Vehicle Systems

Abstract

The present invention is to reduce the capacity of a secondary power source. The vehicle system includes a front and rear force imparting system and a steering system that operate through a common vehicle-mounted power supply device including a main power source and a secondary power source. In the front and rear force imparting system, the front and rear force imparted to the left wheel of the vehicle and the front and rear force imparted to the right wheel are controlled by a front and rear force control unit. In the steering system, the steering angle of the steering wheel of the vehicle is controlled by a steering control unit. In the event of an abnormality in the main power source, the front and rear force imparting system is operated by the power of the secondary power source. The front and rear force control unit turns the vehicle by controlling the left and right difference in the front and rear force between the left wheel and the right wheel. As a result, in the event of an abnormality in the main power source, the power consumed by the steering system can be reduced, and the capacity of the secondary power source can be reduced compared to the case where the steering system and the front and rear force imparting system are operated.

Description

Technical Field

[0001] The present invention relates to a vehicle system having a braking system. Background Art

[0002] Patent document 1 describes the following: a vehicle system comprises: an on-board power supply device having a main power supply and a secondary power supply; and a plurality of actuators that operate by power from the on-board power supply device. In the vehicle system, in the event of an abnormality in the main power supply, the opening and closing of the plurality of actuators are controlled separately based on the voltage of the secondary power supply.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2020-89080 Summary of the invention

[0004] An object of the present invention is to reduce the capacity of a secondary power source.

[0005] The vehicle system involved in the present invention includes a front and rear force imparting system and a steering system that work through a common vehicle-mounted power supply device. In the front and rear force imparting system, the front and rear force imparted to the left wheel of the vehicle and the front and rear force imparted to the right wheel are respectively controlled by a front and rear force control unit with a computer as the main body. In the steering system, the steering angle of the steering wheel of the vehicle is controlled by a steering control unit with a computer as the main body. The vehicle-mounted power supply device includes a main power supply and a secondary power supply. In the abnormal case where the main power supply cannot supply power to the front and rear force imparting system and the steering system, the front and rear force imparting system is operated by the power of the secondary power supply. The front and rear force control unit turns the vehicle by controlling the left and right front and rear force difference, which is the difference between the front and rear force imparted to the left wheel and the front and rear force imparted to the right wheel. Since there is no need to operate the steering system, the power consumed in the steering system can be reduced. Compared with the case where both the steering system and the front and rear force imparting system are operated by the power of the secondary power supply, the capacity of the secondary power supply can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 It is a diagram schematically showing a vehicle system according to an embodiment of the present invention.

[0007] Figure 2 It is a perspective view showing a steering device which is a structural element of the above-mentioned vehicle system.

[0008] Figure 3 is a cross-sectional view showing a friction brake which is a structural element of the above-mentioned vehicle system.

[0009] Figure 4 The present invention is a flowchart showing a steering assist flag setting program stored in a storage unit of a control device as a component of the vehicle system.

[0010] Figure 5 This is a flowchart showing an on / off switching program stored in the storage unit of the control device.

[0011] Figure 6 This is a flowchart showing a brake control program stored in a storage unit of the brake ECU of the control device.

[0012] Figure 7 Schematically showing a first target left-right braking force difference determination map stored in the storage unit of the brake ECU.

[0013] Figure 8 It is a diagram showing the running state of the vehicle when the above-mentioned brake control program is executed.

[0014] Description of Reference Numerals

[0015] 4…on-vehicle power supply device; 5…steering system; 7…brake system; 10…steering device; 12…steering ECU; 14…friction brake; 16…brake ECU; 24…steering actuator; 56…brake actuator; 72…main power supply; 74…secondary power supply; 80…control device; 82…automatic driving ECU; 84…power supply monitoring ECU; 86…CAN; 90…switch; 92…steering operation state detection device; 94…brake operation state detection device. DETAILED DESCRIPTION

[0016] Hereinafter, a vehicle system as one embodiment of the present invention will be described based on the drawings.

[0017] [Example]

[0018] The vehicle system includes a steering system 5 that operates via a common vehicle-mounted power supply device 4 and a brake system 7 that serves as a front-rear force applying system.

[0019] The steering system 5 includes a steering device 10 (see Figure 2 ) are independently arranged on wheels located at the front, rear, left and right of the vehicle (hereinafter, there is a case where the front, rear, left and right wheels are referred to as wheels. In addition, there is a case where the wheels located at the front, rear, left and right are simply referred to as wheels respectively) 8; and a steering ECU (Electronic Control Unit: electronic control unit) 12 as a steering control unit, which is mainly composed of a computer that controls the operation of these steering devices 10 respectively. The steering ECU 12 controls the steering angles of the front, rear, left and right wheels 8 respectively by controlling these steering devices 10.

