Vehicle control device

Abstract

A vehicle control device includes a drive control device (50) configured to be supplied with electric power through a first electric power line (L1) and configured to execute a first process, and a steering control device configured to be supplied with electric power through a second electric power line (L2) and configured to execute a second process. The steering control device is configured to, in a case where it is determined that the supply of electric power through the second electric power line (L2) has stopped during traveling, allow the execution of the second process to stop when it is determined that the drive control device (50) is not in a state in which the first process can be executed, and not allow the execution of the second process to stop when it is determined that the drive control device (50) is in a state in which the first process can be executed.

Description

Technical Field

[0001] This invention relates to vehicle control devices. Background Technology

[0002] A control device exists that controls the motor, which serves as the source of steering force applied to the vehicle's steering mechanism. The control device regulates the power supply to the motor based on vehicle speed and steering torque detected by onboard sensors. Steering force is the torque generated by the motor for steering when the vehicle's direction of travel changes.

[0003] For example, the control device in Japanese Unexamined Patent Application Publication No. 2015-143048 (JP 2015-143048A) can switch between a first power supply path and a second power supply path. The first power supply path includes the ignition switch. The second power supply path includes a power supply line directly drawn from the vehicle battery. The ignition switch is the vehicle's start switch.

[0004] During vehicle operation, the control unit maintains the first power supply path as the power supply path. During vehicle operation, if the power supply through the first power supply path is cut off, for example due to the ignition switch being turned off, the control unit switches the power supply path from the first power supply path to the second power supply path. After a predetermined period of time elapsed since the power supply through the first power supply path was cut off, the control unit cuts off the power supply through the second power supply path.

[0005] This helps prevent the generation of steering force from stopping immediately when the power supply through the first power supply path is cut off while the vehicle is in motion. Summary of the Invention

[0006] After a predetermined period has elapsed since the power supply through the first power supply path was cut off, the control device of JP 2015-143048 A cuts off the power supply through the second power supply path, regardless of the vehicle's state. It is conceivable that in some cases, depending on the vehicle's state, stopping the generation of steering force is not preferable.

[0007] For example, after the generation of driving force for driving stops due to the ignition switch being turned off, the vehicle may continue to move due to inertia. In this case, stopping the generation of steering force is not preferable.

[0008] According to one aspect of the present invention, a vehicle control device includes a drive control device and a steering control device. The drive control device is configured to be powered via a first power line upon activation of a vehicle start switch, and is configured to perform a first process of generating a driving force for driving the vehicle. The steering control device is configured to be powered via a second power line upon activation of a start switch, and is configured to perform a second process of generating a steering force for steering the vehicle. The steering control device is configured such that, if it is determined that the power supply via the second power line has stopped during vehicle operation, when it is determined that the drive control device is not in a state capable of performing the first process, the steering control device allows the execution of the second process to be stopped; and when it is determined that the drive control device is in a state capable of performing the first process, the steering control device does not allow the execution of the second process to be stopped.

[0009] When it is determined that the power supply via the second power line has ceased during vehicle operation, the vehicle control device according to one aspect of the invention can prevent the execution of the second process for generating steering force for vehicle steering from being stopped even though the vehicle is in a state capable of generating driving force for driving. Therefore, it is possible to appropriately stop the generation of steering force according to the vehicle's state. It is also possible to appropriately maintain the steering function according to the vehicle's state.

[0010] In a vehicle control device according to one aspect of the invention, the steering control device can be configured such that, when it is determined that the vehicle has stopped moving and the steering wheel of the vehicle has not been turned, the steering control device stops the execution of the second process, provided that the steering control device has already allowed the execution of the second process to be stopped.

[0011] According to one aspect of the invention, a vehicle control device can prevent the execution of a second process for generating steering forces for vehicle steering from stopping during vehicle operation or when the steering wheel is turned.

[0012] In a vehicle control device according to one aspect of the invention, the steering control device can be configured to determine whether the drive control device is in a state capable of performing a first process based on the voltage level of a first power line.

[0013] According to one aspect of the vehicle control device, a drive control device can determine whether it is in a state capable of performing a first process based on the voltage level of a first power line. In the vehicle control device according to one aspect of the invention, the drive control device can be configured to initiate a specified start preparation triggered by the activation of the vehicle's start switch, and is configured to perform the first process after the start preparation is completed. In this case, the steering control device can be configured to determine whether the drive control device is in a state capable of performing the first process based on whether the start preparation has been completed.

[0014] According to one aspect of the vehicle control device, it can determine whether the drive control device is in a state capable of performing a first process based on whether the start-up preparation of the drive control device has been completed. In the vehicle control device according to one aspect of the invention, the second process may be the process of generating a steering reaction force applied to the steering wheel and generating a rotational force for rotating the wheels, wherein the power transmission from the steering wheel to the wheels of the vehicle is cut off.

[0015] In a vehicle control device according to one aspect of the invention, the second process may be a process of generating an auxiliary force for steering a steering wheel connected to the rotating wheels of the vehicle so that power can be transmitted to the rotating wheels.

[0016] The vehicle control device according to the present invention can appropriately stop generating steering force according to the state of the vehicle. Attached Figure Description

[0017] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which similar reference numerals denote similar elements, and in the drawings:

[0018] Figure 1 This is a configuration diagram of a steer-by-wire steering system according to one embodiment of a vehicle control device.

