Vehicle

Abstract

The invention provides a vehicle equipped with a steer-by-wire type steering device and designed to ensure activation of a wheel deflection actuator before the vehicle starts running, thereby improving the reliability of steering while the vehicle is running. The vehicle (1) comprises a steering member (15) for receiving a steering operation, a wheel deflection actuator (19) mechanically separated from the steering member (15) and configured to deflect a wheel, a state switching device (6) for switching between a fixed state in which the vehicle is fixed at a current position and a released state in which the vehicle is released from being fixed at the current position, and a control device (9) for controlling the wheel deflection actuator (19) and the state switching device (6), wherein the control device permits the state switching device to switch from the fixed state to the released state only when or after completion of activation of the wheel deflection actuator.

Description

TECHNICAL FIELD

[0001] The present application relates to a vehicle equipped with a steer-by-wire type steering device. BACKGROUND

[0002] Known steering devices include steer-by-wire type steering devices, which generally include a steering member for receiving a steering operation, and a wheel deflection actuator that is mechanically separated from the steering member and is configured to deflect a wheel to change a moving direction of the vehicle.

[0003] For example, Patent Literature 1 teaches a steer-by-wire system for a vehicle in which a steering mechanism is mechanically separated from a wheel deflection mechanism.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: JP 2021-075182 A SUMMARY

[0007] TASK TO BE ACCOMPLISHED BY THE INVENTION

[0008] In the case of a vehicle provided with the above-described steer-by-wire system, it is necessary to ensure that the wheel deflection actuator is activated before the vehicle starts running, in order to improve the reliability of steering while the vehicle is running.

[0009] The present application has been made in view of the above-described circumstances, and the primary object of the present application is to provide a vehicle equipped with a steer-by-wire type steering device and designed to ensure that a wheel deflection actuator is activated before the vehicle starts running, thereby improving the reliability of steering while the vehicle is running.

[0010] MEANS FOR SOLVING THE TASK

[0011] One aspect of the present application for achieving the above-described object is a vehicle 1 including: a steering member 15 for receiving a steering operation; a wheel deflection actuator 19 that is mechanically separated from the steering member and is configured to deflect a wheel 30 to change a moving direction of the vehicle; a state switching device 6 for switching between a fixed state in which the vehicle is fixed at a current position and a released state in which the vehicle is released from being fixed at the current position; and a control device 9 for controlling the wheel deflection actuator and the state switching device, wherein the control device permits the state switching device to switch from the fixed state to the released state only when or after an operation for activating the wheel deflection actuator is completed (steps ST4, ST5).

[0012] According to this configuration, the vehicle is released from being fixed at the current position so that the vehicle can travel only when or after the operation for activating the wheel deflection actuator is completed. This ensures that the wheel deflection actuator is activated before the vehicle starts traveling, thereby improving the reliability of steering while the vehicle is traveling.

[0013] The vehicle described above can also be configured so that the vehicle has a power supply state that can be switched between a first power supply state in which the vehicle is prohibited from traveling and a second power supply state in which the vehicle is permitted to travel, and in which the control device is configured so that, when the power supply state of the vehicle is the first power supply state and the wheel deflection actuator is stopped, the control device determines whether the power supply state of the vehicle has been switched from the first power supply state to the second power supply state (step ST3), and when it is determined that the power supply state of the vehicle has been switched from the first power supply state to the second power supply state (step ST3: YES), the control device starts the operation for activating the wheel deflection actuator (step ST4).

[0014] In this configuration, the control device can quickly start activating the wheel deflection actuator when the power supply state of the vehicle is changed from the first power supply state to the second power supply state. As a result, the waiting time of the occupant of the vehicle until the operation for activating the wheel deflection actuator is completed can be shortened.

[0015] The vehicle described above can also be configured so that the vehicle has a power supply state that can be switched between a first power supply state in which the vehicle is prohibited from traveling and a second power supply state in which the vehicle is permitted to travel, and in which the control device is configured so that, when the wheel deflection actuator is operating, the control device determines whether the power supply state of the vehicle is the first power supply state and whether the vehicle is fixed at the current position (step ST11), and when it is determined that the power supply state of the vehicle is the first power supply state and the vehicle is fixed at the current position (step ST11: YES), the control device stops the wheel deflection actuator (step ST12).

[0016] In this configuration, the control device can stop the wheel deflection actuator only after confirming that the vehicle is completely stopped. As a result, the reliability of steering while the vehicle is traveling can be further improved.

[0017] The above vehicle can be further configured such that the vehicle further includes a vehicle speed sensor 41 for detecting a vehicle speed of the vehicle, and an electric parking brake 13 for fixing the vehicle at the current position, wherein the state switching device is a shift device configured to switch a shift range between a fixing range for fixing the vehicle at the current position and a releasing range for releasing the vehicle from being fixed at the current position, and wherein the control device determines that the vehicle is fixed at the current position when at least one of two conditions is satisfied, the two conditions including a first condition that the vehicle speed detected by the vehicle speed sensor is zero and the shift range is the fixing range, and a second condition that the vehicle speed detected by the vehicle speed sensor is zero and the electric parking brake is operating.

[0018] In this configuration, the control device can accurately determine whether the vehicle is fixed at the current position. As a result, the reliability of turning while the vehicle is running can be further improved.

[0019] The above vehicle can be further configured such that the vehicle further includes a reaction actuator 16 for applying a reaction force to the steering member in response to a steering operation received by the steering member, wherein the control device switches an operation mode of the reaction actuator between a running mode for driving the vehicle and a boarding / alighting assistance mode for assisting a driver in boarding and alighting.

