 50 .

is less than the second torque threshold value Tth2 (|Th_act|<Tth2), or the actual steering angle |θh_act| is less than the second steering angle threshold value θth2 (|θh_act |<θth2), the second steering end determination flag value Fr2 is set to “1” (Fr2=1), the actual steering torque |Th_act| is equal to or greater than the second torque threshold Tth2, and the actual steering angle |θh_act is greater than or equal to the second steering angle threshold value θth2 (θth2≦|θh_act|), the second steering end determination flag value Fr2 is set to “0” (Fr2=0).

A specific operation example of the current compensation gain calculator 440b according to the third embodiment will be described in detail below with reference to FIGS. 17A, 17B, 17C, and 17D. 17A is a conceptual diagram showing a specific operation example of a current compensation gain calculator according to the third embodiment; FIG. 17B is a conceptual diagram showing a first modified example of a specific operation example of the current compensation gain calculator according to the third embodiment; FIG. 17C is a conceptual diagram showing a second modified example of the specific operation example of the current compensation gain calculator according to the third embodiment; FIG. 17D is a conceptual diagram showing a third modified example of the specific operation example of the current compensation gain calculator according to the third embodiment; FIG.

17A, 17B, 17C, and 17D, the actual steering torque |Th_act|, the actual steering angle | , second steering end determination flag value Fr2, and current compensation gain Gi.

is greater than or equal to the first torque threshold value Tth1 (Tth1≦|Th_act|), and the actual steering angle |θh_act| is greater than or equal to the first steering angle threshold value θth1 ( When θth1≦|θh_act|), the first steering end determination flag value Fr1 changes from “0” to “1”. At this time, the gain control unit 470 determines that the steering wheel position is the steering end, and changes the current compensation gain Gi from "1" to "0". As a result, in the subsequent output limiter 430 (see FIG. 15), the current command value Iref_a output from the PID controller 420 is multiplied by the current compensation gain Gi "0" derived by the current compensation gain calculator 440b. and the motor current command value Ih_ref becomes "0".

After time t2, the steering state transitions from additional steering to reverse steering, and at time t4 during which reverse steering is being performed, the actual steering torque |Th_act| is less than the second torque threshold Tth2 (|Th_act|<Tth2). or when the actual steering angle |θh_act| becomes less than the second steering angle threshold θth2 (|θh_act|<θth2), the second steering end determination flag value Fr2 changes from "0" to "1". At this time, the gain control unit 470 determines that the steering end has been missed, and changes the current compensation gain Gi from "0" to "1". As a result, in the subsequent output limiter 430 (see FIG. 15), the current command value Iref_a output from the PID controller 420 is multiplied by the current compensation gain Gi "1" derived by the current compensation gain calculator 440b. and the current command value Iref_a is output as the motor current command value Ih_ref.

That is, in the present embodiment, using the actual steering torque Th_act and the actual steering angle θh_act as parameters, the actual steering torque |Th_act| becomes equal to or greater than the first torque threshold value Tth1 (Tth1≦|Th_act|) during additional steering, and becomes equal to or greater than the first steering angle threshold value θth1 (θth1≦|θh_act|), the actual steering torque |Th_act| becomes less than the second torque threshold value Tth2 (|Th_act |<Tth2), or until the actual steering angle |θh_act| becomes less than the second steering angle threshold θth2 (|θh_act|<θth2) which is smaller than the first steering angle threshold θth1, the steering wheel position remains at the steering end. Assuming that there is, the motor current command value Ih_ref is limited to 0 [A]. As a result, the mechanical load applied to the steering mechanism including the stopper 35 at the steering end can be reduced. In addition, the current flowing through the reaction force motor 31 at the steering end can be limited, and an increase in the power consumption of the reaction force motor 31 and the ECU that constitutes the control device 50 can be suppressed.

Although omitted in the present embodiment, as a specific operation example of the current compensation gain calculation unit according to the third embodiment, the same operation as the first modification of the first embodiment or the second modification of the first embodiment is performed. It is good also as an aspect.