[0019] Figure 2 This is a block diagram illustrating the configuration of a vehicle control system according to one embodiment;

[0020] Figure 3 This is a schematic diagram illustrating a comparative example of vehicle state transitions;

[0021] Figure 4 This is a schematic diagram illustrating the state transitions of a vehicle according to one embodiment; and

[0022] Figure 5 This is a configuration diagram of an electric power steering system equipped with a vehicle control device according to another embodiment. Detailed Implementation

[0023] The following describes one embodiment in which the steering control device is implemented as a steer-by-wire steering system. For example... Figure 1 As shown, the vehicle's steer-by-wire system 10 has a steering shaft 12 connected to the steering wheel 11. The steer-by-wire system 10 has a steering shaft 12 along the vehicle's width direction (…). Figure 1 A steering shaft 13 extends in the left-right direction (within the vehicle's steering mechanism). At both ends of the steering shaft 13, rotating wheels 15 are connected by tie rods 14. When the steering shaft 13 moves linearly, the rotation angle θw of the rotating wheels 15 changes. The steering shaft 12 and the rotating shaft 13 constitute the vehicle's steering mechanism. Figure 1 In the image, only one side of the rotating wheel 15 is shown.

[0024] The steer-by-wire steering system 10 includes a reaction force motor 21 and a reduction gear 22. The reaction force motor 21 is, for example, a three-phase brushless motor. The reaction force motor 21 is the source of the steering reaction force. The steering reaction force is a force acting in the opposite direction to the direction from which the driver operates the steering wheel 11. The steering reaction force is the steering force generated by the reaction force motor 21 for steering when the vehicle's direction of travel changes.

[0025] The rotation shaft of the reaction force motor 21 is connected to the steering shaft 12 via a reduction gear 22. The torque of the reaction force motor 21 is applied to the steering shaft 12 as a steering reaction force. Applying the steering reaction force to the steering wheel 11 can give the driver an appropriate steering resistance feel.

[0026] The steer-by-wire steering system 10 includes a rotary motor 31 and a reduction gear 32. The rotary motor 31 is, for example, a three-phase brushless motor. The rotary motor 31 is the source of rotational force. Rotational force refers to the power used to rotate the rotating wheel 15. Rotational force is the steering force generated by the rotary motor 31 for steering when the vehicle's forward direction changes.

[0027] The rotating shaft of the rotary motor 31 is connected to the pinion shaft 33 via a reduction mechanism 32. The pinion teeth 33a of the pinion shaft 33 mesh with the rack teeth 13a of the rotating shaft 13. The torque of the rotary motor 31 is applied to the rotating shaft 13 as a rotational force through the pinion shaft 33. As the rotary motor 31 rotates, the rotating shaft 13 moves along the width direction of the vehicle.

[0028] The steer-by-wire steering system 10 includes a steering control unit 40. The steering control unit 40 constitutes a vehicle control unit. The steering control unit 40 includes a processing circuit, which includes one of the following three configurations: A1, A2, and A3.

[0029] A1. One or more processors that operate according to a computer program as software. A processor includes a central processing unit (CPU) and memory.

[0030] A2. One or more dedicated hardware circuits, such as application-specific integrated circuits (ASICs) that perform at least some of the various processes. The ASIC includes a CPU and memory.

[0031] A3. Combine the hardware circuitry configured with A1 and A2. Memory is a computer-readable medium that stores programs written for computer processing or commands. In this embodiment, the computer is the CPU. Memory includes random access memory (RAM) and read-only memory (ROM). The CPU performs various types of control by executing programs stored in memory in specified arithmetic operation cycles.

[0032] The steering control device 40 includes a reaction force control device 40A and a rotation control device 40B. The reaction force control device 40A controls the drive of the reaction force motor 21, which is the control target. The reaction force control device 40A performs reaction force control to generate a steering reaction force based on the steering torque Th of the reaction force motor 21. The reaction force control device 40A calculates the target steering reaction force based on the steering torque Th detected by the torque sensor 23. The torque sensor 23 is mounted on the steering shaft 12. The reaction force control device 40A controls the power supply to the reaction force motor 21 such that the actual steering reaction force applied to the steering shaft 12 matches the target steering reaction force.

[0033] The reaction force control device 40A and the reaction force motor 21 can be integrated to form a so-called mechatronic reaction force actuator. The rotation control device 40B controls the drive of the rotation motor 31, which is the control target. The rotation control device 40B performs rotation control to generate a rotational force in the rotation motor 31 to rotate the rotating wheel 15 according to the steering state. The rotation control device 40B receives the steering angle θs detected by the steering angle sensor 24 and the stroke Xw of the rotating shaft 13 detected by the stroke sensor 34. The stroke Xw is the offset of the rotating shaft 13 relative to its neutral position and is a state variable reflecting the steering angle θw. The steering angle sensor 24 is disposed on the steering shaft 12, between the torque sensor 23 and the reduction mechanism 22. The stroke sensor 34 is disposed near the rotating shaft 13.