[0020] In this configuration, the reaction force can be applied to the steering member not only when the vehicle is running, but also when the driver is boarding and alighting. As a result, even when the driver touches the steering member to board and alight, the steering member does not tend to move, and thus it becomes easier for the driver to board and alight.

[0021] The above vehicle can be further configured such that the vehicle has a power supply state that can be switched between a first power supply state in which running of the vehicle is prohibited and a second power supply state in which running of the vehicle is permitted, and wherein the control device is configured such that, when the power supply state of the vehicle is the first power supply state and both the wheel deflection actuator and the reaction actuator are stopped from operating, the control device determines whether the driver is boarding (step ST1), and when it is determined that the driver is boarding (step ST1: YES), the control device activates the reaction actuator such that the reaction actuator operates in the boarding / alighting assistance mode while stopping the wheel deflection actuator (step ST2).

[0022] In this configuration, when the driver is getting on the vehicle, a reaction force can be applied to the steering member. As a result, even when the driver touches the steering member to get on the vehicle, the steering member does not tend to move, so getting on the vehicle becomes easier for the driver. Moreover, since the control device activates the reaction actuator while stopping the wheel deflection actuator, wasted power consumption can be reduced.

[0023] The above vehicle can also be configured such that the control device is configured so that, when the power supply state of the vehicle is the first power supply state and the reaction actuator is operating in the getting on / off the vehicle assist mode, the control device determines whether the power supply state of the vehicle has switched from the first power supply state to the second power supply state (step ST3), and when it is determined that the power supply state of the vehicle has switched from the first power supply state to the second power supply state (step ST3: YES), the control device switches the operation mode of the reaction actuator from the getting on / off the vehicle assist mode to the running mode (step ST4).

[0024] In this configuration, in response to a change in the power supply state of the vehicle from the first power supply state to the second power supply state, the operation mode of the reaction actuator can be quickly switched from the getting on / off the vehicle assist mode to the running mode. As a result, the waiting time of the occupant of the vehicle before the switching of the operation mode is completed can be shortened.

[0025] The above vehicle can also be configured so that the vehicle has a power supply state that can be switched between a first power supply state in which the vehicle is prohibited from running and a second power supply state in which the vehicle is permitted to run, and in which the control device is configured so that, when the operation mode of the reaction actuator is the running mode, the control device determines whether the power supply state of the vehicle is the first power supply state and whether the vehicle is fixed at the current position (step ST11), and when it is determined that the power supply state of the vehicle is the first power supply state and the vehicle is fixed at the current position (step ST11: YES), the control device switches the operation mode of the reaction actuator from the running mode to the getting on / off the vehicle assist mode (step ST12).

[0026] In this configuration, when the vehicle is stopped from running, the control device causes the reaction actuator to remain operating so that the reaction actuator continues to apply a reaction force to the steering member. As a result, even when the driver touches the steering member to get off the vehicle, the steering member does not tend to move, so getting off the vehicle becomes easier for the driver.

[0027] The vehicle described above can also be configured such that, when the operation mode of the reaction actuator is the boarding / alighting assistance mode, the control device gradually changes the reaction force applied to the steering member by the reaction actuator.

[0028] In this configuration, a rapid change in the reaction force applied to the steering member caused by a change in the operation mode of the reaction actuator can be suppressed, thereby reducing the sense of discomfort of the driver.

[0029] The vehicle described above can also be configured such that, when a predetermined time has elapsed since the operation mode of the reaction actuator becomes the boarding / alighting assistance mode (step ST13: YES), the control device stops the reaction actuator (step ST14).

[0030] In this configuration, since the reaction actuator is prevented from being continuously operated for a long time, wasted power consumption can be reduced.

[0031] Effects of Invention

[0032] According to the present application, a vehicle equipped with a steer-by-wire type steering device can be configured to ensure that a wheel deflection actuator is activated before the vehicle starts running, thereby improving the reliability of steering while the vehicle is running. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a block diagram illustrating a vehicle according to an embodiment of the present application;

[0034] Figure 2 is a schematic diagram illustrating a steering device and a steering control unit according to an embodiment of the present application;

[0035] Figure 3 is a flowchart illustrating a running start control operation according to an embodiment of the present application;

[0036] Figure 4 is a timing chart illustrating a running start control operation according to an embodiment of the present application;

[0037] Figure 5 is a flowchart illustrating a running end control operation according to an embodiment of the present application; and

[0038] Figure 6 is a timing chart illustrating a running end control operation according to an embodiment of the present application.

[0039] LIST OF REFERENCE NUMERALS

[0040] 1 vehicle

[0041] 6 shift device (state switching device)

[0042] 9 control device

[0043] 13 EPB (electric parking brake)

[0044] 15 steering member

[0045] 16 reaction actuator

[0046] 19 wheel deflection actuator

[0047] 30 front wheel (or any other wheel)

[0048] 41 vehicle speed sensor DETAILED DESCRIPTION

[0049] <vehicle 1>

[0050] A vehicle 1 according to one embodiment of the present application will be described. The vehicle 1 is, for example, a four-wheel vehicle. Referring to Figure 1 , the vehicle 1 includes a power supply device 2, a drive device 3, a brake device 4, a steering device 5, a shift device 6 (an example of a state switching device), an HMI (human machine interface) 7, a vehicle sensor 8, and a control device 9.

[0051] <Power supply device 2>

[0052] The power supply device 2 is a device for supplying electric power to components of the vehicle 1. The power supply device 2 is mainly constituted by a generator and a plurality of batteries. Hereinafter, a power supply state from the power supply device 2 is referred to as a "power supply state of the vehicle 1".

[0053] <Drive device 3>

[0054] The drive device 3 provides the vehicle 1 with a driving force for running of the vehicle 1. In the present embodiment, the drive device 3 is mainly constituted by an internal combustion engine. In other embodiments, the drive device 3 can be mainly constituted by an internal combustion engine and an electric motor, or can be mainly constituted by an electric motor.