For example, the gain control unit 470 controls the actual steering torque |Th_act| to be equal to or greater than the first torque threshold value Tth1 (Tth1≦|Th_act|) and the actual steering angle |θh_act| to be equal to or greater than the first steering angle threshold value θth1 (θth1 ≤|θh_act|), and when the period during which the first steering end determination flag value Fr1 maintains "1" is equal to or greater than the first time threshold value tth1, it is determined that the steering wheel position is at the steering end. The current compensation gain Gi is changed from "1" to "0", and the actual steering torque |Th_act| becomes less than the second torque threshold value Tth2 (|Th_act|<Tth2), or the actual steering angle |θh_act| 2 When the steering angle is less than the threshold θth2 (|θh_act|<θth2) and the period during which the second steering end determination flag value Fr2 is maintained at “1” is equal to or greater than the second time threshold tth2, the steering end is missed. It may be determined that the current compensation gain Gi is changed from "0" to "1".

Further, for example, the gain control unit 470 controls the actual steering torque |Th_act| to be equal to or greater than the first torque threshold value Tth1 (Tth1≦|Th_act|) and the actual steering angle |θh_act| to be equal to or greater than the first steering angle threshold value θth1 (θth1 ≤|θh_act|), and when the period during which the first steering end determination flag value Fr1 maintains "1" is equal to or greater than the first time threshold value tth1, it is determined that the steering wheel position is at the steering end. The current compensation gain Gi is monotonically decreased from "1" to "0" at a predetermined first time rate of change, and the actual steering torque |Th_act| becomes less than the second torque threshold Tth2 (|Th_act|<Tth2), or , the actual steering angle |θh_act| becomes less than the second steering angle threshold θth2 (|θh_act|<θth2), and the period during which the second steering end determination flag value Fr2 maintains "1" is equal to or greater than the second time threshold tth2. In this case, it may be determined that the steering end has been missed, and the current compensation gain Gi may be monotonously increased from "0" to "1" at a predetermined second time change rate.

(Embodiment 4)
FIG. 18 is a block diagram showing a configuration example of a steering torque control section according to the fourth embodiment. FIG. 19 is a block diagram showing a configuration example of a current compensation gain calculator according to the fourth embodiment. In addition, the same code|symbol is attached|subjected to the structure which has the same function as each embodiment mentioned above, and description is abbreviate|omitted.

In the fourth embodiment, a configuration using the actual steering angle θh_act and the actual steering angular velocity ωh_act as parameters for determining that the steering wheel position is the steering end will be described.

As in the second and third embodiments, the steering torque control unit 400c controls the steering torque target value Th_ref output from the steering torque target value generation unit 200, the actual steering torque Th_act detected by the torque sensor 34, and the steering torque Th_act. An actual steering angle θh_act detected by the angle sensor 33 is input.

The actual steering angle θh_act is input to the current compensation gain calculator 440c. The actual steering angle θh_act is differentiated by the differentiation section 480 of the current compensation gain calculation section 440c to derive the actual steering angular velocity ωh_act. Based on the actual steering angle θh_act and the actual steering angular velocity ωh_act, the current compensation gain calculator 440c derives a current compensation gain Gi for suppressing increases in mechanical load and power consumption at the end of steering. It should be noted that the actual steering angular velocity ωh_act is not limited to being derived by differentiating the actual steering angle θh_act.

The first determination unit 450c derives a first steering end determination flag value Fr1 based on the actual steering angle θh_act and the actual steering angular velocity ωh_act.

Specifically, in the present embodiment, the first determination unit 450c includes a first steering angle threshold value θth1 with respect to the actual steering angle |θh_act| and the absolute value |ωh_act| A first steering angular velocity threshold ωth1 is set for the angular velocity |ωh_act|). The first steering angle threshold θth1 and the first steering angular velocity threshold ωth1 are stored in the ROM of the ECU that constitutes the control device 50, for example.

is less than the first steering angle threshold value θth1 (|θh_act|<θth1), or the actual steering angular velocity |ωh_act| is greater than the first steering angular velocity threshold value ωth1. When (ωth<|ωh_act|), the first steering end determination flag value Fr1 is set to “0” (Fr1=0), and the actual steering angle |θh_act| is less than or equal to the first steering angular velocity threshold ωth1 (|ωh_act|≤ωth1), the first steering end determination flag value Fr1 is set to "1" (Fr1=0).

A second determination unit 460c derives a second steering end determination flag value Fr2 based on the actual steering angle θh_act and the actual steering angular velocity ωh_act.

