Steering system

Abstract

To provide a steering system that is able to secure the safety of a vehicle when performing a state transition among control states.SOLUTION: In a steering system 10, an operation ECU 13 has the following control states: a main control state in which a turning device 12 is controlled in conjunction with an operation device 11 and a turning ECU 14 such that an operation of a steering wheel 111 and a turning operation are synchronized with each other; a sub-control state in which at least the operation device 11 is controlled such that an operation of the steering wheel 111 and the turning operation are not synchronized with each other; and a stop state in which actuation of the turning device 12 is stopped in conjunction with the operation device 11 and the turning ECU 14; wherein a state transition can be caused among the control states, i.e., the main control state, the sub-control state, and the stop state; and wherein the operation ECU includes a state transition permission unit 15 configured to determine whether a predetermined state transition condition related to safety of a vehicle 1 is satisfied or not when the state transition is executed, and to permit the state transition when the state transition condition is satisfied.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to steering systems. [Background technology]

[0002] A conventionally known game device is disclosed, for example, in Patent Document 1. The conventional game device includes a terminal for inputting information corresponding to the amount of operation of a steering wheel or the like for driving operation mounted on a real vehicle capable of traveling, and generates images to be displayed on a display and sound effects to be output from a speaker based on the information corresponding to the amount of operation of the steering wheel or the like for driving operation input via this terminal, thereby executing a game based on driving operations. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-330312 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional game devices, when a user issues a command to start a game, if the vehicle is in a non-driving state, the game is executed using the steering wheel. However, in a vehicle steering system, if a state transition is possible between a primary control state in which the steered wheels are steered to drive the vehicle and a secondary control state in which the game is provided using the steering wheel, consideration must be given to the state transition of the control state in order to ensure greater safety in the vehicle.

[0005] An object of the present disclosure is to provide a steering system that can ensure the safety of a vehicle when a state transition of a control state is performed. [Means for solving the problem]

[0006] The steering system of the present disclosure comprises an operating device having an operating member that generates and applies a reaction force to the operation of the operating member; a steering device that turns the steered wheels of the vehicle by releasing the mechanical connection with the operating device; and a controller that causes the steering device to turn the steered wheels in accordance with the operation of the operating member, and the controller has each of the following control states: a main control state in which the operating device and the steering device are controlled to synchronize the operation of the operating member with the steering operation; a sub-control state in which at least the operating device is controlled so as not to synchronize the operation of the operating member with the steering operation; and a stop state in which operation of the operating device and the steering device is stopped, and the controller is capable of transitioning the control state between the main control state, the sub-control state, and the stop state, and when a state transition is performed, the controller comprises a state transition permission unit that determines whether predetermined state transition conditions related to the safety of the vehicle are met, and permits the state transition if the state transition condition is met. [Effects of the Invention]

[0007] According to the present disclosure, the steering system can transition the control state of the controller when the state transition permission unit determines that the state transition condition is met and permits the state transition, thereby ensuring the safety of the vehicle when the steering system transitions between the primary control state and the secondary control state. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic configuration diagram of a vehicle. [Figure 2] FIG. 2 is a functional block diagram of a state transition permission unit (state transition permission section). [Figure 3] FIG. 10 is a diagram for explaining state transitions. [Figure 4] 3 is a diagram for explaining processing by an authentication determination unit in FIG. 2. FIG. [Figure 5] 3 is a diagram for explaining processing by a secondary control state transition permission determination unit in FIG. 2. FIG. [Figure 6] 3 is a diagram for explaining processing by a sub-control state end determination unit in FIG. 2. FIG. [Figure 7] 3 is a diagram for explaining processing by a main control state transition permission determination unit in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0009] A steering system 10 according to an embodiment of the present disclosure will be described in detail below with reference to the drawings. In addition to the embodiment described below, the present disclosure can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art.

[0010] 1. Configuration of vehicle 1 to which steering system 10 is applied In this embodiment, a steering system 10 is applied to a vehicle 1 shown in Fig. 1. The vehicle 1 includes a vehicle body 2, wheels 3 arranged on the front, rear, left and right sides, and suspension units 4 that support the vehicle body 2 and each wheel 3. The wheels 3 are composed of a right front wheel 31, a left front wheel 32, a right rear wheel 33 and a left rear wheel 34. The suspension units 4 are of an independent suspension type arranged corresponding to each wheel 3, and include, for example, coil springs 41 and hydraulic shock absorbers 42. Note that the suspension units 4 may also be, for example, air suspension units equipped with air springs.

[0011] The vehicle 1 also includes a drive system 5 that generates and transmits the driving force required for traveling. The drive system 5 has a front motor 51 and a rear motor 52 as electric motors. The front motor 51 drives the right front wheel 31 and the left front wheel 32 by transmitting rotation of its output shaft to left and right front wheel axles 54R, 54L via a differential gear 53 (including a reduction gear). The rear motor 52 drives the right rear wheel 33 and the left rear wheel 34 by transmitting rotation of its output shaft to left and right rear wheel axles 56R, 56L via a differential gear 55 (including a reduction gear). That is, in this embodiment, a four-wheel drive electric vehicle (EV) is exemplified as the vehicle 1.

[0012] The drive system 5 also has an inverter 57, a DC / DC converter 58, and a battery 59. As a result, the front motor 51 and the rear motor 52 can be driven independently to rotate forward in the forward direction of the vehicle 1 and to rotate backward in the reverse direction of the vehicle 1 by controlling the energization of the inverter 57.

[0013] The inverter 57 also has a charging port (not shown) and has a charging function of, for example, converting AC current supplied from a charging facility into DC current and charging the battery 59 via a DC / DC converter 58. Furthermore, the inverter 57 also has a function of, for example, converting AC current generated by the rear motor 52 into DC current and charging the battery 59 via the DC / DC converter 58, that is, storing regenerative energy.

[0014] The operation of the front motor 51 and the rear motor 52 is controlled by a drive electronic control unit 61 (hereinafter, sometimes simply referred to as the "drive ECU 61") that constitutes the braking / driving controller 6. The drive ECU 61 is an electronic control unit (Electric Control Unit) that includes, as its main component, a microcomputer having a CPU, ROM, RAM, and various interfaces. In FIG. 1, the drive ECU 61 is indicated as the "P-ECU 61."

[0015] The CPU sequentially executes predetermined programs to read data, perform numerical calculations, and output the calculation results. The ROM stores programs and maps executed by the CPU. The RAM temporarily stores data, etc. The various interfaces are connected to a communication line L. The communication line L may be, for example, a CAN (Car Area Network or Controllable Area Network) or a dedicated communication line other than CAN.

[0016] The drive ECU 61 receives a detection signal Sa from an accelerator sensor 71, which detects the amount of accelerator operation, from the sensor group 7, and calculates a driver-requested driving force corresponding to the amount of accelerator operation. The drive ECU 61 then controls the front motor 51 and the rear motor 52 to transmit the front-wheel target driving force and rear-wheel target driving force, which are obtained by dividing the calculated driver-requested driving force between the front and rear wheels, to the right front wheel 31, the left front wheel 32, the right rear wheel 33, and the left rear wheel 34, respectively.

[0017] Furthermore, the drive ECU 61 receives, for example, a detection signal Smf output from a control sensor 72 of the front motor 51, and controls the operation of the inverter 57 to control the energization of the front motor 51. Similarly, the drive ECU 61 receives a detection signal Smr output from a control sensor 73 of the rear motor 52, and controls the operation of the inverter 57 to control the energization of the rear motor 52.

[0018] Furthermore, the drive ECU 61 acquires the operating positions of a shift lever, a shift switch, etc. (not shown) that are operated when moving the vehicle 1 forward or backward or when parking the vehicle 1. To this end, the drive ECU 61 receives a detection signal Ssp that indicates the operating position and is output from the shift position sensor 74 of the sensor group 7.

