Steering control unit, vehicle power system and vehicle

Abstract

This invention discloses a steering control device, a vehicle power system, and a vehicle. The steering control device (50) includes a controller configured to control the drive of an electric motor that generates torque. The torque is the torque applied to the vehicle's steering mechanism using power from at least one of an onboard main power supply (71) and an auxiliary power supply (70A) that is a backup main power supply (71). The controller is configured to, when activated by a vehicle start-up operation and transitioning to a state capable of controlling the electric motor, wait for the auxiliary power supply to be charged to a level sufficient to back up the main power supply before allowing the vehicle to move.

Description

Technical Field

[0001] This invention relates to steering control devices, vehicle power systems, and vehicles. Background Technology

[0002] A steer-by-wire system is known where the power transmission between the steering wheel and the rotating wheel is separate. For example, the steering system disclosed in Japanese Unexamined Patent Application Publication No. 2018-103731 (JP 2018-103731 A) includes: a steering unit that includes a steering reaction force actuator; a rotating unit that includes a rotating actuator; and an electromagnetic clutch that connects the steering unit and the rotating unit or separates the steering unit and the rotating unit.

[0003] Power is supplied from the vehicle's onboard power unit to the steering reaction force actuator and the rotary actuator. The power unit consists of a battery and a generator. When the battery is not in good condition, it is not fully charged, making it difficult for the generator to supply power quickly. Therefore, for example, it may be unable to supply the power required by the rotary actuator.

[0004] Therefore, the steering system engages the electromagnetic clutch when the battery is not functioning properly. Since power can be transmitted between the steering unit and the rotation unit, the steering wheel can be rotated by the driving force of the rotation actuator and the operating force of the steering wheel. Therefore, when the steering system suppresses power consumption, the steering wheel operation is assisted by the driving force of the rotation actuator. Summary of the Invention

[0005] From the perspective of ensuring the reliability of the steering system operation, an auxiliary power supply can be set according to the battery status to back up the power supply to the steering reaction force actuator and the rotation actuator. When the vehicle is in motion, a state where backup can be achieved through the auxiliary power supply is requested.

[0006] A first aspect of the invention is a steering control device. The steering control device includes a controller configured to control the drive of an electric motor that generates torque. The torque is the torque applied to the vehicle's steering mechanism using power from at least one of a main vehicle power supply and an auxiliary power supply as a backup main power supply. The controller is configured to: when the controller is activated upon vehicle start-up and transitions to a state capable of controlling the electric motor, wait for the auxiliary power supply to be charged to a level sufficient to back up the main power supply before allowing the vehicle to move.

[0007] Using the above configuration, the vehicle is not allowed to drive until the auxiliary power supply is charged to a level sufficient to back up the main power supply. Therefore, it prevents the vehicle from starting to drive when the auxiliary power supply is unable to back up the main power supply.

[0008] In the steering control unit, the controller can be configured to allow charging of the auxiliary power supply when the controller transitions to a state capable of controlling the electric motor. Using this configuration, vehicle driving permission can be suppressed even when the controller is not in a state capable of controlling the electric motor.

[0009] In the steering control unit, the main power supply can be configured to use electricity generated by the onboard generator for charging, and the auxiliary power supply can be configured to use electricity from the main power supply for charging. The controller can be configured to: activate upon vehicle start-up, and then transition to a state capable of controlling the electric motor upon generator start-up.

[0010] With the above configuration, the auxiliary power supply begins charging after power generation has started. Therefore, the main power supply consumption can be suppressed.

[0011] A second aspect of the invention is a power supply system. This power supply system includes a main power supply installed in a vehicle, an auxiliary power supply configured to back up the main power supply, and a steering control device including a controller configured to control the drive of a torque-generating electric motor. The torque is the torque applied to the vehicle's steering mechanism using power from at least one of the onboard main power supply and the auxiliary power supply backing up the main power supply. The controller is configured to, when activated by a vehicle start-up operation and transitioning to a state capable of controlling the electric motor, wait for the auxiliary power supply to be charged to a level sufficient to back up the main power supply before allowing the vehicle to move.

[0012] With the above configuration, by providing a steering control device, it is possible to prevent the vehicle from starting to drive when the auxiliary power supply cannot back up the main power supply.

[0013] The power system may also include monitoring circuitry configured to monitor the charging status of the auxiliary power supply and determine whether the auxiliary power supply's charging status is sufficient to back up the main power supply. The controller may be configured to identify, based on the determination result of the monitoring circuitry, whether the auxiliary power supply has been charged to a level sufficient to back up the main power supply.

[0014] Using the above configuration, the monitoring circuit determines whether the auxiliary power supply's charging status is sufficient to back up the main power supply. Since the controller does not need to monitor the auxiliary power supply's charging status, its computational load can be significantly reduced.

[0015] A third aspect of the invention is a vehicle. The vehicle includes operating equipment that operates while the vehicle is in motion, a vehicle control device configured to control the vehicle based on the operation of the operating equipment, and a power system. The power system includes a main power supply installed on the vehicle, an auxiliary power supply configured to back up the main power supply, and a steering control device including a controller configured to control the drive of a torque-generating electric motor. The torque is the torque applied to the vehicle's steering mechanism using power from at least one of the onboard main power supply and the auxiliary power supply backing up the main power supply. The controller is configured to, when activated by a vehicle start-up operation and transitioning to a state capable of controlling the electric motor, wait for the auxiliary power supply to be charged to a level sufficient to back up the main power supply before allowing the vehicle to move. The vehicle control device is configured to lock or disable the operation of the operating equipment when the steering control device does not allow the vehicle to move.

