Vehicle control system, integrated control program, and vehicle steering system

Abstract

A vehicle control system (CCS) controls a plurality of vehicle systems (CS) including a vehicle steering system (STG). First control processing executed by an integrated control device (10) is processing in which a steering control device (20) calculates steering control values (θp*, Ts*) used in control of the vehicle steering system (STG). The first control processing uses a control parameter set in association with the behavior of a vehicle (VC). Second control processing executed by the steering control device (20) is processing for controlling the vehicle steering system (STG) so as to reflect the steering control values (θp*, Ts*) calculated by the integrated control device (10). The second control processing uses a control parameter set in association with the behavior of the vehicle steering system (STG).

Description

Vehicle control system, integrated control program, and vehicle steering system

[0001] The present disclosure relates to a vehicle control system, an integrated control program, and a vehicle steering system.

[0002] For example, Patent Document 1 listed below describes a vehicle control system having a command controller that comprehensively executes control related to the vehicle's running state. Such a vehicle control system has, in addition to the command controller, multiple actuator controllers that individually execute control related to the vehicle's running state. The control related to the vehicle's running state includes control for generating driving force, steering force, and braking force for the vehicle. The command controller generates a control target value for each control related to the vehicle's running state. The generated control target value is transmitted to the corresponding actuator controller and used to control the drive of the actuator in that actuator controller.

[0003] JP 2013-230812 A

[0004] In a vehicle to which the above-described vehicle control system is applied, adjusting the vehicle behavior requires adjusting the control parameters of each of the command controller and the actuator controller. The same applies to adjusting the actuator behavior. This makes the work of adjusting the vehicle and actuator behaviors complicated. This reduces the degree of freedom in designing the vehicle control system. Therefore, improvements are desired in terms of facilitating the work of adjusting the vehicle and actuator behaviors.

[0005] One aspect of the present disclosure provides a vehicle control system configured to control a plurality of vehicle systems including a vehicle steering system for steering a vehicle, the vehicle control system including an integrated control device that integrally controls the plurality of vehicle systems and a steering control device that controls the vehicle steering system, wherein a process for controlling the vehicle steering system includes a first control process and a second control process, the integrated control device is configured to execute the first control process, the steering control device is configured to execute the second control process, the first control process is a process for calculating a steering control value used by the steering control device to control the vehicle steering system, the first control process is a process for using a control parameter that is associated with a behavior of the vehicle, and the second control process is a process for controlling the vehicle steering system so as to reflect the steering control value calculated by the integrated control device, the second control process is a process for using a control parameter that is associated with the behavior of the vehicle steering system.

[0006] Another aspect of the present disclosure provides an integrated control program applicable to a vehicle control system including an integrated control device that integrally controls a plurality of vehicle systems including a vehicle steering system for steering a vehicle, and a steering control device that controls the vehicle steering system, wherein a process for controlling the vehicle steering system includes a first control process executed by the integrated control device and a second control process executed by the steering control device, the integrated control program is configured to cause the integrated control device to execute the first control process, and the first control process is a process for calculating a steering control value used by the steering control device to control the vehicle steering system, the first control process being a process using a control parameter set in association with a behavior of the vehicle.

[0007] Another aspect of the present disclosure provides a vehicle steering system for steering a vehicle, which is applied to a vehicle control system including an integrated control device that controls a plurality of vehicle systems in an integrated manner, wherein the vehicle steering system includes a steering control device that controls the vehicle steering system, and a process for controlling the vehicle steering system includes a first control process executed by the integrated control device and a second control process executed by the steering control device, the first control process being a process for calculating a steering control value used by the steering control device to control the vehicle steering system, the process using a control parameter set in association with a behavior of the vehicle, and the second control process being a process for controlling the vehicle steering system so as to reflect the steering control value calculated by the integrated control device, the process using a control parameter set in association with the behavior of the vehicle steering system.

[0008] Fig. 4 is a diagram showing the configuration of a vehicle control system according to a first embodiment. Fig. 5 is a diagram showing the configuration of a vehicle steering system according to a first embodiment. Fig. 6 is a block diagram showing the processing contents of the integrated control program and steering control program of Fig. 2. Fig. 7 is a diagram showing the allocation of processing of Fig. 3. Fig. 8 is a block diagram showing the processing contents of the integrated control program and steering control program according to a second embodiment.

[0009] First Embodiment A first embodiment will be described below with reference to the drawings. As shown in FIG. 1 , a vehicle control system CCS is a system mounted on a vehicle VC to execute control related to the behavior of the vehicle VC. The behavior of the vehicle VC includes, for example, the running state of the vehicle VC and the steering feel when steering the vehicle VC. The vehicle control system CCS includes an integrated control device 10 and multiple vehicle systems CS. The integrated control device 10 and the multiple vehicle systems CS are communicatively connected to each other via an in-vehicle network GC consisting of lines such as a CAN. The multiple vehicle systems CS are communicatively connected to each other via the in-vehicle network GC. The integrated control device 10 executes control to stabilize the behavior of the vehicle VC by integrally controlling the multiple vehicle systems CS.

[0010] The multiple vehicle systems CS include a vehicle steering system STG as well as multiple other function systems such as a first vehicle function system CSa and a second vehicle function system CSb. The vehicle steering system STG generates a steering force for steering the vehicle VC so as to change the direction of travel of the vehicle VC. The first vehicle function system CSa generates a driving force for driving the vehicle VC. The second vehicle function system CSb generates a braking force for decelerating the vehicle VC.

[0011] Each of the multiple vehicle systems CS is composed of a combination of an actuator 12 and a control device 14 that controls the actuator 12. The vehicle steering system STG is composed of, for example, a combination of a steering actuator Act that generates a steering force and a steering control device 20 that controls the drive of the steering actuator Act. The vehicle first function system CSa is composed of, for example, a combination of a first function actuator 12a that generates a driving force and a first function control device 14a that controls the drive of the first function actuator 12a. The vehicle second function system CSb is composed of, for example, a combination of a second function actuator 12b that generates a braking force and a second function control device 14b that controls the drive of the second function actuator 12b.

[0012] In contrast, the integrated control device 10 is configured to execute various control processes for controlling individual systems in order to integrally control multiple vehicle systems CS. The integrated control device 10 is configured, for example, to execute a steering control process 10stg for controlling the vehicle steering system STG. The integrated control device 10 is configured, for example, to execute a first function control process 10a for controlling the vehicle first function system CSa. The integrated control device 10 is configured, for example, to execute a second function control process 10b for controlling the vehicle second function system CSb.

[0013] <Regarding the Vehicle Steering System> As shown in Fig. 2, the vehicle steering system STG mounted on the vehicle VC includes a steering actuator Act. The steering actuator Act includes a reaction force actuator Ar and a turning actuator At. The vehicle steering system STG has a structure in which the power transmission path between the steering wheel 22 of the vehicle VC, which is an operating member, and the steered wheels 54 of the vehicle VC is mechanically disconnected. In other words, the vehicle steering system STG includes a steer-by-wire steering device.

[0014] A steering shaft 24 is connected to the steering wheel 22. The reaction force actuator Ar is an actuator for applying a steering reaction force to the steering wheel 22. The steering reaction force is a force that acts in the opposite direction to the direction of operation of the steering wheel 22 by the driver. By applying the steering reaction force to the steering wheel 22, it is possible to give the driver an appropriate sense of responsiveness. The reaction force actuator Ar includes a speed reduction mechanism 26, a reaction force motor 30, and a reaction force inverter 32. In this embodiment, the steering reaction force is an example of a steering force related to steering of the vehicle VC.