[0020] The brake system 7 includes: a friction brake 14 (see Figure 3), which are independently provided corresponding to the front, rear, left, and right wheels 8, respectively; and a brake ECU 16 as a front and rear force control unit and a braking force control unit, which is mainly composed of a computer that controls the operation of these friction brakes 14. The brake ECU 16 controls the braking forces applied to the front, rear, left, and right wheels 8 as front and rear forces by controlling these friction brakes 14.

[0021] based on Figure 2 An example of the steering device 10 will be described.

[0022] The wheel 8 is rotatably held by a steering joint (hereinafter referred to as a knuckle) 17. In addition, a lower arm 18 is connected to the knuckle 17, and the lower arm 18 is connected to a vehicle body side member (not shown) via a bushing so as to be swingable in the vertical direction (around an axis extending in the front-rear direction) and the horizontal direction (around an axis extending in the vertical direction). In addition, the knuckle 17 is supported by a vehicle body side member (not shown) via a shock absorber 20 and a suspension spring 21.

[0023] The steering device 10 includes the knuckle 17 , a steering actuator 24 provided on the lower arm 18 , a steering arm 34 connected to an output shaft (not shown) of the steering actuator 24 , and a tie rod 26 connecting the steering arm 34 to the knuckle arm 22 of the knuckle 17 .

[0024] The steering actuator 24 includes a steering motor 30 which is an electric motor as a driving source and a speed reducer 32 which reduces the rotation of the steering motor 30. The steering arm 34 is integrally rotatably connected to the output shaft of the speed reducer 32 which is the output shaft of the steering actuator 24 at one end.

[0025] The other end of the steering arm 34 is connected to one end of the tie rod 26 via a connection portion 36. The other end of the tie rod 26 is connected to the knuckle arm 22 via a connection portion 38.

[0026] In the present steering device 10, if Figure 2 When the steering actuator 24 is driven in the direction indicated by the arrow X shown in the figure, the steering arm 34 is rotated around the axis of the steering actuator 24. With the rotation of the steering arm 34, the tie rod 26 is moved in the direction indicated by the arrow Y, thereby rotating the knuckle arm 22 and the knuckle 17 around the kingpin axis KP, and the wheel 8 is steered in the direction indicated by the arrow Z.

[0027] exist Figure 31 shows an example of a friction brake 14. The friction brake 14 includes: friction plates 52 and 54 as a pair of friction engagement components, which are located on both sides of a brake rotating body 50 that can rotate integrally with the wheel 8; and a pressing device 56 that presses the friction plates 52 and 54 against the brake rotating body 50. The pressing device 56 includes a brake caliper 58, an electric motor 60 as a driving source provided in the brake caliper 58, and a motion conversion device 64 that converts the rotation of the electric motor 60 into a linear movement of the pressing member 62. In this embodiment, the pressing device 56 corresponds to a brake actuator as a front-rear force applying actuator that applies a front-rear force to the wheel, but it can be considered that the electric motor 60 corresponds to the brake actuator.

[0028] The pressing member 62 is moved by driving the electric motor 60, thereby moving the brake caliper 58. As a result, the friction plates 52 and 54 are pressed against the brake rotor 50. The rotation of the wheel 8 is suppressed by the friction engagement between the friction plates 52 and 54 and the brake rotor 50. In addition, the pressing force of the friction plates 52 and 54 against the brake rotor 50 is controlled by controlling the electric motor 60, thereby controlling the braking force applied to the wheel 8.

[0029] In addition, if Figure 2 As shown, an in-wheel motor 70 for applying a driving force as a front-rear force is provided on the wheel 8. In this embodiment, the housing of the in-wheel motor 70 functions as a steering knuckle 17. Thus, in this embodiment, the steering device 10, the friction brake 14, and the in-wheel motor 70 are provided on the front, rear, left, and right wheels 8.

[0030] The vehicle-mounted power supply device 4 includes a main power supply 72 and a secondary power supply 74. For example, the main power supply 72 and the secondary power supply 74 can be lithium-ion batteries, the main power supply 72 can be a lithium-ion battery and the secondary power supply 74 can be a capacitor, etc. In short, the capacity of the secondary power supply 74 is usually smaller than that of the main power supply 72.

[0031] The steering actuator 24 of the steering device 10, the brake actuator 56 of the friction brake 14, etc. are controlled by the control device 80. In addition to the steering ECU 12 and the brake ECU 16, the control device 80 also includes an automatic driving ECU 82 as an automatic driving control unit based on a computer, a power supply monitoring ECU 84, etc. These steering ECU 12, brake ECU 16, automatic driving ECU 82, power supply monitoring ECU 84, etc. are connected to each other in a communicative manner via a CAN (Controller Area Network) 86. The steering ECU 12 and the brake ECU 16 are respectively equipped with communication units 12C and 16C for receiving information supplied via the CAN 86.