[0016] With the above configuration, the operation of the control equipment is locked or disabled when the steering control device does not allow the vehicle to move. Therefore, when the steering control device does not allow the vehicle to move, that is, when the auxiliary power supply is not charged to a level sufficient to back up the main power supply, the vehicle will not begin to move.

[0017] In a vehicle, the operating device can be a gear lever, which is used to shift gears in the transmission installed on the vehicle. Using the above configuration, when the steering control system does not allow the vehicle to move, the operation of the gear lever is locked or disabled. Therefore, when the steering control system does not allow the vehicle to move, that is, when the auxiliary power supply is not charged to a level sufficient to back up the main power supply, the vehicle will not begin to move.

[0018] The vehicle may also include an indicator. The vehicle control unit can be configured to illuminate the indicator when the steering control unit does not allow the vehicle to move.

[0019] Using the above configuration, the driver can identify whether the vehicle is in a state where driving is permitted through a visual recognition indicator.

[0020] According to aspects of the present invention, the reliability of the operation of the controlled target can be ensured. Attached Figure Description

[0021] 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 the same reference numerals denote the same elements, and wherein:

[0022] Figure 1 This is a configuration diagram of a steer-by-wire device equipped with a steering control device;

[0023] Figure 2 It is a block diagram of a power system including a steering control device and a power supply device according to an embodiment.

[0024] Figure 3 This is a sequence diagram illustrating the processing procedures of the power supply unit, steering control unit, and vehicle control unit in the comparative example; and

[0025] Figure 4 This is a sequence diagram illustrating the processing flow of the control circuits of the power supply device, steering control device, and vehicle control device according to an embodiment. Detailed Implementation

[0026] This section will describe an implementation where the steering control device is used as a steer-by-wire device. For example... Figure 1 As shown, the vehicle's steering system 10 has a steering shaft 12 connected to the steering wheel 11. The steering system 10 also has a steering shaft 12 along the vehicle's width direction ( Figure 1 A rotating shaft 14 extends in the left-right direction. Left and right rotating wheels 16 are connected to both ends of the rotating shaft 14 via tie rods 15. As the rotating shaft 14 moves linearly, the rotation angle θ of the rotating wheels 16... w Change. Steering shaft 12 and rotating shaft 14 constitute the vehicle's steering mechanism.

[0027] Configuration for generating steering reaction force: Reaction force unit

[0028] The steering system 10 includes a reaction force motor 31, a reduction gear 32, a rotation angle sensor 33, and a torque sensor 34 configured to generate steering reaction force. The steering reaction force is a force acting in the opposite direction to the direction in which the driver operates the steering wheel 11. By applying the steering reaction force to the steering wheel 11, the driver can be given an appropriate responsiveness.

[0029] The reaction force motor 31 is the source of the steering reaction force. For example, a three-phase brushless motor is used as the reaction force motor 31. The reaction force motor 31 has two winding groups. The winding groups of the first system and the second system are wound on a common stator. The winding groups of the first system and the second system have the same electrical characteristics. The rotating shaft of the reaction force motor 31 is connected to the steering shaft 12 via a reduction gear 32. The torque of the reaction force motor 31 is applied to the steering shaft 12 as the steering reaction force. The torque of the reaction force motor 31 is the driving force applied to the steering shaft 12.

[0030] A rotation angle sensor 33 is installed in the reaction force motor 31. The rotation angle sensor 33 detects the rotation angle θ of the reaction force motor 31. a The rotation angle θ of the reaction force motor 31 a Used to calculate steering angle θ s The reaction force motor 31 and the steering shaft 12 are interlocked via the reduction gear 32. Therefore, the rotation angle θ of the reaction force motor 31...a The rotation angle of the steering shaft 12 and the steering angle θ, which is the rotation angle of the steering wheel 11. s There is a correlation between them. Therefore, it can be based on the rotation angle θ of the reaction force motor 31. a To obtain the steering angle θ s .

[0031] Torque sensor 34 detects steering torque T h Steering torque T h The torque is applied to the steering shaft 12 by rotating the steering wheel 11. The torque sensor 34 detects the steering torque T applied to the steering shaft 12 based on the amount of torsion of the torsion bar located in the middle of the steering shaft 12. h The torque sensor 34 is located on the portion of the steering shaft 12 between the reduction gear 32 and the steering wheel 11.

[0032] Configuration for generating rotational force: Rotating unit

[0033] The steering device 10 has a rotary motor 41, a reduction mechanism 42, and a rotation angle sensor 43 configured to generate rotational force (as a force for rotating the rotating wheel 16).

[0034] Rotary motor 41 is the source of rotational force. For example, a three-phase brushless motor is used as rotary motor 41. Rotary motor 41 has two winding groups. The first system winding group and the second system winding group are wound on a common stator. The first system winding group and the second system winding group have the same electrical characteristics. The rotating shaft of rotary motor 41 is connected to pinion shaft 44 via reduction gear 42.

[0035] The pinion teeth 44a of the pinion shaft 44 mesh with the rack teeth 14b of the rotating shaft 14. The torque of the rotating motor 41 is applied as a rotational force to the rotating shaft 14 via the pinion shaft 44. The torque of the rotating motor 41 is the driving force applied to the rotating shaft 14. As the rotating motor 41 rotates, the rotating shaft 14 moves along the... Figure 1 The vehicle moves in the width direction, either left or right.

[0036] A rotation angle sensor 43 is installed in the rotary motor 41. The rotation angle sensor 43 detects the rotation angle θ of the rotary motor 41. bThe steering device 10 has a pinion shaft 13. The pinion shaft 13 is arranged to intersect with the rotating shaft 14. The pinion teeth 13a of the pinion shaft 13 mesh with the rack teeth 14a of the rotating shaft 14. The reason for providing the pinion shaft 13 is to support the rotating shaft 14 and the pinion shaft 44 together within a housing (not shown). That is, the rotating shaft 14 is movably supported along its axial direction and pressed towards the pinion shafts 13 and 44 by means of a support mechanism (not shown) provided in the steering device 10. Thus, the rotating shaft 14 is supported within the housing. However, another support mechanism for supporting the rotating shaft 14 on the housing can be provided without using the pinion shaft 13.