[0034] The rotation control device 40B calculates the target rotation angle of the rotating wheel 15 based on the steering angle θs detected by the steering angle sensor 24. The rotation control device 40B calculates the rotation angle θw based on the stroke Xw of the rotating shaft 13 detected by the stroke sensor 34. The rotation control device 40B controls the power supply to the rotating motor 31 so that the rotation angle θw calculated based on the stroke Xw matches the target rotation angle.

[0035] The rotation control device 40B and the rotation motor 31 can be integrated to form a so-called mechatronic rotation actuator. The rotation control device 40B and the reaction force control device 40A can communicate with each other. The rotation control device 40B and the reaction force control device 40A can communicate with each other and exchange information therefrom.

[0036] The vehicle has a drive control unit 50. The drive control unit 50 constitutes the vehicle control unit. The configuration of the drive control unit 50 is substantially similar to that of the steering control unit 40. The reaction force control unit 40A and the on-board drive control unit 50 are connected to each other via an on-board network 51. The on-board network 51 is, for example, a controller area network (CAN). The reaction force control unit 40A and the drive control unit 50 exchange information with each other via the on-board network 51.

[0037] Drive control unit 50 controls the movement of the vehicle. Specifically, drive control unit 50 controls, for example, the vehicle's powertrain. The powertrain includes the vehicle's drive source and power transmission mechanism. The drive source generates driving force to move the vehicle. The drive source includes, for example, an engine or a motor. When the drive source is an engine, the control target of drive control unit 50 includes a fuel injection device. The power transmission mechanism is a mechanism that transmits the driving force generated by the drive source to the drive wheels. Reaction force control unit 40A controls the drive of reaction force motor 21 based on information exchanged between reaction force control unit 40A and drive control unit 50.

[0038] The control of the vehicle's powertrain performed by the drive control unit 50 is an example of a first process that generates driving forces for the vehicle's movement. The reaction force control and rotation control performed by the steering control unit 40 are examples of a second process that generates steering forces for the vehicle's steering.

[0039] Configuration of vehicle control system

[0040] Next, the configuration of the vehicle's control system will be described. For example... Figure 2 As shown, in addition to the steering control device 40 and drive control device 50 described above, the vehicle's control system also includes various control devices or control systems. For example, the control system includes a body control device 60, an electrical distribution control device 70, and other systems 80. These other systems 80 include various types of systems required to operate when generating driving forces for travel in the vehicle's drivetrain.

[0041] Various types of control devices, including steering control unit 40, drive control unit 50, body control unit 60, and other systems 80, are powered by an on-board DC power supply 90. The DC power supply 90 is, for example, a battery. Various types of sensors, including torque sensor 23, steering angle sensor 24, and travel sensor 34, are also powered by the DC power supply 90.

[0042] Steering control unit 40, drive control unit 50, body control unit 60, and other systems 80 are interconnected via an in-vehicle network 51. Body control unit 60 and power distribution control unit 70 are communicatively connected to each other via board-to-board connectors 61. The standard for communication between body control unit 60 and power distribution control unit 70 is, for example, a Clock Extended Peripheral Interface (CXPI).

[0043] Drive control unit 50, body control unit 60, power distribution control unit 70, and other systems 80 are connected to DC power supply 90 via first power line L1. Steering control unit 40 is connected to DC power supply 90 via second power line L2 and power distribution control unit 70.

[0044] The first power line L1 has a start switch 91A and a first relay 91B. The start switch 91A is located closer to the DC power supply 90 than the first relay 91B.

[0045] The starter switch 91A is, for example, an ignition switch or a power switch. It operates when the starter switch 91A starts or stops the vehicle's driving source (such as an engine). When the starter switch 91A is turned on, it supplies power from the DC power supply 90 to each of the control units (40, 50, 60, 70) and other systems 80. Turning on the starter switch 91A means the vehicle's power is on. Turning off the starter switch 91A means the vehicle's power is off.

[0046] The first relay 91B opens and closes the first power line L1. The first relay 91B has a coil and contacts. When the coil is energized, the contacts close. When the coil is not energized, the contacts open.

[0047] The vehicle control unit 60 is connected to the first connection point P1 of the first power line L1. The first connection point P1 is located on the first power line L1, between the start switch 91A and the first relay 91B.

[0048] The power distribution control device 70 is connected to the second connection point P2 of the first power line L1. The second connection point P2 is located on the first power line L1, between the first connection point P1 and the first relay 91B.

[0049] The drive control device 50 is connected to the third connection point P3 of the first power line L1. The third connection point P3 is located on the opposite side of the first relay 91B relative to the second connection point P2.

[0050] Other systems 80 are connected to the fourth connection point P4 of the first power line L1. The fourth connection point P4 is located on the opposite side of the third connection point P3 relative to the first relay 91B.

[0051] In the first power line L1, the start switch 91A, the first connection point P1, the second connection point P2, the first relay 91B, the third connection point P3, and the fourth connection point P4 are moved away from the DC power supply 90 in this order.

[0052] The vehicle body control unit 60 includes a control circuit 60A. The control circuit 60A is a CPU. The control circuit 60A controls the functions of the entire vehicle body. The control circuit 60A centrally controls, for example, the air conditioning inside the vehicle cabin, the lighting inside and outside the vehicle cabin, doors, windows, mirrors, and wipers.

[0053] The power distribution control device 70 includes a control circuit 70A and a second relay 70B. The control circuit 70A is a CPU. The control circuit 70A controls the distribution of power supplied by the DC power supply 90. The control circuit 70A can communicate with the control circuit 60A.

