Vehicle motion control device and motion control program

Abstract

To enable a vehicle to turn even when a portion of a plurality of actuators cannot be activated normally.SOLUTION: A move control device 130 comprises: a demand value acquisition section M11 which acquires a momentum demand value MR; a limit value setting section M17 which sets a plurality of momentum limit values ML3, ML6 and ML7; a first command section M19 which sends a first momentum command value on the basis of the momentum demand value MR and the first momentum limit value ML3 to a front wheel steering control section 35; a second command section M21 which sends a second momentum command value on the basis of a first residual demand value MR1 and the second momentum limit value ML6 to a rear wheel steering control section 65; and a third command section M23 which sends a command corresponding to a third momentum command value on the basis of a second residual demand value MR2 and the third momentum limit value ML7 to a drive control section 75 and a brake control section 85.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a vehicle motion control device and a motion control program. [Background technology]

[0002] Patent Document 1 describes that when instructions are input from microcomputers in multiple command units to a control unit of an electric power steering device, the control unit operates the actuator of the electric power steering device in accordance with the instructions input from the microcomputers. The control unit of the electric power steering device determines whether an abnormality has occurred in the microcomputer of the command unit. The control unit then operates the actuator based on an instruction from a microcomputer that has determined that no abnormality has occurred. On the other hand, even if the control unit receives an instruction from a microcomputer that has determined that an abnormality has occurred, it does not operate the actuator in accordance with the instruction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4379793 Summary of the Invention [Problem to be solved by the invention]

[0004] A vehicle is equipped with a plurality of actuators capable of generating a yaw moment on the vehicle, and in such a vehicle, some of the actuators may become unable to operate normally. [Means for solving the problem]

[0005] A vehicle motion control device for solving the above problem is applied to a vehicle including a plurality of wheels, a steering wheel, a front-wheel steering shaft that operates in conjunction with the rotation of the steering wheel of the steering wheel, a front-wheel steering actuator that adjusts the steering angle of the front wheels of the plurality of wheels, a rear-wheel steering actuator that adjusts the steering angle of the rear wheels of the plurality of wheels, and a longitudinal force adjustment actuator that adjusts the longitudinal force of the plurality of wheels. This motion control device includes a required value acquisition unit that acquires a momentum required value that is a required value of the momentum of the vehicle for turning the vehicle, a limit value setting unit that sets a first momentum limit value in accordance with the operable range of the front-wheel steering actuator, a second momentum limit value in accordance with the operable range of the rear-wheel steering actuator, and a third momentum limit value in accordance with the operable range of the longitudinal force adjustment actuator, and a limit value setting unit that derives a value corresponding to the smaller of the momentum required value and the first momentum limit value as a first momentum command value, and controls the operation of the front-wheel steering actuator based on the first momentum command value. a second command unit that derives a value corresponding to the smaller of a first residual demand value, which is a value obtained by subtracting the first momentum command value from the momentum demand value, or the second momentum limit value, as a second momentum command value, and commands operation of the rear wheel steering actuator based on the second momentum command value; and a third command unit that derives a value corresponding to the smaller of a second residual demand value, which is a value obtained by subtracting the second momentum command value from the first residual demand value, or the third momentum limit value, as a third momentum command value, and commands operation of the longitudinal force adjustment actuator based on the third momentum command value.

[0006] In the motion control device described above, the momentum limit value can be set according to the operable range of the corresponding actuator at that time. Therefore, the motion control device can set the first momentum command value to a value that can be realized by operating the front wheel steering actuator. The motion control device can set the second momentum command value to a value that can be realized by operating the rear wheel steering actuator. The motion control device can set the third momentum command value to a value that can be realized by operating the longitudinal force adjustment actuator. Then, the motion control device can cause the vehicle to turn according to the momentum request value by instructing the control unit of the actuator to operate the actuator based on these command values.

[0007] Therefore, even if some of the actuators cannot be operated normally, the vehicle can still be turned. A motion control program for solving the above problems is a program executed by an execution device of a vehicle, the vehicle having a plurality of wheels, a steering wheel, a front-wheel steering shaft that operates in conjunction with the rotation of a handle of the steering wheel, a front-wheel steering actuator that adjusts the steering angle of front wheels among the plurality of wheels, a rear-wheel steering actuator that adjusts the steering angle of rear wheels among the plurality of wheels, and a longitudinal force adjustment actuator that adjusts the longitudinal force of the plurality of wheels. The motion control program includes a required value derivation process for deriving a momentum required value, which is a required value of the momentum of the vehicle for turning the vehicle; a limit value setting process for setting a first momentum limit value in accordance with an operable range of the front wheel steering actuator, a second momentum limit value in accordance with an operable range of the rear wheel steering actuator, and a third momentum limit value in accordance with an operable range of the longitudinal force adjustment actuator; a first command value derivation process for deriving a value corresponding to the smaller of the momentum required value and the first momentum limit value as a first momentum command value; and a third command value derivation process for deriving a value obtained by subtracting the first momentum command value from the momentum required value. The control device causes the execution device to execute a second command value derivation process that derives, as a second momentum command value, a value corresponding to the smaller of a first residual requirement value and the second momentum limit value; a third command value process that derives, as a third momentum command value, a value corresponding to the smaller of the second residual requirement value, which is a value obtained by subtracting the second momentum command value from the first residual requirement value, and the third momentum limit value; and an instruction process that instructs operation of the front wheel steering actuator based on the first momentum command value, instructs operation of the rear wheel steering actuator based on the second momentum command value, and instructs operation of the longitudinal force adjustment actuator based on the third momentum command value.

[0008] By having the execution device execute a plurality of processes of the motion control program, it is possible to obtain the same functions and effects as the motion control device. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a vehicle to which a motion control device according to an embodiment of the present invention is applied. [Figure 2] FIG. 2 is a block diagram showing the control configuration of the vehicle. [Figure 3] FIG. 3 is a block diagram showing the functional configuration of the motion control device. [Figure 4] FIG. 4 is a flowchart showing a processing routine executed by the motion control device. [Figure 5] FIG. 5 is a timing chart for when the vehicle is gently turning. [Figure 6] FIG. 6 is a timing chart for when the vehicle is made to make an emergency turn. [Figure 7] FIG. 7 is a timing chart showing the timing when the vehicle is turned in a state where an abnormality occurs in the front wheel steering actuator. [Figure 8] FIG. 8 is a timing chart showing the timing when the vehicle is turned in a state where the steering angle of the front wheels cannot be adjusted. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of a vehicle motion control device and a motion control program will be described with reference to FIGS. FIG. 1 shows a schematic configuration of a vehicle 10 to which the motion control device of this embodiment is applied.

[0011] <Vehicle> As shown in FIG. 1, a vehicle 10 includes a steering wheel 11, a front wheel steering shaft 12, a rear wheel steering shaft 15, and a plurality of wheels 18F, 18R.

[0012] The steering wheel 11 has a handle 11a that is rotated by operation of the driver of the vehicle 10. The front wheel steering shaft 12 moves linearly in one of two directions along the axis of the front wheel steering shaft 12, depending on the direction of rotation of the handle 11a. A front wheel 18F out of a plurality of wheels 18F, 18R is connected to the front wheel steering shaft 12 via a tie rod 13. When the front wheel steering shaft 12 moves linearly, the front wheel 18F is steered in a direction depending on the direction of movement.