[0037] Steering control unit

[0038] The steering system 10 includes a steering control device 50. The steering control device 50 controls the reaction force motor 31 and the rotation motor 41 based on the detection results of various onboard sensors. In addition to the aforementioned rotation angle sensor 33, torque sensor 34, and rotation angle sensor 43, the sensor also includes a vehicle speed sensor 501. The vehicle speed sensor 501 detects the vehicle speed V.

[0039] Steering control device 50 performs reaction force control by controlling reaction force motor 31 to adjust the steering torque T. h This generates a steering reaction force. The steering control device 50 is based on the steering torque T. h The target steering reaction force is calculated based on the vehicle speed V, and a steering reaction force command value is calculated based on the calculated target steering reaction force. The steering control device 50 supplies the current required to generate the steering reaction force to the reaction force motor 31 according to the steering reaction force command value.

[0040] The steering control unit 50 performs steering control by controlling the rotary motor 41 to rotate the steering wheel 16 according to the steering state. The steering control unit 50 is based on the rotation angle θ of the rotary motor 41 detected by the rotation angle sensor 43. b Calculate the pinion angle θ p pinion angle θ p It is the actual rotation angle of the pinion shaft 44, and it is the rotation angle θ that reflects the rotation of the rotating wheel 16. w The value of θ. Additionally, the steering control device 50 is based on the rotation angle θ of the reaction force motor 31 detected by the rotation angle sensor 33. a Calculate the steering angle θ s And based on the calculated steering angle θ s To calculate the pinion angle θ p The target pinion angle is the target value. The steering control unit 50 obtains the target pinion angle and the actual pinion angle θ. pThe deviation between them is controlled, and the power supply to the rotating motor 41 is controlled to eliminate the deviation.

[0041] Steering control unit 50 and vehicle control unit 60 are interconnected via vehicle network 61. Vehicle network 61 is, for example, a Controller Area Network (CAN). Steering control unit 50 and vehicle control unit 60 exchange information with each other via vehicle network 61. Vehicle control unit 60 controls vehicle equipment 62. Vehicle equipment 62 includes a gear lever and a shift lock mechanism. The shift lock mechanism is a mechanism that switches between locking and unlocking the gear lever. The gear lever is an operating device that is operated while the vehicle is in motion and is operated when changing gears in the transmission. Vehicle control unit 60 unlocks the gear lever when the drive source for driving the vehicle is activated and the foot brake is depressed. Therefore, the gear lever can be moved from the parking position (P).

[0042] Detailed configuration of the steering control unit

[0043] Next, the configuration of the steering control device 50 will be described in detail. For example... Figure 2 As shown, the steering control device 50 includes a reaction force control device 51 and a rotation control device 52. The reaction force control device 51 controls the power supply to the reaction force motor 31. The rotation control device 52 controls the power supply to the rotation motor 41. The reaction force control device 51 and the rotation control device 52 exchange information with each other via a local area network such as serial communication.

[0044] The reaction force control device 51 has a first reaction force controller 51A and a second reaction force controller 51B. The first reaction force controller 51A controls the power supply to the winding group N11 of the first system in the reaction force motor 31. The second reaction force controller 51B controls the power supply to the winding group N12 of the second system in the reaction force motor 31.

[0045] The first reaction force controller 51A comprises a processing circuit including: (1) one or more processors operating according to a computer program (software); (2) one or more dedicated hardware circuits, such as application-specific integrated circuits (ASICs), that perform at least some of various types of processing; and (3) combinations thereof. The processor includes a central processing unit (CPU). The processor also includes memory, such as random access memory (RAM) and read-only memory (ROM). The memory stores program code or commands configured to cause the CPU to perform processing. Memory, i.e., non-transitory computer-readable media, includes any available media accessible by a general-purpose or special-purpose computer.

[0046] The first reaction force controller 51A is based on the steering torque T detected by the torque sensor 34. hThe target steering reaction force to be generated in the reaction force motor 31 is calculated, and a first current command value for the winding group N11 of the first system is calculated based on the calculated target steering reaction force value. However, the first current command value is set to half (50%) of the current required (100%) for the reaction force motor 31 to generate the target steering reaction force. The first reaction force controller 51A provides the current according to the first current command value to the winding group N11 of the first system. Therefore, the winding group N11 of the first system generates torque according to the first current command value.

[0047] The second reaction force controller 51B has essentially the same configuration as the first reaction force controller 51A. The second reaction force controller 51B is based on the steering torque T detected by the torque sensor 34. h The target steering reaction force to be generated in the reaction force motor 31 is calculated, and a second current command value for the winding group N12 of the second system is calculated based on the calculated target steering reaction force value. However, the second current command value is set to half the amount of current required for the reaction force motor 31 to generate the target steering reaction force. The second reaction force controller 51B provides current to the winding group N12 of the second system according to the second current command value. Therefore, the winding group N12 of the second system generates torque according to the second current command value.

[0048] Depending on the product specifications, a master-slave relationship may exist between the first reaction force controller 51A and the second reaction force controller 51B. In this case, for example, the first reaction force controller 51A can act as the master, and the second reaction force controller 51B can act as the slave. Furthermore, depending on the product specifications, the first reaction force controller 51A and the second reaction force controller 51B may have an equal relationship.