[0055] <Brake device 4>

[0056] The brake device 4 includes a brake pedal 11, a conventional brake 12, and an electric parking brake 13 (hereinafter referred to as "EPB 13"). The brake pedal 11 receives a brake operation by a driver. The conventional brake 12 applies a brake force to the vehicle 1 in response to the brake operation on the brake pedal 11. The conventional brake 12 can be a hydraulic brake. The EPB 13 fixes the vehicle 1 at a current position in response to a signal from the control device 9. The EPB 13 includes, for example, an actuator mainly including an electric motor, a brake mechanism provided on a rear wheel, and a reduction mechanism connecting the actuator to the brake mechanism.

[0057] <Steering device 5>

[0058] Referring to Figure 2 , the steering device 5 includes a steering member 15, a reaction actuator 16, a steering angle sensor 17, a wheel deflection mechanism 18, a wheel deflection actuator 19, and a wheel deflection angle sensor 20. The steering device 5 is a steer-by-wire type steering device in which the steering member 15 and the wheel deflection actuator 19 are separated from each other.

[0059] The steering member 15 receives a steering operation by a driver. The steering member 15 includes, for example, a steering shaft 23 and a steering wheel 24 provided at one end of the steering shaft 23. The steering shaft 23 is rotatably supported by a steering column 26 provided on a vehicle body 25, and has a rear end protruding rearward from the steering column 26. The steering wheel 24 is coupled to the rear end of the steering shaft 23, and rotates integrally with the steering shaft 23.

[0060] The reaction actuator 16 mainly consists of an electric motor and is connected to the steering shaft 23 through a gear mechanism (not shown). The reaction actuator 16 applies a reaction force torque to the steering member 15 in response to a steering operation received by the steering member 15, in accordance with a signal from the control device 9. In the present specification, the operation state of the reaction actuator 16 includes not only a state in which the reaction actuator 16 is actually applying the reaction force torque to the steering member 15, but also a state in which the reaction actuator 16 is controlled by the control device 9 so that the reaction force torque can be applied to the steering member 15.

[0061] The steering angle sensor 17 detects a steering angle (a rotation angle of the steering member 15 with respect to a predetermined neutral angle position) of the steering member 15. The steering angle sensor 17 mainly consists of, for example, an absolute angle sensor.

[0062] The wheel deflection mechanism 18 has a rack 27 extending in a vehicle width direction. The rack 27 has left and right ends connected to left and right knuckles 29 through left and right tie rods 28, respectively. The left and right knuckles 29 support left and right front wheels 30, respectively.

[0063] The wheel deflection actuator 19 mainly consists of an electric motor and is connected to the rack 27 of the wheel deflection mechanism 18. The wheel deflection actuator 19 steers the front wheels 30 by moving the rack 27 in the vehicle width direction, in accordance with a signal from the control device 9. In the present specification, the operation state of the wheel deflection actuator 19 includes not only a state in which the wheel deflection actuator 19 is actually moving the rack 27, but also a state in which the wheel deflection actuator 19 is controlled by the control device 9 so that the wheel deflection actuator 19 can move the rack 27.

[0064] The wheel deflection angle sensor 20 is mainly composed of a rack stroke sensor configured to detect the position of the rack 27 in the vehicle width direction. The wheel deflection angle sensor 20 detects the wheel deflection angle of the front wheel 30 based on the position of the rack 27 in the vehicle width direction.

[0065] <Shift device 6>

[0066] With reference to Figure 1 The shift device 6 includes an automatic transmission 32, a shift member 33, and a shift actuator 34. The shift device 6 is a shift-by-wire type shift device in which the shift member 33 and the shift actuator 34 are mechanically separated from each other.

[0067] The automatic transmission 32 is provided in a drive transmission path from the drive device 3 to the wheels (drive wheels) and switches to a differential gear to change the driving force transmitted from the drive device 3 to the wheels. The automatic transmission 32 selects one of shift ranges (hereinafter referred to as "shift ranges") set by the differential gear (switches between the shift ranges), the shift ranges including a P range (parking range), a D range (driving range), an R range (reverse range), and an N range (neutral range). The P range is a shift range in which the wheels are locked against rotation and no driving force is transmitted from the drive device 3 to the wheels. The D range is a shift range in which the driving force is transmitted from the drive device 3 to the wheels so that the vehicle 1 moves forward. The R range is a shift range in which the driving force is transmitted from the drive device 3 to the wheels so that the vehicle 1 moves backward. The N range is a shift range in which the wheels are allowed to rotate but no driving force is transmitted from the drive device 3 to the wheels. The P range is a "fixed range" in which the vehicle 1 is fixed to the current position, and when the shift range is the P range, the vehicle is in a "fixed state" in which the vehicle 1 is fixed to the current position. The D range, the R range, and the N range are each a "release range" in which the vehicle 1 is released from being fixed at the current position so that the vehicle 1 can move, and when the shift range is any one of the D range, the R range, and the N range, the vehicle is in a "release state" in which the vehicle 1 is released from being fixed to the current position.

[0068] The shift member 33 receives a shift range switching operation by the driver. The shift member 33 can include a shift lever and a shift switch.

[0069] The shift actuator 34 is mainly composed of an electric motor and is connected to the automatic transmission 32. The shift actuator 34 operates in response to a signal from the control device 9 and switches the shift range between the P range, the D range, the R range, and the N range.

[0070] <HMI 7>

[0071] The HMI 7 is configured to notify various types of information to the occupant(s) and receive various operations performed by the occupant(s). The HMI 7 can include an ignition switch 36 (an example of a power switch) configured to receive a switching operation for switching a power supply state of the vehicle 1.