[0015] The reaction force motor 30 is a three-phase brushless motor. The reaction force motor 30 is a surface permanent magnet synchronous motor. The reaction force motor 30 is the drive source for the reaction force actuator Ar. The rotating shaft of the reaction force motor 30 is connected to the steering shaft 24 via a reduction mechanism 26. The reaction force inverter 32 is a power conversion circuit and drive circuit that converts the voltage VB of a battery 34, which is a DC voltage source, into AC voltage and applies it to the reaction force motor 30.

[0016] Meanwhile, steering shaft 50 extends along the vehicle width direction, which is the left-right direction in Figure 2. Left and right steered wheels 54 are connected to both ends of steering shaft 50 via tie rods 52. The linear movement of steering shaft 50 changes the steering angle of steered wheels 54.

[0017] The steering actuator At includes a speed reduction mechanism 66, a steering motor 70, and a steering inverter 72. The steering motor 70 is a three-phase brushless motor. The steering motor 70 is the drive source of the steering actuator At. The rotation shaft of the steering motor 70 is connected to a pinion shaft 62 via the speed reduction mechanism 66. The pinion teeth of the pinion shaft 62 mesh with rack teeth 64 of the steering shaft 50. A rack-and-pinion mechanism is formed by the pinion shaft 62 and the steering shaft 50 provided with the rack teeth 64. The torque of the steering motor 70 is applied as a steering force to the steering shaft 50 via the pinion shaft 62. In response to the rotation of the steering motor 70, the steering shaft 50 moves in the vehicle width direction, which is the left-right direction in FIG. 2 . In this embodiment, the steering force is an example of a steering force related to steering of the vehicle VC.

[0018] The vehicle steering system STG includes a steering control device 20. The steering control device 20 controls a steering wheel 22, which is an object to be controlled. The steering control device 20 controls the drive of a reaction force actuator Ar to control the steering reaction force, which is a control variable of the object to be controlled. FIG. 2 shows an operation signal MSs to a reaction force inverter 32. The steering control device 20 controls steered wheels 54, which are an object to be controlled. The steering control device 20 operates a steering actuator At to control the steering angle of steered wheels 54, which is a control variable of the object to be controlled. The steering angle is the turning angle of the tires, i.e., the steered wheels 54. FIG. 2 shows an operation signal MSt to a steering inverter 72.

[0019] The vehicle steering system STG is connected to an in-vehicle network GC via a steering control device 20. That is, the steering control device 20 is connected to the integrated control device 10 via the in-vehicle network GC. The steering control device 20 is connected to other vehicle systems CS, such as a first vehicle function system CSa and a second vehicle function system CSb, via the in-vehicle network GC.

[0020] Steering control device 20 references steering torque Th, which is the input torque to steering shaft 24, detected by torque sensor 80. Torque sensor 80 includes a torsion bar connected to steering shaft 24 and a sensing element that detects the torsion angle of the torsion bar. Steering control device 20 references rotation angle θa of the rotation shaft of reaction force motor 30, detected by rotation angle sensor 82. Steering control device 20 references currents iu1, iv1, iw1 flowing through reaction force motor 30. Currents iu1, iv1, iw1 are quantified as the voltage drop amounts of shunt resistors provided in each leg of reaction force inverter 32. Steering control device 20 references rotation angle θb of the rotation shaft of turning motor 70, detected by rotation angle sensor 84. Steering control device 20 references currents iu2, iv2, iw2 flowing through turning motor 70. The currents iu2, iv2, and iw2 are quantified as the voltage drop amounts of the shunt resistors provided in the respective legs of the steering inverter 72.

[0021] The steering control device 20 includes a control unit 92, a storage device 94, and peripheral circuits 96. The control unit 92 is a software processing device such as a CPU, a GPU, or a TPU. The software processing device employed in the control unit 92 has, for example, a control cycle that is shorter than the communication cycle of the in-vehicle network GC. The storage device 94 includes a storage medium such as an electrically rewritable nonvolatile memory and a disk medium. A steering control program 94a is stored in the storage device 94. The peripheral circuits 96 include a circuit that generates a clock signal that defines internal operations, a power supply circuit, a reset circuit, and the like. The steering control device 20 controls the control amount by the control unit 92 executing the steering control program 94a stored in the storage device 94.

[0022] The steering control device 20 outputs a steering state variable SVstg obtained from the vehicle steering system STG to the in-vehicle network GC. The steering state variable SVstg includes the steering torque Th and the rotation angle θa referenced by the steering control device 20, as well as a turning torque command value Tt*, which will be described later.

[0023] The integrated control device 10 inputs the steering state variable SVstg transmitted by the in-vehicle network GC. That is, the integrated control device 10 refers to the steering torque Th, the rotation angle θa, and the steering torque command value Tt*. The integrated control device 10 inputs the vehicle speed V transmitted by the in-vehicle network GC. The vehicle speed V is the traveling speed of the vehicle VC detected by the vehicle speed sensor 86. The integrated control device 10 inputs the system state variable SVcs transmitted by the in-vehicle network GC. The system state variable SVcs is a state variable obtained from the vehicle system CS other than the vehicle steering system STG. The system state variable SVcs includes a first function state variable SVa obtained from the first vehicle function system CSa and a second function state variable SVb obtained from the second vehicle function system CSb. The first function state variable SVa indicates, for example, an operation state of the accelerator pedal of the vehicle VC or a state including the magnitude of the generated driving force, which is a state related to the drive of the first function actuator 12a in the first vehicle function system CSa. The second function state variable SVb indicates, for example, an operation state of the brake pedal of the vehicle VC or a state including the magnitude of the generated braking force, which is a state related to the drive of the second function actuator 12b in the second vehicle function system CSb.

[0024] The integrated control device 10 includes a control unit 102, a storage device 104, and peripheral circuits 106. The control unit 102 is a software processing device such as a CPU, a GPU, or a TPU. The software processing device employed in the control unit 102 has a control cycle longer than the communication cycle of the in-vehicle network GC, for example. As a result, the control cycle of the control unit 92 is shorter than the control cycle of the control unit 102. In other words, the steering control device 20 is configured to execute various processes at cycles shorter than the control cycles at which various processes are executed in the integrated control device 10. The storage device 104 includes a storage medium such as an electrically rewritable nonvolatile memory and a disk medium. An integrated control program 104a is stored in the storage device 104. The peripheral circuits 106 include a circuit that generates a clock signal that defines internal operation, a power supply circuit, a reset circuit, and the like. The integrated control device 10 controls the control amount by the control unit 102 executing the integrated control program 104a stored in the storage device 104.

[0025] <Processing for Controlling the Vehicle Steering System> Figure 3 shows part of the processing executed to control the vehicle steering system STG. The steering angle calculation process M10 is a process that uses the rotation angle θa as an input to calculate the steering angle θh, which is the rotation angle of the steering wheel 22. The steering angle calculation process M10 includes a process that converts the rotation angle θa into an integrated angle that includes a range exceeding 360° by counting the number of rotations of the reaction force motor 30 from a steering neutral position, which is the position of the steering wheel 22 when the vehicle VC is traveling straight. The steering angle calculation process M10 includes a process that calculates the steering angle θh by multiplying the converted integrated angle by a conversion coefficient based on the rotational speed ratio of the reduction mechanism 26. Note that the steering angle θh is expressed as a positive value when the steering angle is to the right of the steering neutral position and a negative value when the steering angle is to the left of the steering neutral position, for example.