[0049] The first reaction force controller 51A and the second reaction force controller 51B can exchange information with each other via a local area network. Furthermore, the first reaction force controller 51A and the second reaction force controller 51B can exchange information with each other via an in-vehicle network 61.

[0050] The rotation control device 52 has a first rotation controller 52A and a second rotation controller 52B. The first rotation controller 52A controls the power supply to the winding group N21 of the first system in the rotation motor 41. The second rotation controller 52B controls the power supply to the winding group N22 of the second system in the rotation motor 41.

[0051] The first rotation controller 52A has essentially the same configuration as the first reaction force controller 51A. For example, the first rotation controller 52A is based on the steering angle θ calculated by the first reaction force controller 51A. sTo calculate the target pinion angle θ p The target value is the target pinion angle. The first rotation controller 52A is based on the rotation angle θ of the rotation motor 41 detected by the rotation angle sensor 43. b Calculate the pinion angle θ p The first rotation controller 52A, through execution, causes the pinion angle θ to... p The target rotational force to be generated in the rotating motor 41 is calculated using angle feedback control following the target pinion angle, and a third current command value for the winding group N21 of the first system is calculated based on the calculated target rotational force value. However, the third current command value is set to half (50%) of the current required for the rotating motor 41 to generate the target rotational force. The first rotation controller 52A provides current to the winding group N21 of the first system according to the third current command value. Therefore, the winding group N21 of the first system generates torque according to the third current command value.

[0052] The second rotation controller 52B has essentially the same configuration as the first rotation controller 52A. For example, the second rotation controller 52B is based on the steering angle θ calculated by the second reaction force controller 51B. s To calculate the pinion angle θ p The target value is the target pinion angle. The second rotation controller 52B is based on the rotation angle θ of the rotation motor 41 detected by the rotation angle sensor 43. b Calculate the pinion angle θ p The second rotation controller 52B, by executing actions, causes the pinion angle θ to... p The target rotational force to be generated in the rotating motor 41 is calculated using angle feedback control following the target pinion angle, and a fourth current command value for the winding group N22 of the second system is calculated based on the calculated target rotational force value. However, the fourth current command value is set to half (50%) of the current required for the rotating motor 41 to generate the target rotational force. The second rotation controller 52B provides the current to the winding group N22 of the second system according to the fourth current command value. Therefore, the winding group N22 of the second system generates torque according to the fourth current command value.

[0053] Depending on the product specifications, a master-slave relationship may exist between the first rotation controller 52A and the second rotation controller 52B. In this case, for example, the first rotation controller 52A can act as the master, and the second rotation controller 52B can act as the slave. Furthermore, depending on the product specifications, the first rotation controller 52A and the second rotation controller 52B may be in an equal relationship.

[0054] The first rotation controller 52A and the second rotation controller 52B can exchange information with each other via a local area network. The first rotation controller 52A and the second rotation controller 52B can exchange information with each other via an in-vehicle network 61. The first rotation controller 52A and the first reaction force controller 51A can exchange information with each other via a local area network. The second rotation controller 52B and the second reaction force controller 51B can exchange information with each other via a local area network.

[0055] Power supply path

[0056] Next, the power supply path for the steering control device 50 will be described. For example... Figure 2 As shown, the steering control unit 50 is connected to the vehicle's main power supply 71 via a power supply unit 70. The main power supply 71 is, for example, a battery that serves as a DC power source. The steering control unit 50 operates by consuming the power supplied from the main power supply 71 via the power supply unit 70. The main power supply 71 is connected to a generator 72, for example, an alternator. The generator 72 uses the rotation of the engine, which serves as the driving source for the vehicle, as a power source for generating electricity. The alternating current generated by the generator 72 is converted into direct current and stored in the main power supply 71.

[0057] The power supply unit 70 is connected to the main power supply 71 via two power lines L1 and L2. Power line L2 branches off from the connection point P0 of power line L1. A start switch 73 is provided on power line L2. The start switch 73 is, for example, an ignition switch or a power switch. The start switch 73 is activated when the vehicle's driving source starts or stops.

[0058] The first reaction force controller 51A is connected to the main power supply 71 via the power supply device 70. The first reaction force controller 51A is connected to power line L1 via power line L11A and the power supply device 70. In addition, the first reaction force controller 51A is connected to power line L2 via power line L11B and the power supply device 70.

[0059] Power from the main power supply 71 is supplied via power line L11A to the power circuit of the first reaction force controller 51A. This power circuit is designed to handle larger amounts of power and includes, for example, an inverter that converts the DC power from the main power supply 71 into AC power. Additionally, power from the main power supply 71 is supplied via power line L11B to the control circuit of the first reaction force controller 51A. This control circuit is used to control the reaction force motor 31 and includes, for example, a CPU and a memory.

[0060] The second reaction force controller 51B is not connected to the main power supply 71 via the power supply unit 70. The second reaction force controller 51B is connected to power line L1 via power line L12A. Additionally, the second reaction force controller 51B is connected to power line L2 via power line L12B. Power from the main power supply 71 is supplied to the power circuit of the second reaction force controller 51B via power line L12A. Furthermore, power from the main power supply 71 is supplied to the control circuit of the second reaction force controller 51B via power line L12B.

[0061] The first rotation controller 52A is connected to the main power supply 71 via the power supply unit 70. The first rotation controller 52A is connected to power supply line L11A via power line L13A. Furthermore, the first rotation controller 52A is connected to power supply line L11B via power line L13B. Power from the main power supply 71 is supplied to the power circuit of the first rotation controller 52A via power line L13A. Additionally, power from the main power supply 71 is supplied to the control circuit of the first rotation controller 52A via power line L13B.