[0072] <vehicle sensor 8>

[0073] The vehicle sensor 8 detects various states of the vehicle 1 and provides the detection results to the control device 9. The vehicle sensor 8 can include a seating sensor 39 for detecting an occupant seated on each seat of the vehicle 1, a door opening / closing sensor 40 for detecting opening / closing of each door of the vehicle 1, a vehicle speed sensor 41 for detecting a vehicle speed, and other types of sensors. Hereinafter, the vehicle speed detected by the vehicle speed sensor 41 is referred to as "detected vehicle speed"

[0074] <control device 9>

[0075] The control device 9 includes an arithmetic processing device (a processor such as a CPU or an MPU) and a storage device (a memory such as a ROM or a RAM). The control device 9 is an electronic control device (ECU) mainly composed of a computer configured to perform various processing operations as the running start control operation and the running end control operation described later. The arithmetic processing device (processor) as a main part of the control device 9 is programmed to read necessary data and application software from the storage device (memory) and perform predetermined arithmetic processing operations according to the application software. The control device 9 can be configured as a single hardware or a unit module including a plurality of hardware. The control device 9 is connected to various structural and / or functional components of the vehicle 1 through a communication network such as a CAN (Control Area Network) and controls various components of the vehicle 1.

[0076] The control device 9 includes a steering control unit 44, a shift control unit 45, and a power supply control unit 46 as functional units. At least a part of each functional unit of the control device 9 can be implemented by hardware such as an LSI, an ASIC, an FPGA, or a combination of software and hardware.

[0077] The steering control unit 44 controls the steering device 5. Specifically, the steering control unit 44 controls the wheel deflection actuator 19 and the reaction actuator 16 based on the detection results of the steering angle sensor 17 and the wheel deflection angle sensor 20. In some cases, the steering control unit 44 can determine a target wheel deflection angle based on the steering angle detected by the steering angle sensor 17 and drive the wheel deflection actuator 19 so that the wheel deflection angle detected by the wheel deflection angle sensor 20 matches the target wheel deflection angle. The steering control unit 44 can determine a target torque based on the difference between the wheel deflection angle detected by the wheel deflection angle sensor 20 and the target wheel deflection angle and drive the reaction actuator 16 so that the reaction force torque applied by the reaction actuator 16 to the steering member 15 matches the target torque.

[0078] The steering control unit 44 switches the operation mode of the reaction actuator 16 between a running mode for driving the vehicle 1 and a boarding / alighting assistance mode for assisting the driver in boarding and alighting of the vehicle 1. In the running mode, the reaction force torque is determined based on the running state of the vehicle 1 (e.g., the steering state of the wheels, the yaw rate, the lateral acceleration), thus allowing the vehicle 1 to run in a normal manner. In the boarding / alighting assistance mode, the reaction force torque is determined regardless of the running state of the vehicle 1, thus not allowing the vehicle 1 to run in a normal manner.

[0079] The shift control unit 45 controls the shift device 6. Specifically, the shift control unit 45 controls the shift actuator 34 based on the shift position switching operation of the driver on the shift member 33. In other words, the shift control unit 45 causes the shift actuator 34 to switch the shift position in accordance with the shift position switching operation of the driver on the shift member 33.

[0080] The power supply control unit 46 switches the power supply state of the vehicle 1 between a first power supply state and a second power supply state in accordance with the switching operation of the driver on the ignition switch 36. In the present embodiment, the first power supply state is an ignition-off state (IG-OFF state), and the second power supply state is an ignition-on state (IG-ON state). In the IG-OFF state, electric power for driving the vehicle 1 is not supplied from the power supply device 2 to the drive device 3, thus not allowing the vehicle 1 to run. In the IG-ON state, electric power for driving the vehicle 1 is supplied from the power supply device 2 to the drive device 3, thus allowing the vehicle 1 to run.

[0081] <Running start control operation>

[0082] Next, the running start control operation of the vehicle 1 will be described with reference to FIG. 6. The running start control operation is performed when the driver starts running the vehicle 1 from a standstill. Figure 3The running start control operation (control operation performed at the time of start of running of the vehicle 1) performed by the control device 9 is described. In the following description, it is assumed that the power supply state of the vehicle 1 is the IG-OFF state, and that the reaction force actuator 16 and the wheel deflection actuator 19 are stopped at the start of the running start control operation. It is also assumed that the shift control unit 45 controls the shift actuator such that the shift range is fixed to the P range; that is, at this time, the shift control unit 45 prohibits the shift actuator 34 from switching the shift range from the P range to any one of the D range, the R range, and the N range at the start of the running start control operation.

[0083] When the control device 9 starts the running start control operation, the steering control unit 44 determines whether the driver is getting on the vehicle 1 on the basis of the detection results of the vehicle sensors 8 (step ST1). For example, when the seating sensor 39 does not detect an occupant seated in the driver's seat and the door opening / closing sensor 40 detects that the door on the driver's seat side is open, the steering control unit 44 determines that the driver is getting on the vehicle 1. When the seating sensor 39 detects an occupant seated in the driver's seat, or when the door opening / closing sensor 40 does not detect that the door on the driver's seat side is open, the steering control unit 44 determines that the driver is not getting on the vehicle 1. When the steering control unit 44 determines that the driver is not getting on the vehicle 1 (step ST1: No), the steering control unit 44 repeats the determination operation of step ST1 until the determination result is "Yes".

[0084] When the steering control unit 44 determines that the driver is getting on the vehicle 1 (step ST1: Yes), the steering control unit 44 executes an activation operation (that is, an operation for activating the reaction force actuator 16) on the reaction force actuator 16 while stopping the wheel deflection actuator 19, thereby activating the reaction force actuator 16 in the getting-on / getting-off assist mode (step ST2). As a result, the reaction force actuator 16 applies the reaction force torque to the steering member 15.