[0054] The second relay 70B has a configuration similar to that of the first relay 91B. The input terminal of the second relay 70B is connected to the second connection point P2 of the first power line L1 via a connecting line LC. The output terminal of the second relay 70B is connected to the second power line L2. The connecting line LC has a diode 70C for preventing backflow. The anode of the diode 70C is connected to the second connection point P2. The cathode of the diode 70C is connected to the input terminal of the second relay 70B.

[0055] Steering control device 40 is connected to the fifth connection point P5 of the second power line L2. Drive control device 50 is connected not only to the first power line L1, but also to the sixth connection point P6 of the second power line L2.

[0056] Control circuit 70A controls the opening and closing of the first relay 91B and the second relay 70B. When the first relay 91B is closed, the portion of the first electric field line L1 between the second connection point P2 and the third connection point P3 becomes conductive. When the first relay 91B is closed, the conduction of the first electric field line L1 between the second connection point P2 and the third connection point P3 is interrupted. When the second relay 70B is closed, the connecting line LC and the second electric field line L2 become conductive. When the second relay 70B is closed, the conduction between the connecting line LC and the second electric field line L2 is interrupted.

[0057] The control circuit 70A has a first input terminal 70D and a second input terminal 70E. The first input terminal 70D is connected to the seventh connection point P7 of the connecting line LC via a first lead-in line LW1. The seventh connection point P7 is located at the connecting line LC, between the second connection point P2 and the diode 70C. The first input terminal 70D and the first lead-in line LW1 are connected to each other, for example, via a connector.

[0058] The second input terminal 70E is connected to the eighth connection point P8 of the connecting line LC via the second lead-in line LW2. The eighth connection point P8 is located between the diode 70C and the second relay 70B of the connecting line LC. The second input terminal 70E and the second lead-in line LW2 are connected to each other, for example, via a connector.

[0059] Control circuit 70A receives power supplied to first relay 91B via connection line LC and first input line LW1. Control circuit 70A receives power supplied to second relay 70B via connection line LC and second input line LW2. Control circuit 70A monitors the voltage level of first input terminal 70D and the voltage level of second input terminal 70E.

[0060] When the voltage level at the first input terminal 70D is equal to or higher than the first voltage threshold, the control circuit 70A turns on the first relay 91B. That is, the control circuit 70A supplies an electrical signal to the first relay 91B to energize its coil. When the coil of the first relay 91B is energized, the contacts of the first relay 91B close. When the first relay 91B is on, power from the DC power supply 90 is supplied to the drive control device 50 and other systems 80 via the first power line L1.

[0061] When the start switch 91A is turned on, a first voltage threshold is set based on the voltage applied to the first input terminal 70D. The voltage level of the first input terminal 70D is an example of the voltage level of the first power line L1.

[0062] Control circuit 70A sets the value of a first flag based on the voltage level of the first input terminal 70D. When the voltage level of the first input terminal 70D is equal to or higher than a first voltage threshold, control circuit 70A sets the value of the first flag to 1 (=Hi). When the voltage level of the first input terminal 70D is lower than the first voltage threshold, control circuit 70A sets the value of the first flag to "0 (=Lo)". The first flag indicates the on or off state of the start switch 91A.

[0063] When the voltage level at the second input terminal 70E is equal to or higher than the second voltage threshold, the control circuit 70A turns on the second relay 70B. That is, the control circuit 70A supplies an electrical signal to the second relay 70B to energize its coil. When the coil of the second relay 70B is energized, the contacts of the second relay 70B close. When the second relay 70B is on, power from the DC power supply 90 is supplied to the steering control device 40 and the drive control device 50 through the second power line L2.

[0064] When the start switch 91A is turned on, a second voltage threshold is set based on the voltage applied to the second input terminal 70E. The voltage level of the second input terminal 70E is an example of the voltage level of the second power line L2.

[0065] Control circuit 70A sets the value of the second flag based on the voltage level of the second input terminal 70E. When the voltage level of the second input terminal 70E is equal to or higher than the second voltage threshold, control circuit 70A sets the value of the second flag to "1 (=Hi)". When the voltage level of the second input terminal 70E is lower than the second voltage threshold, control circuit 70A sets the value of the second flag to "0 (=Lo)". The second flag indicates the on or off state of the start switch 91A.

[0066] The body control unit 60 receives the values ​​of a first indicator and a second indicator. The values ​​of the first and second indicators are shared among various types of control units or control systems via an in-vehicle network 51. The control units include steering control unit 40, drive control unit 50, body control unit 60, and control units for other systems 80.

[0067] The steering control unit 40 is connected to a DC power supply 90 via a power relay (not shown). When the power relay is on, power from the DC power supply 90 is supplied to the steering control unit 40 through the power relay. When the power relay is off, the power supply through the power relay is cut off. The steering control unit 40 controls the on and off states of the power relay. When the start switch 91A is on, the steering control unit 40 turns on the power relay. When the start switch 91A is off, the steering control unit 40 turns off the power relay.

[0068] The steering control device 40 can be configured to perform power latching control after the start switch 91A is turned off, that is, to keep the power relay in the on state for a specified period of time. Therefore, the steering control device 40 can also operate after the start switch 91A is turned off. When the specified period of time has elapsed, the steering control device 40 cuts off its own power supply by turning off the power relay.