[0013] The rear wheel steering shaft 15 is capable of linear movement in two directions along the axis of the rear wheel steering shaft 15. Of the multiple wheels 18F, 18R, the rear wheel 18R is connected to the rear wheel steering shaft 15 via a tie rod 16. When the rear wheel steering shaft 15 moves linearly, the rear wheel 18R is steered in a direction corresponding to the direction of movement of the rear wheel steering shaft 15.

[0014] As shown in FIGS. 1 and 2, a vehicle 10 includes a front wheel steering device 30, a rotation angle difference adjusting device 40, a handle lock device 50, a rear wheel steering device 60, a drive device 70, and a braking device 80.

[0015] The front wheel steering device 30 has a front wheel steering actuator 31 and a front wheel steering control unit 35 that controls the front wheel steering actuator 31. The front wheel steering control unit 35 has, for example, an electronic control device. The front wheel steering actuator 31 has an electric motor 32 and a front wheel transmission mechanism 33. The drive shaft of the electric motor 32 is connected to the front wheel steering shaft 12 via the front wheel transmission mechanism 33. The front wheel transmission mechanism 33 converts the rotational movement of the drive shaft of the electric motor 32 into linear movement of the front wheel steering shaft 12. Therefore, when the front wheel steering control unit 35 drives the electric motor 32, the front wheel steering shaft 12 moves linearly. In other words, the front wheel steering control unit 35 adjusts the steering angle of the front wheels 18F by operating the front wheel steering actuator 31.

[0016] The rotation angle difference adjustment device 40 has a rotation angle adjustment actuator 41 and a rotation angle difference control unit 45 that controls the rotation angle adjustment actuator 41. The rotation angle difference control unit 45 has, for example, an electronic control device. The rotation angle adjustment actuator 41 has an input shaft 42 that rotates integrally with the handle 11a, and an output shaft 43 that rotates in synchronization with the linear movement of the front wheel steering shaft 12. The rotation angle adjustment actuator 41 operates to adjust the rotation angle difference Δθ, which is the difference between the rotation angle of the input shaft 42 and the rotation angle of the output shaft 43. When the operation of the rotation angle adjustment actuator 41 is stopped, the rotation angle difference Δθ is maintained.

[0017] Pinion teeth 43a are provided on the output shaft 43, and rack teeth 12a that mesh with the pinion teeth 43a are provided on the front wheel steering shaft 12. Therefore, the front wheel steering shaft 12 operates in synchronization with the rotation of the output shaft 43. In other words, when the rotation angle of the input shaft 42 is maintained, the rotation angle difference control section 45 adjusts the steering angle of the front wheels 18F by changing the rotation angle difference Δθ through the operation of the rotation angle adjustment actuator 41.

[0018] The steering wheel lock device 50 has a steering wheel lock mechanism 51 and a lock control unit 55 that controls the steering wheel lock mechanism 51. The lock control unit 55 has, for example, an electronic control device. The steering wheel lock mechanism 51 switches between a non-operated state that allows rotation of the steering wheel 11a and an activated state that disables rotation of the steering wheel 11a. Under the control of the lock control unit 55, the state of the steering wheel lock mechanism 51 switches from one of the non-operated state and the activated state to the other state. When the steering wheel lock mechanism 51 switches to the activated state and the rotation of the steering wheel 11a is restricted, the rotation angle of the input shaft 42 is maintained. Note that the configuration of the steering wheel lock mechanism 51 is publicly known, so a detailed description thereof will be omitted.

[0019] The rear wheel steering device 60 has a rear wheel steering actuator 61 and a rear wheel steering control unit 65 that controls the rear wheel steering actuator 61. The rear wheel steering control unit 65 has, for example, an electronic control device. The rear wheel steering actuator 61 has an electric motor 62 and a rear wheel transmission mechanism 63. The drive shaft of the electric motor 62 is connected to the rear wheel steering shaft 15 via the rear wheel transmission mechanism 63. The rear wheel transmission mechanism 63 converts the rotational movement of the drive shaft of the electric motor 62 into linear movement of the rear wheel steering shaft 15. Therefore, by driving the electric motor 62 with the rear wheel steering control unit 65, the rear wheel steering shaft 15 moves linearly. In other words, the rear wheel steering control unit 65 adjusts the steering angle of the rear wheels 18R by operating the rear wheel steering actuator 61.

[0020] The drive unit 70 has a traction motor 71, which is the power source of the vehicle 10, and a drive control unit 75 that controls the traction motor 71. The drive control unit 75 has, for example, an electronic control device. In the example shown in FIG. 1, the vehicle 10 is a front-wheel drive vehicle. In this case, the drive force output from the traction motor 71 is transmitted to the two front wheels 18F, but the drive force is not transmitted to the two rear wheels 18R.

[0021] The braking device 80 has a braking actuator 81 and a braking control unit 85 that controls the braking actuator 81. The braking control unit 85 has, for example, an electronic control device. The braking actuator 81 is configured so that the braking force applied to the multiple wheels 18F, 18R can be individually adjusted. The configuration of the braking actuator 81 is well known, so a detailed description thereof will be omitted.

[0022] In the following description, the force that adjusts the longitudinal acceleration of the vehicle 10 will be referred to as the "longitudinal force." When the vehicle 10 is accelerating, the longitudinal force will be a positive value. On the other hand, when the vehicle 10 is decelerating, the longitudinal force will be a negative value. The driving force transmitted to the wheels by driving the power source of the vehicle 10 and the braking force applied to the wheels by operation of the brake actuator 81 correspond to the longitudinal force. Therefore, the brake actuator 81 and the travel motor 71 correspond to the "longitudinal force adjustment actuator" that adjusts the longitudinal force of the multiple wheels 18F, 18R.

[0023] <Vehicle detection system> The detection system of the vehicle 10 includes multiple types of sensors that detect vehicle state quantities that indicate the state of the vehicle 10. For example, the vehicle 10 includes such sensors as a vehicle speed sensor 91, a longitudinal acceleration sensor 92, a lateral acceleration sensor 93, a yaw rate sensor 94, an output shaft sensor 95, and a steering angle sensor 96. The vehicle speed sensor 91 detects the vehicle speed V, which is the traveling speed of the vehicle 10. The longitudinal acceleration sensor 92 detects the longitudinal acceleration Gx of the vehicle 10. The lateral acceleration sensor 93 detects the lateral acceleration Gy of the vehicle 10. The yaw rate sensor 94 detects the yaw rate Yr of the vehicle 10. The output shaft sensor 95 detects the rotation angle θu of the output shaft 43. The steering angle sensor 96 detects the steering angle θh of the steering wheel 11a.

[0024] The detection system of the vehicle 10 includes a monitoring device 100 that monitors the periphery of the vehicle 10. The monitoring device 100 has an imaging device 101, a radar 102, and a GPS receiver 103. The imaging device 101 captures images of the periphery of the vehicle 10. The radar 102 detects the distance between the vehicle 10 and other vehicles, the distance from the vehicle 10 to an obstacle, the distance from the vehicle 10 to a pedestrian, etc. The GPS receiver 103 acquires the position of the vehicle 10.