[0019] The vehicle 1 is also equipped with a brake system 8 that generates braking force required for braking. The brake system 8 includes a right front wheel brake 81, a left front wheel brake 82, a right rear wheel brake 83, a left rear wheel brake 84, and a brake actuator 85. In FIG. 1, the brake actuator 85 is indicated as "B / A85."

[0020] Although not shown, each of the right front wheel brake 81, left front wheel brake 82, right rear wheel brake 83, and left rear wheel brake 84 includes a brake disc that rotates integrally with the wheel 3, a pair of brake pads that press against the brake disc from both sides, and a brake caliper to which the brake pads are fixed. A brake actuator 85 is connected to the brake caliper via brake piping that is not shown, and a hydraulic circuit of working oil is formed between the brake actuator 85 and each of the right front wheel brake 81, left front wheel brake 82, right rear wheel brake 83, and left rear wheel brake 84. As a result, in the brake system 8, when the brake actuator 85 pressurizes the working oil, the brake pads press against the brake disc, resulting in the generation of frictional force, i.e., braking force.

[0021] The brake actuator 85 includes a reservoir tank that stores hydraulic fluid, a master cylinder that pressurizes the hydraulic fluid, a pump, and the like. The reservoir tank, master cylinder, and pump are not shown in the figure. The brake actuator 85 is controlled by a brake electronic control unit 62 (hereinafter, may be simply referred to as the "brake ECU 62") that constitutes the braking / driving controller 6. That is, the brake actuator 85 adjusts the pressure of hydraulic fluid applied to each of the right front wheel brake 81, the left front wheel brake 82, the right rear wheel brake 83, and the left rear wheel brake 84 in accordance with the control of the brake ECU 62. In this way, the brake actuator 85 can generate braking force in each of the right front wheel brake 81, the left front wheel brake 82, the right rear wheel brake 83, and the left rear wheel brake 84.

[0022] The brake ECU 62 is an electronic control unit (ECU) that includes, as its main component, a microcomputer having a CPU, ROM, RAM, and various interfaces. The brake ECU 62 is connected to a communication line L via the various interfaces. In FIG. 1, the brake ECU 62 is indicated as "B-ECU 62."

[0023] The brake ECU 62 is connected to a hydraulic sensor, various control valves, a pump, etc. (not shown) that are provided in the brake actuator 85. Also connected to the brake ECU 62 are the following sensors 7: a brake sensor 75 that detects the amount of braking operation by the driver from the amount of depression of the brake pedal (not shown), four wheel speed sensors 76 that detect the wheel speeds of the respective wheels 3, and a parking brake sensor 77. The four wheel speed sensors 76 output a detection signal Swv1 that indicates the wheel speed of the right front wheel 31, a detection signal Swv2 that indicates the wheel speed of the left front wheel 32, a detection signal Swv3 that indicates the wheel speed of the right rear wheel 33, and a detection signal Swv4 that indicates the wheel speed of the left rear wheel 34, respectively.

[0024] The brake ECU 62 receives the detection signal Sb from the brake sensor 75 and calculates a driver-requested braking force corresponding to the amount of brake operation. The brake ECU 62 then calculates the friction braking force to be generated in each of the right front wheel brake 81, the left front wheel brake 82, the right rear wheel brake 83, and the left rear wheel brake 84, and the regenerative braking force to be generated in the rear motor 52, so as to realize the driver-requested braking force.

[0025] Here, the brake ECU 62 controls the operation of the brake actuator 85 based on the detection signals Swv1, Swv2, Swv3, and Swv4 of the wheel speed sensors 76 so as to generate the calculated friction braking force. As a result, the brake actuator 85 pressurizes the hydraulic oil and supplies it to each of the right front wheel brake 81, the left front wheel brake 82, the right rear wheel brake 83, and the left rear wheel brake 84. As a result, the brake pads in each of the right front wheel brake 81, the left front wheel brake 82, the right rear wheel brake 83, and the left rear wheel brake 84 press against the brake discs, and braking force is applied to each wheel 3.

[0026] Furthermore, the brake ECU 62 transmits information indicating the calculated regenerative braking force to the drive ECU 61. As a result, when the drive ECU 61 receives a regenerative braking command transmitted from the brake ECU 62, the drive ECU 61 outputs a control signal to the inverter 57 that is generated so that the required regenerative braking force is applied to the right rear wheel 33 and the left rear wheel 34. As a result, the duty ratio of the switching elements of the inverter 57 is controlled, and a current corresponding to the regenerative braking force flows from the rear motor 52 to the battery 59 via the DC / DC converter 58, and braking force is applied to the right rear wheel 33 and the left rear wheel 34.

[0027] Furthermore, when the vehicle 1 is stopped, the brake ECU 62 activates a well-known parking brake device (not shown) based on the detection signals Swv1, Swv2, Swv3, and Swv4 of the wheel speed sensors 76. When the parking brake device is activated to apply braking force to the wheels 3 (for example, the right rear wheel 33 and the left rear wheel 34), the brake ECU 62 receives a detection signal Spb that is output from the parking brake sensor 77 and indicates that the parking brake device is applying braking force.

[0028] 2. Configuration of steering system 10 In this embodiment, the steering system 10 mounted on the vehicle 1 described above steers a right front wheel 31 and a left front wheel 32 as steered wheels. The steering system 10 is a steer-by-wire type equipped with an operating device 11 and a steering device 12 that are mechanically independent from each other.

[0029] The operation device 11 mainly includes a steering wheel 111, a steering shaft 112, a steering column 113, and a reaction force imparting mechanism 114. The steering wheel 111 is an operation member that is operated (steered) by a driver who is an authenticated administrator as described below and an authorized user who is also authenticated as described below. The steering shaft 112 has the steering wheel 111 attached to its tip and is rotatably supported by a steering column 113. The steering column 113 is supported by an instrument panel reinforcement (not shown).

[0030] The reaction force applying mechanism 114 uses a reaction force motor 115 as a driving force source to apply a reaction force Fc (strictly speaking, this is a "reaction torque," but hereinafter will be referred to as "operation reaction force Fc") against the steering operation to the steering wheel 111 via the steering shaft 112. The reaction force motor 115 can be, for example, a three-phase brushless DC motor. Here, the reaction force motor 115 has its own motor rotation angle sensor 116 that detects the motor rotation angle ω within one rotation in order to switch the conduction phase in the power supply to the reaction force motor 115. Note that the reaction force applying mechanism 114 has a general structure including a reducer and the like, and therefore a description of the specific structure will be omitted.

[0031] The operation device 11 also has an operation angle sensor 117 that detects an operation angle δ that indicates the operation position of the steering wheel 111. Here, if the position of the steering wheel 111 when the vehicle 1 is traveling straight is defined as a neutral position, the rotation angle from the neutral position to the left and right is the operation angle δ of the steering wheel 111.

[0032] Similarly to a so-called general power steering system, the operation device 11 also has a torsion bar 118 incorporated in the steering shaft 112. The operation device 11 also has an operation torque sensor 119 that detects an operation torque To as an operation force applied to the steering wheel 111 by the driver based on the amount of twist of the torsion bar 118.

[0033] The steering device 12 integrally steers each of the right front wheel 31 and the left front wheel 32, which are steerably supported on the vehicle body 2, by rotating a steering knuckle 43 that constitutes the suspension unit 4. The steering device 12 has a steering actuator 121 as a main component.

[0034] Steering actuator 121 mainly comprises a steering rod 122, a housing 123, and a rod moving mechanism 124. Both ends of steering rod 122 are connected to left and right steering knuckles 43 via tie rods 125. Housing 123 is fixed to vehicle body 2, and supports steering rod 122 so that it can move in the left-right direction.

[0035] Rod moving mechanism 124 moves steering rod 122 in the left-right direction using steering motor 126 as a drive power source. Rod moving mechanism 124 can be exemplified as a mechanism that mainly includes a ball screw mechanism that is configured by a ball groove (not shown) provided in steering rod 122 and a nut (not shown) that is screwed into the ball groove via a bearing ball (not shown) and is rotated by steering motor 126.