Specifically, in the present embodiment, a second steering angle threshold θth2 for the actual steering angle |θh_act| and a second steering angular velocity threshold ωth2 for the actual steering angular velocity |ωh_act| are set in the second determination unit 460c. there is The second steering angle threshold θth2 is set to a value smaller than the first steering angle threshold θth1 set in the first determination section 450b. The second steering angular velocity threshold ωth2 is set to a value larger than the first steering angular velocity threshold ωth1 set in the first determination section 450c. The second steering angle threshold value θth2 and the second steering angle threshold value θth2 are stored in the ROM of the ECU that constitutes the control device 50, for example.

is less than the second steering angle threshold value θth2 (|θh_act|<θth2), or the actual steering angular velocity |ωh_act| is greater than the second steering angular velocity threshold value ωth2. When (ωth2<|ωh_act|), the second steering end determination flag value Fr2 is set to “1” (Fr2=1), and the actual steering angle |θh_act| is less than or equal to the second steering angular velocity threshold ωth2 (|ωh_act|≤ωth2), the second steering end determination flag value Fr2 is set to "0" (Fr2=0).

A specific operation example of the current compensation gain calculator 440c according to the fourth embodiment will be described in detail below with reference to FIGS. 20A, 20B, 20C, and 20D. 20A is a conceptual diagram showing a specific operation example of a current compensation gain calculator according to the fourth embodiment; FIG. 20B is a conceptual diagram showing a first modified example of a specific operation example of the current compensation gain calculator according to the fourth embodiment; FIG. FIG. 20C is a conceptual diagram showing a second modified example of the specific operation example of the current compensation gain calculator according to the fourth embodiment. FIG. 20D is a conceptual diagram showing a third modified example of the specific operation example of the current compensation gain calculator according to the fourth embodiment.

20A, 20B, 20C, and 20D, the actual steering angle |θh_act|, the actual steering angular velocity |ωh_act|, and the first steering end determination flag value Fr1 are , second steering end determination flag value Fr2, and current compensation gain Gi.

is equal to or greater than the first steering angle threshold value θth1 (θth1≦|θh_act|), and the actual steering angular velocity |ωh_act| is equal to or less than the first steering angular velocity threshold value ωth1 at time t2 when the additional steering is performed. When (|ωh_act|≦ωth1), the first steering end determination flag value Fr1 changes from "0" to "1". At this time, the gain control unit 470 determines that the steering wheel position is the steering end, and changes the current compensation gain Gi from "1" to "0". As a result, in the subsequent output limiter 430 (see FIG. 18), the current command value Iref_a output from the PID controller 420 is multiplied by the current compensation gain Gi "0" derived by the current compensation gain calculator 440c. and the motor current command value Ih_ref becomes "0".

After time t2, the steering state transitions from additional steering to reverse steering, and at time t4 during which reverse steering is being performed, the actual steering angle |θh_act| becomes less than the second steering angle threshold θth2 (|θh_act|<θth2 ), or when the actual steering angular velocity |ωh_act| is greater than the second steering angular velocity threshold ωth2 (ωth2<|ωh_act|), the second steering end determination flag value Fr2 changes from "0" to "1". do. At this time, the gain control unit 470 determines that the steering end has been missed, and changes the current compensation gain Gi from "0" to "1". As a result, in the subsequent output limiter 430 (see FIG. 18), the current command value Iref_a output from the PID controller 420 is multiplied by the current compensation gain Gi "1" derived by the current compensation gain calculator 440c. and the current command value Iref_a is output as the motor current command value Ih_ref.

That is, in the present embodiment, the actual steering angle θh_act and the actual steering angular velocity ωh_act are used as parameters, and the actual steering angle |θh_act| , after the actual steering angular velocity |ωh_act| becomes equal to or less than the first steering angular velocity threshold ωth1 (|ωh_act|≦ωth1), the actual steering angle |θh_act| Until the actual steering angular velocity |ωh_act| becomes larger than the second steering angular velocity threshold ωth2 (ωth2<|ωh_act|), the steering wheel position is The motor current command value Ih_ref is limited to 0 [A] assuming the steering end. As a result, the mechanical load applied to the steering mechanism including the stopper 35 at the steering end can be reduced. In addition, the current flowing through the reaction force motor 31 at the steering end can be limited, and an increase in the power consumption of the reaction force motor 31 and the ECU that constitutes the control device 50 can be suppressed.