[0025] <Vehicle control system> As shown in FIG. 2, the control system of the vehicle 10 includes a driving assistance device 120 and a motion control device 130 of this embodiment.

[0026] <<Driving assistance devices>> The driving assistance device 120 is an electronic control device. For example, the driving assistance device 120 has a CPU and a memory. In this case, the memory stores a control program executed by the CPU.

[0027] The CPU executes the control program, causing the driving assistance device 120 to function as multiple types of application request units. The application request units are functional units for realizing driving assistance functions that assist the driver in driving the vehicle 10. The application request units transmit request values ​​for realizing the driving assistance functions to the motion control device 130.

[0028] The driving assistance function includes a function to automatically turn the vehicle 10. Examples of driving assistance functions that automatically turn the vehicle 10 include lane keep assist and autonomous driving. When the application request unit requests the vehicle 10 to turn, the request value output by the application request unit includes a request value XR of the state quantity of the vehicle 10 that represents the turning state of the vehicle 10. The state quantity of the vehicle 10 that represents the turning state of the vehicle 10 is, for example, a yaw rate or a lateral acceleration. Such a request value XR of the state quantity is a request value of the yaw rate or a request value of the lateral acceleration. Hereinafter, the request value XR of the state quantity of the vehicle 10 that represents the turning state of the vehicle 10 will be referred to as the "turning state quantity request value XR."

[0029] When the driving assistance device 120 automatically turns the vehicle 10, it derives a momentum requirement value MR based on information input from the monitoring device 100 and transmits the derived momentum requirement value MR to the motion control device 130.

[0030] <<Motion control device>> The motion control device 130 communicates with other control devices in the vehicle, namely the driving assistance device 120, the front wheel steering control unit 35, the rotation angle difference control unit 45, the lock control unit 55, the rear wheel steering control unit 65, the drive control unit 75 and the braking control unit 85.

[0031] The motion control device 130 receives various types of information from the monitoring device 100 and detection signals from the various sensors 91 to 96. The motion control device 130 then instructs the operation of a plurality of actuators based on the turning state quantity requirement value XR transmitted from the driving assistance device 120, the information received from the monitoring device 100, the detection signals from the various sensors 91 to 96, and information obtained from the plurality of control units 35, 45, 55, 65, 75, and 85.

[0032] The motion control device 130 includes a processing circuit 131. The processing circuit 131 has a CPU 132 and a memory 133. A plurality of control programs are stored in the memory 133. One of the plurality of control programs is a motion control program for turning the vehicle 10 by operating actuators related to the turning of the vehicle 10. The CPU 132 executes these control programs. In this respect, the CPU 132 corresponds to an "execution device."

[0033] 3, the CPU 132 executes the control program stored in the memory 133, whereby the CPU 132 functions as a request value acquisition unit M11, an abnormality determination unit M13, an availability derivation unit M15, and a limit value setting unit M17. The CPU 132 also functions as a first command unit M19, a second command unit M21, and a third command unit M23.

[0034] The required value acquisition unit M11 acquires a momentum required value MR, which is a required value of the momentum of the vehicle 10 for turning the vehicle 10, based on the turning state quantity required value XR transmitted by the driving assistance device 120. The momentum of the vehicle 10 for turning the vehicle 10 is, for example, a yaw moment. In this embodiment, when the turning state quantity required value XR is a yaw rate, the required value acquisition unit M11 acquires the momentum required value MR based on the turning state quantity required value XR and a calculated value derived by feedback control using the deviation between the momentum required value MR and the yaw rate Yr as an input. When the turning state quantity required value XR is a lateral acceleration, the required value acquisition unit M11 acquires the momentum required value MR based on the turning state quantity required value XR and a calculated value derived by feedback control using the deviation between the turning state quantity required value XR and the lateral acceleration Gy as an input.

[0035] The abnormality determination unit M13 determines whether or not an abnormality has occurred in each of the above-mentioned multiple actuators. When the abnormality determination unit M13 receives information indicating that an abnormality has occurred in an actuator from the control unit of that actuator, it determines that an abnormality has occurred in that actuator. For example, when the abnormality determination unit M13 receives information indicating that an abnormality has occurred in the front wheel steering actuator 31 from the front wheel steering control unit 35, it determines that an abnormality has occurred in the front wheel steering actuator 31.

[0036] Furthermore, when communication with a control unit is lost, the abnormality determination unit M13 may determine that an abnormality has occurred in the actuator corresponding to that control unit. For example, when communication with the front wheel steering control unit 35 is lost, the abnormality determination unit M13 may determine that an abnormality has occurred in the front wheel steering actuator 31.

[0037] In this way, the abnormality determination unit M13 grasps the state of the front wheel steering actuator 31, the state of the rear wheel steering actuator 61, the state of the rotation angle adjustment actuator 41, the state of the handlebar lock mechanism 51, the state of the travel motor 71, and the state of the brake actuator 81. The "state of the actuator" here means "whether or not an abnormality has occurred in the actuator."

[0038] The availability derivation unit M15 derives the operable range of the front wheel steering actuator 31 as an availability MA3 of the front wheel steering actuator 31. The availability derivation unit M15 derives the operable range of the rotation angle adjustment actuator 41 as an availability MA4 of the rotation angle adjustment actuator 41. The availability derivation unit M15 derives the operable range of the rear wheel steering actuator 61 as an availability MA6 of the rear wheel steering actuator 61. The availability derivation unit M15 derives the operable range of the longitudinal force adjustment actuator as an availability MA7 of the longitudinal force adjustment actuator.

[0039] The availability derivation unit M15 derives the availability of the actuator based on the design value of the upper limit of the actuator's actuation amount, the actuator's current actuation state, and the judgment result of the abnormality judgment unit M13. The actuator's actuation state includes at least the actuation amount of the actuator, the rate of change of the actuation amount, and the acceleration of the change of the actuation amount. The availability derivation unit M15 estimates a predicted actuation amount, which is the actuation amount that can be reached after a predetermined time, based on the actuator's current actuation state. The availability derivation unit M15 then selects the smaller of the estimated predicted actuation amount value and the design value of the upper limit of the actuator's actuation amount. The larger the selected value, the larger the value that the availability derivation unit M15 derives as the availability. However, if it is determined that an abnormality has occurred in the actuator, the availability derivation unit M15 derives 0 (zero) as the availability of the actuator. In this way, the availability derivation unit M15 derives the availability MA3 of the front wheel steering actuator 31, the availability MA4 of the rotation angle adjustment actuator 41, and the availability MA6 of the rear wheel steering actuator 61.

[0040] When deriving the availability MA4 of the rotation angle adjustment actuator 41, the availability derivation unit M15 also takes into consideration whether or not an abnormality has occurred in the handle lock mechanism 51. In other words, if it is determined that an abnormality has occurred in the handle lock mechanism 51, the availability derivation unit M15 derives 0 (zero) as the availability MA4 even if it is determined that no abnormality has occurred in the rotation angle adjustment actuator 41. This is because, if the rotation angle of the input shaft 42 cannot be maintained, the steering angle of the front wheels 18F will not change even if the rotation angle difference Δθ is changed by operating the rotation angle adjustment actuator 41.