[0036] Since the ball screw mechanism is a common structure, a description of the specific structure of the rod moving mechanism 124 will be omitted. Furthermore, the structure of the rod moving mechanism 124 is not limited to the ball screw mechanism, and other mechanisms can also be used.

[0037] Here, like reaction force motor 115, steering motor 126 can also be, for example, a three-phase brushless DC motor. And steering motor 126 also has its own motor rotation angle sensor 127 that detects motor rotation angle v within one rotation in order to switch the current-carrying phase in the power supply to steering motor 126. And steering motor 126 also has its own current sensor 128 that detects current I actually supplied to itself (hereinafter may be referred to as "steering current I").

[0038] Furthermore, steering device 12 has steering angle sensor 129 that detects steering angle θ that indicates the steering position of right front wheel 31 and left front wheel 32, which are steered wheels. Here, when the position of steering rod 122 when vehicle 1 is traveling straight is set to the neutral position, steering angle sensor 129 detects the steering angle θ of right front wheel 31 and left front wheel 32, the amount of movement of steering rod 122 in each of the left and right directions from the neutral position.

[0039] Control of the operation device 11, more specifically, control of the operation reaction force Fc, i.e., control of the reaction force motor 115 of the operation device 11, is executed by an operation electronic control unit 13 (hereinafter, may be simply referred to as "operation ECU 13"). The operation ECU 13 is an electronic control unit (Electric Control Unit) that includes, as its main part, a microcomputer having a CPU, ROM, RAM, and various interfaces. The operation ECU 13 is connected to a communication line L via various interfaces. In FIG. 1, the operation ECU 13 is indicated as "O-ECU 53."

[0040] Control of the steering device 12, more specifically, control of the steering angle θ, that is, control of the steering motor 126 of the steering device 12, is executed by a steering electronic control unit 14 (hereinafter sometimes simply referred to as "steering ECU 14"). The steering ECU 14 is an electronic control unit that includes, as its main component, a microcomputer having a CPU, ROM, RAM, and various interfaces. The steering ECU 14 is connected to a communication line L via various interfaces. In FIG. 1, the steering ECU 14 is indicated as "S-ECU 14."

[0041] Here, the control of steering system 10 will be explained, including steering control, which is control of steering device 12, and reaction force control, which is control of reaction force applying mechanism 114 of operation device 11. First, the steering control will be explained. The steering control is control for steering right front wheel 31 and left front wheel 32 in response to a steering request, that is, in response to the operation angle δ of steering wheel 111 in the case of manual driving by the driver. The steering control is executed by cooperation between operation ECU 13 and steering ECU 14 in the main control state, as will be described later.

[0042] In steering system 10, motor rotation angle ω of reaction force motor 115 of operation device 11 and operation angle δ of steering wheel 111 have a relationship that forms a predetermined gear ratio. For this reason, operation ECU 13 obtains operation angle δ based on motor rotation angle ω detected via motor rotation angle sensor 116. Then, steering ECU 14 obtains information about operation angle δ from operation ECU 13, and determines target steering angle θd, which is a target for steering angle θ of right front wheel 31 and left front wheel 32, by multiplying the obtained operation angle δ by a set steering gear ratio Rg according to the following equation (1). θd=Rg×δ …Equation (1)

[0043] In steering system 10, control of steering angle θ of right front wheel 31 and left front wheel 32 is performed using motor rotational angle ν instead of steering angle θ. For this reason, steering ECU 14 determines target motor rotational angle νd, which is a target for v, the motor rotational angle of steering motor 126, based on target steering angle θd determined in accordance with equation (1) above. Then, steering ECU 14 detects actual motor rotational angle ν of steering motor 126 via motor rotational angle sensor 127, and determines motor rotational angle deviation Δν, which is the deviation of motor rotational angle ν from target motor rotational angle νd, in accordance with equation (2) below. Δν=νd-ν …Equation (2)

[0044] Here, in steering system 10, steering ECU 14 determines torque Ts to be generated by steering motor 126 (hereinafter referred to as "turning torque Ts") in accordance with a feedback control law based on motor rotational angle deviation Δν. That is, steering ECU 14 determines turning torque Ts in accordance with the following equation (3). Ts=Gp×Δν+Gi×∫Δνdt+Gd×dΔν / dt…Formula (3) In the above formula (3), the first term is a proportional term, the second term is an integral term, and the third term is a differential term. Also, in the above formula (3), Gp represents the proportional term gain, Gi represents the integral term gain, and Gd represents the differential term gain.

[0045] In the steering control, steering ECU 14 supplies steering current I to steering motor 126 according to steering torque Ts determined in accordance with equation (3) above. Here, steering current I is approximately proportional to steering torque Ts. Therefore, steering ECU 14 determines steering current I to be supplied to steering motor 126 based on the determined steering torque Ts, for example, in accordance with the proportional relationship. Then, steering ECU 14 operates steering motor 126 by supplying steering current I to steering motor 126, for example, via an inverter not shown, and turns wheels 3, i.e., right front wheel 31 and left front wheel 32, until target steering angle θd is reached.

[0046] The reaction force control is a control that applies an operation reaction force Fc to the steering wheel 111 in order to give the driver a steering feel. The reaction force control is executed by the operation ECU 13 in a primary control state and a secondary control state, which will be described later. Specifically, the operation ECU 13 determines the operation reaction force Fc according to the following equation (4) that uses two components: a steering load-dependent component Fs and an operation force-dependent decrease component Fa. Fc=Fs-Fa…Equation (4)

[0047] Here, the turning load dependent component Fs in equation (4) is a component related to the turning force (the turning torque Ts of the turning motor 126) required to turn the right front wheel 31 and the left front wheel 32, and is determined based on the turning current I supplied to the turning motor 126. Although a detailed explanation will be omitted, the larger the turning current I, the greater the turning load on the right front wheel 31 and the left front wheel 32 is recognized, and the larger the value of the turning load dependent component Fs is determined to be. In the primary control state, information related to the turning current I actually supplied to the turning motor 126 is supplied from the turning ECU 14 to the operation ECU 13 via the communication line L. In the secondary control state, the information related to the turning current I is generated by the operation ECU 13 based on, for example, a preset relationship or the like.

[0048] The operation force dependent reduction component Fa in the above equation (4) is a component for providing the driver with the same operation feeling as in a conventional power steering system. In a conventional power steering system, an assist torque corresponding to the operation torque To is generally generated by, for example, an electric motor and applied to the steering shaft 112.

[0049] Therefore, the operation force dependent decrease component Fa is determined in accordance with the following equation (5) so as to reproduce the assist torque. Then, the operation ECU 13 obtains the operation torque To via the operation torque sensor 119. Fa = β × To ... Equation (5) In the above equation (5), β represents a gain for determining the operating force dependent decrease component Fa.

[0050] The operation ECU 13 determines a reaction force current Ic, which is a current to be supplied to the reaction force motor 115, according to the following equation (6) based on the operation reaction force Fc determined according to the above equation (4). Then, the operation ECU 13 supplies the determined reaction force current Ic to the reaction force motor 115. Ic=α×Fc…Equation (6) In the above equation (6), α represents a preset power determination coefficient.

[0051] 3. Configuration of the state transition permission unit 15 As described above, operation ECU 13 as a controller can realize a main control state in which it controls the steering operation of right front wheel 31 and left front wheel 32, which are steered wheels, by cooperating with steering ECU 14 as a controller in response to the operation of steering wheel 111, which is an operation member. On the other hand, operation ECU 13 can transition to a sub-control state in which, unlike the main control state, it controls the operation of steering wheel 111 in a state in which synchronization with right front wheel 31 and left front wheel 32 is released, for example, while battery 59 mounted on vehicle 1 is being charged as will be described later.