[0032] Furthermore, the automatic driving ECU 82 , the power monitoring ECU 84 , and the like may operate with the power of the same vehicle power supply device 4 as the steering ECU 12 and the brake ECU 16 , or may operate with the power of a vehicle power supply device different from the vehicle power supply device 4 .

[0033] In addition, a switch 90 is provided between the main power supply 72, the secondary power supply 74, and the steering ECU 12, the brake ECU 16, the steering actuator 24, the brake actuator 56, etc. (the steering system 5 and the brake system 7). Through the switch 90, either the main power supply 72 or the secondary power supply 74 is selectively connected to the steering system 5 and the brake system 7.

[0034] In the steering ECU 12, the steering actuator 24 respectively provided at the front, rear, left and right wheels 8 is connected via a driving circuit not shown in the figure, and the steering operation state detection device 92 and the like are connected. The steering operation state detection device 92 detects the operation state (including the direction of operation, the operation amount, etc.) of the steering operation component not shown in the figure that can be operated by the driver. The steering operation state detection device 92 can, for example, output the operation amount of the steering operation component of one of the right operation and the left operation of the steering operation component as a positive value, and output the other as a negative value. Therefore, based on the detection value of the steering operation state detection device 92, the direction and the operation amount of the operation can be obtained.

[0035] The brake ECU 16 is connected to the brake actuators 56 provided at the front, rear, left and right wheels 8 via a drive circuit (not shown) and a brake operation state detection device 94. The brake operation state detection device 94 detects the operation amount of a brake operation member (not shown) operable by the driver.

[0036] In addition, the automatic driving ECU 82 is connected to a peripheral information acquisition device 96. The peripheral information acquisition device 96 includes a camera, a radar device, etc., and recognizes the environment around the vehicle, such as objects located in the surroundings, dividing lines of the surrounding roads, etc., based on the shooting information of the camera, and obtains information indicating the relative positional relationship between the object and the vehicle, the curvature of the road, etc. The automatic driving ECU 82 obtains an automatic braking request as a braking request and an automatic steering request as a steering request {including the direction of steering, the strength of the steering request (which can be expressed by a target yaw rate, etc.) and other information based on the information obtained by the peripheral information acquisition device 96, and outputs them to the CAN 86.

[0037] The power supply monitoring ECU84 monitors the status of the vehicle-mounted power supply device 4, for example, based on the voltage of the main power supply 72, monitors whether the main power supply 72 is able to supply power to the steering system 5 and the front and rear force application system 7, and outputs the main power supply information as information representing its monitoring results to CAN86.

[0038] The main power supply information includes main power supply abnormal information indicating that the main power supply 72 is in a state where it cannot supply power to the steering system 5 and the braking system 7 (these can be collectively referred to as power consuming devices) (hereinafter, there is a case where this state is referred to as abnormal), and main power supply normal information indicating that the main power supply 72 is in a state where it can supply power to the steering system 5 and the braking system 7 (hereinafter, there is a case where this state is referred to as normal).

[0039] The operation of the vehicle system configured as above will be described.

[0040] When the main power supply 72 is normal, the switch 90 disconnects the steering system 5 and the brake system 7 from the secondary power supply 74 and connects them to the main power supply 72. The power of the main power supply 72 is supplied to the steering ECU 12, the brake ECU 16, and the like.

[0041] When the communication unit 12C receives an automatic steering request supplied via the CAN 86, or when it is determined based on the detection value of the steering operation state detection device 92 that the steering operation member is operated and there is a steering request (this steering request is referred to as an operation steering request), the steering ECU 12 controls the operation of the steering actuator 24 provided on at least one of the front, rear, left, and right wheels 8, and steers the at least one wheel 8. As a result, the vehicle turns.

[0042] In addition, when the brake ECU16 receives an automatic braking request supplied via CAN86 in the communication unit 16C, or when it is determined based on the detection value of the brake operation state detection device 94 that the brake operation component is operated and there is a braking request (the braking request in this case is referred to as an operation braking request), the brake ECU16 controls the operation of the brake actuator 56 arranged on at least one of the front, rear, left and right wheels 8, and applies the braking force generated by the friction brake 14 to the at least one wheel 8.

[0043] However, when the main power supply 72 is abnormal, the switch 90 is switched to a state in which the steering system 5 and the brake system 7 are disconnected from the main power supply 72 and connected to the secondary power supply 74 .