[0062] The second rotation controller 52B is not connected to the main power supply 71 via the power supply unit 70. The second rotation controller 52B is connected to power line L1 via power line L14A. Furthermore, the second rotation controller 52B is connected to power line L2 via power line L14B. Power from the main power supply 71 is supplied to the power circuit of the second rotation controller 52B via power line L14A. Additionally, power from the main power supply 71 is supplied to the control circuit of the second rotation controller 52B via power line L14B.

[0063] The main power supply 71, the power supply device 70, and the steering control device 50 constitute the vehicle power system.

[0064] Power supply device

[0065] Next, the configuration of the power supply unit 70 will be described. The power supply unit 70 includes an auxiliary power supply 70A, a switching circuit 70B, and a control circuit 70C. The auxiliary power supply 70A is an energy storage device capable of charging and discharging charge, and utilizes, for example, a capacitor. The voltage of the auxiliary power supply 70A is, for example, set to be higher than the lower limit of the voltage required for the normal operation of the steering control device 50 and lower than the voltage of the main power supply 71.

[0066] Based on commands from control circuit 70C, switching circuit 70B switches the connection state of auxiliary power supply 70A with power line L1, thereby charging auxiliary power supply 70A. Additionally, based on commands from control circuit 70C, switching circuit 70B switches the power supply of first reaction force controller 51A and first rotation controller 52A between main power supply 71 and auxiliary power supply 70A.

[0067] Power from the main power supply 71 or the auxiliary power supply 70A, switched by the switching circuit 70B, is supplied to the first reaction force controller 51A via power lines L11A and L11B. Additionally, power from the main power supply 71 or the auxiliary power supply 70A, switched by the switching circuit 70B, is supplied to the first rotation controller 52A via power lines L13A and L13B.

[0068] Control circuit 70C controls the switching of switch circuit 70B. Furthermore, control circuit 70C monitors the voltage of main power supply 71. When the voltage of main power supply 71 falls below a threshold voltage, control circuit 70C determines that the voltage of main power supply 71 has decreased. The threshold voltage is a reference for determining when the voltage of main power supply 71 has decreased, and is set with reference to the lower limit of the voltage required for normal operation of reaction force motor 31, rotation motor 41, first reaction force controller 51A, and first rotation controller 52A.

[0069] When no voltage drop in the main power supply 71 is detected, the control circuit 70C generates a first command to the switching circuit 70B. This first command switches the power supply of the first reaction force controller 51A and the first rotation controller 52A to the main power supply 71. Additionally, the first command also switches the connection state of the auxiliary power supply 70A to the power line L1, thereby charging the auxiliary power supply 70A.

[0070] When a voltage drop in the main power supply 71 is detected, the control circuit 70C generates a second command for the switching circuit 70B. This second command switches the power supply to the first reaction force controller 51A and the first rotation controller 52A from the main power supply 71 to the auxiliary power supply 70A. The second command also switches the connection between the auxiliary power supply 70A and the power line L1, disconnecting the connection between the power line L1 and the auxiliary power supply 70A and preventing the auxiliary power supply 70A from being charged.

[0071] Control circuit 70C detects the amount of charge in auxiliary power supply 70A. Control circuit 70C detects the voltage of auxiliary power supply 70A via a voltage sensor located in auxiliary power supply 70A, and determines the amount of charge in auxiliary power supply 70A based on the detected voltage. When auxiliary power supply 70A is a capacitor, control circuit 70C detects the amount of charge in the capacitor based on the voltage between the capacitor's terminals. Control circuit 70C also functions as a monitoring circuit for monitoring the charging state of auxiliary power supply 70A.

[0072] Comparison of startup sequences

[0073] Next, a comparative example of a startup sequence executed when the start switch 73 is turned on will be described. The startup sequence is a series of processing segments executed when the vehicle control unit 60, steering control unit 50, and power supply unit 70 are started.

[0074] However, for example, the vehicle control unit 60, steering control unit 50, and power supply unit 70 can detect the on or off state of the start switch 73 by monitoring the voltage across its terminals. The start switch 73 being on means the vehicle's power is on. The start switch 73 being off means the vehicle's power is off.

[0075] like Figure 3 As shown in the sequence diagram, the vehicle control unit 60 performs an initial check (step S101) when the start switch 73 is turned on. The initial check is a series of processing steps required for the vehicle system to operate. The initial check includes, for example, hardware checks, central processing unit (CPU) initialization, and initialization of variables or flags. When the initial check is completed and the generator 72 is detected to start generating electricity as a driving source for vehicle movement (step S102), for example, the vehicle control unit 60 sends an auxiliary start permission signal S1 to the first reaction force controller 51A of the steering control unit 50. When the generator 72 is detected to start generating electricity (step S102), the vehicle control unit 60 recognizes that the vehicle is in a drivable state (step S103).

[0076] When the start switch 73 is turned on, the first reaction force controller 51A performs an initial check (step S201). After the initial check is completed, the first reaction force controller 51A waits for the vehicle to complete its driving preparation (step S202). When it receives the auxiliary start permission signal S1 while waiting for the vehicle to complete its driving preparation, the first reaction force controller 51A transitions to the auxiliary start state (step S203). The auxiliary start state is a state in which reaction force control via the reaction force motor 31 can be performed. When the transition to the auxiliary start state is executed, the first reaction force controller 51A sends the charging start permission signal S2 to the control circuit 70C of the power supply device 70 (step S203).

[0077] The transition from the state of the first reaction force controller 51A to the auxiliary start state is sent to the second reaction force controller 51B, the first rotation controller 52A, and the second rotation controller 52B. Therefore, at the moment when the state of the first reaction force controller 51A transitions to the auxiliary start state, the states of the second reaction force controller 51B, the first rotation controller 52A, and the second rotation controller 52B also transition to the auxiliary start state.