[0052] Here, an example of the main control state is a control state in which, when vehicle 1 is traveling, operation device 11 and steering device 12 cooperate to steer right front wheel 31 and left front wheel 32 in synchronization to a steering angle θ in accordance with operation angle δ of steering wheel 111. Also, an example of the secondary control state is a control state in which, when vehicle 1 is stopped (parked) to charge battery 59, synchronization between operation device 11 and steering device 12 is released, that is, operation device 11 and steering device 12 cooperate to prohibit steering of right front wheel 31 and left front wheel 32.

[0053] As a result, in the sub-control state, when the steering wheel 111 is operated, the operation ECU 13 applies an operation reaction force Fc to the operation of the steering wheel 111 via the operation device 11, but the steering ECU 14 does not operate the steering device 12, and as a result, the right front wheel 31 and the left front wheel 32 are not steered. In other words, in the sub-control state, the operation device 11 can be made independent of the steering device 12. Therefore, in the sub-control state, entertainment mainly consisting of a game can be provided to the occupant of the vehicle 1, that is, a specific user who is an administrator or authorized user and will be described later, for example, by using the steering wheel 111 to instruct and control the movement of a virtual moving object such as a virtual vehicle or a virtual airplane while charging.

[0054] Incidentally, the primary control state is a control state that appropriately steers the right front wheel 31 and the left front wheel 32 while the vehicle 1 is traveling, and so naturally it is more important and should be prioritized over the secondary control state that enables entertainment. For this reason, it is essential that the state transition from the primary control state to the secondary control state is not easy and that the state transition from the secondary control state to the primary control state is safe. Therefore, when executing a state transition between the primary control state and the secondary control state, preset state transition conditions related to the safety of the vehicle 1 must be determined, and the state transition must be permitted if the state transition condition is met.

[0055] Therefore, the steering system 10 mounted on the vehicle 1 is provided with a state transition permission unit 15 as a state transition permission section that determines the state transition condition and permits the state transition when the state transition condition is met. In Fig. 1, the state transition permission unit 15 is indicated as "S / P-UNIT 15".

[0056] In this embodiment, the state transition permission unit 15 is provided integrally with the operation ECU 13, which is the controller. Therefore, the state transition permission unit 15 is also configured with a microcomputer having a CPU, ROM, RAM, and various interfaces as its main part. Since the state transition permission unit 15 has a microcomputer as its main part, it can also be configured as a standalone electronic control unit. Furthermore, the state transition permission unit 15 can also be provided integrally with an ECU other than the operation ECU 13.

[0057] Moreover, state transition permission unit 15 is capable of communicating with various ECUs such as the drive ECU 61, brake ECU 62, and steering ECU 14 described above via communication line L, and is also capable of acquiring detection values from various sensors such as the sensor group 7 described above. Furthermore, state transition permission unit 15 is connected to authentication device 16, input device 17, and display device 18.

[0058] The state transition permission unit 15 determines the "state transition conditions" and permits state transitions between the primary control state, the secondary control state, and the stopped state. The "state transition conditions" include a "vehicle-related condition," an "authentication condition," and a "stop condition." In this embodiment, seven conditions are exemplified as the "vehicle-related condition," two conditions are exemplified as the "authentication condition," and two conditions are exemplified as the "stop condition."

[0059] First, the vehicle-related conditions are conditions for determining the state of the vehicle 1, more specifically, the vehicle speed, vehicle speed state, drivetrain state, powertrain state, steer-by-wire system state, vehicle communication state, and steering state, which represent the state of the vehicle 1 being safely stopped. That is, in this embodiment, the vehicle-related conditions are made up of "vehicle-related condition 1," "vehicle-related condition 2," "vehicle-related condition 3," "vehicle-related condition 4," "vehicle-related condition 5," "vehicle-related condition 6," and "vehicle-related condition 7."

[0060] Specifically, vehicle-related condition 1 is a condition for determining whether the vehicle speed is "0." Therefore, vehicle-related condition 1 can be, for example, a condition for determining whether the vehicle speed obtained using the detection signals Swv1-Swv4 of wheel speed sensor 76 is "0." Vehicle-related condition 1 can also be, for example, a condition for determining whether braking force is being applied by the parking brake based on the detection signal Spb of parking brake sensor 77.

[0061] Vehicle-related condition 1 may also be a condition that the accelerator operation amount is "0" based on the detection signal Sa of the accelerator sensor 71 (the accelerator is not being operated), or that the brake operation amount is not "0" based on the detection signal Sb of the brake sensor 75 (the brake is being operated). In this case, when determining the state transition, it is determined that the accelerator operation amount is "0" based on the detection signal Sa of the accelerator sensor 71 and that the brake operation amount is not "0" based on the detection signal Sb of the brake sensor 75, but this is not the case after the determination.

[0062] Vehicle-related condition 2 is a condition for determining whether the vehicle speed state, i.e., the vehicle speed detection state, is valid. Therefore, vehicle-related condition 2 can be, for example, a condition for determining whether the wheel speed sensor 76 is operating properly, i.e., the accuracy and output state of the detection signals Swv1-Swv4 of the wheel speed sensor 76.

[0063] Vehicle-related condition 3 is a condition for determining the drivetrain state when the vehicle 1 is stopped. Therefore, vehicle-related condition 3 is a condition for determining whether or not driving force is not being output from the front motor 51 and the rear motor 52 to the front axles 54R, 54L and the rear axles 56R, 56L via the differential gear 53 and the differential gear 55, and the wheels 3 are locked. Specifically, vehicle-related condition 3 may be, for example, a condition that the detection signal Smf of the control sensor 72 and the detection signal Smr of the control sensor 73 are "0" and the detection signal Ssp of the shift position sensor 74 is in the "parking range."

[0064] The vehicle-related condition 4 is a condition for determining the powertrain state of the vehicle 1, that is, the states of the front motor 51, the rear motor 52, the inverter 57, the DC / DC converter 58, and the battery 59. Therefore, the vehicle-related condition 4 is a condition for determining, for example, whether the vehicle 1 is "ready to drive" for traveling or whether the battery 59 is "charging" and is being charged, and specifically, the vehicle-related condition 4 can be a condition for determining whether the detection signal Smf of the control sensor 72 and the detection signal Smr of the control sensor 73 are "0" and the inverter 57 is in a charging state where AC current is supplied from the outside.

[0065] Vehicle-related condition 5 is a condition for determining the state of the steer-by-wire system of vehicle 1, i.e., the operating state of steering system 10 including operation device 11 and steering device 12. For this reason, vehicle-related condition 5 can be a condition for determining whether or not the detected values by each of the sensors, motor rotation angle sensor 116, operation angle sensor 117, and operation torque sensor 119 provided in operation device 11, and motor rotation angle sensor 127, current sensor 128, and steering angle sensor 129 provided in steering device 12, are appropriate.

[0066] The vehicle-related condition 6 is a condition for determining the state of the communication line L established in the vehicle 1. Therefore, the vehicle-related condition 6 can be a condition for determining whether the communication line L is normal or not, based on the exchange of signals via the communication line L between the operation ECU 13 and the steering ECU 14, the drive ECU 61, and the brake ECU 62, for example.

[0067] Vehicle-related condition 7 is a condition for determining whether steering wheel 111, which is an operating member, is in a non-operated state and whether steering actuator 121 is in a non-steered state. Therefore, vehicle-related condition 7 can be a condition for determining whether the detection values of operation angle sensor 117 and operation torque sensor 119 are "0" and the detection values of motor rotation angle sensor 127, current sensor 128 and steering angle sensor 129 are "0", for example.

[0068] Next, the authentication conditions include an "administrator authentication condition" that authenticates an administrator who manages the vehicle 1 from among specific users who are allowed to ride in the vehicle 1, and an "authorized user authentication condition" that authenticates an authorized user authorized by the administrator from among the specific users. The administrator authentication conditions are, for example, a key matching condition that matches a physical key (such as a smart key or a smartphone) linked to the vehicle 1 on the authentication device 16 side of the vehicle 1, and a biometric authentication condition that authenticates biometric information.