[0044] If the steering system 5 and the brake system 7 are operated by the power of the secondary power supply 74 when the main power supply 72 fails, the capacity of the secondary power supply 74 needs to be increased. This causes problems such as increased cost and increased size of the secondary power supply 74.

[0045] In addition, for computer-based ECUs such as the steering ECU 12 and the brake ECU 16, standby current is required even when the steering actuator 24 and the brake actuator 56 are in a non-operating state. For example, the steering ECU 12 always reads the detection value of the steering operation state detection device 92, obtains the operating state of the steering operation component based on the detection value, and monitors whether there is an operation steering request. In addition, the steering ECU 12 monitors and appropriately receives and processes the information supplied via CAN 86. For example, the steering ECU 12 receives and processes the automatic steering request output from the automatic driving ECU 82, the main power supply information output from the power supply monitoring ECU 84, etc. In this way, it is necessary to continuously supply standby current to ECUs such as the steering ECU 12 and the brake ECU 16.

[0046] On the other hand, the following situation can be considered, that is, when the main power supply 72 is abnormal, the steering ECU 12 is turned off, the brake ECU 16 determines whether there is a steering request, and when it is determined that there is a steering request, the steering ECU 12 is switched on to control the steering actuator 24. However, in this case, there is another problem of generating a steering delay.

[0047] According to the above situation, in the present embodiment, when the main power supply 72 is abnormal, the brake ECU 16 determines whether there is a steering request. When it is determined that there is a steering request, the vehicle is turned by controlling the left and right braking force difference. Specifically, by controlling the operation of at least one of the front, rear, left and right wheels 8, the left wheel (representing at least one of the left front wheel and the left rear wheel, hereinafter referred to as the left wheel 8L) located on the left side of the vehicle is controlled. Figure 8 The vehicle turns by the difference in braking force between the right wheel 8R and the right wheel 8R, which is a wheel located on the right side of the vehicle (including at least one of the right front wheel and the right rear wheel. Hereinafter, it is recorded as the right wheel 8R). Thus, the steering delay can be suppressed.

[0048] As a result, the steering ECU 12 only needs to have the function of receiving and processing the power information supplied via CAN 86 (this function is called a communication function), and there is no need to determine whether there is power for steering operation request based on the detection value of the steering operation state detection device 92, thereby reducing the standby current supplied to the steering ECU 12.

[0049] In addition, electric power for operating the steering actuator 24 is not required. Therefore, the capacity of the secondary power supply 74 can be reduced, and the secondary power supply 74 can be miniaturized.

[0050] The brake ECU 16 executes the operation at a predetermined cycle time. Figure 4 A flowchart showing the steering assist flag setting procedure.

[0051] In step 1 (hereinafter referred to as S1. The same applies to other steps), it is determined whether the main power supply information supplied by the power supply monitoring ECU 84 via the CAN 86 is received in the communication unit 16C. In the case where the determination in S1 is yes, it is determined in S2 whether the received information is the main power supply abnormality information. In the case where the determination is no, that is, when the received information is the main power supply normal information, in S3, the switch 90 is changed to a state of connecting the main power supply 72 to the steering system 5 and the brake system 7, and in S4, the steering assist flag is turned off. The steering assist flag is a flag that is turned on when the brake ECU 16 is required to replace the steering ECU 12 to control the vehicle to turn.

[0052] On the other hand, when the received information is main power supply abnormality information, the determination in S2 is YES, and in S5, the switch 90 is switched to a state where the secondary power supply 74 is connected to the steering system 5 and the brake system 7. In addition, in S6, the steering assist flag is turned on.

[0053] In addition, the steering ECU 12 executes the operation at a predetermined cycle time. Figure 5 The flowchart represents the on-off switching procedure.

[0054] In S11, it is determined whether the main power supply information supplied via the CAN 86 is received in the communication unit 12C, and in S12 it is determined whether the received information is the main power supply abnormality information. If the determination is negative, in S13, the steering ECU 12 is turned on. On the other hand, if the determination in S12 is positive, in S14, the steering ECU 12 turns off the parts except the communication unit 12C. In addition, the steering actuator 24 is also turned off.

[0055] In addition, even if the main power supply 72 is abnormal, the Figure 5 Therefore, when the main power supply 72 switches from abnormal to normal, the steering ECU 12 can be quickly turned back on.

[0056] In addition, in this embodiment, Figure 4 The steering assist flag setting program is executed by the brake ECU 16. Figure 5 The on / off switching program is described as being executed by the steering ECU 12, but it is also possible to consider Figure 4 Steering assist sign setting procedure, Figure 5 The on / off switching program is executed by one or more ECUs of the control device 80.