Although omitted in this embodiment, as a specific operation example of the current compensation gain calculation unit according to the fourth embodiment, the same operation as the first modification of the first embodiment or the second modification of the first embodiment is performed. It is good also as an aspect.

That is, the gain control unit 470 controls the actual steering angle |θh_act| to be equal to or greater than the first steering angle threshold θth1 (θth1≦|θh_act|) and the actual steering angular velocity |ωh_act| to be equal to or less than the first steering angular velocity threshold ωth1 (|ωh_act). |≤ωth1), and when the period during which the first steering end determination flag value Fr1 maintains "1" is greater than or equal to the first time threshold value tth1, it is determined that the steering wheel position is at the steering end, and the current The compensation gain Gi is changed from "1" to "0", and the actual steering angle |θh_act| becomes less than the second steering angle threshold θth2 (|θh_act|<θth2), or the actual steering angular velocity |ωh_act| 2 (ωth2<|ωh_act|), and the period during which the second steering termination determination flag value Fr2 is maintained at “1” is equal to or greater than the second time threshold tth2. It may be determined that the current compensating gain Gi is changed from "0" to "1".

Further, for example, the gain control unit 470 controls the actual steering angle |θh_act| to be equal to or greater than the first steering angle threshold θth1 (θth1≦|θh_act|) and the actual steering angular velocity |ωh_act| to be equal to or less than the first steering angular velocity threshold ωth1 ( |ωh_act|≦ωth1), and when the period during which the first steering end determination flag value Fr1 is maintained at "1" is equal to or greater than the first time threshold value tth1, it is determined that the steering wheel position is at the steering end. to monotonically decrease the current compensation gain Gi from "1" to "0" at a predetermined first time change rate, and whether the actual steering angle |θh_act| becomes less than the second steering angle threshold value θth2 (|θh_act|<θth2). Alternatively, the actual steering angular velocity |ωh_act| becomes greater than the second steering angular velocity threshold ωth2 (ωth2<|ωh_act|) and the second steering end determination flag value Fr2 is maintained at "1" is the second time. When the threshold value tth2 or more is reached, it may be determined that the steering end has been missed, and the current compensation gain Gi may be monotonically increased from "0" to "1" at a predetermined second time rate of change.

(Embodiment 5)
21 is a block diagram illustrating a configuration example of an output limiter according to the fifth embodiment; FIG. In each of the above-described embodiments, an example in which the output limiting unit 430 is a multiplier has been described. can be done.

Specifically, the output limiter 430 a according to the fifth embodiment includes a sign extractor 431 , an absolute value calculator 432 , a multiplier 433 , a current command lower limit value setter 434 , a comparator 435 and a multiplier 436 .

Sign extractor 431 extracts the sign of current command value Iref_a output from PID controller 420 . Specifically, for example, the value of the current command value Iref_a is divided by the absolute value of the current command value Iref_a. Thereby, the sign extraction unit 431 outputs “1” when the sign of the current command value Iref_a is “+”, and outputs “−1” when the sign of the current command value Iref_a is “−”. do. Specifically, the sign extractor 431 generates, for example, a sign function Sgn(Iref_a) of the current command value Iref_a.

The absolute value calculator 432 performs absolute value processing on the current command value Iref_a. The current command value |Iref_a| that has undergone absolute value processing in the absolute value calculation section 432 is input to the multiplication section 433 . The multiplier 433 outputs a current command value |Iref_a|×Gi obtained by multiplying the current command value |Iref_a| by the current compensation gain Gi. In the present disclosure, the current command value |Iref_a|×Gi corresponds to the “third current command value”.

A lower limit value Iref_lower_lim for the current command value |Iref_a| is set in the current command value lower limit setting unit 434 . The current command value lower limit value Iref_lower_lim is stored, for example, in the ROM of the ECU that constitutes the control device 50 .

The comparison unit 435 performs a comparison operation process between the current command value |Iref_a|×Gi and the current command lower limit value Iref_lower_lim. Specifically, the comparison unit 435 outputs the current command value |Iref_a|×Gi when the following formula (1) is satisfied, and outputs the current command lower limit value Iref_lower_lim when the following formula (2) is satisfied.

|Iref_a|×Gi>Iref_lower_lim (1)

|Iref_a|×Gi≦Iref_lower_lim (2)

Multiplying unit 436 multiplies the output value of comparing unit 435 by sign function Sgn(Iref_a) of current command value Iref_a, and outputs the result as motor current command value Ih_ref.