[0026] Pinion angle calculation process M12 is a process that uses rotation angle θb as an input to calculate pinion angle θp, which is the rotation angle of pinion shaft 62. Pinion angle calculation process M12 includes, for example, a process of counting the number of rotations of steering motor 70 from a rack neutral position, which is the position of steering shaft 50 when vehicle VC is traveling straight, and converting the counted number of rotations into an integrated angle that includes a range exceeding 360°. Pinion angle calculation process M12 includes a process of multiplying the converted integrated angle by a conversion coefficient based on the rotational speed ratio of speed reduction mechanism 66 to calculate pinion angle θp, which is the actual rotation angle of pinion shaft 62. Note that pinion angle θp is expressed as a positive value when it is an angle to the right of the rack neutral position and a negative value when it is an angle to the left of the rack neutral position, for example. Steering motor 70 and pinion shaft 62 are linked via speed reduction mechanism 66. Therefore, there is a one-to-one correspondence between the integrated value of rotation angle θb of steering motor 70 and pinion angle θp. Using this correspondence, pinion angle θp can be found from rotation angle θb of steering motor 70. Furthermore, pinion shaft 62 is meshed with steered shaft 50. Therefore, there is also a one-to-one correspondence between pinion angle θp and the amount of movement of steered shaft 50. And there is also a one-to-one correspondence between pinion angle θp and the steering angle of steered wheels 54.

[0027] The target pinion angle calculation process M14 is a process that calculates a target pinion angle θp* using the steering angle θh and the vehicle speed V as inputs. The target pinion angle θp* is a target value of the pinion angle θp according to the operation of the steering wheel 22 by the driver. The target pinion angle calculation process M14 includes a process that variably sets the steering angle ratio Dr according to the vehicle speed V. Therefore, the target pinion angle θp* output by the target pinion angle calculation process M14 will be a different value depending on the vehicle speed V, even if the input steering angle θh is the same.

[0028] The target pinion angle calculation process M14 can be realized, for example, by calculating the steering angle ratio Dr through map calculation using map data stored in advance in the storage device 104. This map data is data that uses the steering angle θh and the vehicle speed V as input variables and the steering angle ratio Dr as an output variable. The map data for calculating the steering angle ratio Dr through the map is an example of a control parameter for adjusting the behavior of the vehicle VC. This map data is information that is adjusted by a vehicle manufacturer or the like during the design or manufacturing process depending on the type and specifications of the vehicle VC, for example.

[0029] Map data is a set of data consisting of discrete values ​​of input variables and values ​​of output variables corresponding to each of the input variable values. A map operation may be a process in which, when the value of an input variable matches one of the input variable values ​​in the map data, the value of the corresponding output variable in the map data is used as the calculation result. Furthermore, when the value of an input variable does not match any of the input variable values ​​in the map data, the map operation may be a process in which, when the value of an input variable does not match any of the input variable values ​​in the map data, the value of the output variable in the map data that corresponds to the closest value among the output variable values ​​in the map data is used as the calculation result. Alternatively, when the value of an input variable does not match any of the input variable values ​​in the map data, the map operation may be a process in which, when the value of an input variable does not match any of the input variable values ​​in the map data, the value of the output variable in the map data that corresponds to the closest value among the output variable values ​​in the map data is used as the calculation result.

[0030] Pinion angle feedback process M16 is a process for calculating a turning torque command value Tt* in order to control pinion angle θp to target pinion angle θp* by feedback control. Turning torque command value Tt* is a command value for the torque of turning motor 70. In other words, pinion angle feedback process M16 is a feedback process for calculating the turning torque command value Tt* by feedback control so that pinion angle θp becomes target pinion angle θp*. In the present embodiment, pinion angle θp is a state variable, target pinion angle θp* is a target control value, and turning torque command value Tt* is an example of the feedback control value.

[0031] Pinion angle feedback process M16 can be realized, for example, by angle feedback process of pinion angle θp using PID control. The angle feedback process includes a process of multiplying an angle deviation Δθp, which is a value obtained by subtracting the pinion angle θp from the target pinion angle θp*, by an angle proportional gain. The angle feedback process includes a process of adding a value obtained by multiplying the angle deviation Δθp by an angle integral gain. The angle feedback process includes a process of multiplying a first-order time derivative value of the angle deviation Δθs by an angle differential gain. The feedback gains used in the angle feedback process, which are made up of the angle proportional gain, angle integral gain, and angle differential gain, are one example of control parameters for adjusting the behavior of the steering actuator Act, i.e., the turning actuator At. This feedback gain is information adjusted by a supplier manufacturer or the like during the design or manufacturing process, for example, from the perspective of ensuring the responsiveness and control stability of the steering actuator Act and the turning actuator At. In particular, in the case of the vehicle steering system STG, the pinion angle feedback processing M16 is required to be a highly responsive process, and therefore it is necessary to ensure control stability while ensuring high responsiveness.

[0032] The steering operation process M18 is a process that receives as input the steering torque command value Tt*, currents iu2, iv2, iw2, and rotation angle θb, and outputs an operation signal MSt for the steering inverter 72. The steering operation process M18 includes a process that calculates a d-axis current command value It* as a target current based on the steering torque command value Tt*. The steering operation process M18 also includes a process that calculates a d-axis current It as an actual steering current based on the currents iu2, iv2, iw2, and the rotation angle θb. The steering operation process M18 then includes a process that calculates an operation signal MSt to control the drive of the steering inverter 72 so that the d-axis current It becomes the current command value It*. In other words, the steering operation process M18 is a feedback process that calculates the operation signal MSt by feedback controlling the d-axis current It to become the current command value It*. In this embodiment, the current It on the dq axes is an example of a state variable, the current command value It* is an example of a target control value, and the operation signal MSt is an example of a feedback control value.

[0033] The steering operation process M18 can be realized, for example, by current feedback processing of the d- and q-axis current It using PID control. The current feedback processing includes multiplying a current deviation ΔIt, which is a value obtained by subtracting the d- and q-axis current It from the current command value It*, by a current proportional gain. The current feedback processing includes adding a value obtained by multiplying the current deviation ΔIt by a current integral gain. The current feedback processing includes multiplying a first-order time derivative of the current deviation ΔIt by a current differential gain. The feedback gains used in the current feedback processing, which are made up of the current proportional gain, current integral gain, and current differential gain, are examples of control parameters for adjusting the behavior of the steering actuator Act, i.e., the steering actuator At. This feedback gain is information adjusted by a supplier manufacturer or the like during the design or manufacturing process, for example, with a view to ensuring the responsiveness and control stability of the steering actuator Act and the steering actuator At. In particular, in the case of the vehicle steering system STG, the steering operation process M18 is required to be a highly responsive process, and therefore it is necessary to ensure control stability while ensuring high responsiveness.

[0034] Axial force calculation process M19 includes a process of calculating axial force Taf using turning torque command value Tt* as input. Here, axial force Taf is an axial force applied to steered shaft 50. Note that axial force calculation process M19 may use current command value It* or d-axis current It as input instead of turning torque command value Tt*.

[0035] The base target torque calculation process M20 is a process for calculating a base target torque Thb*, which is a base value of the target steering torque Th* that the driver should input to the steering shaft 24 via the steering wheel 22, based on the axial force Taf. The axial force Taf is an amount that depends on the lateral force acting on the steered wheels 54, so the lateral force can be determined from the axial force Taf. On the other hand, it is desirable to determine the torque that the driver should input to the steering shaft 24 via the steering wheel 22 depending on the lateral force. Therefore, the base target torque calculation process M20 is a process for calculating the base target torque Thb* depending on the lateral force determined from the axial force Taf.