[0069] When the power supply to the steering control device 40 via the power relay is cut off, the execution of reaction force control and rotation control by the steering control device 40 stops.

[0070] Turn off the start switch while driving.

[0071] The following problem exists in the vehicle. It is conceivable that the start switch 91A can be turned off while the vehicle is in motion. However, since the vehicle is in motion, it is not preferable to immediately stop the execution of reaction force control and steering control by the steering control device 40 when the power supply to the steering control device 40 via the power relay is cut off.

[0072] To handle the situation where the start switch 91A is turned off during driving, one approach is to configure the steering control device 40 as follows: For example, the steering control device 40 determines that the start switch 91A has been turned off during vehicle driving when all three conditions B1 to B3 are met. When it is determined that the start switch 91A has been turned off during vehicle driving, the steering control device 40 continues to execute reaction force control and steering control.

[0073] B1.”V2 <V 2th "

[0074] "V2" is the voltage level of the second electric field line L2. 2th "This is the voltage threshold. The voltage threshold is a criterion used to determine whether the start switch 91A has been turned off, and is set, for example, based on the voltage level of the second power line L2 when the start switch 91A is turned off."

[0075] B2.”V>V th1 "

[0076] "V" represents the vehicle speed value obtained through the vehicular network 51. th1 "This is the first vehicle speed threshold. The first vehicle speed threshold V" th1 It is a standard used to determine whether a vehicle is moving, and it is set based on a very low speed, such as a few kilometers per hour.

[0077] B3.”FG2=0”

[0078] "FG2" is the value of a second flag set by the power distribution control unit 70. A value of "0" for the second flag FG2 means that the voltage level at the second input terminal 70E is lower than a second voltage threshold. The steering control unit 40 obtains the value of the second flag FG2 through the vehicle network 51.

[0079] When it is determined that the start switch 91A has been turned off during vehicle operation, the steering control device 40 allows the execution of reaction force control and steering control to cease. When it is determined that the start switch 91A has been turned off during vehicle operation, the steering control device 40 stops the execution of reaction force control and steering control if either of the following two conditions, C1 or C2, is met.

[0080] C1.”V≤V th2 "and" T1≥T1 th "

[0081] V th2 "This is the second vehicle speed threshold. The second vehicle speed threshold V..." th2 With the first vehicle speed threshold V th1 Possibly the same. "T1" is the time since the vehicle speed V has decreased to be equal to or less than the second vehicle speed threshold V. th2 The value is the time that has elapsed since then. "T1" th "This is the first time threshold. The first time threshold is the standard used to determine whether a vehicle is stationary."

[0082] C2.”Th≤Th th "and" T2≥T2 th "

[0083] "Th" refers to steering torque. th "T2" is the torque threshold. The torque threshold is the standard used to determine whether the steering wheel 11 is not being turned. "T2" is the time elapsed since the steering torque Th has decreased to a value equal to or less than the torque threshold. th "This is the second time threshold. The second time threshold is the standard used to determine whether the situation causes the steering wheel 11 to not be turned."

[0084] As condition C1, the following conditions can be used.

[0085] C1.”T3≥T3 th "

[0086] "T3" represents the elapsed time since the automatic start switch 91A was turned off while the vehicle was in motion. th "This is the third time threshold. The third time threshold T3..." th Set to the first time threshold T1 th Compared to sufficiently large values. Third time threshold T3 th It is a standard used to determine whether a vehicle is stationary.

[0087] Therefore, even if the start switch 91A is turned off while the vehicle is in motion, the execution of reaction force control and steering control by the steering control device 40 will not stop immediately. When the vehicle stops moving and the steering wheel 11 is no longer being turned, the execution of reaction force control and steering control by the steering control device 40 ceases.

[0088] However, the following phenomena may occur in a vehicle. For example... Figure 3 As shown in part (a), it is conceivable that the connector 100, which connects the second input terminal 70E of the power distribution control device 70 to the second lead line LW2, may detach during vehicle operation. In this case, although the start switch 91A has not been turned off, the steering control device 40 may stop executing reaction force control and steering control.

[0089] Specifically, when the connector is disconnected, the voltage level at the second input terminal 70E decreases to a value lower than the second voltage threshold. Therefore, the power distribution control device 70 sets the value of the second flag FG2 to "0". Furthermore, when the voltage level at the second input terminal 70E decreases to a value lower than the second voltage threshold, the power distribution control device 70 turns off the second relay 70B. Therefore, the power supply from the DC power supply 90 to the second power line L2 is stopped.

[0090] Therefore, when the vehicle is moving and the value of the vehicle speed V is greater than the first vehicle speed threshold V th1 In this case, the steering control device 40 incorrectly determines that the start switch 91A has been turned off during vehicle operation because all three conditions B1 to B3 mentioned above are met.

[0091] like Figure 3 As shown in parts (b) and (c), when the above-mentioned condition C1 is satisfied due to the vehicle stopping, and the above-mentioned condition C2 is satisfied due to the steering wheel 11 no longer being turned, the steering control device 40 stops executing the reaction force control and rotation control.