With the configuration of the output limiter 430a according to the fifth embodiment described above, the lower limit value of the motor current command value |Ih_ref| is limited to the current command value lower limit value Iref_lower_lim regardless of the current compensation gain Gi. As a result, it is possible to suppress rapid fluctuations in the motor current command value Ih_ref at the end of steering.

(Embodiment 6)
22 is a block diagram illustrating a configuration example of an output limiter according to the sixth embodiment; FIG. In addition, the same code|symbol is attached|subjected to the structure which has the same function as Embodiment 5 mentioned above, and description is abbreviate|omitted.

In the fifth embodiment, the lower limit value of the motor current command value |Ih_ref| is limited to the current command value lower limit value Iref_lower_lim. A mode of limiting the upper limit of |Ih_ref| will be described.

Specifically, the output limiting unit 430b according to the sixth embodiment includes a sign extracting unit 431, an absolute value computing unit 432, a current command lower limit value setting unit 434, a multiplying unit 436, a current command upper limit value generating unit 437, a first A comparison unit 438 and a second comparison unit 439 are included.

The current command value upper limit value generator 437 receives the current compensation gain Gi and the current command value lower limit value Iref_lower_lim. FIG. 23 is a block diagram showing an example of the internal configuration of a current command value upper limit value generator according to the sixth embodiment.

In addition, the maximum value Iref_lim_max for the current command value |Iref_a| is set in the current command value upper limit generation unit 437 . The maximum current command value Iref_lim_max is stored in the ROM of the ECU that constitutes the control device 50, for example. In the present disclosure, the current command value lower limit value Iref_lower_lim is, for example, approximately 10[%] of the current command value maximum value Iref_lim_max.

A current command value upper limit value generation unit 437 generates a current command value upper limit value Iref_upper_lim according to the current compensation gain Gi. In the configuration shown in FIG. 23, the current command value upper limit value generation unit 437 has the current command value upper limit value Iref_upper_lim represented by the following equation (3).

Iref_upper_lim=(Iref_lim_max−Iref_lower_lim)×Gi+Iref_lower_lim (3)

The current command value upper limit value generation unit 437 may be configured to calculate the current command value upper limit value Iref_upper_lim using the above equation (3), or may use the input/output characteristics obtained by the above equation (3) as a map. It is also possible to store the current command value upper limit value Iref_upper_lim based on the map. FIG. 24 is a diagram showing an example of input/output characteristics of a current command value upper limit generator according to the sixth embodiment.

The first comparison unit 438 performs a comparison operation process between the current command value |Iref_a| and the current command upper limit value Iref_upper_lim. Specifically, the first comparison unit 438 outputs the current command value |Iref_a| when the following formula (4) is satisfied, and outputs the current command upper limit value Iref_upper_lim when the following formula (5) is satisfied.

|Iref_a|≤Iref_upper_lim (4)

|Iref_a|>Iref_upper_lim (5)

The second comparison unit 439 performs comparison operation processing between the output value Comp_a of the first comparison unit 438 and the current command value lower limit value Iref_lower_lim. Specifically, the comparison unit 435 outputs the output value Comp_a of the first comparison unit 438 when the following expression (6) is satisfied, and outputs the current command value lower limit value Iref_lower_lim when the following expression (7) is satisfied. In the present disclosure, the output value Comp_a of the first comparison unit 438 corresponds to "third current command value".

Comp_a>Iref_lower_lim (6)

Comp_a≦Iref_lower_lim (7)

The multiplier 436 multiplies the output value of the second comparator 439 by the sign function Sgn(Iref_a) of the current command value Iref_a, and outputs the result as the motor current command value Ih_ref.

With the configuration of the output limiter 430b according to the sixth embodiment described above, the upper limit value of the motor current command value |Ih_ref| is limited to the current command value upper limit value Iref_upper_lim according to the current compensation gain Gi. As a result, unnecessary fluctuations in the motor current command value Ih_ref due to noise or the like can be suppressed.

Note that the diagrams used in the above-described embodiments are conceptual diagrams for qualitatively explaining the present disclosure, and are not limited to these. In addition, although the above-described embodiment is an example of the preferred implementation of the present disclosure, it is not limited to this, and various modifications can be implemented without departing from the gist of the present disclosure.