[0085] Next, the steering control unit 44 determines whether the power supply state of the vehicle 1 has switched from the IG-OFF state to the IG-ON state (step ST3). When it is determined that the power supply state of the vehicle 1 has not switched from the IG-OFF state to the IG-ON state (step ST3: No), the steering control unit 44 repeats the determination operation of step ST3 until the determination result is "Yes".

[0086] When it is determined that the power supply state of the vehicle 1 has switched from the IG-OFF state to the IG-ON state (step ST3: YES), the steering control unit 44 executes a mode change operation (i.e., an operation for changing the operation mode of the reaction actuator 16) on the reaction actuator 16 to switch the operation mode from the boarding / alighting assist mode to the running mode. Further, the steering control unit 44 executes an activation operation (i.e., an operation for activating the wheel deflection actuator 19) on the wheel deflection actuator 19 to activate the wheel deflection actuator 19 (step ST4).

[0087] In step ST4, when the mode change operation on the reaction actuator 16 and the activation operation on the wheel deflection actuator 19 are completed, the shift control unit 45 releases the shift range from being fixed to the P range. In other words, the shift control unit 45 allows the shift actuator 34 to switch the shift range from the P range to any one of the D range, the R range, and the N range (step ST5). As a result, the vehicle 1 can run, and the control device 9 ends the running start control operation of the vehicle 1.

[0088] Next, the following description with reference to Figure 4 is an example of the operation of the components of the vehicle 1 when the control device 9 executes the above-described running start control operation. In the following description, Figure 4 the term "permitted shift range" refers to the shift range that the shift control unit 45 is permitted to select, and the term "actual shift range" refers to the shift range that the shift control unit 45 has actually selected.

[0089] At time T1, the steering control unit 44 determines that the driver is boarding the vehicle 1. In response to this determination, the steering control unit 44 starts the activation operation (i.e., an operation for activating the reaction actuator 16) on the reaction actuator while stopping the wheel deflection actuator 19. At time T2, the activation operation on the reaction actuator is completed. In response to the completion of the activation operation, the steering control unit 44 activates the reaction actuator 16 such that the reaction actuator 16 operates in the boarding / alighting assist mode.

[0090] At time T3, in response to the switching operation of the ignition switch 36, the power supply control unit 46 switches the power supply state of the vehicle 1 from the IG-OFF state to the IG-ON state. In response to this switching of the power supply state, the steering control unit 44 starts the mode change operation for switching the operation mode of the reaction actuator 16 from the boarding / alighting assist mode to the running mode, and also starts the activation operation on the wheel deflection actuator 19.

[0091] At time T4, both the mode change operation to the reaction actuator 16 and the activation operation to the wheel deflection actuator 19 are completed. In response to this completion, the shift control unit 45 releases the shift range from being fixed to the P range. In other words, the shift control unit 45 allows the shift actuator 34 to switch the shift range from the P range to any one of the D range, the R range, and the N range.

[0092] In the example described above, the mode change operation to the reaction actuator 16 and the activation operation to the wheel deflection actuator 19 are both completed at time T4. However, in other cases, the mode change operation to the reaction actuator 16 and the activation operation to the wheel deflection actuator 19 can be completed at different times. In such a case, one of the mode change operation to the reaction actuator 16 and the activation operation to the wheel deflection actuator 19 is completed earlier than the other, and upon completion of the operation completed later, the shift control unit 45 can release the shift range from being fixed to the P range. Figure 4

[0093] After both the mode change operation to the reaction actuator 16 and the activation operation to the wheel deflection actuator 19 are completed, at time T4, the control device 9 performs a start operation (an operation of starting the internal combustion engine) to the internal combustion engine that forms the drive device 3. As a result, in some cases, the voltage of the power supply device 2 drops due to the starting, causing the reaction actuator 16 and the wheel deflection actuator 19 to be reset at time T5. In such a case, the steering control unit 44 needs to perform a restart operation to the reaction actuator 16 and the wheel deflection actuator 19. During the restart operation to the reaction actuator 16 and the wheel deflection actuator 19, the shift control unit 45 again fixes the shift range to the P range.

[0094] At time T6, the restart operation to the reaction actuator 16 and the wheel deflection actuator 19 is completed. In response to this completion, the shift control unit 45 again releases the shift range from being fixed to the P range.

[0095] <End-of-travel control operation>

[0096] Next, the end-of-travel control operation (a control operation performed at the end of travel of the vehicle 1) performed by the control device 9 will be described with reference to Figure 5 In the following description, it is assumed that the power supply state of the vehicle 1 is the IG-OFF state, the reaction actuator 16 is operated in the travel mode, and the wheel deflection actuator 19 is operated at the start of the end-of-travel control operation. It is also assumed that the shift control unit 45 has released the shift range from being fixed to the P range; that is, at the start of the end-of-travel control operation, the shift control unit 45 allows the shift actuator 34 to switch the shift range from the P range to any one of the D range, the R range, and the N range. ​

[0097] When the travel end control operation starts, the steering control unit 44 determines whether the power supply state of the vehicle 1 is the IG-OFF state and whether the vehicle 1 is fixed at the current position (step ST11). When it is determined that at least one of the following first condition and second condition is satisfied, the steering control unit 44 determines that the vehicle 1 is fixed at the current position. When it is determined that neither the first condition nor the second condition is satisfied, the steering control unit 44 determines that the vehicle 1 is not fixed at the current position.

[0098] <First Condition>

[0099] The detected vehicle speed is zero, and the shift range is at the P range.