[0057] The brake ECU 16 executes the Figure 6 The flowchart represents the brake control procedure.

[0058] In S21, it is determined whether the steering assist flag is on. If the determination in S21 is yes, in S22, the operating state of the steering operating component is obtained based on the detection value of the steering operating state detection device 92, and in S23, it is determined whether the steering operating component has been operated. For example, when the absolute value of the operating amount detected by the steering operating state detection device 92 is greater than the set value, it can be determined that the steering operating component has been operated. If the determination in S23 is yes, in S24, the target yaw rate is obtained based on the operating state of the steering operating component (operation amount, direction of operation), and in S25, the target left and right braking force difference (hereinafter referred to as the first target left and right braking force difference) ΔFs corresponding to the operation is obtained based on the target yaw rate. For example, as Figure 7 As shown, when the absolute value of the target yaw rate is large, the first target left-right braking force difference ΔFs is determined to be a larger value than when it is small. On the other hand, when it is determined that the steering operating member is not operated, the determination of S23 becomes negative, and the first target left-right braking force difference ΔFs is determined to be 0 in S26.

[0059] Next, in S27, it is determined whether an automatic steering request is provided via CAN86. If the determination in S27 is yes, in S28, the target left and right braking force difference corresponding to the automatic driving (hereinafter referred to as the second target left and right braking force difference) ΔFa is obtained based on the automatic steering request. If the determination in S27 is no, in S29, the second target left and right braking force difference ΔFa is determined to be 0. Moreover, in S30, the larger of the first target left and right braking force difference ΔFs and the second target left and right braking force difference ΔFa is determined as the target left and right braking force difference ΔF. When both the first target left and right braking force difference ΔFs and the second target left and right braking force difference ΔFa are 0, the target left and right braking force difference ΔF also becomes 0.

[0060] If the steering assist flag is off, the determination in S21 is negative, and the target left-right braking force difference ΔF is determined to be zero in S31 .

[0061] In addition, while the steering assist flag is on, the brake ECU 16 receives the automatic steering request supplied from the automatic driving ECU 82 .

[0062] Next, in S32, the detection value based on the brake operation state detection device 94 is obtained, and in S33, it is determined whether the detection value is greater than the set brake operation value, and whether the brake operation member is operated. For example, if the determination in S33 is yes, in S34, the operation corresponding target braking force (hereinafter referred to as the first target braking force) Fs is obtained based on the brake operation state. In the case where the operation amount of the brake operation member is large, the first target braking force Fs is determined to be a value larger than the case where the operation amount of the brake operation member is small. In addition, in the case where the determination in S33 is no, the first target braking force Fs is determined to be 0 in S35.

[0063] Next, in S36, it is determined whether an automatic braking request is received. If the determination in S36 is yes, in S37, the automatic driving corresponding target braking force (hereinafter referred to as the second target braking force) Fa is obtained according to the automatic braking request, and if the determination in S36 is no, in S38, the second target braking force Fa is determined to be 0. In S39, the larger one of the first target braking force Fs and the second target braking force Fa is determined as the target braking force F. There is also a case where the target braking force F is 0.

[0064] Furthermore, in S40, the braking forces to be applied to the left wheel 8L and the right wheel 8R are obtained based on the target braking force F and the target left-right braking force difference ΔF determined in S39 and S30, the direction of the turn, etc. Specifically, the left wheel 8L and the right wheel 8R, which are located on the inner side of the turn, and the right wheel 8R, which are located on the outer side of the turn, are identified based on the direction of the turn. Furthermore, the braking forces to be applied to the front, rear, left, and right wheels 8 are determined so that the total braking force Fin applied to one or more wheels 8 located on the inner side of the turn among the left wheel 8L and the right wheel 8R is greater than the total braking force Fout applied to one or more wheels 8 located on the outer side of the turn by the target left-right braking force difference ΔF.

[0065] Fin=F / 2+Fx

[0066] Fout=F / 2-Fy

[0067] Fin-Fout=Fx+Fy=ΔF

[0068] For example, on either the front wheel side or the rear wheel side (for example, the front wheel side), the braking forces applied to the right front wheel and the left front wheel can be controlled so that the difference between the two becomes the target left-right braking force difference ΔF, and the braking forces applied to the left rear wheel and the right rear wheel can be controlled to be the same. In addition, the braking forces applied to the front, rear, left and right wheels 8 can be controlled so that the sum (ΔFf+ΔFr) of the difference ΔFf applied to the left front wheel and the right front wheel and the difference ΔFr applied to the left rear wheel and the right rear wheel approaches the target left-right braking force difference ΔF.