Reference Signs List 1 steering wheel 2 column shaft 3a, 3b tie rod 5L, 5R steering wheel 10 vehicle speed sensor 11 ignition key 12 battery 30 reaction force device 31 reaction force motor 32 reduction mechanism 33 steering angle sensor 34 torque sensor 35 stopper (rotation limiting mechanism)
40 Steering device 41 Steering motor 42 Reduction mechanism 43 Angle sensor 44 Pinion rack mechanism 50 Control device 60 Reaction force control system 70 Steering control system 200 Steering torque target value generation unit 400, 400a, 400b, 400c Steering torque control unit 410 subtractor 420 PID controller 430, 430a, 430b output limiter 431 sign extractor 432 absolute value calculator 433 multiplier 434 current command value lower limit value setting unit 435 comparator 436 multiplier 437 current command value upper limit value generator 438 First comparison section 439 Second comparison section 440, 440a, 440b, 440c Current compensation gain calculation section 450, 450a, 450b, 450c First determination section 460, 460a, 460b, 460c Second determination section 470 Gain control section 500 Current control Part 600 Turning angle target value generation part 700 Turning angle control part 800 Current control part

Claims (17)

A rotation limiting mechanism is provided at the steering end of the steering wheel, and includes a reaction force motor that applies a steering reaction force to the steering wheel according to the steering angle of the steering wheel, and a steering wheel that steers the steered wheels according to the steering angle of the steering wheel. A control device for a vehicle steering system comprising a rudder motor,
a steering torque target value generator that generates a steering torque target value that is a steering torque target value for obtaining the steering reaction force;
a steering torque control unit that generates a first current command value based on the steering torque target value;
with
The steering torque control unit
a current compensation gain calculator that derives a current compensation gain that limits the first current command value at the steering end;
an output limiter that limits the first current command value based on the current compensation gain to generate a second current command value for driving the reaction force motor;
comprising
A controller for a vehicle steering system. The current compensation gain calculation unit
determining that the steering end is reached when the actual steering torque, which is the actual steering torque of the steering wheel, is greater than or equal to a first torque threshold;
After determining that the steering end has been reached, if the actual steering torque becomes less than a second torque threshold smaller than the first torque threshold, it is determined that the steering end has been missed.
The control device for a steering system for a vehicle according to claim 1. The current compensation gain calculation unit
When the actual steering torque, which is the actual steering torque of the steering wheel, becomes equal to or greater than a first torque threshold and a predetermined first time elapses, it is determined that the steering is terminated;
After the steering end is determined, the actual steering torque becomes less than a second torque threshold smaller than the first torque threshold, and when a predetermined second time elapses, it is determined that the steering end has been missed.
The control device for a steering system for a vehicle according to claim 1. The current compensation gain calculation unit
when the actual steering angle, which is the actual steering angle of the steering wheel, is greater than or equal to a first steering angle threshold value, determining that the steering end is reached;
After determining that the steering end has been reached, if the actual steering angle becomes less than a second steering angle threshold that is smaller than the first steering angle threshold, it is determined that the steering end has been missed.
The control device for a steering system for a vehicle according to claim 1. The current compensation gain calculation unit
When the actual steering angle, which is the actual steering angle of the steering wheel, becomes equal to or greater than a first steering angle threshold value and a predetermined first time elapses, it is determined that the steering is terminated;
After the steering end is determined, the actual steering angle becomes less than a second steering angle threshold that is smaller than the first steering angle threshold, and when a predetermined second time elapses, it is determined that the steering end has been missed.
The control device for a steering system for a vehicle according to claim 1. The current compensation gain calculation unit
When the actual steering torque, which is the actual steering torque of the steering wheel, becomes equal to or greater than a first torque threshold, and the actual steering angle, which is the actual steering angle of the steering wheel, becomes equal to or greater than the first steering angle threshold, the steering end is reached. determined to be
After the steering end is determined, the actual steering torque becomes less than a second torque threshold smaller than the first torque threshold, or the actual steering angle becomes a second steering angle smaller than the first steering angle threshold. Determining that the steering end has been missed if the threshold is less than
The control device for a steering system for a vehicle according to claim 1. The current compensation gain calculation unit
The actual steering torque, which is the actual steering torque of the steering wheel, has become equal to or greater than the first torque threshold, and the actual steering angle, which is the actual steering angle of the steering wheel, has become equal to or greater than the first steering angle threshold, and a predetermined first time has elapsed. In the case, it is determined that the steering is terminated,