[0041] In this embodiment, as described above, the travel motor 71 and the braking actuator 81 correspond to the longitudinal force control actuator. Therefore, the availability derivation unit M15 derives the availability of the travel motor 71 and the availability of the braking actuator 81, and derives the availability MA7 of the longitudinal force control actuator based on these. At this time, if the abnormality determination unit M13 determines that an abnormality has occurred in at least one of the travel motor 71 and the braking actuator 81, the availability derivation unit M15 derives 0 (zero) as the availability MA7.

[0042] The limit value setting unit M17 sets the first momentum limit value ML3 according to the availability MA3 of the front wheel steering actuator 31. The first momentum is the momentum (yaw moment in this embodiment) that can be realized by the operation of the front wheel steering actuator 31. Therefore, the first momentum limit value ML3 is the upper limit of the first momentum at that time that can be estimated from the availability MA3. The limit value setting unit M17 sets a larger value as the first momentum limit value ML3 as the availability MA3 is larger. At this time, it is preferable that the limit value setting unit M17 also take the vehicle speed V into consideration when setting the first momentum limit value ML3.

[0043] The limit value setting unit M17 sets the second momentum limit value ML6 according to the availability MA6 of the rear wheel steering actuator 61. The second momentum is the momentum that can be realized by the operation of the rear wheel steering actuator 61. Therefore, the second momentum limit value ML6 is the upper limit of the second momentum at that time that can be estimated from the availability MA6. The limit value setting unit M17 sets a larger value as the availability MA6 is larger as the limit value setting unit M17 sets the second momentum limit value ML6. At this time, it is preferable that the limit value setting unit M17 also take the vehicle speed V into consideration when setting the second momentum limit value ML6.

[0044] The limit value setting unit M17 sets a third momentum limit value ML7 according to the availability MA7 of the longitudinal force control actuator. The third momentum is the momentum that can be realized by the operation of the longitudinal force control actuator, i.e., the travel motor 71 and the braking actuator 81. Therefore, the third momentum limit value ML7 is the upper limit of the third momentum at that time that can be estimated from the availability MA7. The limit value setting unit M17 sets a larger value as the availability MA7 is larger as the limit value setting unit M17 sets the third momentum limit value ML7. At this time, it is preferable that the limit value setting unit M17 also take into consideration the vehicle speed V when setting the third momentum limit value ML7.

[0045] The limit value setting unit M17 sets a fourth momentum limit value ML4 according to the availability MA4 of the rotation angle adjustment actuator 41. The fourth momentum is the momentum that can be realized by the operation of the rotation angle adjustment actuator 41. Therefore, the fourth momentum limit value ML4 is the upper limit of the fourth momentum that can be estimated from the availability MA4. The limit value setting unit M17 sets a larger value as the availability MA4 is larger as the limit value setting unit M17 sets the fourth momentum limit value ML4. In this case, it is preferable that the limit value setting unit M17 also take into consideration the vehicle speed V when setting the fourth momentum limit value ML4.

[0046] In this embodiment, the limit value setting unit M17 does not set the fourth momentum limit value ML4 if it is determined that no abnormality has occurred in the front wheel steering actuator 31. On the other hand, the limit value setting unit M17 sets the fourth momentum limit value ML4 if it is determined that an abnormality has occurred in the front wheel steering actuator 31. This is because the rotation angle adjustment actuator 41 is not operated if no abnormality has occurred in the front wheel steering actuator 31 and the steering angle of the front wheels 18F can be adjusted by the front wheel steering actuator 31.

[0047] Furthermore, the limit value setting unit M17 sets 0 (zero) as the momentum limit value for the actuator that is determined to have an abnormality. For example, if it is determined that the front wheel steering actuator 31 has an abnormality, the limit value setting unit M17 sets 0 (zero) as the first momentum limit value ML3. For example, if it is determined that the rear wheel steering actuator 61 has an abnormality, the limit value setting unit M17 sets 0 (zero) as the second momentum limit value ML6.

[0048] The first command unit M19 derives a first momentum command value MC3. That is, when it is determined that no abnormality has occurred in the front wheel steering actuator 31, the first command unit M19 derives a value corresponding to the smaller of the momentum required value MR and the first momentum limit value ML3 as the first momentum command value MC3. For example, the first command unit M19 derives the smaller of the momentum required value MR and the first momentum limit value ML3 as the first momentum command value MC3. Then, the first command unit M19 commands the front wheel steering actuator 31 to operate based on the first momentum command value MC3. That is, the first command unit M19 transmits the first momentum command value MC3 to the front wheel steering control unit 35.

[0049] On the other hand, if it is determined that an abnormality has occurred in the front wheel steering actuator 31, the first command unit M19 derives a value corresponding to the smaller of the momentum required value MR and the fourth momentum limit value ML4 as the first momentum command value MC3. For example, the first command unit M19 derives the smaller of the momentum required value MR and the fourth momentum limit value ML4 as the first momentum command value MC3. Then, the first command unit M19 instructs the rotation angle adjustment actuator 41 to operate based on the first momentum command value MC3, and instructs the steering lock mechanism 51 to be activated. In other words, the first command unit M19 transmits the first momentum command value MC3 to the rotation angle difference control unit 45, and transmits a command to the lock control unit 55 to activate the steering lock mechanism 51.

[0050] It should be noted that there may be cases where an abnormality occurs in both the front wheel steering actuator 31 and the rotation angle adjustment actuator 41. In this case, the vehicle 10 is turned by operating the rear wheel steering actuator 61 and the longitudinal force adjustment actuator. When the steering angle of the front wheels 18F cannot be adjusted in this way, the first command unit M19 may send a command to the lock control unit 55 to activate the steering lock mechanism 51.

[0051] The second command unit M21 derives, as the second momentum command value MC6, a value corresponding to the smaller of a first residual request value MR1, which is the value obtained by subtracting the first momentum command value MC3 from the momentum request value MR, and a second momentum limit value ML6. For example, the second command unit M21 derives the smaller of the first residual request value MR1 and the second momentum limit value ML6 as the second momentum command value MC6. Then, the second command unit M21 instructs the rear wheel steering actuator 61 to operate based on the second momentum command value MC6. In other words, the second command unit M21 transmits the second momentum command value MC6 to the rear wheel steering control unit 65.

[0052] The third command unit M23 derives a value corresponding to the smaller of the second residual request value MR2, which is the value obtained by subtracting the second momentum command value MC6 from the first residual request value MR1, and the third momentum limit value ML7, as the third momentum command value MC7. For example, the third command unit M23 derives the smaller of the second residual request value MR2 and the third momentum limit value ML7 as the third momentum command value MC7. Then, the third command unit M23 commands the longitudinal force adjustment actuator to operate based on the third momentum command value MC7. That is, the third command unit M23 transmits a command corresponding to the third momentum command value MC7 to the drive control unit 75 and the braking control unit 85.

[0053] <Vehicle turning control> A processing routine executed by the CPU 132 when automatically turning the vehicle 10 will be described with reference to Fig. 4. The processing routine shown in Fig. 4 is executed by the CPU 132 executing a motion control program at each predetermined control cycle.