[0078] When the start switch 73 is turned on, the control circuit 70C of the power supply device 70 performs an initial check (step S301). After the initial check is completed, the control circuit 70C waits for the state of the first reaction force controller 51A to change to the auxiliary start state (step S302). When a charging start permission signal S2 is received while waiting for the state of the first reaction force controller 51A to change to the auxiliary start state, the control circuit 70C checks the charging status of the auxiliary power supply 70A (step S303) and determines whether the amount of charge in the auxiliary power supply 70A is sufficient to back up the main power supply 71 (step S304).

[0079] The control circuit 70C detects the amount of charge on the capacitor, for example, based on the voltage between the terminals of the capacitor serving as the auxiliary power supply 70A. When the voltage between the capacitor terminals is less than a threshold voltage, the control circuit 70C determines that the auxiliary power supply 70A is undercharged. When the voltage between the capacitor terminals is equal to or higher than the threshold voltage, the control circuit 70C determines that the auxiliary power supply 70A is adequately charged. The threshold voltage is a reference for determining whether the auxiliary power supply 70A is adequately charged. The threshold voltage is set with reference to the lower limit of the voltage required for normal operation of the reaction force motor 31, the rotation motor 41, the first reaction force controller 51A, and the first rotation controller 52A.

[0080] When it is determined that the charge level in the auxiliary power supply 70A is insufficient ("No" in step S304), the control circuit 70C starts charging the auxiliary power supply 70A and waits until the charge level in the auxiliary power supply 70A reaches a sufficient amount. When it is determined that the charge level in the auxiliary power supply 70A is sufficient ("Yes" in step S304), the control circuit 70C recognizes that there is a state where the main power supply 71 can be backed up (step S305).

[0081] However, when adopting Figure 3 There are concerns regarding the startup sequence of the comparative example shown. Specifically, after the vehicle's generator 72 starts generating electricity and the vehicle is drivable, the control circuit 70C of the power supply unit 70 begins charging the auxiliary power supply 70A, triggered by receiving a charging start permission signal S2 from the steering control device 50 (here, the first reaction force controller 51A). Then, the auxiliary power supply 70A reaches a charging state sufficient to back up the main power supply 71.

[0082] Since the state where the auxiliary power supply 70A cannot back up the power supply due to insufficient charge at startup is not an abnormal state, the vehicle can be driven. However, although the vehicle can be driven, there is a concern that there may be a period ΔT during which the auxiliary power supply 70A cannot back up the main power supply 71. From the viewpoint of ensuring the reliability of the operation of the steering device 10, it is requested that the main power supply 71 be able to be backed up by the auxiliary power supply 70A while the vehicle is driving. In this embodiment, the following startup sequence is adopted.

[0083] Example of a startup sequence

[0084] Next, the startup sequence of this embodiment will be described. For example... Figure 4 As shown in the sequence diagram, the vehicle control unit 60 performs an initial check when the start switch 73 is turned on (step S101). When the initial check is completed and the generator 72 is detected to start generating electricity as the vehicle's drive source starts (step S102), for example, the vehicle control unit 60 sends an auxiliary start permission signal S1 to the first reaction force controller 51A of the steering control unit 50. When the generator 72 is detected to start generating electricity (step S102), the vehicle control unit 60 transitions to a waiting-for-driving-permission state (step S104). Afterwards, the vehicle control unit 60 determines whether to permit vehicle movement (step S105).

[0085] When the start switch 73 is turned on, the first reaction force controller 51A performs an initial check (step S201). After the initial check is completed, the first reaction force controller 51A waits for the vehicle to complete its driving preparation (step S202). When it receives the auxiliary start permission signal S1 while waiting for the vehicle to complete its driving preparation, the first reaction force controller 51A transitions to the auxiliary start state (step S203). When transitioning to the auxiliary start state, the first reaction force controller 51A sends the charging start permission signal S2 to the control circuit 70C of the power supply device 70. Afterward, the first reaction force controller 51A determines whether the main power supply 71 can be backed up by the auxiliary power supply 70A (step S204).

[0086] When the start switch 73 is turned on, the control circuit 70C of the power supply device 70 performs an initial check (step S301). After the initial check is completed, the control circuit 70C waits for the state of the first reaction force controller 51A to change to the auxiliary start state (step S302). When a charging start permission signal S2 is received while waiting for the state of the first reaction force controller 51A to change to the auxiliary start state, the control circuit 70C checks the charging status of the auxiliary power supply 70A (step S303) and determines whether the amount of charge in the auxiliary power supply 70A is sufficient to back up the main power supply 71 (step S304).

[0087] When it is determined that the charge level in the auxiliary power supply 70A is insufficient (No in step S304), the control circuit 70C begins charging the auxiliary power supply 70A and waits until the charge level in the auxiliary power supply 70A reaches a sufficient amount. When it is determined that the charge level in the auxiliary power supply 70A is insufficient (No in step S304), the control circuit 70C sends flag F10 to the first reaction force controller 51A. Flag F10 indicates that the main power supply 71 cannot be backed up by the auxiliary power supply 70A.

[0088] When it is determined that the auxiliary power supply 70A has sufficient charge ("Yes" in step S304), the control circuit 70C identifies a state where the auxiliary power supply 70A can back up the main power supply 71 (step S305). When it is determined that the auxiliary power supply 70A has sufficient charge ("Yes" in step S304), the control circuit 70C sends flag F11 to the first reaction force controller 51A. Flag F11 indicates that the main power supply 71 can be backed up by the auxiliary power supply 70A.

[0089] Upon receiving flag F10, the first reaction force controller 51A determines that the main power supply 71 cannot be backed up by the auxiliary power supply 70A (No in step S204). When it is determined that the main power supply 71 cannot be backed up by the auxiliary power supply 70A, the first reaction force controller 51A sends flag F20 to the vehicle control device 60. Flag F20 indicates that the vehicle is not allowed to move.

