Steering system

Abstract

This steering system is provided with: an operation device including an operation member and a reaction force imparting device; a deflection device which is mechanically separated from the operation device and deflects the wheel according to the control current; and a controller that controls the deflection device and the reaction force applying device on the basis of an operation signal relating to the operation of the operation member. The steering system is configured so as to switch between a normal mode in which wheels are deflected on the basis of the operation signal and a virtual mode in which a virtual moving body is steered on the basis of the operation signal. The controller sets the control current to a current value at which the wheel does not deflect in the virtual mode regardless of the operation signal, and sets the operation reaction force on the basis of a predetermined vibration component in a signal received from the deflection device.

Description

Technical Field

[0001] The present invention relates to a steering system. Background Art

[0002] Recently, a steering system has been developed. This steering system is a steer-by-wire type in which an operating member and a deflector are mechanically separated, and in this steering system, it is configured that a user plays a game using the operating member. For example, Japanese Unexamined Patent Application Publication No. 2022-1925 discloses a vehicle capable of switching an operation target of an operation unit of a steering control device between a vehicle and a virtual moving body in a game. That is, such a steering system is configured to switch between a normal mode in which the vehicle is the operation target and a game mode in which the virtual moving body is the operation target.

[0003] The steer-by-wire type steering system is configured such that when a user operates the operating member, a reaction force applying device applies a reaction force (operation reaction force) to the operating member according to the movement of the operating member. Further, in the normal mode, the vehicle acquires information on the driving road surface, and the reaction force applying device applies an operation reaction force to the operating member based on the road surface information. Since the steering load varies depending on the road surface condition, the detected value of the control current supplied to the electric motor of the deflector that deflects the wheels sometimes changes according to the road surface condition. Therefore, by detecting the current value of the control current input to the electric motor, the road surface condition can be estimated. By using this estimation, in the normal mode, the reaction force applying device can make the operation reaction force reflect the road surface condition.

[0004] However, in the game mode, the magnitude of the control current of the electric motor of the deflector does not correspond to the road surface condition in the game. Also, in the game mode, since the vehicle does not actually travel on the road surface, information on the road surface condition cannot be acquired based on the control current of the electric motor. Therefore, in the game mode, an operation reaction force that does not reflect the road surface condition is applied to the operating member. It is difficult for a user who operates the operating member to feel a high sense of presence only with an operation reaction force that does not reflect the road surface condition. Summary of the Invention

[0005] As described above, there is room for improvement in the conventional steering system in terms of enhancing the sense of presence in a game. The present invention provides a steering system that can enhance the sense of presence given to a user when an operating member is used in a game.

[0006] The steer-by-wire type steering system according to the first aspect of the present invention includes: an operation device including an operation member for a user to perform a steering operation and a reaction force applying device configured to apply a reaction force to the operation member; a deflection device configured to be mechanically separated from the operation device and deflect a wheel according to a supplied control current; and a controller configured to control the deflection device and the reaction force applying device based on an operation signal related to the operation of the operation member received from the operation device. The steering system is configured to switch between a normal mode of deflecting the wheel based on the operation signal and a virtual mode of steering a virtual moving body created as an image based on the operation signal. The controller is configured to: in the virtual mode, set the control current to a current value at which the wheel does not deflect regardless of the operation signal, and set the operation reaction force based on a specified vibration component in the signal received from the deflection device.

[0007] Based on the steering system of the first aspect of the present invention, the controller may also be configured to: in the virtual mode, cause the operation reaction force set based on the operation signal to reflect the specified vibration component.

[0008] Based on the steering system of the first aspect of the present invention, the deflection device may also include: an electric motor configured to deflect a wheel; and a current sensor configured to detect a current value of the control current input to the electric motor. The controller may also be configured to: in the virtual mode, extract a specified frequency component from a signal related to the detection value received from the current sensor as the specified vibration component.

[0009] The steering system of the first aspect of the present invention may further include: a band-pass filter configured to allow only signals in a specified permitted frequency band to pass through; and an amplifier configured to amplify the signal that has passed through the band-pass filter. The controller may also be configured to: set the operation reaction force using the detection signal of the current sensor that has passed through the band-pass filter and the amplifier as the specified vibration component.