[0054] In step S11 of this processing routine, the CPU 132 functions as a required value acquisition unit M11 to acquire the momentum required value MR. That is, the CPU 132 acquires, as the momentum required value MR, a value derived based on the latest value of the turning state quantity required value XR transmitted by the driving assistance device 120 and the latest value of the sensor detection value. In this embodiment, step S11 corresponds to the "required value derivation process."

[0055] In step S13, the CPU 132 functions as the abnormality determination unit M13 to determine whether or not an abnormality has occurred in each of the actuators. The process of step S13 is referred to as an "abnormality determination process."

[0056] In step S15, CPU 132 functions as availability derivation unit M15, thereby deriving availability MA3 of front wheel steering actuator 31, availability MA6 of rear wheel steering actuator 61, and availability MA7 of the longitudinal force adjustment actuator. CPU 132 also derives availability MA4 of rotation angle adjustment actuator 41. The processing of step S15 is referred to as "availability derivation processing."

[0057] In step S17, the CPU 132 functions as the limit value setting unit M17, thereby setting a first momentum limit value ML3, a second momentum limit value ML6, a third momentum limit value ML7, and a fourth momentum limit value ML4. However, if it is determined that no abnormality has occurred in the front wheel steering actuator 31, the CPU 132 does not set the fourth momentum limit value ML4. In this case, the CPU 132 sets 0 (zero) as the fourth momentum limit value ML4. In this embodiment, step S17 corresponds to the "limit value setting process."

[0058] In step S19, CPU 132 functions as first command section M19, thereby deriving a first momentum command value MC3. If it is determined that no abnormality has occurred in front wheel steering actuator 31, CPU 132 derives first momentum command value MC3 as a command value for front wheel steering actuator 31. If it is determined that an abnormality has occurred in front wheel steering actuator 31, and if it is determined that no abnormality has occurred in rotation angle adjustment actuator 41 or handlebar lock mechanism 51, CPU 132 derives first momentum command value MC3 as a command value for rotation angle adjustment actuator 41. In this embodiment, step S19 corresponds to the "first command value derivation process."

[0059] In step S21, the CPU 132 functions as a second command unit M21 to derive a second momentum command value MC6 as a command value for the rear wheel steering actuator 61. At this time, if the first momentum command value MC3 is equal to the momentum request value MR, the CPU 132 derives 0 (zero) as the second momentum command value MC6. In this embodiment, step S21 corresponds to the "second command value derivation process."

[0060] In step S23, the CPU 132 functions as a third command unit M23, thereby deriving a third momentum command value MC7 as a command value for the longitudinal force adjusting actuator. At this time, if the sum of the first momentum command value MC3 and the second momentum command value MC6 is equal to the momentum request value MR, the CPU 132 derives 0 (zero) as the third momentum command value MC7. In this embodiment, step S23 corresponds to the "third command value derivation process."

[0061] In step S25, CPU 132 instructs the actuators to be operated. That is, if it is determined that no abnormality has occurred in front wheel steering actuator 31, CPU 132 functions as first command unit M19, thereby instructing front wheel steering control unit 35 to operate front wheel steering actuator 31 based on first momentum command value MC3. If it is determined that an abnormality has occurred in front wheel steering actuator 31, CPU 132 functions as first command unit M19, thereby instructing rotation angle difference control unit 45 to operate rotation angle adjustment actuator 41 based on first momentum command value MC3, and instructing lock control unit 55 to activate handlebar lock mechanism 51. Furthermore, CPU 132 functions as second command unit M21, thereby instructing rear wheel steering control unit 65 to operate rear wheel steering actuator 61 based on second momentum command value MC6. Furthermore, the CPU 132 functions as a third command unit M23, thereby instructing the drive control unit 75 and the braking control unit 85 to operate the running motor 71 and the braking actuator 81 in accordance with the third momentum command value MC7. In this embodiment, step S25 corresponds to "instruction processing." Then, the CPU 132 temporarily ends this processing routine.

[0062] <Actions and Effects of This Embodiment> The operation and effect when turning the vehicle 10 will be described with reference to FIGS. 5, 6, 7 and 8. FIG.

[0063] (A1) The example shown in FIG. 5 will be explained. In this example, no abnormality occurs in any of the multiple actuators related to turning, and the vehicle 10 is turned gently. The thick solid lines in (A) and (E) of Figure 5 show the progress of the momentum requirement value MR.

[0064] In this example, as shown in FIG. 5A, the first momentum limit value ML3 does not fall below the momentum required value MR. Therefore, a value equal to the momentum required value MR is derived as the first momentum command value MC3. Then, when the first momentum command value MC3 is transmitted from the motion control device 130 to the front wheel steering control unit 35, the front wheel steering control unit 35 operates the front wheel steering actuator 31 based on the first momentum command value MC3. By such operation of the front wheel steering actuator 31, as shown in FIG. 5E, the momentum actual value MRp, which is the actual momentum of the vehicle 10, changes in the same manner as the momentum required value MR. The momentum required value MR is a value corresponding to the turning state quantity required value XR derived by the driving support device 120. Therefore, by operating the front wheel steering actuator 31, it is possible to realize turning of the vehicle 10 in accordance with the request of the driving support device 120.

[0065] In this example, no abnormality has occurred in the front wheel steering actuator 31. Therefore, as shown in Fig. 5(B), 0 (zero) is set as the fourth momentum limit value ML4, which is the limit value for the rotation angle adjusting actuator 41. Furthermore, because it is possible to realize the turning of the vehicle 10 in accordance with the request of the driving assist device 120 by adjusting the steering angle of the front wheels 18F, 0 (zero) is derived as the second momentum command value MC6, which is the command value for the rear wheel steering actuator 61, and as the third momentum command value MC7, which is the command value for the longitudinal force adjusting actuator, as shown in Fig. 5(C) and (D).

[0066] (A2) The example shown in FIG. 6 will be explained. This example shows a case where the vehicle 10 is forced to make an emergency turn even though no abnormality has occurred in any of the turning-related actuators. In this case, the momentum requirement value MR increases at a high rate, as shown by the thick solid lines in (A) and (E) of Figure 6.

[0067] In this example, no abnormality has occurred in the front wheel steering actuator 31. Therefore, as shown in Figures 6(A) and 6(B), the motion control device 130 sends the first momentum command value MC3 to the front wheel steering control unit 35, but does not send the first momentum command value MC3 to the rotational angle difference control unit 45. Therefore, the steering angle of the front wheels 18F is adjusted by the front wheel steering actuator 31.

[0068] 6A, during the period from timing t11 to timing t12, the first momentum limit value ML3 falls below the momentum requirement value MR. In this case, the same value as the first momentum limit value ML3 is derived as the first momentum command value MC3. That is, during this period, the first momentum command value MC3 falls below the momentum requirement value MR. Therefore, simply adjusting the steering angle of the front wheels 18F using the front wheel steering actuator 31 is not enough to achieve turning of the vehicle 10 in accordance with the request of the driving assistance device 120.