[0090] Upon receiving the flag F11, the first reaction force controller 51A determines that the main power supply 71 can be backed up by the auxiliary power supply 70A ("Yes" in step S204). When it is determined that the main power supply 71 can be backed up by the auxiliary power supply 70A, the first reaction force controller 51A sends the flag F21 to the vehicle control device 60. The flag F21 indicates that the vehicle is permitted to move.

[0091] When the flag F20 is received, the vehicle control unit 60 determines that the vehicle is not allowed to move ("No" in step S105) and keeps the vehicle in a non-movable state (step S106). The vehicle control unit 60, for example, keeps the shift lock mechanism in a locked state. Therefore, the vehicle is kept in a non-movable state. Furthermore, when it is determined that the vehicle is not allowed to move ("No" in step S105), the vehicle control unit 60 notifies the driver of this fact (step S107). The vehicle control unit 60 illuminates, for example, an indicator located on the dashboard near the driver's seat. Through visual recognition of the indicator, the driver can identify the presence of a state where the vehicle is not allowed to move. This indicator is one of the in-vehicle devices 62.

[0092] When the flag F21 is received, the vehicle control unit 60 determines that the vehicle is permitted to drive ("Yes" in step S105) and identifies that the vehicle is in a drivable state (step S103). When it is determined that the vehicle is permitted to drive, the vehicle control unit 60 unlocks the shift lock mechanism. Therefore, the gear lever can be operated and the vehicle can be driven. The vehicle control unit 60 controls the vehicle's movement according to the driver's vehicle operation. In addition, when it is determined that the vehicle is permitted to drive, the vehicle control unit 60 turns off the indicator that indicates a state where the vehicle is not permitted to drive. Using the visual recognition of the indicator, the driver can recognize that the vehicle is in a drivable state.

[0093] Effects of the implementation method

[0094] Therefore, according to this embodiment, the following effects can be obtained. When the first reaction force controller 51A is activated and transitions to the auxiliary start state triggered by a vehicle start operation (here, the operation of turning on the start switch 73), the first reaction force controller 51A waits until the auxiliary power supply 70A is charged to a level sufficient to back up the main power supply 71 and allow the vehicle to move. The auxiliary start state is a state in which the control of the reaction force motor 31, which is the control target of the first reaction force controller 51A, can be performed. Therefore, the vehicle is not allowed to move until the auxiliary power supply 70A is charged to a level sufficient to back up the main power supply 71. Thus, it is possible to prevent the vehicle from starting to move when the auxiliary power supply 70A cannot back up the main power supply 71. It is also possible to ensure the reliability of the operation of the steering device 10.

[0095] When the system transitions to a state where it can control the reaction motor 31, the first reaction controller 51A allows the auxiliary power supply 70A to charge. Therefore, even if the first reaction controller 51A is not in a state where it can control the reaction motor 31, it can suppress the vehicle's driving permission.

[0096] The first reaction force controller 51A is activated upon vehicle start-up and then transitions to a state where it can control the reaction force motor 31 upon generator 72 starting to generate electricity. Since generator 72 starts generating electricity, and then auxiliary power supply 70A starts charging, the consumption of main power supply 71 is suppressed. This is because the electricity generated by generator 72 is used to charge main power supply 71.

[0097] The power system consists of a main power supply 71 installed on the vehicle, an auxiliary power supply 70A that backs up the main power supply 71, and a steering control device 50. When the power system includes the steering control device 50, it can prevent the vehicle from starting to drive when the auxiliary power supply 70A cannot back up the main power supply 71.

[0098] The power supply system includes a control circuit 70C. The control circuit 70C acts as a monitoring circuit, monitoring the charging state of the auxiliary power supply 70A and determining whether the charging state of the auxiliary power supply 70A is sufficient to back up the main power supply 71. Based on the determination result of the control circuit 70C, the first reaction force controller 51A identifies whether the auxiliary power supply 70A is charged to a level sufficient to back up the main power supply 71. Because the control circuit 70C determines whether the charging state of the auxiliary power supply 70A is sufficient to back up the main power supply 71, the first reaction force controller 51A does not need to monitor the charging state of the auxiliary power supply 70A. This reduces the computational load of the first reaction force controller 51A significantly.

[0099] The vehicle has a gearshift lever and a vehicle control device 60. The gearshift lever is an operating device that is operated while the vehicle is in motion, and the vehicle control device 60 controls the vehicle based on the operation of the gearshift lever. When the first reaction force controller 51A does not allow the vehicle to move, the vehicle control device 60 locks or disables the operation of the gearshift lever. Therefore, when the first reaction force controller 51A does not allow the vehicle to move, that is, when the auxiliary power supply 70A is not charged to a level sufficient to back up the main power supply 71, the vehicle does not start moving.

[0100] The vehicle is equipped with an indicator. When the first reaction force controller 51A disallows the vehicle to move, the vehicle control unit 60 illuminates the indicator. Therefore, through visual recognition of the indicator, the driver can determine whether the vehicle is in a state where it is permitted to move.

[0101] Other implementation methods

[0102] This implementation can be achieved through the following modifications. Figure 4 In step S106, the vehicle control device 60 keeps the shift lock mechanism in a locked state to keep the vehicle in a non-driving state. However, this can also be achieved in the following ways: For example, the vehicle control device 60 can disable the operation of the accelerator pedal instead of keeping the shift lock mechanism in the locked state, or disable the operation of the accelerator pedal in addition to keeping the shift lock mechanism in the locked state. In this way, even if the driver presses the accelerator pedal, the vehicle will not move. Alternatively, the vehicle control device 60 can keep the accelerator pedal locked instead of keeping the shift lock mechanism in the locked state, or keep the accelerator pedal locked in addition to keeping the shift lock mechanism in the locked state. In this way, the driver cannot press the accelerator pedal. Therefore, the vehicle cannot move. The accelerator pedal is an operating device that is operated while the vehicle is in motion.