[0069] Specifically, the administrator of the vehicle 1 usually possesses a physical key and operates the physical key when getting into the vehicle 1. In response to this operation, the authentication device 16 verifies the physical key, and if the verification is successful, for example, the doors are unlocked and the administrator can get into the vehicle 1. Therefore, the key verification condition is whether or not the administrator was able to get into the vehicle 1 by operating the physical key. In addition, once inside the vehicle, the administrator inputs biometric information such as an image of the face captured by the authentication device 16 (or the input device 17) or a fingerprint obtained by touching the authentication device 16 (or the input device 17). The authentication device 16 then verifies the biometric information of the specific user information registered in advance, thereby authenticating the administrator.

[0070] The authorized user authentication condition is, for example, a condition for authenticating the biometric information of a specific user who has boarded the vehicle 1 together with the administrator. Specifically, the authorized user may be, for example, the administrator's child. The specific user who has boarded the vehicle 1 together with the administrator inputs biometric information such as a facial image captured by the authentication device 16 (or the input device 17) or a finger print acquired by touching the authentication device 16 (or the input device 17). The authentication device 16 then compares the biometric information with the biometric information of the specific user information registered in advance, thereby authenticating the authorized user.

[0071] Furthermore, the stop condition is a condition for stopping the operation of the operation device 11 in a game mode that provides an entertainment game in the secondary control state, i.e., for transitioning the state to a stopped state, as will be described later. The stop condition is a condition that includes an "abnormality determination condition" that determines that an abnormality has occurred in the state of the vehicle 1, and a "shutoff determination condition" that determines that the power supply of the vehicle 1 has been shut off.

[0072] Specifically, the abnormality determination condition is a condition for determining whether at least one of the vehicle-related conditions consisting of the above-mentioned vehicle-related conditions 1 to 6 (excluding vehicle-related condition 7) and the authentication conditions is not satisfied, or whether an abnormality has occurred in vehicle 1. The shutdown determination condition is a condition for determining whether the power supply to vehicle 1 has been shut off, and is a condition for determining whether a start / stop switch, power switch, ignition switch, etc. provided on vehicle 1 has been switched from an on state to an off state.

[0073] As shown in FIG. 2, the state transition permission unit 15 includes an authentication determination unit 151, a secondary control state transition permission determination unit 152, a secondary control state end determination unit 153, and a main control state transition permission determination unit 154.

[0074] When permitting a state transition between the primary control state and the secondary control state, the authentication determination unit 151 authenticates the specific user operating the steering wheel 111, specifically, the administrator and authorized user. To this end, the authentication determination unit 151 cooperates with the authentication device 16 (and the input device 17) to determine whether the above-described authentication conditions, i.e., the administrator authentication condition and the authorized user authentication condition, are met. As a result, the authentication determination unit 151 authenticates the administrator or authorized user among the specific users. The authentication determination unit 151 then outputs an authentication result indicating that the administrator and / or authorized user has been properly authenticated to each of the secondary control state transition permission determination unit 152, the secondary control state termination determination unit 153, and the main control state transition permission determination unit 154.

[0075] When a state transition request to the secondary control state is made, the secondary control state transition permission determination unit 152 determines whether to permit the state transition to the secondary control state. Specifically, when the secondary control state transition determination unit 152 transitions the operation ECU 13 from the primary control state to the secondary control state or when the secondary control state transition is to be made immediately after the vehicle 1 is powered on, the secondary control state transition permission determination unit 152 determines whether each of the seven vehicle-related conditions 1 to 7 described above is satisfied and determines whether an authentication result is obtained from the authentication determination unit 151. Furthermore, the secondary control state transition permission determination unit 152 determines whether the drive system 5, brake system 8, and steering system 10 of the vehicle 1 are normal. Then, when all of the seven vehicle-related conditions 1 to 7 are satisfied, an authentication result has been obtained, and the vehicle 1 is normal, the secondary control state transition permission determination unit 152 permits the state transition to the secondary control state.

[0076] The sub-control state termination determination unit 153 determines whether the above-described stop condition is met when the sub-control state should be terminated. Specifically, the sub-control state termination determination unit 153 determines whether the above-described abnormality determination condition is met with priority. As a result, when an abnormality occurs in the vehicle 1, the sub-control state termination determination unit 153 cooperates with the operation ECU 13 to notify the administrator or authorized user via the display device 18 (e.g., AR (Augmented Reality) glasses, an in-vehicle display, etc.) that the abnormality has occurred and the state will be terminated. Furthermore, when an abnormality occurs in the vehicle 1, the sub-control state termination determination unit 153 cooperates with the operation ECU 13 to terminate the sub-control state, for example, by gradually reducing the control amount of the reaction force application mechanism 114.

[0077] Furthermore, the sub-control state termination determination unit 153 determines whether the above-described shut-off determination condition is met. As a result, when a termination operation is performed by an administrator or an authorized user, for example, when the administrator or authorized user performs an operation to shut off the power supply to the vehicle 1, the sub-control state termination determination unit 153 cooperates with the operation ECU 13 to, for example, stop the operation of the reaction force application mechanism 114 to terminate the sub-control state, and finally shut off the power supply to the vehicle 1, in the same way as the stop processing during a normal power-off operation.

[0078] The main control state transition permission determination unit 154 determines whether to permit a state transition from the sub-control state to the main control state, i.e., whether to permit a state transition from the sub-control state to the main control state when a return request is received. Specifically, when the main control state transition permission determination unit 154 causes the operation ECU 13 to transition from the sub-control state to the main control state, it determines whether each of the seven vehicle-related conditions 1 to 7 described above is satisfied, and determines whether an authentication result is received from the authentication determination unit 151. Furthermore, the sub-control state transition permission determination unit 152 determines whether the drive system 5, brake system 8, and steering system 10 of the vehicle 1 are normal. Then, when a return request is received, all seven vehicle-related conditions 1 to 7 are satisfied, an authentication result is obtained, and the vehicle 1 is normal, the sub-control state transition permission determination unit 152 permits a state transition from the sub-control state to the main control state.

[0079] Furthermore, when main control state transition permission determination unit 154 permits a state transition from the secondary control state to the primary control state, it executes alignment control in cooperation with operation ECU 13, for example, by activating reaction force application mechanism 114 to rotate steering wheel 111. As a result, operation ECU 13 matches the operation angle δ of steering wheel 111 with the steering angle θ of right front wheel 31 and left front wheel 32, which are steered wheels steered by steering actuator 121 of steering device 12.

[0080] 4. Processing contents of the state transition permission unit 15 Next, a specific description will be given of the processing by the state transition permission unit 15. In the following description, a case will be exemplified in which the secondary control state is a "game mode" that provides a game as entertainment to the administrator or authorized users.

[0081] In this embodiment, four state transitions are illustrated as shown in Fig. 3. That is, in this embodiment, a state transition from the main control state to the game mode, which is a sub-control state, is referred to as "state transition A," a state transition directly to the game mode after the initial check is completed, i.e., after the power of the vehicle 1 is turned on is referred to as "state transition B," a state transition from the game mode to the stopped state is referred to as "state transition C," and a state transition from the game mode to the main control state is referred to as "state transition D."

[0082] 4-1. State transition A and state transition B State transition A is a case where the state transition to the main control state occurs after the initial check is completed, and then the state transition to the game mode, as shown in Fig. 3. State transition B is a case where the state transition to the game mode occurs directly after the initial check is completed, as shown in Fig. 3. In either case of state transition A or state transition B, the state transition permission unit 15 executes the following processing to safely transition the state to the game mode.

[0083] That is, in state transition A and state transition B, as shown in Fig. 4, for example, a specific user (administrator) who gets in by operating a physical key inputs a state transition request to the game mode via the input device 17. As a result, the authentication determination unit 151 of the state transition permission unit 15 authenticates the administrator and / or authorized user in cooperation with the authentication device 16 (and the input device 17) and outputs the authentication result.