[0036] More specifically, the base target torque calculation process M20 is a process for variably setting the absolute value of the base target torque Thb* in accordance with the vehicle speed V even when the absolute value of the axial force Taf is the same. This process may be a process for calculating the absolute value of the base target torque Thb* so that the absolute value of the base target torque Thb* when the vehicle speed V is low is equal to or less than the absolute value of the base target torque Thb* when the vehicle speed V is high. The base target torque calculation process M20 includes a process for variably setting the absolute value of the base target torque Thb* in accordance with the system state variable SVcs. Therefore, even when the absolute value of the axial force Taf is the same, the base target torque Thb* output by the base target torque calculation process M20 will be a different value depending on the system state variable SVcs. In other words, the base target torque calculation process M20 is a process for enabling the vehicle steering system STG to cooperate with the other vehicle systems CS.

[0037] The base target torque calculation process M20 can be realized, for example, by calculating the base target torque Thb* through map calculation using map data stored in advance in the storage device 104. This map data is data in which the axial force Taf or the lateral acceleration and vehicle speed V determined from the axial force Taf are input variables, and the base target torque Thb* is an output variable. The map data for calculating the base target torque Thb* through the map calculation is a basic parameter that defines the basic characteristics of the steering reaction force and is an example of a control parameter for adjusting the behavior of the vehicle VC. This map data is, for example, information adjusted by a vehicle manufacturer or the like during the design or manufacturing process according to the type and specifications of the vehicle VC.

[0038] The compensation amount calculation process M21 is a process for calculating and outputting a compensation amount Thr for compensating for the base target torque Thb* based on the steering angle θh. Specifically, the compensation amount calculation process M21 includes a process for distinguishing between when the steering wheel 22 is being turned and when it is being turned back, based on changes in the steering angle θh, etc., and calculating the compensation amount Thr. Specifically, the compensation amount calculation process M21 includes a process for calculating the compensation amount Thr so ​​that the absolute value of the target steering torque Th* is larger when the steering wheel 22 is being turned back than when it is being turned back. The compensation amount calculation process M21 includes a process for variably setting the compensation amount Thr depending on the vehicle speed V. The compensation amount calculation process M21 includes a process for variably setting the compensation amount Thr depending on the system state variable SVcs. Therefore, the compensation amount Thr output by the compensation amount calculation process M21 will be a different value depending on the system state variable SVcs, even if the situation identified based on changes in the steering angle θh, etc., and the vehicle speed V are the same. That is, the compensation amount calculation process M21 is a process for the vehicle steering system STG to cooperate with the other vehicle systems CS.

[0039] The compensation amount calculation process M21 can be implemented, for example, by calculating the compensation amount Thr by multiplying the system state variable SVcs by a gain that is variably set according to the system state variable SVcs. The gain used to calculate the compensation amount Thr is a compensation parameter that compensates for the basic characteristics of the steering reaction force and is an example of a control parameter used to adjust the behavior of the vehicle VC. This gain is information that is adjusted by a vehicle manufacturer or the like during the design or manufacturing process according to the type and specifications of the vehicle VC.

[0040] The addition process M22 is a process for calculating a target steering torque Th* by adding the compensation amount Thr to the base target torque Thb*. The target reaction force calculation process M23 is a process for calculating a target reaction force Ts* corresponding to the steering reaction force to be applied to the steering wheel 22 using the steering torque Th and the target steering torque Th* as inputs. The target reaction force Ts* is actually a torque command value for the reaction force motor 30. The steering reaction force is obtained by multiplying the target reaction force Ts* by a coefficient corresponding to the reduction ratio of the reduction mechanism 26. The target reaction force calculation process M23 includes a process for calculating the target reaction force Ts* so that the steering torque Th becomes the target steering torque Th*.

[0041] The target reaction force calculation process M23 can be realized, for example, by torque feedback processing of the steering torque Th using PID control. The torque feedback processing includes multiplying a torque deviation ΔTh, which is a value obtained by subtracting the target steering torque Th* from the steering torque Th, by a torque proportional gain. The torque feedback processing includes adding a value obtained by multiplying the torque deviation ΔTh by a torque integral gain. The torque feedback processing includes multiplying a first-order time derivative value of the torque deviation ΔTh by a torque differential gain. The feedback gains used in the torque feedback processing, which are made up of the torque proportional gain, torque integral gain, and torque differential gain, are examples of control parameters for adjusting the behavior of the vehicle VC. These feedback gains are information adjusted, for example, by a vehicle manufacturer or the like during the design or manufacturing process depending on the type and specifications of the vehicle VC.

[0042] The reaction force operation process M24 receives the target reaction force Ts*, currents iu1, iv1, iw1, and rotation angle θa as inputs and outputs an operation signal MSs for the reaction force inverter 32. The reaction force operation process M24 includes a process of calculating a d-axis current command value Is* as a target current based on the target reaction force Ts*. The reaction force operation process M24 also includes a process of calculating a d-axis current Is as an actual current based on the currents iu1, iv1, iw1, and rotation angle θa. The reaction force operation process M24 then includes a process of calculating an operation signal MSs to control the drive of the reaction force inverter 32 so that the d-axis current Is becomes the current command value Is*. In other words, the reaction force operation process M24 is a feedback process that calculates the operation signal MSs by feedback controlling the d-axis current Is to become the current command value Is*. In this embodiment, the current Is on the dq axes is an example of a state variable, the current command value Is* is an example of a target control value, and the operation signal MSs is an example of a feedback control value.

[0043] The reaction force operation process M24 can be realized, for example, by current feedback processing of the d- and q-axis current Is using PID control. The current feedback processing includes multiplying a current deviation ΔIs, which is a value obtained by subtracting the d- and q-axis current Is from the current command value Is*, by a current proportional gain. The current feedback processing includes adding a value obtained by multiplying the current deviation ΔIs by a current integral gain. The current feedback processing includes multiplying a first-order time derivative of the current deviation ΔIs by a current differential gain. The feedback gains used in the current feedback processing, which are made up of the current proportional gain, current integral gain, and current differential gain, are examples of control parameters for adjusting the behavior of the steering actuator Act, i.e., the reaction force actuator Ar. This feedback gain is information adjusted by a supplier manufacturer or the like during the design or manufacturing process, for example, with a view to ensuring the responsiveness and control stability of the steering actuator Act and the reaction force actuator Ar. In particular, in the case of the vehicle steering system STG, the reaction force operation processing M24 requires highly responsive processing, and this is similar to the steering operation processing M18 described above in that it is necessary to ensure control stability while ensuring high responsiveness.

[0044] <Assignment of processes for controlling the vehicle steering system> As shown in Figure 3, each process executed to control the vehicle steering system STG is assigned to be executed by either the integrated control device 10 or the steering control device 20.

[0045] More specifically, steering angle calculation process M10 and target pinion angle calculation process M14 are processes assigned to be executed by integrated control device 10. Each of processes M10, M14 is a steering servo target value calculation process that calculates a steering torque command value Tt*, i.e., a target pinion angle θp* for calculating operation signal MSt, which is related to the drive of steering motor 70. In the present embodiment, the steering servo target value calculation process is an example of a first control process. In other words, target pinion angle θp* is an example of a steering control value.