[0069] In this embodiment, the value obtained by subtracting the first momentum limit value ML3 from the momentum requirement value MR is derived as the first residual requirement value MR1. As described above, during the period from timing t11 to timing t12, the first momentum limit value ML3 is lower than the momentum requirement value MR, so a value other than 0 (zero) is derived as the first residual requirement value MR1, as shown in FIGS. 6B and 6C. Therefore, during this period, the smaller of the first residual requirement value MR1 and the second momentum limit value ML6 is derived as the second momentum command value MC6. Then, the second momentum command value MC6 is transmitted from the motion control device 130 to the rear wheel steering control unit 65, and the rear wheel steering control unit 65 operates the rear wheel steering actuator 61 based on the second momentum command value MC6. That is, the steering angle of the rear wheels 18R is adjusted in accordance with the second momentum command value MC6.

[0070] In this example, the vehicle 10 cannot turn in accordance with the momentum requirement value MR simply by operating the front wheel steering actuator 31 and the rear wheel steering actuator 61. That is, because the second momentum command value MC6 is lower than the first residual requirement value MR1 as shown in FIG. 6C, a value other than 0 (zero) is derived as the second residual requirement value MR2 as shown in FIG. 6D. That is, the value obtained by subtracting the second momentum command value MC6 from the first residual requirement value MR1 is derived as the second residual requirement value MR2. Then, during this period, the smaller of the second residual requirement value MR2 and the third momentum limit value ML7 is derived as the third momentum command value MC7. Then, a command corresponding to the third momentum command value MC7 is transmitted from the motion control device 130 to the drive control unit 75 and the braking control unit 85. Based on this command, the drive control unit 75 activates the traction motor 71, and the braking control unit 85 activates the braking actuator 81. That is, the difference in longitudinal force between the front wheel on the inside of the turning and the front wheel on the outside of the turning of the front wheels 18F is adjusted.

[0071] During the period when the first momentum limit value ML3 is lower than the momentum requirement value MR, in addition to adjusting the steering angle of the front wheels 18F by the front wheel steering actuator 31, the steering angle of the rear wheels 18R is adjusted by the rear wheel steering actuator 61, and the longitudinal force difference between the front wheels 18F is adjusted by the longitudinal force adjustment actuator. As a result, even if a sharp turn is requested by the driving assistance device 120 while the vehicle 10 is traveling autonomously, the behavior of the vehicle 10 can be made closer to the request of the driving assistance device 120, as shown in (E) of FIG.

[0072] After timing t12, the first momentum limit value ML3 exceeds the momentum requirement value MR. Therefore, the second momentum command value MC6 and the third momentum command value MC7 are each derived as 0 (zero). As a result, the front wheel steering actuator 31 adjusts the steering angle of the front wheels 18F, allowing the vehicle 10 to turn in accordance with the request of the driving assistance device 120.

[0073] (A3) The example shown in FIG. 7 will be explained. In this example, the driving assistance device 120 requests that the vehicle 10 be turned gently, but an abnormality has occurred in the front wheel steering actuator 31. On the other hand, among the multiple actuators related to turning, no abnormality has occurred in the actuators other than the front wheel steering actuator 31.

[0074] In this example, as shown in FIG. 7A, an abnormality has occurred in the front wheel steering actuator 31, so the first momentum limit value ML3 is set to 0 (zero). On the other hand, as shown in FIG. 7B, a fourth momentum limit value ML4 is set. Moreover, the fourth momentum limit value ML4 does not fall below the momentum requirement value MR. Therefore, a value equal to the momentum requirement value MR is derived as the first momentum command value MC3. Then, a signal to activate the steering wheel lock mechanism 51 is sent from the motion control device 130 to the lock control unit 55, and the first momentum command value MC3 is sent from the motion control device 130 to the rotational angle difference control unit 45. Then, the steering wheel lock mechanism 51 is activated by the lock control unit 55, so that rotation of the steering wheel 11a is restricted. In other words, the rotational angle of the input shaft 42 is maintained. In this state, the rotational angle difference control unit 45 operates the rotational angle adjustment actuator 41 based on the first momentum command value MC3. As a result, the rotation angle difference Δθ becomes a magnitude corresponding to the first momentum command value MC3 by the rotation angle adjustment actuator 41. That is, the steering angle of the front wheels 18F is adjusted by the rotation angle adjustment actuator 41. As a result, as shown in FIG. 7(E), the momentum actual value MRp changes in the same manner as the momentum request value MR. Therefore, in this example, the operation of the rotation angle adjustment actuator 41 makes it possible to realize the turning of the vehicle 10 in accordance with the request of the driving assistance device 120. That is, even if the front wheel steering actuator 31, among the multiple actuators related to turning, cannot be operated normally, the vehicle 10 can be turned.

[0075] In this example, the vehicle 10 can be turned in accordance with the request of the driving assistance device 120 by adjusting the steering angle of the front wheels 18F, so as shown in (C) and (D) of FIG. 7, the second momentum command value MC6, which is the command value for the rear wheel steering actuator 61, and the third momentum command value MC7, which is the command value for the longitudinal force adjustment actuator, are both set to 0 (zero).

[0076] It should be noted that there are cases where the operation of the rotation angle adjustment actuator 41 alone is not enough to achieve the turning of the vehicle 10 in accordance with the request of the driving assistance device 120. In such cases, the rear wheel steering actuator 61 and the longitudinal force adjustment actuator are operated in addition to the rotation angle adjustment actuator 41. Even in this case, the rear wheel steering actuator 61 is operated preferentially among the rear wheel steering actuator 61 and the longitudinal force adjustment actuator.

[0077] (A4) The example shown in FIG. 8 will be explained. In this example, although the driving assistance device 120 requests that the vehicle 10 be turned gently, an abnormality has occurred in both the front wheel steering actuator 31 and the rotation angle adjustment actuator 41. In other words, the front wheels 18F cannot be steered. On the other hand, no abnormality has occurred in the rear wheel steering actuator 61 or the longitudinal force adjustment actuator.

[0078] 8A and 8B, the first momentum limit value ML3 and the fourth momentum limit value ML4 are set to 0 (zero). Therefore, the first momentum command value MC3 is derived to be 0 (zero). Furthermore, a command to activate the handlebar lock mechanism 51 is sent from the motion control device 130 to the handlebar lock mechanism 51. When the handlebar lock mechanism 51 is activated, the rotation angles of the handlebar 11a and the input shaft 42 are maintained.

[0079] The value obtained by subtracting the first momentum limit value ML3 from the momentum requirement value MR is derived as the first residual requirement value MR1. In this example, a value equal to the momentum requirement value MR is derived as the first residual requirement value MR1. Also, as shown in FIG. 8C, the second momentum limit value ML6 does not fall below the first residual requirement value MR1. Therefore, the first residual requirement value MR1 is set as the second momentum command value MC6. The second momentum command value MC6 is transmitted from the motion control device 130 to the rear wheel steering control unit 65, and the rear wheel steering control unit 65 operates the rear wheel steering actuator 61 based on the second momentum command value MC6. That is, the steering angle of the rear wheels 18R is adjusted in accordance with the second momentum command value MC6. Furthermore, when adjusting the steering angle of the rear wheels 18R in this manner, restricting the rotation of the steering wheel 11a, i.e., the steering of the front wheels 18F, makes it easier to turn the vehicle 10. As a result, by adjusting the steering angle of the rear wheels 18R, the actual momentum value MRp changes in the same manner as the required momentum value MR, as shown in (E) of Figure 8. Therefore, in this example, the operation of the rear wheel steering actuator 61 makes it possible to realize the turning of the vehicle 10 in accordance with the request of the driving assistance device 120. In other words, even if the front wheel steering actuator 31 and the rotation angle adjustment actuator 41, among the multiple actuators related to turning, cannot be operated normally, the vehicle 10 can be turned.