[0084] For state transitions A and B, as shown in FIG. 5 , for example, an administrator or authorized user inputs a state transition request via the input device 17. When such a state transition request is made, the secondary-control state transition permission determination unit 152 of the state transition permission unit 15 determines whether to permit a state transition from the primary-control state to the game mode, which is a secondary-control state. Specifically, the secondary-control state transition permission determination unit 152 permits the state transition of the operation ECU 13 to the game mode when all seven vehicle-related conditions 1 to 7 are satisfied, an authentication result is obtained indicating that the administrator authentication condition and the authorized user authentication condition are satisfied, and the drive system 5, brake system 8, and steering system 10 of the vehicle 1 are normal. In the following description, the precondition that all seven vehicle-related conditions 1 to 7 are satisfied and an authentication result is obtained, i.e., the precondition that permits a state transition to the game mode by state transition A or state transition B, is referred to as the “game mode state transition precondition.”

[0085] Here, when the state transition permission unit 15 permits a state transition to the game mode, it is first essential to ensure the safety of the vehicle 1. That is, it is essential to confirm that the vehicle 1 is completely stopped and cannot move, that the drive system 5, brake system 8, and steering system 10 of the vehicle 1 are normal, and that the state transition request to the game mode is reliable.

[0086] For this reason, in the state transition permission unit 15, the drive system 5, the brake system 8, and the steering system 10 are in a normal state after the initial check, and the authentication determination unit 151 authenticates the administrator and / or authorized user after the state transition request is input. Then, assuming that the authentication of the administrator and / or authorized user has been successful, i.e., that the authentication result has been obtained, the state transition permission unit 15 determines that all seven vehicle-related conditions 1 to 7 are met, that is, that the vehicle 1 is safely stopped and normal. Here, if an abnormality has occurred in the drive system 5, the brake system 8, and the steering system 10 of the vehicle 1 during the initial check, the state transition permission unit 15 transitions the state from the initial check to the stopped state, as shown in FIG. 3.

[0087] 4-2.State transition C State transition C is a case where the state transition occurs from the game mode to the stopped state due to an abnormal termination or a termination operation by an authenticated administrator or authorized user, as shown in Fig. 3. In particular, in the case of an abnormal termination, the state transition permission unit 15 executes the following process to give top priority to safely transitioning the state to the stopped state.

[0088] That is, in state transition C, as shown in Fig. 6, the sub-control state termination determination unit 153 determines whether or not the abnormality determination condition is satisfied to permit a state transition to a stopped state due to an abnormal termination. Here, the sub-control state termination determination unit 153 determines, as the abnormality determination condition, whether or not any of the six vehicle-related conditions 1 to 6 that form the game mode state transition preconditions is satisfied. Note that in game mode, since there is a high possibility that the steering wheel 111 is being operated, "vehicle-related condition 7," which includes the steering wheel 111 being in a non-operated state, is excluded.

[0089] In other words, in this case, some of the preconditions for transitioning to the game mode are not met. Therefore, if any of the six vehicle-related conditions 1 to 6 is not met, the sub-control state termination determination unit 153 determines that the game mode (sub-control state) should be terminated, thereby permitting the operation ECU 13 to transition from the game mode to the stopped state.

[0090] 6, in state transition C, a state transition to a stopped state due to an abnormal termination is permitted by determining whether or not an abnormality has occurred in drive system 5, brake system 8, and steering system 10 of vehicle 1. That is, in this case, for example, some abnormality has occurred in vehicle 1, such as an abnormality in the charging system including battery 59 or in steering actuator 121 of steering device 12. Therefore, when an abnormality has occurred in vehicle 1, sub-control state termination determination unit 153 determines that the game mode (sub-control state) has been terminated, thereby permitting a state transition from the game mode of operation ECU 13 to a stopped state.

[0091] If an abnormality occurs in the vehicle 1, the sub-control state end determination unit 153 cooperates with the operation ECU 13 to notify the administrator or authorized user via the display device 18 that an abnormality has occurred and that the game will be ended. Furthermore, if an abnormality occurs in the vehicle 1, the sub-control state end determination unit 153 cooperates with the operation ECU 13 to stop the operation of the steering system 10.

[0092] Furthermore, in state transition C, the sub-control state termination determination unit 153 determines whether the shut-off determination condition is met to allow a state transition to the stopped state due to a termination operation, as shown in Fig. 6. That is, the sub-control state termination determination unit 153 determines whether a start / stop switch, a power switch, an ignition switch, or the like provided on the vehicle 1 has been switched from an on state to an off state, as a termination operation.

[0093] That is, in this case, the authenticated administrator or authorized user ends the game mode by cutting off the power supply to the vehicle 1. Therefore, when the power supply to the vehicle 1 is cut off, the sub-control state end determination unit 153 determines that the game mode (sub-control state) has ended, thereby permitting the operation ECU 13 to transition from the game mode to a stopped state. When the power supply to the vehicle 1 is cut off, the sub-control state end determination unit 153 cooperates with the operation ECU 13 to stop the operation of the steering system 10 and finally cuts off the power supply to the vehicle 1.

[0094] Here, when a determination is made regarding a state transition to the stopped state for some reason other than the state transition to the stopped state due to the abnormal termination described above or the state transition to the stopped state due to the termination operation, the previous determination result is maintained in the determination process executed subsequently by the sub-control state termination determination unit 153. This makes it possible to prevent the state transition permission unit 15 from repeatedly determining the state transition to the stopped state.

[0095] 3, even when the state transition from the main control state to the stopped state occurs in a normal usage mode of the vehicle 1, the state transition permission unit 15 can permit the state transition from the main control state to the stopped state. That is, the state transition permission unit 15 can permit the state transition to the stopped state if the power supply to the vehicle 1 is cut off by an end operation in the main control state. When an end operation is performed, the power supply to the vehicle 1 is ultimately cut off. Furthermore, if an abnormality occurs in the vehicle 1 in the main control state, the state transition permission unit 15 can notify the user via the display device 18 that the abnormality has occurred and permit the state transition to the stopped state.

[0096] 4-3.State transition D State transition D is a case where the state transition occurs from the game mode to the main control state after the initial check is completed, as shown in Fig. 3. The state transition permission unit 15 executes the following processing to safely leave the game mode and transition (return) to the main control state.

[0097] That is, in state transition D, as shown in Fig. 7, for example, an administrator or authorized user inputs a request to return to the main control state (state transition request) via the input device 17. When such a return request is made, the main control state transition permission determination unit 154 of the state transition permission unit 15 determines whether to permit a state transition from the game mode, which is the secondary control state, to the main control state. Specifically, when the game mode state transition preconditions are met and the drive system 5, brake system 8, and steering system 10 of the vehicle 1 are normal, the main control state transition permission determination unit 154 permits the state transition from the game mode of the operation ECU 13 to the main control state.

[0098] That is, in order to safely transition (return) the state to the main control state, the state transition permission unit 15 permits the state transition from the game mode to the main control state only when there is a return request from the administrator or authorized user, the game mode state transition preconditions are met, and the vehicle 1 is normal. For this reason, the state transition permission unit 15 gives priority to the above-mentioned state transition C and causes the state transition to the stopped state, for example, when the game mode state transition preconditions are not met or when an abnormality occurs in any of the drive system 5, brake system 8, and steering system 10 of the vehicle 1 during the initial check.

[0099] In state transition D, even if vehicle-related condition 7 is satisfied, that is, even if the steering wheel 111 is not being operated, the steering wheel 111 is being operated in game mode, so a situation may arise in which the operation angle δ of the steering wheel 111 is not synchronized with the steering angle θ of the right front wheel 31 and the left front wheel 32. For this reason, in state transition D, an initial check following a state transition from game mode executes alignment control to synchronize the operation angle δ with the steering angle θ, and then the state transitions to the main control state. In addition, because a strict initial check is performed when the power of the vehicle 1 is turned on, it is possible to omit some check items from the initial check performed in state transition D.