[0092] like Figure 3 As shown in section (d), even when the steering control device 40 has stopped executing reaction force control and rotation control, the drive control device 50 continues to operate normally. Therefore, although the vehicle is in a driving state, it may lose its steering function. The steering function is the function of turning the steering wheel 15 according to the amount of operation of the steering wheel 11.

[0093] In addition, when the second lead wire LW2 or the second power line L2 breaks or experiences a grounding fault during vehicle operation, the same phenomenon as when connector 100 falls off may occur.

[0094] Processing to determine the status of the start switch during driving.

[0095] In this embodiment, the steering control device 40 is therefore configured as follows. In addition to the three conditions B1 to B3 mentioned above, the steering control device 40 also includes the following condition B4 as a condition for determining the state of the start switch 91A during vehicle operation.

[0096] B4.”FG1=0”

[0097] "FG1" is the value of a first flag set by the power distribution control unit 70. A value of "0" for the first flag FG1 means that the voltage level at the first input terminal 70D is lower than a first voltage threshold. The steering control unit 40 obtains the value of the first flag FG1 through the vehicle network 51.

[0098] When all four conditions B1 to B4 are met, the steering control device 40 determines that the start switch 91A has been turned off during vehicle operation. When it is determined that the start switch 91A has been turned off during vehicle operation, the steering control device 40 allows the execution of reaction force control and steering control to cease. If it is determined that the start switch 91A has been turned off during vehicle operation, and either of the two conditions C1 or C2 is met, the steering control device 40 stops the execution of reaction force control and steering control.

[0099] How the implementation method works

[0100] Next, the working principle of the implementation method will be described. For example... Figure 4 As shown in part (a), it is conceivable that the connector 100, which connects the second input terminal 70E of the power distribution control device 70 to the second lead-in line LW2, may detach during vehicle operation. In this case, the voltage level of the second input terminal 70E decreases to a value lower than the second voltage threshold. Therefore, the power distribution control device 70 sets the value of the second flag FG2 to "0". Furthermore, when the voltage level of the second input terminal 70E decreases to a value lower than the second voltage threshold, the power distribution control device 70 turns off the second relay 70B. Therefore, the power supply from the DC power supply 90 to the second power line L2 stops. Therefore, when the vehicle is traveling and the value of the vehicle speed V is greater than the first vehicle speed threshold V, the power supply is interrupted. th1 When the above three conditions B1 to B3 are met.

[0101] However, when the start switch 91A is not actually turned off, the voltage level of the first input terminal 70D remains equal to or greater than the first voltage threshold. That is, the value of the first flag FG1 is maintained at "1". Since condition B4 is not met, the steering control device 40 is unsure whether the start switch 91A has been turned off during vehicle operation.

[0102] Therefore, even when either of the two conditions C1 or C2 is met, the steering control device 40 does not cease executing the reaction force control and rotation control. Correspondingly, the drive control device 50 continues to operate normally, thus preventing the vehicle from losing its steering function despite being in a drivable state. Because the steering control device 40 continues to execute the reaction force control and rotation control, the steering function is maintained.

[0103] Furthermore, if the second lead wire LW2 or the second power line L2 breaks or experiences a ground fault during vehicle operation, the same procedure as when connector 100 detaches is performed. Figure 4 As shown in section (b), when the start switch 91A is actually turned off during vehicle operation, the voltage level at the first input terminal 70D decreases to a value lower than the first voltage threshold. Therefore, the power distribution control unit 70 sets the value of the first flag FG1 to "0". Furthermore, when the voltage level at the first input terminal 70D decreases to a value lower than the first voltage threshold, the power distribution control unit 70 turns off the first relay 91B. Therefore, the power supply from the DC power supply 90 to the first power line L1 stops. Accordingly, the drive control unit 50 and other systems 80 cease operation, so that the vehicle's powertrain does not generate driving force for travel. However, when the start switch 91A is turned off during vehicle operation, the vehicle can continue to travel by inertia.

[0104] When the start switch 91A is actually turned off during vehicle operation, the voltage level at the second input terminal 70E decreases to a value lower than the second voltage threshold. Therefore, the power distribution control device 70 sets the value of the second flag FG2 to "0". Furthermore, when the voltage level at the second input terminal 70E decreases to a value lower than the second voltage threshold, the power distribution control device 70 turns off the second relay 70B. Therefore, the power supply from the DC power supply 90 to the second power line L2 stops. Thus, when the vehicle is moving and the vehicle speed V is greater than the first vehicle speed threshold V... th1 At that time, all four conditions B1 to B4 above are satisfied.

[0105] Since all four conditions B1 to B4 above are met, the steering control device 40 determines that the start switch 91A has been turned off during vehicle operation. Figure 4 As shown in parts (c), (d), and (e), when condition C1 is subsequently met due to the vehicle stopping, and condition C2 is met further due to the steering wheel 11 no longer being turned, the steering control device 40 ceases to execute reaction force control and rotation control. The drive control device 50, other systems 80, and the vehicle's powertrain remain in a state of inactivity.

[0106] Advantages of the implementation method

[0107] This implementation method can provide the following advantages.