[0100] <Second Condition>

[0101] The detected vehicle speed is zero, and the EPB 13 is operating.

[0102] When it is determined that the power supply state of the vehicle 1 is not the IG-OFF state or the vehicle 1 is not fixed (step ST11: No), the steering control unit 44 repeats the determination operation of step ST11 until the determination result of ST11 is "Yes".

[0103] When it is determined that the power supply state of the vehicle 1 is the IG-OFF state and the vehicle 1 is fixed at the current position (step ST11: Yes), the steering control unit 44 performs a mode change operation on the reaction actuator 16, thereby switching the operation mode of the reaction actuator 16 from the travel mode to the boarding / alighting assistance mode. In addition, the steering control unit 44 stops the wheel deflection actuator 19 (step ST12). As described above after the operation mode of the reaction actuator 16 is switched from the travel mode to the boarding / alighting assistance mode, the steering control unit 44 gradually changes the reaction force torque applied by the reaction actuator 16 to the steering member 15.

[0104] Next, the steering control unit 44 determines whether a predetermined time has elapsed since the operation mode of the reaction actuator 16 was switched from the travel mode to the boarding / alighting assistance mode (step ST13). When it is determined that the predetermined time has not elapsed (step ST13: No), the steering control unit 44 repeats the determination operation of step ST13 until the determination result of step ST13 is "Yes".

[0105] When it is determined that the predetermined time has elapsed (step ST13: Yes), the steering control unit 44 stops the reaction actuator 16 (step ST14). Then, the travel end control operation of the vehicle 1 is completed.

[0106] Next, the following will be described with reference to Figure 6The description is an example of the operation of the components of the vehicle 1 when the control device 9 performs the travel end control operation. In the description, the term "permitted shift range" refers to a shift range that the shift control unit 45 is permitted to select, and the term "actual shift range" refers to a shift range that the shift control unit 45 has actually selected. Figure 6

[0107] The vehicle 1 starts decelerating to end the travel of the vehicle 1. Then, the detected vehicle speed becomes zero at time Tll. At time T12, the shift actuator 34 switches the shift range from the D range, the R range, or the N range to the P range in accordance with the shift range switching operation on the shift member 33. As a result, the first condition is satisfied, and the steering control unit 44 determines that the vehicle 1 is fixed at the current position. However, at time T12, since the power supply state of the vehicle 1 is the IG-ON state, the steering control unit 44 does not switch the operation mode of the reaction actuator 16, and does not stop the wheel deflection actuator 19.

[0108] At time T13, the EPB 13 starts operating. As a result, the second condition is also satisfied, and the steering control unit 44 determines that the vehicle 1 is fixed at the current position. However, at time T13, since the power supply state of the vehicle 1 is the IG-ON state, the steering control unit 44 does not switch the operation mode of the reaction actuator 16, and does not stop the wheel deflection actuator 19.

[0109] At time T14, in response to the driver's switching operation on the ignition switch 36, the power supply control unit 46 switches the power supply state of the vehicle 1 from the IG-ON state to the IG-OFF state. At time T14, since the first condition and the second condition are still satisfied, the steering control unit 44 determines that the power supply state of the vehicle 1 is the IG-OFF state, and the vehicle 1 is fixed at the current position. In response to the switching of the power supply state, the steering control unit 44 starts the mode change operation to switch the operation mode of the reaction actuator 16 from the travel mode to the boarding / alighting assistance mode, and also starts the activation operation on the wheel deflection actuator 19.

[0110] At time T15, a predetermined time has elapsed from time T14, and the steering control unit 44 stops the reaction actuator 16.

[0111] In some cases, the power source of the EPB 13 can be turned on while the vehicle 1 is traveling (the vehicle speed is not zero). In this case, the control device 9 can decelerate the vehicle 1 by using the regular brake 12 while keeping the power source of the EPB 13 on, and start operating the EPB 13 in response to detecting that the vehicle has completely stopped. As a result, the second condition can be satisfied when the vehicle 1 stops.

[0112] ​In some cases, the power supply state of the vehicle 1 can be changed from the IG-ON state to the IG-OFF state when the vehicle 1 is stopped (the detected vehicle speed is zero) and the shift range is in the D range, the R range, or the N range. In this case, the shift control unit 45 can automatically switch the shift range from the D range, the R range, or the N range to the P range in accordance with the change in the power supply state. As a result, the first condition can be satisfied when the power supply state is switched.

[0113] In some cases, the ignition switch 36 is operated to switch from the IG-ON state to the IG-OFF state while the vehicle 1 is running (the vehicle speed is not zero). In this case, the shift control unit 45 can automatically switch the shift range from the D range, the R range, or the N range to the P range in response to detecting that the vehicle is completely stopped. Therefore, the first condition can be satisfied when the vehicle 1 is stopped.

[0114] In some cases, the ignition switch 36 is operated to switch from the IG-ON state to the IG-OFF state while the vehicle 1 is running (the vehicle speed is not zero), and the power supply to the EPB 13 is turned on. In this case, the control device 9 can decelerate the vehicle 1 by the regular brake 12 while keeping the power supply to the EPB 13 turned on, and operate the EPB 13 when the vehicle 1 is stopped. The shift control unit 45 can automatically switch the shift range from the D range, the R range, or the N range to the P range in response to detecting that the vehicle is completely stopped. As a result, the first condition and the second condition can be satisfied when the vehicle 1 is stopped.

[0115] In some cases, the ignition switch 36 is operated to switch from the IG-ON state to the IG-OFF state while the vehicle 1 is running at a vehicle speed equal to or less than a predetermined reference vehicle speed and the shift range is in the N range. In this case, the shift control unit 45 keeps the shift range in the N range for a predetermined reference time, and as the predetermined reference time has elapsed, the shift control unit 45 automatically changes the shift range from the N range to the P range. As a result, the first condition can be satisfied when the predetermined reference time has elapsed.