After the steering end is determined, the actual steering torque becomes less than a second torque threshold smaller than the first torque threshold, or the actual steering angle becomes a second steering angle smaller than the first steering angle threshold. If it is less than the threshold value and a predetermined second time has elapsed, it is determined that the steering end has been missed.
The control device for a steering system for a vehicle according to claim 1. The current compensation gain calculation unit
When the actual steering angle, which is the actual steering angle of the steering wheel, is greater than or equal to a first steering angle threshold and the actual steering angular velocity, which is the actual steering angular velocity of the steering wheel, is less than or equal to the first steering angular velocity threshold, the steering is performed. determine the end,
After determining that the steering end is reached, the actual steering angle becomes smaller than the second steering angle threshold smaller than the first steering angle threshold, or the actual steering angular velocity becomes a second steering angle larger than the first steering angular velocity threshold. Determining that the steering end has been missed when the steering angular velocity is greater than
The control device for a steering system for a vehicle according to claim 1. The current compensation gain calculation unit
The actual steering angle, which is the actual steering angle of the steering wheel, becomes equal to or greater than the first steering angle threshold, and the actual steering angular velocity, which is the actual steering angular velocity of the steering wheel, becomes equal to or less than the first steering angular velocity threshold, and a predetermined first time elapses. When it is determined that the steering is terminated,
After determining that the steering end is reached, the actual steering angle becomes smaller than the second steering angle threshold smaller than the first steering angle threshold, or the actual steering angular velocity becomes a second steering angle larger than the first steering angular velocity threshold. When the steering angular velocity becomes greater than the steering angular velocity and a predetermined second time elapses, it is determined that the steering end has been missed.
The control device for a steering system for a vehicle according to claim 1. The current compensation gain calculation unit
transitioning the current compensation gain from a first gain to a second gain smaller than the first gain when the steering end is determined;
transitioning the current compensation gain from the second gain to the first gain when it is determined that the steering end has been missed;
A control device for a vehicle steering system according to any one of claims 1 to 9. The current compensation gain calculation unit
monotonically decreasing the current compensation gain from a first gain to a second gain smaller than the first gain at a predetermined first time rate of change when the steering end is determined;
monotonically increasing the current compensation gain from the second gain to the first gain at a predetermined second time rate of change when it is determined that the steering end has been missed;
A control device for a vehicle steering system according to any one of claims 1 to 9. The output limiter is
multiplying the first current command value by the current compensation gain to generate the second current command value;
A control device for a vehicle steering system according to any one of claims 1 to 11. The output limiter is
limiting the lower limit of the second current command value;
A control device for a vehicle steering system according to any one of claims 1 to 11. The output limiter is
a comparison unit that compares a third current command value obtained by multiplying the first current command value by the current compensation gain with a predetermined current command lower limit value;
The comparison unit
outputting the third current command value as the second current command value when the third current command value is greater than the lower limit value of the current command value;
When the third current command value is equal to or less than the current command value lower limit value, outputting the current command value lower limit value as the second current command value;
The control device for a vehicle steering system according to claim 13. The output limiter is
limiting the upper and lower limits of the second current command value;
A control device for a vehicle steering system according to any one of claims 1 to 12. The output limiter is
a first comparison unit that compares the first current command value with a predetermined upper limit current command value;
a second comparison unit that compares a third current command value, which is the output value of the first comparison unit, with a predetermined current command lower limit value;
with
The first comparison unit is
outputting the first current command value when the first current command value is equal to or less than the upper limit value of the current command value;
outputting the current command upper limit value when the first current command value is greater than the current command lower limit value;
The second comparison unit
outputting the third current command value as the second current command value when the third current command value is greater than the lower limit value of the current command value;
When the third current command value is equal to or less than the current command value lower limit value, outputting the current command value lower limit value as the second current command value;
16. The control device for a vehicle steering system according to claim 15. The output limiter is
A current command value upper limit generation unit that generates the current command value upper limit value,
The current command value upper limit value generation unit
As the current compensation gain increases, the current command value upper limit value is monotonically increased from the current command value lower limit value to a predetermined current command value maximum value.
17. The control device for a vehicle steering system according to claim 16.

Images