[0069] In addition, when the target braking force F is 0, for example, the braking forces applied to one or more wheels located on the inner side of the turn are controlled so that the total of these braking forces becomes a size corresponding to the target left and right braking force difference ΔF, and the braking forces applied to one or more wheels located on the outer side of the turn are controlled so that the total of these braking forces becomes 0.

[0070] In this way, Figure 8 As shown, for example, the total braking force Fin applied to one or more wheels 8R located on the inner side of the turn of the vehicle V is controlled to be greater than the total braking force Fout applied to one or more wheels 8L located on the outer side of the turn by a target left-right braking force difference ΔF determined based on a steering request (operation steering request, automatic steering request). As a result, the vehicle V can turn based on the operation steering request or the automatic steering request.

[0071] In addition, Figure 6 In the braking control program of , the case where the target left-right braking force difference ΔF is determined based on both the automatic steering request and the operational steering request, that is, based on the larger steering request, is described, but the present invention is not limited to this. For example, it can also be determined based on either the automatic steering request or the operational steering request, for example, the one with a higher priority. The same is true for the target braking force. The target braking force F can be determined based on both the automatic braking request and the operational braking request, or based on either one.

[0072] In addition, the braking force is not limited to that generated by the friction brake 14, and the regenerative braking force of the in-wheel motor 70, the driving force (negative braking force) of the in-wheel motor 70, etc. can also be given to the left wheel 8L and the right wheel 8R. In addition, by controlling at least one of the regenerative braking force and the driving force generated by the in-wheel motor 70, the left and right braking force difference between the left wheel 8L and the right wheel 8R can be made close to the target left and right front and rear force difference. In addition, the in-wheel motor 70 can also be supplied with power from a power source different from the vehicle-mounted power supply device 4.

[0073] Furthermore, the structure of the brake system 7 is not limited. For example, the brake actuator 56 may include an electric motor or a hydraulic cylinder. When the brake actuator 56 includes a hydraulic cylinder, a hydraulic control mechanism capable of controlling the hydraulic pressure of the hydraulic cylinder is provided in the brake system 7, and the operation of the brake actuator 56 is controlled by the control of the hydraulic control mechanism, thereby controlling the braking force applied to the wheel 8.

[0074] In addition, the structure of the steering system 5 is not limited. For example, the steering system 5 can include: a steering rod that is held to be movable in the width direction of the vehicle and is connected to the steering wheel via a tie rod; and a steering actuator that moves the steering rod and includes a moving device that moves the steering rod by driving the steering actuator.

[0075] Furthermore, when the main power supply 72 is abnormal, the steering ECU 12 can be turned on and the brake ECU 16 can be turned off, and the steering ECU 12 can control the steering device 10 to apply braking force to the vehicle. For example, the steering angle of the left wheel 8L is controlled to 90° in the toe direction, and the steering angle of the right wheel 8R is controlled to 90° in the toe direction. In this way, the vehicle can be stopped.

[0076] In this way, the steering ECU 12 and the brake ECU 16 have parts that can replace each other.

[0077] In addition, the present invention can be implemented in various forms after various changes and improvements are made based on the knowledge of those skilled in the art.

[0078] [Inventions that can be protected]

[0079] (1) A vehicle system, wherein the vehicle system comprises: a steering system comprising one or more steering actuators for steering a plurality of steering wheels of the vehicle, and a steering control unit which is mainly composed of a computer and controls the operation of the one or more steering actuators to respectively control the steering angles of the plurality of steering wheels; a fore-and-aft force imparting system comprising a fore-and-aft force imparting actuator for respectively imparting fore-and-aft forces to a left wheel which is one or more wheels located on the left side of the vehicle and a right wheel which is one or more wheels located on the right side of the vehicle, and a fore-and-aft force control unit which is mainly composed of a computer and controls the operation of the plurality of fore-and-aft force imparting actuators to respectively control the fore-and-aft forces respectively imparted to the left wheel and the right wheel; and an on-vehicle power supply device comprising a main power supply and a secondary power supply and capable of supplying power to the fore-and-aft force imparting system and the steering system, wherein, in an abnormal situation where the main power supply cannot supply power to the fore-and-aft force imparting system and the steering system, the fore-and-aft force control unit controls the operation of the plurality of fore-and-aft force imparting actuators to control the difference between the fore-and-aft forces imparted to the left wheel and the right wheel to turn the vehicle.

[0080] The left side wheel may include a left front wheel and a left rear wheel, or may include either the left front wheel or the left rear wheel. The same is true for the right side wheel.

[0081] There are two types of steering actuators: one is commonly provided for a plurality of steering wheels and the other is independently provided. When a steering actuator is commonly provided for a plurality of steering wheels, the steering actuator steers the plurality of steering wheels to the same steering angle. When a steering actuator is independently provided for a plurality of steering wheels, the plurality of steering wheels can be controlled to different steering angles.