[0046] The axial force calculation process M19, the base target torque calculation process M20, the compensation amount calculation process M21, the addition process M22, and the target reaction force calculation process M23 are processes assigned to be executed by the integrated control device 10. Each of the processes M19, M20, M21, M22, and M23 is a reaction force servo target value calculation process that calculates a target reaction force Ts*, which is a control value for calculating an operation signal MSs related to the drive of the reaction force motor 30. In this embodiment, the reaction force servo target value calculation process is an example of a first control process. In other words, the target reaction force Ts* is an example of a steering control value.

[0047] Pinion angle calculation process M12, pinion angle feedback process M16, and steering operation process M18 are processes assigned to be executed by steering control device 20. Each of processes M12, M16, and M18 is a steering servo control process that controls the drive of steering motor 70, i.e., the steering actuator At, so as to reflect target pinion angle θp*. In the present embodiment, the steering servo control process is an example of a second control process.

[0048] The reaction force operation process M24 is a process assigned to be executed by the steering control device 20. The reaction force operation process M24 is a reaction force servo control process that controls the drive of the reaction force motor 30, i.e., the reaction force actuator Ar, so as to reflect the target reaction force Ts*. In this embodiment, the reaction force servo control process is an example of a second control process.

[0049] <Regarding the Integrated Control Program and the Steering Control Program> As shown in FIG. 4, in the integrated control device 10, the integrated control program 104a of the control unit 102 includes a steering control process 10stg. In addition, the integrated control program 104a includes not only a first function control process 10a and a second function control process 10b, but also control processes for controlling other vehicle systems CS. The steering control process 10stg includes a steering servo target value calculation process (M10, M14) and a reaction force servo target value calculation process (M19, M20, M21, M22, M23) among the processes executed to control the vehicle steering system STG. In other words, the integrated control device 10 can allocate only a portion of its overall resources to the steering servo target value calculation process and the reaction force servo target value calculation process.

[0050] In the steering control device 20, the steering control program 94a includes steering servo control processing (M12, M16, M18) and reaction force servo control processing (M24) among the processes executed to control the vehicle steering system STG. In other words, the steering control device 20 can allocate all of its resources to the steering servo control processing and reaction force servo control processing.

[0051] As a result, the integrated control device 10 executes a steering servo target value calculation process based on the integrated control program 104a to calculate a target pinion angle θp* used for controlling the vehicle steering system STG. The integrated control device 10 also executes a reaction force servo target value calculation process based on the integrated control program 104a to calculate a target reaction force Ts* used for controlling the vehicle steering system STG. When executing these processes, the integrated control device 10 references the steering state variable SVstg and the system state variable SVcs transmitted by the in-vehicle network GC. The integrated control device 10 outputs the calculated target pinion angle θp* and target reaction force Ts* to the in-vehicle network GC.

[0052] In response to this, steering control device 20 inputs target pinion angle θp* and target reaction force Ts* transmitted via in-vehicle network GC. When steering control device 20 inputs target pinion angle θp*, it executes steering servo control processing based on steering control program 94a to calculate operation signal MSt. That is, steering control device 20 controls steering actuator At by controlling the drive of steering motor 70. Also, when steering control device 20 inputs target reaction force Ts*, it executes reaction force servo control processing based on steering control program 94a to calculate operation signal MSs. That is, steering control device 20 controls reaction force actuator Ar by controlling the drive of reaction force motor 30.

[0053] The integrated control device 10 executes the first function control process 10a based on the integrated control program 104a to calculate a first function control value CSa* used to control the first vehicle function system CSa. When executing this process, the integrated control device 10 references the steering state variable SVstg and the system state variable SVcs transmitted via the in-vehicle network GC. The integrated control device 10 outputs the calculated first function control value CSa* to the in-vehicle network GC. The first function control device 14a can control the first function actuator 12a by inputting the first function control value CSa* transmitted via the in-vehicle network GC. In other words, the integrated control device 10 enables the first vehicle function system CSa to cooperate with the other vehicle systems CS. This also applies to the other vehicle systems CS, including the second vehicle function system CSb. The integrated control device 10, for example, executes a second function control process 10b based on the integrated control program 104a to calculate a control value CSb* for the second function used to control the second vehicle function system CSb.

[0054] <Operation of the Present Embodiment> As shown in Figures 3 and 4, the steering servo target value calculation process (M10, M14) and the reaction force servo target value calculation process (M19, M20, M21, M22, M23) are assigned to processes executed by the integrated control device 10. The integrated control device 10 can adjust the behavior of the vehicle VC, for example, by adjusting map data used to map-calculate the steering angle ratio Dr in the target pinion angle calculation process M14. The integrated control device 10 can adjust the behavior of the vehicle VC, for example, by adjusting map data used to map-calculate the base target torque Thb* in the base target torque calculation process M20. The integrated control device 10 can adjust the behavior of the vehicle VC, for example, by adjusting a gain used to calculate the compensation amount Thr in the compensation amount calculation process M21. The integrated control device 10 can adjust the behavior of the vehicle VC, for example, by adjusting a feedback gain used to calculate the target reaction force Ts* in the target reaction force calculation process M23. That is, when adjusting the behavior of the vehicle VC, it is sufficient to adjust the control parameters used in the processes M14, M20, M21, and M23 executed by the integrated control device 10.

[0055] In contrast, the steering servo control processing (M12, M16, M18) and the reaction force servo control processing (M24) are allocated to the processing executed by steering control device 20. In steering control device 20, for example, the behavior of the steering actuator At can be adjusted by adjusting the feedback gain of pinion angle feedback processing M16. In steering control device 20, for example, the behavior of the steering actuator At can be adjusted by adjusting the feedback of steering operation processing M18. In steering control device 20, for example, the behavior of the reaction force actuator Ar can be adjusted by adjusting the feedback gain of reaction force operation processing M24. In other words, when adjusting the behavior of the steering actuator At and the reaction force actuator Ar, it is sufficient to adjust the control parameters used in the respective processing M16, M18, M24 executed by steering control device 20.

[0056] This makes it possible to separately carry out the work related to adjusting the behavior of the vehicle VC and the work related to adjusting the behavior of the steering actuator At and the reaction force actuator Ar. <Effects of this embodiment> (1-1) For example, a vehicle manufacturer or the like can independently adjust the behavior of the vehicle VC during the design or manufacturing process according to the type and specifications of the vehicle VC. In contrast, a supplier manufacturer or the like can independently adjust the behavior of the vehicle steering system STG during the design or manufacturing process, with the aim of ensuring the responsiveness and control stability of the steering actuator At and the reaction force actuator Ar. This facilitates the work related to adjusting the behavior of the vehicle VC and the vehicle steering system STG. This is effective in improving the degree of freedom in the design of the vehicle control system CCS.

[0057] (1-2) Adjustment of the control parameters used in the base target torque calculation process M20 executed by the integrated control device 10 enables easy optimization of the output characteristics of the steering reaction force, which is effective for, for example, vehicle manufacturers to realize the desired behavior of the vehicle VC.

[0058] (1-3) Adjustment of the control parameters used in the compensation amount calculation process M21 executed by the integrated control device 10 enables more detailed optimization of the output characteristics of the steering reaction force, which is effective in diversifying the behavior of the vehicle VC that can be realized.