[0103] In this embodiment, the first reaction force controller 51A allows the vehicle to move based on the charging state of the auxiliary power supply 70A, but the first rotation controller 52A can also allow the vehicle to move. In this case, Figure 4 In the sequence diagram, the first reaction force controller 51A is replaced by the first rotation controller 52A. Furthermore, the reaction force motor 31 is replaced by the rotation motor 41. The second reaction force controller 51B or the second rotation controller 52B allows the vehicle to move.

[0104] In this embodiment, the reaction force motor 31 and the rotation motor 41 have two winding groups, but they can also have only one winding group. In this case, the reaction force control device 51 can have only either the first reaction force controller 51A or the second reaction force controller 51B. Similarly, in this case, the rotation control device 52 can have only either the first rotation controller 52A or the second rotation controller 52B. The first reaction force controller 51A or the second reaction force controller 51B corresponds to a reaction force controller. The first rotation controller 52A or the second rotation controller 52B corresponds to a rotation controller.

[0105] The steering device 10 can be an electric steering device. The electric steering device is connected via a mechanical link. Figure 1 The steering wheel 11 and the rotating wheel 16 are formed as shown. That is, the steering shaft 12, the pinion shaft 13, and the rotating shaft 14 serve as the power transmission path between the steering wheel 11 and the rotating wheel 16. As the steering wheel 11 turns, the rotating wheel 16 rotates by an angle θ. w It is changed by the linear movement of the rotating shaft 14.

[0106] The electric steering system includes an auxiliary motor and an auxiliary control unit. The auxiliary motor is located in conjunction with... Figure 1 The reaction force motor 31 or the rotation motor 41 shown is located at the same position. The auxiliary motor generates an auxiliary force to assist in the operation of the steering wheel 11. The auxiliary force is a torque in the same direction as the steering direction of the steering wheel 11. An auxiliary control device corresponds to the steering control device. The auxiliary control device controls the drive of the auxiliary motor for the control objective. The auxiliary control device has a... Figure 2 The reaction force control device 51 or rotation control device 52 shown have the same configuration.

Claims

1. A steering control device (50), characterized in that... Includes a controller configured to control the drive of a torque-generating electric motor, the torque being applied to the vehicle's steering mechanism using power from at least one of the vehicle's main power supply (71) and an auxiliary power supply (70A) that serves as a backup to the main power supply (71). The controller is configured to: when the controller is activated by the vehicle start-up operation and transitions to a state capable of controlling the electric motor, wait for the auxiliary power supply (70A) to be charged to a level sufficient to back up the main power supply (71), and then allow the vehicle to drive.

2. The steering control device (50) according to claim 1, characterized in that, The controller is configured to allow charging of the auxiliary power supply (70A) when the controller transitions to a state capable of controlling the motor.

3. The steering control device (50) according to claim 1 or 2, characterized in that: The main power supply (71) is configured to use power generated by the on-board generator (72) for charging, and the auxiliary power supply (70A) is configured to use power from the main power supply (71) for charging; and The controller is configured to start upon the start-up operation of the vehicle and then transition to a state capable of controlling the electric motor upon the generator (72) starting to generate electricity.

4. A power supply system, characterized in that, include: Main power supply (71) installed on the vehicle; An auxiliary power supply (70A) is configured to back up the main power supply; A steering control device (50) includes a controller configured to control the drive of a torque-generating electric motor, the torque being applied to the vehicle's steering mechanism using power from at least one of the main power source (71) and an auxiliary power source (70A) that serves as a backup to the main power source (71). The controller is configured to: when the controller is activated by the vehicle start-up operation and transitions to a state capable of controlling the electric motor, wait for the auxiliary power supply (70A) to be charged to a level sufficient to back up the main power supply (71), and then allow the vehicle to drive.

5. The power supply system according to claim 4, characterized in that, It also includes a monitoring circuit (70C), which is configured to monitor the charging state of the auxiliary power supply (70A) and determine whether the charging state of the auxiliary power supply (70A) is sufficient to back up the main power supply (71). The controller is configured to identify, based on the determination result of the monitoring circuit (70C), whether the auxiliary power supply (70A) has been charged to a level that can back up the main power supply (71).

6. A vehicle, characterized in that... include: The operating equipment that is operated while the vehicle is in motion; A vehicle control device (60) is configured to control the vehicle based on the operation of the operating equipment; as well as Power system, wherein: The power system includes a main power supply (71) installed on the vehicle, an auxiliary power supply (70A) configured to back up the main power supply, and a steering control device (50) including a controller configured to control the drive of a motor that generates torque. The torque is the torque applied to the steering mechanism of the vehicle using power from at least one of the main power source (71) and the auxiliary power source (70A) that backs up the main power source (71); The controller is configured to: when the controller is activated by the vehicle's start-up operation and transitions to a state capable of controlling the electric motor, wait for the auxiliary power supply (70A) to be charged to a level sufficient to back up the main power supply (71), and then allow the vehicle to proceed; and The vehicle control device (60) is configured to lock or disable the operation of the operating equipment when the steering control device (50) does not allow the vehicle to move.

7. The vehicle according to claim 6, characterized in that, The operating device is a gear lever operated when switching gears in the transmission installed on the vehicle.

8. The vehicle according to claim 6 or 7, characterized in that, It also includes indicators, The vehicle control device (60) is configured to illuminate the indicator when the steering control device (50) does not allow the vehicle to move.

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