[0082] In addition, the steering actuator may include a hydraulic cylinder or an electric motor. In the former case, a hydraulic control mechanism capable of controlling the hydraulic pressure of the steering actuator is provided in the steering system, and the hydraulic control mechanism is controlled by the steering control unit to control the operation of the steering actuator. In the latter case, the current supplied to the electric motor is often controlled by the steering control unit via the drive circuit.

[0083] Furthermore, the front-rear force imparting actuator can impart braking force to the wheels as the front-rear force, or can impart driving force. In addition, the braking force can be the regenerative braking force of the in-wheel motor, the reverse braking force, the friction braking force generated by the friction brake, and the like.

[0084] (2) The vehicle system according to item (1), wherein when the main power supply is abnormal, a portion of the steering control unit other than the communication unit is turned off.

[0085] (3) A vehicle system according to item (1) or (2), wherein the vehicle system includes a power supply monitoring unit that monitors whether the main power supply is abnormal, and the steering control unit includes a communication unit capable of communicating with the power supply monitoring unit, and when the communication unit receives main power supply abnormality information as information indicating that the main power supply is abnormal supplied from the power supply monitoring unit, the steering system or the steering control unit except for the communication unit is turned off.

[0086] (4) A vehicle system according to any one of items (1) to (3), wherein the vehicle system includes a steering operation state detection device for detecting the operating state of a steering operating component operable by a driver, the steering operation state detection device being connected to the steering control unit and the front and rear force control unit, and when the main power supply is not abnormal, the steering control unit controls the operation of the one or more steering actuators based on the operating state of the steering operating component detected by the steering operation state detection device, and when the main power supply is abnormal, the front and rear force control unit controls the operation of the multiple front and rear force applying actuators based on the operating state of the steering operating component detected by the steering operation state detection device.

[0087] (5) A vehicle system according to any one of items (1) to (4), wherein the vehicle system includes: a peripheral information acquisition device for acquiring information indicating the periphery of the above-mentioned vehicle; and an automatic driving control unit for acquiring a steering request for the above-mentioned multiple steering wheels based on the information indicating the periphery of the above-mentioned vehicle acquired by the peripheral information acquisition device, the above-mentioned steering control unit and the above-mentioned front and rear force control unit are communicatively connected to the above-mentioned automatic driving control unit, and when the above-mentioned main power supply is not the above-mentioned abnormality, the above-mentioned steering control unit controls the operation of the above-mentioned one or more steering actuators based on the above-mentioned steering request acquired by the above-mentioned automatic driving control unit, and when the above-mentioned main power supply is the above-mentioned abnormality, the above-mentioned front and rear force control unit controls the operation of the above-mentioned multiple front and rear force applying actuators based on the above-mentioned steering request acquired by the above-mentioned automatic driving control unit.

[0088] The front-rear force control unit receives the steering request supplied from the automatic driving control unit while the parts of the steering control unit other than the communication unit are turned off.

[0089] (6) A vehicle system according to any one of items (1) to (5), wherein the front and rear force imparting actuator is independently provided corresponding to each of the left wheels and each of the right wheels, and the steering actuator is independently provided corresponding to at least one of the left wheels and at least one of the right wheels.

[0090] The steering actuator does not necessarily need to be provided on all the front, rear, left and right wheels, and may be provided on any one of the left and right front wheels or the left and right rear wheels.

[0091] (7) A vehicle system according to any one of items (1) to (6), wherein the fore-and-aft force imparting actuator comprises: a brake actuator, which is respectively provided at each of the left wheels and each of the right wheels, and respectively imparts a braking force as the fore-and-aft force; and a drive actuator, which is respectively provided at at least one of the left wheels and at least one of the right wheels, and imparts a driving force as the fore-and-aft force, and the fore-and-aft force control unit controls at least one of the operations of the plurality of brake actuators and the operations of the plurality of drive actuators.

[0092] By controlling at least one of the braking force and the driving force applied to the wheels, the front-rear force applied to the wheels can be controlled, and the front-rear force difference between the left wheel and the right wheel can be controlled.

[0093] (8) A vehicle system according to any one of items (1) to (7), wherein the fore-and-aft force imparting actuator is a brake actuator respectively provided at each of the left wheels and each of the right wheels and respectively applying a braking force as the fore-and-aft force, the fore-and-aft force imparting system is a brake system having a friction brake, the friction brake comprising: a pair of friction plates respectively provided at each of the left wheels and each of the right wheels and located on both sides of a braking rotating body capable of rotating integrally with the wheels; and a pressing device for pressing the pair of friction plates against the braking rotating body, the brake actuator is a pressing device of the friction brake, and the fore-and-aft force control unit controls the braking force respectively imparted to the left wheels and the braking force respectively imparted to the right wheels by respectively controlling the operation of the plurality of brake actuators.