[0100] As can be understood from the above explanation, steering system 10 has steering wheel 111 as an operation member, and comprises operation device 11 that generates and applies operation reaction force Fc which is a reaction force against the operation of steering wheel 111, steering device 12 that is mechanically connected to operation device 11 to steer wheels 3 (right front wheel 31 and left front wheel 32) which are steerable wheels of vehicle 1, and operation ECU 13 and steering ECU 14 that serve as controllers that realize the steering operation of wheels 3 by steering device 12 in accordance with the operation of steering wheel 111, and of operation ECU 13 and steering ECU 14, operation ECU 13 controls the operation of steering wheel 111 and the steering operation simultaneously. The control system has a main control state in which the steering device 12 is controlled in cooperation with the operation device 11 and the steering ECU 14 so as to synchronize the operation of the steering wheel 111 with the steering action, a sub-control state in which at least the operation device 11 is controlled so as not to synchronize the operation of the steering wheel 111 with the steering action, and a stop state in which the operation of the steering device 12 is stopped in cooperation with the operation device 11 and the steering ECU 14, and is capable of transitioning the control state between the main control state, the sub-control state and the stop state. When a state transition is executed, the system is provided with a state transition permission unit 15 as a state transition permission section which determines whether or not a predetermined state transition condition related to the safety of the vehicle 1 is met, and permits the state transition if the state transition condition is met.

[0101] In this case, the state transition conditions may include at least vehicle-related conditions related to the state of vehicle 1. In this case, the vehicle-related conditions may include a condition for determining at least one of the following: a stopped state of vehicle 1, a communication state via communication line L established in vehicle 1, an operating state of operation device 11, and an operating state of steering device 12. In this case, if vehicle 1 is an electric vehicle that requires charging of battery 59 for driving front motor 51 and rear motor 52, which are electric motors, the vehicle-related conditions may include a condition for determining the charging state of battery 59.

[0102] In this case, the state transition condition may include an authentication condition for authenticating a specific user who is allowed to instruct the operation ECU 13 to execute a state transition. In this case, the authentication condition may include an administrator authentication condition for authenticating an administrator who manages the vehicle 1, among the specific users. In this case, the authentication condition may include an authorized user authentication condition for authenticating an authorized user who is authorized by the administrator, among the specific users.

[0103] In this case, the state transition condition may include a stop condition that stops the operation of the operation device 11 in the sub-control state. In this case, the stop condition may include an abnormality determination condition that determines that an abnormality has occurred in the state of the vehicle 1. In this case, the stop condition may include a cut-off determination condition that determines that the power supply to the vehicle 1 has been cut off.

[0104] In this case, when determining whether to permit a state transition, the state transition permission unit 15 can determine whether the state transition conditions are met, as well as whether the drive system 5, brake system 8, and steering system 10, which are systems that make up the vehicle 1, are normal.

[0105] In this case, the vehicle 1 is an electric vehicle that requires charging of the battery 59 for driving the front motor 51 and the rear motor 52, and if a state transition is permitted by the state transition permission unit 15 when the state transition condition is met while the battery 59 is being charged, the operation ECU 13 can execute a state transition from the primary control state to the secondary control state.

[0106] Furthermore, in this case, when executing a state transition from the secondary control state to the primary control state in response to permission from state transition permission unit 15, if there is a difference between the operation angle δ, which indicates the operation position of steering wheel 111 operated in the secondary control state, and the steering angle θ, which indicates the steering position associated with the steering operation of right front wheel 31 and left front wheel 32, operation ECU 13 can execute position alignment control to match the operation angle δ with the steering angle θ. In this case, in the position alignment control, operation ECU 13 can match the operation angle δ with the steering angle θ by operating operation device 11 to generate an operation reaction force Fc on steering wheel 111.

[0107] In this case, in the sub-control state, the operation ECU 13 can provide entertainment using the steering wheel 111 in the vehicle 1. In this case, the entertainment is a game in which the user instructs the movement of a virtual moving object by operating devices mounted on the vehicle 1, including the steering wheel 111.

[0108] According to the steering system 10, when the state transition permission unit 15 provided in the operation ECU 13 determines that the state transition condition is satisfied and permits the state transition, the control state of the operation ECU 13 can be transitioned. Specifically, when the state transition condition is satisfied and the state transition is permitted, the operation ECU 13 can transition the control state among the primary control state, the secondary control state, and the stop state. This allows the steering system 10 to ensure the safety of the vehicle 1, particularly when a state transition is performed between the primary control state and the secondary control state.

[0109] Furthermore, when permitting a state transition, the state transition permission unit 15 can determine whether the drive system 5, the brake system 8, and the steering system 10 of the vehicle 1 are normal, in addition to determining whether the state transition conditions are met. This makes it possible to prevent problems from occurring in the running of the vehicle 1, particularly when the state transition occurs from the secondary control state to the primary control state, and ultimately ensures the safety of the vehicle 1.

[0110] Furthermore, according to the steering system 10, for example, if the vehicle 1 is an electric vehicle, and the state transition permission unit 15 permits a state transition to the sub-control state in response to the establishment of a state transition condition while the battery 59 is being charged, the operation ECU 13 can provide the administrator or authorized user with the execution of a game, which is entertainment, using the steering wheel 111. Even in this case, the provision of the game is realized based on the permission of the state transition permission unit 15, so the safety of the vehicle 1 can be ensured. In this case, for example, even if it takes a long time to charge the battery 59, the administrator or authorized user can still enjoy the game.

[0111] 5. Variations In the above-described embodiment, the operation ECU 13, which is the controller of the steering system 10, is provided with the state transition permission unit 15 as a state transition permission section, and the state transition permission unit 15 permits state transition of the control state in the operation ECU 13. In addition to this, it is also possible to provide a state transition permission section in the drive ECU 61 and the brake ECU 62, which constitute the braking / driving controller 6, for example.

[0112] As a result, for example, when a game is provided as entertainment in the secondary control state as described above, the administrator or authorized user can operate the accelerator pedal and brake pedal in addition to the steering wheel 111 of the steering system 10 while ensuring the safety of the vehicle. In other words, when the drive ECU 61 and the brake ECU 62 perform a state transition between the primary control state and the secondary control state, the state transition can be considered to ensure greater safety in the vehicle, thereby ensuring the safety of the vehicle. Therefore, in this case as well, the same effects as those of the above-described embodiment can be obtained.

[0113] Furthermore, in the above-described embodiment, for example, a steering system 10 mounted on a vehicle 1 that travels under manual driving by a driver who is an administrator has been exemplified. That is, a case has been exemplified in which the steering wheel 111 is manually operated in the primary control state and the secondary control state. Alternatively, the steering system may not be operated by automatic driving in the primary control state, but may be manually operated when providing a game as entertainment in the secondary control state. In this case as well, the safety of the vehicle 1 can be ensured when transitioning between the primary control state and the secondary control state, regardless of whether the vehicle is being driven manually or automatically. Therefore, in this case as well, the same effects as those of the above-described embodiment can be obtained.

[0114] Furthermore, in the above-described embodiment, the vehicle 1 is an electric vehicle (EV (Electric Vehicle)) that uses only an electric motor as a driving force source. However, the vehicle 1 may be, for example, a vehicle that uses an internal combustion engine and an electric motor as a driving force source (such as an HEV (Hybrid Electric Vehicle) or a PHEV (Plug-in Hybrid Electric Vehicle)), or a vehicle that uses only an internal combustion engine as a driving force source. In this case, the same effects as those of the above-described embodiment can be obtained.

[0115] Here, a steering system of a first form of the present disclosure comprises an operating device having an operating member that generates and applies a reaction force against the operation of the operating member; a steering device that steers the steered wheels of the vehicle by releasing the mechanical connection with the operating device; and a controller that causes the steering device to turn the steered wheels in accordance with the operation of the operating member, and the controller has each of the control states of a main control state that controls the operating device and the steering device so as to synchronize the operation of the operating member with the steering operation, a sub-control state that controls at least the operating device so as not to synchronize the operation of the operating member with the steering operation, and a stop state that stops the operation of the operating device and the steering device, and is capable of transitioning the control state between the main control state, the sub-control state, and the stop state, and when executing a state transition, comprises a state transition permission unit that determines whether or not predetermined state transition conditions related to the safety of the vehicle are met, and permits the state transition if the state transition condition is met.