[0116] <Effects of the Present Embodiment>

[0117] In the present embodiment, when the activation operation of the wheel deflection actuator 19 is completed, the shift control unit 45 allows the shift device 6 to switch the shift range from the P range to the D range, the R range, or the N range. As a result, when the activation operation of the wheel deflection actuator 19 is completed, the vehicle 1 is released from being fixed at the current position so that the vehicle 1 can move. This ensures that the wheel deflection actuator 19 is activated before the vehicle 1 starts running, thereby improving the reliability of the steering while the vehicle 1 is running.

[0118] In particular, in the present embodiment, the control device executes a start operation on the internal combustion engine that forms the drive device 3 after the activation operation on the wheel deflection actuator 19 is completed. As a result, in some cases, the voltage of the power supply device 2 drops due to the start, resulting in the reaction force actuator 16 and the wheel deflection actuator 19 being reset. In this case, the steering control unit 44 needs to execute a restart operation on the reaction force actuator 16 and the wheel deflection actuator 19. During the restart operation on the reaction force actuator 16 and the wheel deflection actuator 19, the shift control unit 45 again fixes the shift range to the P range. This ensures that the wheel deflection actuator 19 is activated before the vehicle 1 starts moving, thereby improving the reliability of steering while the vehicle 1 is moving.

[0119] Further, the steering control unit 44 starts the activation operation on the wheel deflection actuator 19 when it is determined that the power supply state of the vehicle 1 has switched from the IG-OFF state to the IG-ON state. Therefore, the control device can quickly start activating the wheel deflection actuator 19 when the power supply state of the vehicle 1 changes from the IG-OFF state to the IG-ON state. As a result, the waiting time of the occupant of the vehicle until the operation of activating the wheel deflection actuator is completed can be shortened.

[0120] Moreover, the steering control unit 44 stops the wheel deflection actuator 19 when it is determined that the power supply state of the vehicle 1 is the IG-OFF state and that the vehicle 1 is stationary at the current position. Therefore, the control device can stop the wheel deflection actuator 19 only after confirming that the vehicle 1 is completely stopped. As a result, the reliability of steering while the vehicle is moving can be further improved.

[0121] The steering control unit 44 determines that the vehicle 1 is stationary at the current position when it is determined that at least one of the first condition and the second condition is satisfied. Therefore, the control device can accurately determine whether the vehicle is stationary at the current position. As a result, the reliability of steering while the vehicle is moving can be further improved.

[0122] Furthermore, the steering control unit 44 switches the operation mode of the reaction force actuator 16 between a moving mode for driving the vehicle 1 and an on / off boarding assistance mode for assisting the driver in getting on and off the vehicle 1. Therefore, the reaction force can be applied to the steering member 15 not only while the vehicle 1 is moving, but also when the driver is getting on and off the vehicle 1. As a result, even when the driver touches the steering member 15 to get on and off, the steering member 15 does not tend to move, and thus it becomes easier for the driver to get on and off.

[0123] When the steering control unit 44 determines that the driver is getting on the vehicle 1, the steering control unit 44 activates the reaction force actuator 16 in the getting-on / getting-off assist mode while stopping the wheel deflection actuator 19. Therefore, the reaction force can be applied to the steering member 15 when the driver is getting on the vehicle 1. As a result, the steering member 15 does not tend to move even when the driver touches the steering member 15 to get on the vehicle 1, so it becomes easier for the driver to get on the vehicle 1. Moreover, since the control device activates the reaction force actuator 16 while stopping the wheel deflection actuator 19, it is possible to reduce wasteful electric power consumption.

[0124] When it is determined that the power supply state of the vehicle 1 has switched from the IG-OFF state to the IG-ON state, the steering control unit 44 switches the operation mode of the reaction force actuator 16 from the getting-on / getting-off assist mode to the running mode. Therefore, in response to the change in the power supply state of the vehicle from the IG-OFF to the IG-ON state, the operation mode of the reaction force actuator 16 can be quickly switched from the getting-on / getting-off assist mode to the running mode. As a result, it is possible to shorten the waiting time of the occupant of the vehicle until the operation mode switching is completed.

[0125] When it is determined that the power supply state of the vehicle 1 is the IG-OFF state and the vehicle 1 is fixed at the current position, the steering control unit 44 switches the operation mode of the reaction force actuator 16 from the running mode to the getting-on / getting-off assist mode. Therefore, when the vehicle 1 stops running, the control device keeps the reaction force actuator 16 operating so that the reaction force actuator 16 continues to apply the reaction force to the steering member 15. As a result, the steering member 15 does not tend to move even when the driver touches the steering member 15 to get off, so it becomes easier for the driver to get off the vehicle 1.

[0126] When the operation mode of the reaction force actuator 16 is the getting-on / getting-off assist mode, the steering control unit 44 gradually changes the reaction force torque applied by the reaction force actuator 16 to the steering member 15. Therefore, it is possible to suppress the rapid change in the reaction force applied to the steering member 15, thereby reducing the discomfort of the driver.

[0127] When it is determined that the predetermined time has not elapsed since the operation mode of the reaction force actuator 16 was switched from the running mode to the getting-on / getting-off assist mode, the steering control unit 44 stops the reaction force actuator 16. As a result, since the continuous operation of the reaction force actuator 16 is prevented for a long time, it is possible to reduce wasteful electric power consumption.