[0080] It should be noted that there are cases where the operation of the rear wheel steering actuator 61 alone is not enough to achieve the turning of the vehicle 10 in accordance with the request of the driving assistance device 120. In this case, in addition to the rear wheel steering actuator 61, the longitudinal force adjustment actuator is operated.

[0081] Here, consider a case where, when an abnormality occurs in the actuators 31, 41 that adjust the steering angle of the front wheels 18F, the longitudinal force adjustment actuator is operated preferentially instead of the rear wheel steering actuator 61. In this case, by increasing the braking force applied to the front wheel on the inside of the left and right front wheels 18F during a turn, a longitudinal force difference is generated between the left and right front wheels 18F, and a yaw moment can be generated in the vehicle 10. However, this increases the braking force of the vehicle 10 as a whole, causing the vehicle 10 to decelerate. In order to suppress such deceleration of the vehicle 10, the driving force of the traction motor 71 can be increased to suppress the deceleration of the vehicle 10 caused by the longitudinal force difference between the left and right front wheels 18F, but this reduces the energy efficiency of the vehicle 10.

[0082] In this regard, in this embodiment, the rear wheel steering actuator 61 is operated with priority over the longitudinal force adjustment actuator. As a result, even in cases where it is not possible to adjust the steering angle of the front wheels 18F or where adjustment of the steering angle of the front wheels 18F alone is not enough to achieve turning of the vehicle 10 in accordance with a request from the motion control device 130, it is possible to achieve turning of the vehicle 10 in accordance with the request while suppressing a decrease in the energy efficiency of the vehicle 10.

[0083] <Example of change> The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0084] In the above embodiment, the availability of an actuator is derived taking into account the determination result of whether or not an abnormality has occurred in that actuator. However, this is not limited to this. That is, the availability of that actuator may be derived without taking into account the determination result of whether or not an abnormality has occurred in the actuator. In this case, however, when setting the momentum limit value of the actuator, it is advisable to take into account the determination result of whether or not an abnormality has occurred in the actuator. That is, it is advisable to set 0 (zero) as the momentum limit value for an actuator determined to have an abnormality.

[0085] The momentum limit value for an actuator determined to have an abnormality does not have to be set to 0 (zero). In this case, the motion control device 130 may be configured not to instruct the control unit of the actuator determined to have an abnormality to operate the actuator.

[0086] The motion control device 130 may be applied to a vehicle that does not have a rotational angle difference adjustment device 40. In this case, if it is determined that an abnormality has occurred in the front wheel steering actuator 31, an instruction to operate the rear wheel steering actuator 61 will be issued. Furthermore, if the vehicle cannot be turned in accordance with the momentum requirement value MR by operating the rear wheel steering actuator 61 alone, an instruction to operate the longitudinal force adjustment actuator will also be issued.

[0087] Even if it is determined that no abnormality has occurred in the rotation angle adjusting actuator 41, the fourth momentum limit value ML4 for the rotation angle adjusting actuator 41 may be derived.

[0088] In the above embodiment, 0 (zero) is set as the motion limit value for an actuator determined to have an abnormality, but this is not limited to this. That is, even if an actuator has an abnormality, it may be possible to obtain an operation state value indicating the operation state of that actuator. Being able to obtain an operation state value for an actuator in which an abnormality has occurred means that a turning moment is being generated by the operation of that actuator. Therefore, if an operation state value for an actuator can be obtained even when an abnormality has occurred, a value corresponding to the current value of the operation state value may be set as the momentum limit value. The value corresponding to the operation state value is a value obtained by converting the operation state value into momentum. However, even in this case, if an operation state value for an actuator in which an abnormality has occurred cannot be obtained, the momentum limit value will be set to 0 (zero).

[0089] The first momentum command value MC3 may be calculated by subtracting a predetermined correction amount from the smaller of the momentum required value MR and the first momentum limit value ML3. Even in this case, the first momentum command value MC3 can be calculated based on the smaller of the momentum required value MR and the first momentum limit value ML3.

[0090] The second momentum command value MC6 may be derived by subtracting a predetermined correction amount from the smaller of the first residual requirement value MR1 and the second momentum limit value ML6. Even in this case, the second momentum command value MC6 can be derived as a value corresponding to the smaller of the first residual requirement value MR1 and the second momentum limit value ML6.

[0091] The third momentum command value MC7 may be derived by subtracting a predetermined correction amount from the smaller of the second residual requirement value MR2 and the third momentum limit value ML7. Even in this case, a value corresponding to the smaller of the second residual requirement value MR2 and the third momentum limit value ML7 can be derived as the third momentum command value MC7.

[0092] In the above embodiment, when the vehicle 10 is turned in a state where the steering angle of the front wheels 18F cannot be adjusted, the lock control unit 55 is instructed to put the steering lock mechanism 51 into an activated state, but this is not limited to this. In other words, when the vehicle 10 is turned in a state where the steering angle of the front wheels 18F cannot be adjusted, the state of the steering lock mechanism 51 does not have to be switched from a non-activated state to an activated state.

[0093] The drive device may be equipped with an engine as a power source for the vehicle in addition to the drive motor 71. Also, the drive device may be configured not to include the drive motor 71 as long as it is equipped with an engine as a power source for the vehicle. In such a case, the engine also corresponds to the longitudinal force adjustment actuator.

[0094] The drive unit may be configured to include a drive motor for each of the plurality of wheels 18F, 18R. In this case, a yaw moment can be generated in the vehicle by adjusting the difference in drive force between the right wheel and the left wheel.

[0095] The vehicle may be rear-wheel drive or all-wheel drive. The processing circuit 131 of the motion control device 130 is not limited to one that includes a CPU and ROM and executes software processing. In other words, the processing circuit 131 may have any one of the following configurations (a) to (c): (a) Having one or more processors that execute various processes according to a computer program. The processor includes a CPU and memory such as RAM and ROM. The memory stores program code or instructions configured to cause the CPU to execute processes. Memory, i.e., computer-readable media, includes any available medium that can be accessed by a general-purpose or special-purpose computer. (b) It is equipped with one or more dedicated hardware circuits that perform various processes. Examples of dedicated hardware circuits include application-specific integrated circuits, i.e., ASIC or FPGA. ASIC is an abbreviation for "Application Specific Integrated Circuit." FPGA is an abbreviation for "Field Programmable Gate Array." (c) It is equipped with a processor that executes part of the various processes in accordance with a computer program, and a dedicated hardware circuit that executes the remaining part of the various processes.