[0059] (1-4) Adjustment of the control parameters used in the pinion angle feedback processing M16 and the steering operation processing M18 executed by the steering control device 20 enables optimization of the responsiveness of the steering actuator At. Also, adjustment of the control parameters used in the reaction force operation processing M24 executed by the steering control device 20 enables optimization of the responsiveness of the reaction force actuator Ar. This is effective in enabling, for example, a supplier manufacturer or the like to realize the desired behavior of the vehicle steering system STG.

[0060] (1-5) Of the processes executed to control the vehicle steering system STG, processes specialized for achieving cooperation with other vehicle systems CS can be assigned to and executed by the integrated control device 10. In other words, resources can be allocated to the integrated control device 10 for cooperation with other vehicle systems CS.

[0061] In response to this, steering control device 20 can be assigned and made to execute processes specialized for controlling the steering actuator At and the reaction force actuator Ar, among the processes executed to control vehicle steering system STG. In other words, resources can be allocated to steering control device 20 to improve the responsiveness of the steering actuator At and the reaction force actuator Ar.

[0062] In this embodiment, the allocation of the processing related to cooperation with other vehicle systems CS and the processing related to improving the responsiveness of the steering actuator At and the reaction force actuator Ar to the integrated control device 10 and the steering control device 20 is devised. This allows the steering control device 20 to easily execute highly responsive control as the control of the vehicle steering system STG. Therefore, it is possible to preferably achieve both high performance of the vehicle steering system STG and improved compatibility with other vehicle systems CS.

[0063] (1-6) The steering servo control processing (M12, M16, M18) executed by steering control device 20 basically realizes control that references information obtained from steering actuator At, other than target pinion angle θp*. The information obtained from steering actuator At is state variables such as rotation angle θb and currents iu2, iv2, iw2. As a result, the time required to obtain necessary information in the steering servo control processing is shorter than when information is obtained from, for example, another vehicle system CS. Therefore, steering control device 20 can preferably execute highly responsive control as control of steering actuator At. The effects described here also apply to reaction force servo control processing (M24) executed by steering control device 20.

[0064] (1-7) Control that can also respond to high response is generally required for the drive control of reaction force motor 30 and steering motor 70 that constitute vehicle steering system STG. In response to this, steering control device 20 can suitably execute high response control as the control of reaction force actuator Ar and steering actuator At, and can therefore suitably meet the above demand.

[0065] (1-8) The steering servo control process and the reaction force servo control process each include current feedback processing (M18, M24). The steering servo control process further includes angle feedback processing (M16). In other words, the steering servo control process and the reaction force servo control process include feedback processing, and this feedback processing is assigned to be executed by the steering control device 20. This is effective in achieving the high-response control required for the steering servo control process and the reaction force servo control process.

[0066] (1-9) The control period of the steering control device 20 is set to be shorter than the control period of the integrated control device 10. In addition, the period at which the in-vehicle network GC communicates is set to be shorter than the control period of the integrated control device 10 and longer than the control period of the steering control device 20. This is effective in easily achieving high-response control for controlling the drive of the reaction force actuator Ar and the turning actuator At.

[0067] Second Embodiment The second embodiment will be described below with reference to the drawings, focusing on the differences from the first embodiment. For ease of explanation, the same components as those in the first embodiment will be assigned the same reference numerals as those in the first embodiment, and the description thereof will be omitted.

[0068] As indicated by the two-dot chain line in Figure 2, the vehicle steering system STG of this embodiment includes a steering device in which the steering wheel 22 and the steered wheels 54 are mechanically connected. In other words, the end of the steering shaft 24 opposite to the end to which the steering wheel 22 is connected is mechanically connected to the end of the pinion shaft 62 opposite to the end to which the steered shaft 50 is connected. For example, the steering actuator Act does not include the reaction force actuator Ar and is composed only of the steering actuator At. In other words, the steering actuator Act is an actuator for applying an assist force to the steering wheel 22.

[0069] <Processing for Controlling the Vehicle Steering System> FIG. 5 shows part of the processing executed to control the vehicle steering system STG of this embodiment.

[0070] The base target torque calculation process M30 is similar to the base target torque calculation process M20 in the first embodiment, except that an input torque Tin is input instead of an axial force Taf. The compensation amount calculation process M31 is similar to the compensation amount calculation process M21 in the first embodiment, except that a target pinion angle θp* is input instead of a steering angle θh. The addition process M32 is similar to the addition process M22 in the first embodiment. The target assist force calculation process M33 is similar to the target reaction force calculation process M23 in the first embodiment, except that a target assist force Ta* is output instead of a target reaction force Ts*.

[0071] More specifically, the assist force calculation process M34 includes a process of calculating input torque Tin using target assist force Ta* as an input. Here, input torque Tin is the motor torque of steering motor 70 applied to steering shaft 24. Since input torque Tin is an amount proportional to the lateral force acting on steered wheels 54, the lateral force can be determined from input torque Tin.

[0072] The base target torque calculation process M30 is a process for calculating a base target torque Thb*, which is a base value of the target steering torque Th* that the driver should input to the steering shaft 24 via the steering wheel 22, based on the input torque Tin.

[0073] The target assist force calculation process M33 is a process that uses the steering torque Th and the target steering torque Th* as inputs to calculate a target assist force Ta* that corresponds to the assist force to be applied to the steering shaft 24. The target assist force calculation process M33 includes a process that calculates the target assist force Ta* so that the steering torque Th becomes the target steering torque Th*.

[0074] The target pinion angle calculation process M36 is a process for calculating a target pinion angle θp* using the target assist force Ta* and the vehicle speed V as inputs. The target pinion angle calculation process M36 includes a process for calculating the target pinion angle θp* from the input torque Tin based on a reference model. The reference model is a mathematical expression of the relationship between the ideal pinion angle θp and the input torque Tin, assuming a steering device in which the steering wheel 22 and the steered wheels 54 are mechanically coupled. For example, the reference model includes a viscosity term related to a viscosity coefficient that models the friction of the steering device. The reference model also includes an inertia term related to an inertia coefficient that models the inertia of the steering device. The reference model also includes a spring term related to a spring coefficient that models the specifications of the suspension, wheel alignment, and the like of the vehicle in which the steering device is installed, as springs.

[0075] The target pinion angle calculation process M36 can be realized, for example, by calculating the viscosity term, the inertia term, and the spring term using map data stored in advance in the storage device 104. This map data has the input torque Tin and the vehicle speed V as input variables and the viscosity term, the inertia term, and the spring term as output variables. The map data for calculating the viscosity term, the inertia term, and the spring term using maps is an example of a control parameter for adjusting the behavior of the vehicle VC. This map data is information adjusted by a vehicle manufacturer or the like during the design or manufacturing process depending on the type and specifications of the vehicle VC, for example.

[0076] Pinion angle calculation processing M38 is processing similar to pinion angle calculation processing M12 in the first embodiment. Pinion angle feedback processing M40 is processing similar to pinion angle feedback processing M16 in the first embodiment except that the target pinion angle θp* calculated in target pinion angle calculation processing M36 is input instead of the target pinion angle calculated in target pinion angle calculation processing M14. Steering operation processing M42 is processing similar to steering operation processing M18 in the first embodiment.

[0077] <Assignment of processes for controlling the vehicle steering system> As shown in Figure 5, each process executed to control the vehicle steering system STG of this embodiment is assigned to be executed by either the integrated control device 10 or the steering control device 20.

[0078] More specifically, base target torque calculation processing M30, compensation amount calculation processing M31, addition processing M32, target assist force calculation processing M33, assist force calculation processing M34, and target pinion angle calculation processing M36 are processing assigned to be executed by integrated control device 10. Each of processing M30, M31, M32, M33, M34, and M36 is steering servo target value calculation processing that calculates target pinion angle θp*.