[0108] (1) When it is determined that the power supply through the second power line L2 has stopped during vehicle operation, and when it is determined that the drive control device 50 is not in a state capable of performing the process of generating driving force for driving, the steering control device 40 allows the execution of reaction force control and rotation control to be stopped. On the other hand, when it is determined that the power supply through the second power line L2 has stopped during vehicle operation, and when it is determined that the drive control device 50 is in a state capable of performing the process of generating driving force for driving, the steering control device 40 does not allow the execution of reaction force control and rotation control to be stopped.

[0109] Therefore, by determining that the power supply through the second power line L2 has ceased during vehicle operation, it is possible to avoid situations where the execution of reaction force control and steering control stops even when the vehicle is in a state capable of generating driving force for propulsion. In other words, by ceasing the execution of reaction force control and steering control based on the vehicle's state, the steering function can be appropriately stopped. Furthermore, by continuing the execution of reaction force control and steering control based on the vehicle's state, the steering function can be appropriately maintained.

[0110] (2) It is conceivable that the power supply through the second power line L2 can be stopped, for example, due to the disconnection of connector 100. When connector 100 is disconnected, only the power supply through the second power line L2 stops, while the power supply through the first power line L1 continues. On the other hand, when the start switch 91A is turned off, both the power supply through the first power line L1 and the power supply through the second power line L2 stop.

[0111] Therefore, when it is determined that the power supply through the second power line L2 has stopped during vehicle operation, and when it is determined that the drive control device 50 is in a state capable of performing the processing to generate driving force for driving, the steering control device 40 is not allowed to stop the execution of reaction force control and rotation control. That is, even if conditions B1 to B3 are met, the steering control device 40 is not allowed to stop the execution of reaction force control and rotation control unless condition B4 is met. Therefore, it is possible to more accurately determine whether the start switch 91A has been turned off. This helps prevent the steering control device 40 from erroneously stopping the execution of reaction force control and rotation control due to connector 100 detachment.

[0112] This also applies to situations where the second lead line LW2 or the second power line L2 is broken or has a grounding fault.

[0113] (3) When the steering control device 40 has already allowed the execution of reaction force control and rotation control to stop, when the above two conditions C1 and C2 are met and it is therefore determined that the vehicle has stopped moving and the steering wheel 11 is not being turned, the steering control device 40 stops the execution of reaction force control and rotation control. Therefore, the situation where the execution of reaction force control and rotation control stops during vehicle movement or when the steering wheel 11 is being turned can be avoided.

[0114] (4) The steering control device 40 can easily determine whether the drive control device 50 is in a state capable of performing the process of generating driving force for driving based on the voltage level of the first power line L1. The voltage level of the first power line L1 can be identified based on the value of the first flag FG1 set by the power distribution control device 70.

[0115] (5) In the steer-by-wire system 10, the power transmission between the steering wheel 11 and the turning wheel 15 is cut off. Therefore, the steer-by-wire system 10 needs to maintain or stop the steering function appropriately depending on the vehicle's condition. In this regard, even when it is determined that the start switch 91A has been turned off during vehicle operation, the steering control device 40 does not stop executing the reaction force control and rotation control during vehicle operation or when the steering wheel 11 is turned. Therefore, this embodiment is applicable to the steer-by-wire system 10.

[0116] Other implementation methods

[0117] The implementation can be achieved by making the following changes.

[0118] The reaction force motor 21 may have a set of windings for a first system and a set of wiring for a second system. The first and second system wirings are wound around a common stator. The first and second system wirings are electrically equivalent to each other. The reaction force control device 40A independently controls the power supply to the two sets of windings for each system in the reaction force motor 21.

[0119] In this configuration, the reaction force control device 40A may have a first system circuit and a second system circuit. The first system circuit controls the power supply to a set of windings of the first system in the reaction force motor 21 based on the steering torque Th detected by the torque sensor 23. The second system circuit controls the power supply to a set of windings of the second system in the reaction force motor 21 based on the steering torque Th detected by the torque sensor 23.

[0120] The rotary motor 31 may have a set of windings for a first system and a set of wiring for a second system. The first and second sets of wiring are wound around a common stator. The first and second sets of wiring are electrically equivalent to each other. The rotation control device 40B independently controls the power supply to the two sets of windings for each of the two systems in the rotary motor 31.

[0121] In this configuration, the rotation control device 40B may have a first system circuit and a second system circuit. The first system circuit controls the power supply to a set of windings of the first system in the rotation motor 31 based on the steering angle θs detected by the steering angle sensor 24 and the travel Xw of the rotation shaft 13 detected by the travel sensor 34. The second system circuit controls the power supply to a set of windings of the second system in the rotation motor 31 based on the steering angle θs detected by the steering angle sensor 24 and the travel Xw of the rotation shaft 13 detected by the travel sensor 34.

[0122] When the start switch 91A is turned on, i.e., when the vehicle power is turned on, the drive control unit 50 begins to execute the specified start preparation. After the start preparation is completed, the drive control unit 50 starts the vehicle's powertrain. When the execution of the powertrain start process is completed, the drive control unit 50 activates the preparation completion signal. The preparation completion signal indicates that the vehicle's powertrain is in a state capable of generating driving force for travel. The preparation completion signal can be a third flag. When the vehicle's powertrain is in a state capable of generating driving force for travel, the drive control unit 50 sets the value of the third flag to "1". When the vehicle's powertrain is not in a state capable of generating driving force for travel, the drive control unit 50 sets the value of the third flag to "0".