[0094] When the brake actuator includes an electric motor, the pressing force is controlled by controlling the supply current to the electric motor via the drive circuit, thereby controlling the braking force. When the pressing device includes a hydraulic cylinder, a solenoid valve device capable of controlling the hydraulic pressure of the hydraulic cylinder is provided in the brake system, and the operation of the hydraulic cylinder is controlled by controlling the solenoid valve device, thereby controlling the hydraulic pressure.

[0095] (9) A vehicle system according to any one of items (1) to (8), wherein the fore-and-aft force imparting actuator is a driving actuator that applies the driving force as the fore-and-aft force to at least one of the left wheels and at least one of the right wheels, respectively, and the driving actuator is an in-wheel motor that is independently provided in at least one of the left wheels and at least one of the right wheels, respectively, and the fore-and-aft force control unit controls the driving force imparted to the left wheel and the driving force imparted to the right wheel by respectively controlling the supply current to the plurality of in-wheel motors.

Claims

1. A vehicle system, wherein: The vehicle system comprises: A steering system comprising one or more steering actuators for steering a plurality of steering wheels of a vehicle, and a steering control unit which is mainly composed of a computer and controls the operation of the one or more steering actuators to control the steering angles of the plurality of steering wheels respectively; A front-rear force imparting system, comprising a plurality of front-rear force imparting actuators for imparting front-rear forces to a left wheel, which is one or more wheels located on the left side of the vehicle, and a right wheel, which is one or more wheels located on the right side of the vehicle, respectively, and a front-rear force control unit, which is mainly composed of a computer and controls the operations of the plurality of front-rear force imparting actuators to respectively control the front-rear forces respectively imparted to the left wheel and the right wheel; as well as The vehicle-mounted power supply device includes a main power supply and a secondary power supply, and is capable of supplying power to the front and rear force imparting system and the steering system. In the abnormal situation that the main power supply cannot supply power to the front and rear force application system and the steering system, the front and rear force control unit controls the operation of the multiple front and rear force application actuators respectively, thereby controlling the difference in the front and rear forces applied to the left wheel and the right wheel to make the vehicle turn.

2. The vehicle system according to claim 1, wherein: The vehicle system includes a power supply monitoring unit that monitors whether the main power supply is abnormal. The steering control unit includes a communication unit having a function of communicating with the power supply monitoring unit. When the communication unit receives main power supply abnormality information which is information indicating that the main power supply is abnormal and is supplied from the power supply monitoring unit, the steering system or the steering control unit except the communication unit is turned off.

3. The vehicle system according to claim 1 or 2, wherein: The vehicle system includes a steering operation state detection device for detecting an operation state of a steering operation member operable by a driver, The steering operation state detection device is connected to the steering control unit and the front and rear force control unit. When the main power supply is not abnormal, the steering control unit controls the operation of the one or more steering actuators based on the operating state of the steering operating component detected by the steering operation state detection device. When the main power supply is abnormal, the front and rear force control unit controls the operation of the multiple front and rear force applying actuators based on the operating state of the steering operating component detected by the steering operation state detection device.

4. The vehicle system according to any one of claims 1 to 3, wherein: The vehicle system includes: a surrounding information acquisition device that acquires information indicating the surroundings of the vehicle; and an automatic driving control unit that obtains a steering request for the plurality of steering wheels based on information indicating the surroundings of the vehicle obtained by the surrounding information obtaining device, The steering control unit and the front and rear force control unit are communicably connected to the automatic driving control unit. When the main power supply is not abnormal, the steering control unit controls the operation of the one or more steering actuators based on the steering request obtained by the automatic driving control unit. When the main power supply is abnormal, the front and rear force control unit controls the multiple front and rear force applying actuators based on the steering request obtained by the automatic driving control unit.

5. The vehicle system according to any one of claims 1 to 4, wherein: The front-rear force applying actuator is a brake actuator which is respectively provided at each of the left wheels and each of the right wheels and respectively applies a braking force as the front-rear force. The front-rear force imparting system includes a friction brake, which includes: a pair of friction plates, which are respectively provided on each of the left wheels and each of the right wheels, and are located on both sides of a brake rotating body that can rotate integrally with the wheels; and a pressing device, which presses the pair of friction plates against the brake rotating body, The brake actuator is a pressing device of the friction brake, The front-rear force control unit controls the braking force applied to the left wheels and the braking force applied to the right wheels by controlling the operations of the plurality of brake actuators.

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