[0096] (technical thought) Next, the technical ideas that can be understood from the above-described embodiment and modified examples will be described. (A) A vehicle motion control method for turning a vehicle comprising a plurality of wheels, a steering wheel, a front wheel steering shaft that operates in conjunction with the rotation of a handle of the steering wheel, a front wheel steering actuator that adjusts the steering angle of front wheels among the plurality of wheels, a rear wheel steering actuator that adjusts the steering angle of rear wheels among the plurality of wheels, and a longitudinal force adjustment actuator that adjusts longitudinal forces of the plurality of wheels, a required value derivation process for deriving a momentum required value, which is a required value of the momentum of the vehicle for turning the vehicle; a limit value setting process for setting a first momentum limit value in accordance with an operable range of the front wheel steering actuator, a second momentum limit value in accordance with an operable range of the rear wheel steering actuator, and a third momentum limit value in accordance with an operable range of the longitudinal force adjustment actuator; a first command value derivation process for deriving a value corresponding to the smaller one of the exercise amount required value and the first exercise amount limit value as a first exercise amount command value; a second command value derivation process for deriving a value corresponding to the smaller of a first residual requirement value, which is a value obtained by subtracting the first momentum command value from the momentum requirement value, and the second momentum limit value, as a second momentum command value; a third command value process for deriving a value corresponding to the smaller of a second remaining requirement value, which is a value obtained by subtracting the second momentum command value from the first remaining requirement value, and the third momentum limit value, as a third momentum command value; and an instruction process of instructing operation of the front wheel steering actuator based on the first momentum command value, instructing operation of the rear wheel steering actuator based on the second momentum command value, and instructing operation of the longitudinal force adjustment actuator based on the third momentum command value.

[0097] By executing a plurality of processes of the motion control method, it is possible to obtain the same functions and effects as the motion control device. [Explanation of symbols]

[0098] 10...Vehicle 11...Steering wheel 11a...Handle 12...Front wheel steering shaft 18F…Front wheel 18R…rear wheel 31...Front wheel steering actuator 41...Rotation angle adjustment actuator 42...Input shaft 43...Output shaft 51...Handle lock mechanism 61...Rear wheel steering actuator 71...Traction motor (an example of a longitudinal force adjustment actuator) 81...Braking actuator (an example of a longitudinal force adjustment actuator) 130...Motion control device 132...CPU (an example of an execution device) M11: Request value acquisition section M17: Limit value setting section M19…1st command department M21…Second Command Department M23...Third Command Department

Claims

1. The present invention is applied to a vehicle including a plurality of wheels, a steering wheel, a front-wheel steering shaft that operates in conjunction with the rotation of a handle of the steering wheel, a front-wheel steering actuator that adjusts the steering angle of front wheels among the plurality of wheels, a rear-wheel steering actuator that adjusts the steering angle of rear wheels among the plurality of wheels, and a longitudinal force adjustment actuator that adjusts the longitudinal force of the plurality of wheels, a required value acquisition unit that acquires a momentum required value that is a required value of the momentum of the vehicle for turning the vehicle; a limit value setting unit that sets a first momentum limit value in accordance with an operable range of the front wheel steering actuator, a second momentum limit value in accordance with an operable range of the rear wheel steering actuator, and a third momentum limit value in accordance with an operable range of the longitudinal force adjustment actuator; a first command unit that derives a value corresponding to the smaller of the momentum required value and the first momentum limit value as a first momentum command value, and commands operation of the front wheel steering actuator based on the first momentum command value; a second command unit that derives a second momentum command value corresponding to the smaller of a first residual requirement value, which is a value obtained by subtracting the first momentum command value from the momentum requirement value, and the second momentum limit value, and commands the rear wheel steering actuator to operate based on the second momentum command value; a third command unit that derives a value corresponding to the smaller of a second residual requirement value, which is a value obtained by subtracting the second momentum command value from the first residual requirement value, and the third momentum limit value, as a third momentum command value, and instructs operation of the longitudinal force adjustment actuator based on the third momentum command value, The limit value setting unit sets, as the momentum limit value for the actuator in which an abnormality has occurred, a value corresponding to a current value of the operating state value of the actuator in which an abnormality has occurred, if an operating state value indicating the operating state of the actuator can be acquired even if an abnormality has occurred, and sets 0 (zero) if the operating state value of the actuator in which an abnormality has occurred cannot be acquired. Vehicle motion control device.

2. The vehicle is a handle lock mechanism that switches between a non-operating state that allows rotation of the handle and an operating state that disables rotation of the handle; a rotation angle adjustment actuator that has an input shaft that rotates integrally with the steering wheel and an output shaft that rotates in synchronization with the operation of the front wheel steering shaft, and that operates to adjust the difference between the rotation angle of the input shaft and the rotation angle of the output shaft, the limit value setting unit sets a fourth momentum limit value in accordance with an operable range of the rotation angle adjustment actuator; When an abnormality occurs in the front wheel steering actuator, the first command unit derives a value corresponding to the smaller of the momentum requirement value and the fourth momentum limit value as the first momentum command value, commands the operation of the rotation angle adjustment actuator based on the first momentum command value, and commands the state of the handle lock mechanism to be set to the activated state. The vehicle motion control device according to claim 1 .

3. The first command unit instructs the steering lock mechanism to be in the activated state when the vehicle is turned in a state in which the steering angle of the front wheels cannot be adjusted. The vehicle motion control device according to claim 2.

4. A motion control program executed by an execution device of a vehicle, The vehicle comprises a plurality of wheels, a steering wheel, a front-wheel steering shaft that operates in conjunction with the rotation of a handle of the steering wheel, a front-wheel steering actuator that adjusts the steering angle of front wheels among the plurality of wheels, a rear-wheel steering actuator that adjusts the steering angle of rear wheels among the plurality of wheels, and a longitudinal force adjustment actuator that adjusts longitudinal forces of the plurality of wheels, a required value derivation process for deriving a momentum required value, which is a required value of the momentum of the vehicle for turning the vehicle; a limit value setting process for setting a first momentum limit value in accordance with an operable range of the front wheel steering actuator, a second momentum limit value in accordance with an operable range of the rear wheel steering actuator, and a third momentum limit value in accordance with an operable range of the longitudinal force adjustment actuator; a first command value derivation process for deriving a value corresponding to the smaller one of the exercise amount required value and the first exercise amount limit value as a first exercise amount command value; a second command value derivation process for deriving a value corresponding to the smaller of a first residual requirement value, which is a value obtained by subtracting the first momentum command value from the momentum requirement value, and the second momentum limit value, as a second momentum command value; a third command value process for deriving a value corresponding to the smaller of a second remaining requirement value, which is a value obtained by subtracting the second momentum command value from the first remaining requirement value, and the third momentum limit value, as a third momentum command value; an instruction process for instructing the operation of the front wheel steering actuator based on the first momentum command value, instructing the operation of the rear wheel steering actuator based on the second momentum command value, and instructing the operation of the longitudinal force adjustment actuator based on the third momentum command value, The limit value setting process is a process of setting a value corresponding to a current value of the operating state value of the actuator in which an abnormality has occurred as the momentum limit value for the actuator in which an abnormality has occurred, if an operating state value indicating the operating state of the actuator can be obtained even if an abnormality has occurred, and setting 0 (zero) if the operating state value of the actuator cannot be obtained. Motor control program.

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