[0079] Pinion angle calculation processing M38, pinion angle feedback processing M40, and steering operation processing M42 are processing assigned to be executed by steering control device 20. Each of processing M38, M40, and M42 is a steering servo control processing for controlling the drive of steering motor 70, i.e., the steering actuator At.

[0080] According to the second embodiment described above, effects similar to those of the first embodiment can be obtained. <Other Embodiments> Note that the above-described embodiments can be modified and implemented as follows. The above-described embodiments and the following other embodiments can be implemented in combination with each other within the scope of technical compatibility.

[0081] In the first embodiment, the target reaction force Ts* may be calculated based on the steering torque Th and the vehicle speed V. For example, the greater the absolute value of the steering torque Th or the slower the vehicle speed V, the greater the absolute value of the calculated target reaction force Ts*. In other embodiments described herein, the reaction force servo control process executed by the steering control device 20 may include a phase compensation process for adjusting the response delay of the operation of the steering wheel 22 in response to changes in the steering torque Th. This phase compensation process can be realized, for example, by performing a filter process so as to advance the phase of the target reaction force Ts*. A filter constant such as a cutoff frequency of the filter process is an example of a control parameter for adjusting the behavior of the reaction force actuator Ar. This filter constant is information adjusted, for example, by a supplier manufacturer or the like during the design or manufacturing process in order to ensure the responsiveness and control stability of the steering actuator Act. In other words, when adjusting the behavior of the reaction force actuator Ar, it is sufficient to adjust, for example, the control parameters used in the phase lead compensation process executed by the steering control device 20. The phase compensation process may also include a process of delaying the phase of the steering torque Th in order to adjust the frequency characteristics of the phase difference that occurs with respect to the steering torque Th in response to the torsion of the steering shaft 24. This can be similarly applied to the second embodiment in which the vehicle steering system STG includes a steering device in which the steering wheel 22 and the steered wheels 54 are mechanically coupled. For example, this can be achieved by applying a filter process so as to advance the phase of the target assist force Ta*.

[0082] In the first embodiment, the reaction force servo control process executed by the steering control device 20 may include angle feedback processing, similar to the steering servo control process. This angle feedback process may be, for example, a process for calculating a reaction force manipulation amount in order to control the steering angle θh to the target steering angle θh*. The target steering angle θh* is calculated, for example, using the above-mentioned reference model. In the other embodiments described herein, the angle feedback process may be realized, for example, by angle feedback processing of the steering angle θh using PID control, similar to the pinion angle feedback process M16. In other words, in the steering control device 20, the behavior of the steering actuator Act, i.e., the reaction force actuator Ar, can be adjusted, for example, by adjusting the feedback gain of the angle feedback processing of the steering angle θh.

[0083] In the first embodiment, the steering angle calculation process M10 may be included in the reaction force servo control process or the turning servo process executed by the steering control device 20. In this case, the steering control device 20 may output the steering angle θh calculated in the steering angle calculation process M10 to the in-vehicle network GC. In other words, the steering state variable SVstg includes the steering angle θh calculated by the steering control device 20.

[0084] In the first embodiment, the processing executed to control the vehicle steering system STG only needs to include at least the base target torque calculation processing M20. In other words, the compensation amount calculation processing M21 may be omitted. The other embodiments described herein can be similarly applied to the second embodiment.

[0085] In the first embodiment, the compensation amount calculation process M21 compensates for the hysteresis characteristic of the target steering torque Th*, but it may also be a process for compensating for other characteristics. The other embodiments described herein can be similarly applied to the second embodiment.

[0086] In the first embodiment, the processing executed to control the vehicle steering system STG may include a process of calculating and outputting a target compensation amount that compensates for the target reaction force Ts*. The target compensation amount may, for example, be a process for compensating for the return movement of the steering wheel 22 to the steering neutral position. The target compensation amount may, for example, be a process for compensating to reduce micro-vibrations occurring in the steering wheel 22. The target compensation amount may, for example, be a process for compensating to suppress a feeling of sticking at the start of steering the steering wheel 22 or a feeling of drift at the end of steering. The target compensation amount may be variably set in accordance with the system state variable SVcs. The gain, etc. used to calculate the target compensation amount is an example of a control parameter for adjusting the behavior of the vehicle VC. The other embodiments described herein can be similarly applied to the second embodiment. For example, it is sufficient to include a process for calculating and outputting a target compensation amount that compensates for the target assist force Ta*.

[0087] In the first embodiment, the pinion angle feedback processing M16 may include processing for variably setting a feedback gain in accordance with the vehicle speed V. In this case, the feedback gain may be calculated by the integrated control device 10 in accordance with the vehicle speed V and output to the in-vehicle network GC. In other words, the steering control device 20 may variably set the feedback gain of the pinion angle feedback processing M16 by inputting the feedback gain transmitted by the in-vehicle network GC. This can be similarly applied to the feedback gains of the turning operation processing M18 and the reaction force operation processing M24. The other embodiments described herein can be similarly applied to the pinion angle feedback processing M40 of the second embodiment. This can be similarly applied to the turning operation processing M42.

[0088] In the first embodiment, the target reaction force calculation process M23 may be, for example, torque feedback processing using PI control or PD control. The target reaction force Ts* may also be calculated using open-loop control. The open-loop gain for this open-loop control is an example of a control parameter for adjusting the behavior of the vehicle VC. The other embodiments described herein can also be similarly applied to the target assist force calculation process M33 of the second embodiment.

[0089] In the first embodiment, the pinion angle feedback process M16 may be angle feedback process using, for example, PI control or PD control. The target pinion angle θp* may also be calculated using open-loop control. An open-loop gain for this open-loop control is an example of a control parameter for adjusting the behavior of the steering actuator Act, i.e., the turning actuator At. The other embodiments described herein can also be similarly applied to the pinion angle feedback process M40 of the second embodiment.

[0090] In the first embodiment, the steering operation process M18 may be, for example, current feedback process using PI control or PD control. This may also be applied to the reaction force operation process M24. The other embodiments described herein may also be applied to the steering operation process M42 of the second embodiment.

[0091] The second embodiment may be similarly applied to a case where the steering actuator Act is configured with only the reaction force actuator Ar, without the turning actuator At. In this case, the steering servo control process executed by the steering control device 20 may be changed to a steering servo control process that controls the steering angle θh to the target steering angle θh*. For example, the steering servo control process may include angle feedback processing, similar to the turning servo control process. The target steering angle θh* is calculated, for example, using the reference model described above.

[0092] In the second embodiment, the compensation amount calculation process M31 may input the pinion angle θp instead of the target pinion angle θp*. In the other embodiments described herein, the steering state variable SVstg includes the pinion angle θp.

[0093] In each of the above embodiments, the software processing device employed in the control unit 102 may have a control cycle that is shorter than or approximately the same as the cycle of communication of the in-vehicle network GC. In other words, the control cycle of the control unit 92 may be longer than or approximately the same as the control cycle of the control unit 102.

[0094] In the first embodiment, the torque sensor 80 and the rotation angle sensor 82 may be directly connected to the in-vehicle network GC, or may be directly connected to the integrated control device 10. In the second embodiment, the torque sensor 80 may be directly connected to the in-vehicle network GC, or may be directly connected to the integrated control device 10. In other words, the method of acquiring information required for processing by the integrated control device 10 is not limited to the method in each of the above embodiments.