[0128] <Modification of Embodiment>

[0129] In the present embodiment, when the starting operation on the wheel deflection actuator 19 is completed, the shift control unit 45 allows the shift device 6 to be shifted from the P range to the D range, the R range, or the N range. In other embodiments, the shift control unit 45 allows the shift device 6 to be shifted from the P range to the D range, the R range, or the N range at a certain time after the starting operation on the wheel deflection actuator 19 is completed.

[0130] In the present embodiment, the shift device 6 is used as the state switching device. In other embodiments, the EPB 13 can be used as the state switching device. In this case, the fixed state and the released state can be determined such that the EPB 13 is operated in the fixed state, and the EPB 13 is released from the operation in the released state.

[0131] In the present embodiment, the shift device 6 is a shift-by-wire type shift device in which the shift member 33 is mechanically separated from the shift actuator 34. In other embodiments, the shift device 6 can be a shift device in which the shift member 33 is mechanically connected to the shift actuator 34.

[0132] In the present embodiment, the EPB 13 (electric parking brake) is used as the parking brake. In other embodiments, a mechanical parking brake can be used as the parking brake.

[0133] For the purpose of illustration, specific embodiments of the present application are described herein. However, the present application is not limited to those specific embodiments, and various changes can be made to the elements of the embodiments without departing from the scope of the present application.

Claims

1. A vehicle comprising: a steering member for receiving a steering operation; a wheel deflection actuator that is mechanically separated from the steering member and is configured to deflect a wheel to change a moving direction of the vehicle; a state switching device for switching between a fixed state in which the vehicle is fixed at a current position and a released state in which the vehicle is released from being fixed at the current position; and a control device for controlling the wheel deflection actuator and the state switching device, wherein the control device permits the state switching device to switch from the fixed state to the released state only when or after an operation for activating the wheel deflection actuator is completed, wherein the vehicle further comprises a reaction actuator for applying a reaction force to the steering member in response to a steering operation received by the steering member, wherein the control device switches a mode of operation of the reaction actuator between a traveling mode for driving the vehicle and a boarding / alighting assistance mode for assisting a driver to board and alight, and wherein, when the mode of operation of the reaction actuator is the boarding / alighting assistance mode, the control device gradually changes the reaction force applied to the steering member by the reaction actuator, thereby preventing a rapid change in the reaction force applied to the driver's hand via the steering member. the vehicle has a power supply state that is switchable between a first power supply state in which the vehicle is prohibited from traveling and a second power supply state in which the vehicle is permitted to travel, and 2. The vehicle of claim 1, wherein, wherein the control device is configured such that, when the power supply state of the vehicle is the first power supply state and the wheel deflection actuator is stopped from operating, the control device determines whether the power supply state of the vehicle has switched from the first power supply state to the second power supply state, and, when it is determined that the power supply state of the vehicle has switched from the first power supply state to the second power supply state, the control device starts an operation for activating the wheel deflection actuator. the vehicle has a power supply state that is switchable between a first power supply state in which the vehicle is prohibited from traveling and a second power supply state in which the vehicle is permitted to travel, and 3. The vehicle of claim 1, wherein, wherein the control device is configured such that, when the wheel deflection actuator is operating, the control device determines whether the power supply state of the vehicle is the first power supply state and whether the vehicle is fixed at the current position, and, when it is determined that the power supply state of the vehicle is the first power supply state and the vehicle is fixed at the current position, the control device stops the wheel deflection actuator.

4. The vehicle according to claim 3, further comprising: a vehicle speed sensor for detecting a vehicle speed of the vehicle; and an electric parking brake for fixing the vehicle at the current position, ​ ​ The state switching device is a shift device configured to switch a shift range between a fixed range for fixing the vehicle at the current position and a release range for releasing the vehicle from being fixed at the current position, and The control device determines that the vehicle is fixed at the current position when at least one of two conditions is satisfied, the two conditions including a first condition that the vehicle speed detected by the vehicle speed sensor is zero and the shift range is the fixed range, and a second condition that the vehicle speed detected by the vehicle speed sensor is zero and the electric parking brake is operating.

5. The vehicle of claim 1, wherein, The vehicle has a power supply state that can be switched between a first power supply state in which the vehicle is prohibited from traveling and a second power supply state in which the vehicle is permitted to travel, and The control device is configured such that, when the power supply state of the vehicle is the first power supply state and both the wheel deflection actuator and the reaction actuator are stopped from operating, the control device determines whether the driver is getting on the vehicle, and when it is determined that the driver is getting on the vehicle, the control device activates the reaction actuator so that the reaction actuator operates in the getting on / off assistance mode while stopping the wheel deflection actuator.

6. The vehicle of claim 5, wherein, The control device is configured such that, when the power supply state of the vehicle is the first power supply state and the reaction actuator is operating in the getting on / off assistance mode, the control device determines whether the power supply state of the vehicle has been switched from the first power supply state to the second power supply state, and when it is determined that the power supply state of the vehicle has been switched from the first power supply state to the second power supply state, the control device switches the operation mode of the reaction actuator from the getting on / off assistance mode to the traveling mode.

7. The vehicle of claim 1, wherein, The vehicle has a power supply state that can be switched between a first power supply state in which the vehicle is prohibited from traveling and a second power supply state in which the vehicle is permitted to travel, and The control device is configured such that, when the operation mode of the reaction actuator is the traveling mode, the control device determines whether the power supply state of the vehicle is the first power supply state and whether the vehicle is fixed at the current position, and when it is determined that the power supply state of the vehicle is the first power supply state and the vehicle is fixed at the current position, the control device switches the operation mode of the reaction actuator from the traveling mode to the getting on / off assistance mode.

8. The vehicle of claim 1, wherein, The control device stops the reaction actuator when a predetermined time has elapsed since the operation mode of the reaction actuator became the getting on / off assistance mode.

Images