[0123] Based on this premise, the steering control device 40 may use the following condition B5 instead of the above condition B4 as the condition for determining the state of the start switch 91A during vehicle operation.

[0124] B5.”FG3=0”

[0125] "FG3" is the value of the third flag set by the drive control unit 50. The steering control unit 40 obtains the value of the third flag FG3 through the vehicle network 51.

[0126] Therefore, the steering control device 40 can determine whether the drive control device 50 is in a state capable of performing the process of generating driving force for driving based on whether the start preparation of the drive control device 50 has been completed. Furthermore, the steering control device 40 can determine whether the start switch 91A has been turned off during vehicle operation based on whether all four conditions B1 to B3 and B5 mentioned above are met. When it is determined that the start switch 91A has been turned off during vehicle operation, the steering control device 40 allows the execution of reaction force control and steering control to stop. When either of the two conditions (C1) or (C2) mentioned above is met, the steering control device 40 stops the execution of reaction force control and steering control.

[0127] The steering control device 40 can be incorporated into the electric power steering system. In the electric power steering system 200, the aforementioned… Figure 1 The steering wheel 11 and the rotating wheel 15 shown are mechanically connected to each other. Therefore, the steering shaft 12, pinion shaft 33, and rotating shaft 13 serve as the power transmission path between the steering wheel 11 and the rotating wheel 15. When the rotating shaft 13 performs a linear movement according to the steering of the steering wheel 11, the rotation angle θw of the rotating wheel 15 changes.

[0128] The electric power steering system 200 includes an auxiliary motor 201 and an auxiliary control device 202. The auxiliary motor 201 is disposed in conjunction with the aforementioned... Figure 1 The reaction force motor 21 or the rotation motor 31 shown are in the same position. Figure 5 In the example, the auxiliary motor 201 is set with... Figure 1 The reaction force motor 21 shown is located at the same position. The auxiliary control device 202 is an example of a steering control device. The auxiliary control device 202 controls the drive of the auxiliary motor 201, which is the control target. The auxiliary control device 202 performs auxiliary control to generate an auxiliary force in the auxiliary motor 201. The auxiliary force is a torque used to assist the operation of the steering wheel 11, and is a torque in the same direction as the steering direction of the steering wheel 11. The auxiliary force is a steering force generated by the auxiliary motor 201 for steering when the vehicle's forward direction changes.

[0129] The auxiliary control device 202 determines whether the start switch 91A has been turned off during vehicle operation based on whether all four conditions B1 to B4 are met. When all four conditions B1 to B4 are met, the auxiliary control device 202 determines that the start switch 91A has been turned off during vehicle operation. If the start switch 91A is determined to be turned off during vehicle operation, the auxiliary control device 202 stops executing auxiliary control when either of the two conditions C1 or C2 is met.

[0130] When connector 100 detaches while the vehicle is in motion, condition B4 is not met. Therefore, when connector 100 detaches while the vehicle is in motion, the auxiliary control device 202 will not incorrectly determine that the start switch 91A was turned off while the vehicle is in motion. Even when both of the above conditions C1 and C2 are met, the auxiliary control device 202 continues to execute auxiliary control. Therefore, it avoids a situation where the vehicle loses its steering function even when it is in a drivable state.

Claims

1. A vehicle control device, characterized in that... include: A drive control device (50) is configured to be supplied with power via a first power line (L1) triggered by the activation of the vehicle's start switch (91A), and is configured to perform a first process to generate a driving force for the vehicle's movement. as well as A steering control device, configured to be powered via a second power line (L2) triggered by the activation of the start switch (91A), and configured to perform a second process of generating a steering force for steering the vehicle, wherein... The steering control device is configured such that, when it is determined that the power supply through the second power line (L2) has stopped during vehicle operation, the steering control device allows the execution of the second process to be stopped when it is determined that the drive control device (50) is not in a state capable of performing the first process, and when it is determined that the drive control device (50) is in a state capable of performing the first process, the steering control device does not allow the execution of the second process to be stopped.

2. The vehicle control device according to claim 1, characterized in that, The steering control device is configured such that, when it is determined that the vehicle has stopped moving and the steering wheel of the vehicle has not been turned, the steering control device stops the execution of the second process if the steering control device has already allowed the execution of the second process to be stopped.

3. The vehicle control device according to claim 1 or claim 2, characterized in that, The steering control device is configured to determine whether the drive control device (50) is in a state capable of performing the first process based on the voltage level of the first power line (L1).

4. The vehicle control device according to claim 1 or claim 2, characterized in that: The drive control device (50) is configured to initiate a specified start preparation by triggering the opening of the vehicle's start switch (91A), and to perform the first process after the start preparation is completed; as well as The steering control device is configured to determine whether the drive control device (50) is in a state capable of performing the first process based on whether the start-up preparation has been completed.

5. The vehicle control device according to claim 1 or claim 2, characterized in that, The second process is the generation of a steering reaction force applied to the steering wheel and a rotational force for rotating the wheels, wherein the power transmission from the steering wheel to the wheels of the vehicle is cut off.

6. The vehicle control device according to claim 1 or claim 2, characterized in that, The second process is the generation of an auxiliary force for steering a steering wheel connected to the rotating wheels of the vehicle, so that power can be transmitted to the rotating wheels.

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