[0116] In addition, a steering system of a second aspect of the present disclosure is the steering system of the first aspect, wherein the state transition conditions include at least a vehicle-related condition related to the state of the vehicle.

[0117] Furthermore, in a third form of steering system of the present disclosure, in the second form of steering system, the vehicle-related conditions include conditions for determining at least one of the following: the stopped state of the vehicle, the communication state via a communication line established in the vehicle, the operating state of the operating device, and the operating state of the steering device.

[0118] Furthermore, in a fourth form of the steering system of the present disclosure, in the steering system of the first or second form, when the vehicle is an electric vehicle that requires charging of the battery to drive the electric motor, the vehicle-related conditions include conditions for determining the state of charge of the battery.

[0119] Furthermore, a fifth form of steering system of the present disclosure is a steering system of any one of the first to fourth forms, in which the state transition conditions include authentication conditions for authenticating a specific user who can instruct the controller to execute a state transition.

[0120] Furthermore, in a steering system of a sixth aspect of the present disclosure, in the steering system of the fifth aspect, the authentication conditions include an administrator authentication condition for authenticating an administrator who manages the vehicle, among the specific users.

[0121] Furthermore, a steering system of a seventh form of the present disclosure is a steering system of the fifth or sixth form, in which the authentication conditions include an authorized user authentication condition that authenticates an authorized user among specific users who has been authorized by an administrator who manages the vehicle.

[0122] Furthermore, a steering system of an eighth aspect of the present disclosure is the steering system of any one of the first to seventh aspects, wherein the state transition condition includes a stop condition that stops the operation of the operating device in the secondary control state.

[0123] In addition, in a steering system of a ninth aspect of the present disclosure, in the steering system of the eighth aspect, the stop condition includes an abnormality determination condition for determining that an abnormality has occurred in the state of the vehicle.

[0124] A steering system of a tenth aspect of the present disclosure is the steering system of the eighth or ninth aspect, wherein the stop condition includes a cut-off determination condition for determining that the power supply to the vehicle has been cut off.

[0125] Furthermore, in a steering system of an eleventh form of the present disclosure, in any one of the steering systems of the first form to the tenth form, when determining whether to permit a state transition, the state transition permission unit determines whether the state transition conditions are met, and also determines whether the systems that constitute the vehicle are normal.

[0126] Furthermore, a steering system of a twelfth form of the present disclosure is a steering system of any one of the first to eleventh forms, in which the vehicle is an electric vehicle that requires charging of a battery for driving an electric motor, and when a state transition is permitted by the state transition permission unit upon the establishment of a state transition condition while the battery is being charged, the controller executes a state transition from the primary control state to the secondary control state.

[0127] Furthermore, in a steering system of a thirteenth form of the present disclosure, in any one of the steering systems of the first to twelfth forms, when a state transition from a secondary control state to a primary control state is executed in response to permission from the state transition permission unit, if there is a difference between the operating position of the operating member operated in the secondary control state and the steering position associated with the steering operation of the steered wheels, the controller executes alignment control to match the operating position and the steering position.

[0128] Furthermore, a steering system of a fourteenth form of the present disclosure is the steering system of the thirteenth form, in which the controller, in the positioning control, activates the operating device to generate a reaction force against the operating member, thereby aligning the operating position with the steering position.

[0129] Furthermore, a steering system of a fifteenth aspect of the present disclosure is a steering system of any one of the first to fourteenth aspects, in which, in a secondary control state, the controller provides entertainment using operating members in the vehicle.

[0130] Furthermore, a steering system of a sixteenth form of the present disclosure is the steering system of the fifteenth form, in which the entertainment is a game in which the movement of a virtual moving object is directed by operating equipment mounted on the vehicle, including an operating member. [Explanation of symbols]

[0131] 1...vehicle, 2...vehicle body, 3...wheel, 4...suspension unit, 5...drive system, 51...front motor, 52...rear motor, 59...battery, 6...braking / driving controller, 61...driving electronic control unit, 62...brake electronic control unit, 7...sensor group, 8...brake system, 10...steering system, 11...operation device, 12...steering device, 13...operation electronic control unit (controller), 14...steering electronic control unit (controller), 15...state transition permission unit (state transition permission section)

Claims

1. an operating device having an operating member and generating and applying a reaction force to the operation of the operating member; a steering device that is mechanically disconnected from the operation device and steers the steered wheels of the vehicle; a controller that realizes a steering operation of the steered wheels by the steering device in accordance with operation of the operating member, The controller: The control system has a main control state that controls the operation device and the steering device so as to synchronize the operation of the operation member with the steering operation, a sub-control state that controls at least the operation device so as not to synchronize the operation of the operation member with the steering operation, and a stop state that stops the operation of the operation device and the steering device, and is capable of transitioning the control state between the main control state, the sub-control state, and the stop state, A steering system comprising a state transition permission unit that, when executing the state transition, determines whether a predetermined state transition condition related to the safety of the vehicle is met, and permits the state transition if the state transition condition is met.

2. The steering system according to claim 1 , wherein the state transition conditions include at least a vehicle-related condition related to a state of the vehicle.

3. 3. The steering system according to claim 2, wherein the vehicle-related conditions include a condition for determining at least one of a stopped state of the vehicle, a communication state via a communication line established in the vehicle, an operating state of the operation device, and an operating state of the steering device.

4. The vehicle is an electric vehicle that requires charging of a battery for driving an electric motor, The steering system according to claim 3 , wherein the vehicle-related conditions include a condition for determining a state of charge for the battery.

5. The steering system according to claim 1 , wherein the state transition conditions include an authentication condition for authenticating a specific user who is allowed to instruct the controller to execute the state transition.

6. The steering system according to claim 5 , wherein the authentication conditions include an administrator authentication condition for authenticating an administrator who manages the vehicle among the specific users.

7. The steering system according to claim 6 , wherein the authentication conditions include an authorized user authentication condition for authenticating authorized users authorized by the administrator among the specific users.

8. The steering system according to claim 1 , wherein the state transition condition includes a stop condition for stopping the operation of the operating device in the secondary control state.

9. 9. The steering system according to claim 8, wherein the stop condition includes an abnormality determination condition for determining that an abnormality has occurred in the state of the vehicle.

10. The steering system according to claim 9 , wherein the stop condition includes a cutoff determination condition for determining that a power source of the vehicle has been cut off.

11. The state transition permission unit When determining whether to permit the state transition, 2. The steering system according to claim 1, further comprising: a step of determining whether a system constituting the vehicle is normal, in addition to determining whether the state transition condition is satisfied.

12. the vehicle is an electric vehicle that requires charging of a battery for driving an electric motor, During charging of the battery, When the state transition condition is satisfied and the state transition is permitted by the state transition permitting unit, The steering system of claim 1 , wherein the controller executes the state transition from the primary control state to the secondary control state.

13. When the state transition from the sub-control state to the main control state is executed in response to permission by the state transition permission unit, if there is a difference between the operation position of the operating member operated in the sub-control state and the steering position associated with the steering operation of the steered wheels, The steering system according to claim 1 , wherein the controller executes alignment control to match the operation position with the steering position.

14. The controller, in the alignment control, The steering system according to claim 13, wherein the operation position is made to coincide with the steering position by actuating the operation device to generate the reaction force on the operation member.

15. In the secondary control state, The controller The steering system according to claim 1 , wherein entertainment is provided using the operating member in the vehicle.

16. The entertainment is 16. The steering system according to claim 15, which is a game in which a movement of a virtual moving object is instructed by operating a device mounted on the vehicle including the operating member.

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