[0095] In the first embodiment, the control method for each of the motors 30, 70 is not limited to current feedback processing. For example, if DC motors are used as each of the motors 30, 70 and the drive circuits are H-bridge circuits, it is sufficient to simply control the current flowing through each of the motors 30, 70. The other embodiments described herein can also be similarly applied to the steering motor 70 of the second embodiment.

[0096] In the first embodiment, the displacement amount of the steering wheel 22 is not limited to an amount calculated based on an integration process of the rotation angle θa. For example, it may be a value detected by a steering angle sensor that directly detects the rotation angle of the steering shaft 24. Note that the steering angle sensor may be provided, for example, on the steering shaft 24 between the steering wheel 22 and the torque sensor 80.

[0097] In the first embodiment, the base target torque calculation process M20 is not limited to a process that uses the vehicle speed V as an input in addition to the axial force Taf. It is not essential to calculate the base target torque Thb* using the axial force Taf as an input. For example, the base target torque Thb* may be calculated using the steering torque Th and the vehicle speed V as inputs. The other embodiments described herein can be similarly applied to the base target torque calculation process M30 of the second embodiment. For example, the base target torque Thb* may be calculated using the sum of the input torque Tin and the steering torque Th, and the vehicle speed V as inputs.

[0098] In the first embodiment, instead of pinion angle feedback process M16, a process may be used that controls the detected value of the movement amount of steered shaft 50 to a target value. In this case, in the above embodiment, the control amount and the like related to pinion angle θp are replaced with a control amount and the like related to the movement amount of steered shaft 50. The other embodiments described here can be similarly applied to pinion angle feedback process M40 of the second embodiment.

[0099] In each of the above embodiments, the operating member operated by the driver to steer the vehicle VC is not limited to the steering wheel 22. For example, it may be a joystick.

[0100] In the first embodiment, it is not essential to provide the speed reducing mechanism 26. In each of the above embodiments, the integrated control device 10 is not limited to a device that includes a control unit 102 and a storage device 104 and executes software processing. The integrated control device 10 may also include a dedicated hardware circuit, such as an ASIC, that executes at least part of the processing executed in the above embodiments. That is, the integrated control device 10 may include a processing circuit having any of the following configurations (a) to (c):

[0101] (a) A processing circuit comprising a processing device that executes all of the above processes according to a program and a program storage device such as a memory device that stores the program. (b) A processing circuit comprising a processing device and program storage device that executes part of the above processes according to a program, and a dedicated hardware circuit that executes the remaining processes.

[0102] (c) A processing circuit including a dedicated hardware circuit that executes all of the above processes. Here, there may be a plurality of software execution devices including a processing device and a program storage device. Also, there may be a plurality of dedicated hardware circuits. The other embodiments described herein can be similarly applied to the steering control device 20.

[0103] In each of the above embodiments, the steering actuator At may be, for example, one in which the steering motor 70 is disposed coaxially with the steering shaft 50. Alternatively, for example, one that is connected to the steering shaft 50 via a belt-type reducer using a ball screw mechanism may be employed.

[0104] In the first embodiment, the vehicle steering system STG may include a steering device in which the steering wheel 22 and the steered wheels 54 are mechanically separably connected by a clutch.

[0105] In each of the above embodiments, the steering actuator At is not limited to a configuration in which the right steered wheels 54 and the left steered wheels 54 are linked together. In other words, the steering actuator At may be configured to be able to control the right steered wheels 54 and the left steered wheels 54 independently.

Claims

1. 1. A vehicle control system configured to control a plurality of vehicle systems including a vehicle steering system for steering a vehicle, the vehicle control system comprising: an integrated control device that controls the plurality of vehicle systems in an integrated manner; a steering control device for controlling the vehicle steering system; an in-vehicle network that communicatively connects the integrated control device and the vehicle steering system to each other; the process for controlling the vehicle steering system includes a first control process and a second control process, the integrated control device includes an integrated control program and is configured to execute the first control process in accordance with the integrated control program; the steering control device includes a steering control program and is configured to execute the second control process in accordance with the steering control program, the first control process is a process of calculating a steering control value used by the steering control device to control the vehicle steering system, the first control process being a process of using a control parameter set in association with a behavior of the vehicle, the second control process is a process of controlling the vehicle steering system so as to reflect the steering control value calculated by the integrated control device, and is a process of using a control parameter that is set in association with a behavior of the vehicle steering system, The first control process is a vehicle control system that calculates the steering control value based on information obtained from the vehicle steering system via the in-vehicle network.

2. the vehicle steering system is a steering actuator using a motor as a drive source, the control parameter used in the first control process is a parameter that defines a relationship between information obtained from the vehicle and the steering control value, 2. The vehicle control system according to claim 1, wherein the control parameter used in the second control process is a parameter related to the responsiveness of the steering actuator.

3. the steering control value includes a base control value and a compensation control value that compensates for the base control value, 3. The vehicle control system according to claim 2, wherein the control parameters used in the first control process include basic parameters that define basic characteristics that are relationships between the basic control values ​​and information obtained from the vehicle.

4. 4. The vehicle control system according to claim 3, wherein the control parameters used in the first control process are compensation parameters that define a relationship between the compensation control value and information obtained from the vehicle, and include a compensation parameter that compensates for the basic characteristic.

5. the second control process includes a process of controlling driving of a drive circuit of the motor, The process of controlling the driving of the motor driving circuit includes: a feedback process for calculating a feedback control value by feedback control so that a state variable that changes as a result of driving the steering actuator becomes a target control value obtained based on the steering control value; and controlling the driving of the driving circuit based on the feedback control value, 5. The vehicle control system according to claim 2, wherein the control parameters used in the second control process include a feedback gain of the feedback process.

6. An integrated control program applied to a vehicle control system including an integrated control device that integrally controls a plurality of vehicle systems including a vehicle steering system for steering a vehicle, and a steering control device that controls the vehicle steering system, wherein the integrated control device and the vehicle steering system are connected to each other so as to be able to communicate with each other via an in-vehicle network, the process for controlling the vehicle steering system includes a first control process executed by the integrated control device and a second control process executed by the steering control device, the integrated control program is configured to cause the integrated control device to execute the first control process; the first control process is a process of calculating a steering control value used to control the vehicle steering system in the second control process executed in accordance with a steering control program included in the steering control device, and is a process of using a control parameter set in association with a behavior of the vehicle; The first control process is an integrated control program that calculates the steering control value based on information obtained from the vehicle steering system via the in-vehicle network.

7. A vehicle steering system for steering a vehicle, which is applied to a vehicle control system including an integrated control device that controls a plurality of vehicle systems in an integrated manner, a steering control device for controlling the vehicle steering system, the integrated control device and the vehicle steering system are communicatively connected to each other via an in-vehicle network, the process for controlling the vehicle steering system includes a first control process executed by the integrated control device and a second control process executed by the steering control device, the integrated control device includes an integrated control program and is configured to execute the first control process in accordance with the integrated control program; the steering control device includes a steering control program and is configured to execute the second control process in accordance with the steering control program, the first control process is a process of calculating a steering control value used by the steering control device to control the vehicle steering system, the first control process being a process of using a control parameter set in association with a behavior of the vehicle, the second control process is a process of controlling the vehicle steering system so as to reflect the steering control value calculated by the integrated control device, and is a process of using a control parameter that is set in association with a behavior of the vehicle steering system, The first control process is a vehicle steering system that calculates the steering control value based on information obtained from the vehicle steering system via the in-vehicle network.