[0010] Based on the steering system of the first aspect of the present invention, the band-pass filter and the amplifier may also be used in both the normal mode and the virtual mode. The controller may also be configured to: in the normal mode, set the specified permitted frequency band of the band-pass filter and the gain of the amplifier to values for the normal mode, and in the virtual mode, set the specified permitted frequency band of the band-pass filter and the gain of the amplifier to values for the virtual mode.

[0011] Based on the steering system of the first aspect of the present invention, the controller may also be configured to set the control current to 0 regardless of the operation signal in the virtual mode.

[0012] Based on the steering system of the first aspect of the present invention, the controller may also be configured to supply a corrected control current obtained by adding an additional current value that increases and decreases at a specified frequency to the control current to the deflection device in the virtual mode, so that the wheels deflect left and right repeatedly regardless of the operation signal.

[0013] Based on the steering system of the first aspect of the present invention, the controller may also be configured to receive an acceleration signal related to the operation of an acceleration operation component provided in the vehicle for acceleration operation and a braking signal related to the operation of a braking operation component provided in the vehicle for braking operation, and may also be configured to set the additional current value based on the acceleration signal or the braking signal in the virtual mode.

[0014] Based on the steering system of the first aspect of the present invention, the controller may also be configured to receive an acceleration signal related to the operation of an acceleration operation component provided in the vehicle for acceleration operation and a braking signal related to the operation of a braking operation component provided in the vehicle for braking operation, and may also be configured to set the operation reaction force based on the operation signal and the acceleration signal, or based on the operation signal and the braking signal in the virtual mode.

[0015] Based on the steering system of the first aspect of the present invention, the controller may also be configured to reduce the operation reaction force according to the acceleration signal corresponding to the forward movement of the virtual moving body in the virtual mode.

[0016] Based on the steering system of the first aspect of the present invention, the controller may also be configured to increase the operation reaction force according to the braking signal during the forward movement of the virtual moving body in the virtual mode.

[0017] The steer-by-wire type steering system according to the second aspect of the present invention includes: an operation device including an operation member for a user to perform a steering operation and a reaction force imparting device configured to impart a reaction force to the operation member; a deflection device configured to be mechanically separated from the operation device and deflect a wheel according to a supplied control current; and a controller configured to control the deflection device and the reaction force imparting device based on an operation signal related to the operation of the operation member received from the operation device. The steering system is configured to switch between a normal mode in which the wheel is deflected based on the operation signal and a virtual mode in which a virtual moving body created as an image is steered based on the operation signal. The controller is configured to: in the virtual mode, supply the control current to the deflection device so that the wheel is deflected repeatedly to the left and right regardless of the operation signal.

[0018] Based on the steering system of the second aspect of the present invention, the controller may also be configured to: in the virtual mode, supply the control current to the deflection device that increases and decreases at a specified frequency.

[0019] Based on the steering system of the second aspect of the present invention, the controller may also be configured to: receive an acceleration signal related to the operation of an acceleration operation member provided in the vehicle for acceleration operation and a braking signal related to the operation of a braking operation member provided in the vehicle for braking operation, and may also be configured to: in the virtual mode, supply the control current to the deflection device in a manner that the wheel is deflected repeatedly to the left and right based on the acceleration signal or the braking signal.

[0020] The steer-by-wire type steering system according to the third aspect of the present invention includes: an operation device including an operation member for a steering operation by a user and a reaction force imparting device configured to impart a reaction force to the operation member; a deflection device configured to be mechanically separated from the operation device and deflect a wheel according to a supplied control current; and a controller configured to control the deflection device and the reaction force imparting device based on an operation signal related to the operation of the operation member received from the operation device. The steering system is configured to switch between a normal mode in which the wheel is deflected based on the operation signal and a virtual mode in which a virtual moving body created as an image is steered based on the operation signal. The controller is configured to receive an acceleration signal related to the operation of an acceleration operation member provided in the vehicle for an acceleration operation and a braking signal related to the operation of a braking operation member provided in the vehicle for a braking operation, and is configured to, in the virtual mode, set the control current to a current value at which the wheel does not deflect regardless of the operation signal, and set the operation reaction force based on the operation signal and the acceleration signal, or based on the operation signal and the braking signal.

[0021] Based on the steering system according to the third aspect of the present invention, the controller may also be configured to, in the virtual mode, reduce the operation reaction force according to the acceleration signal corresponding to the forward movement of the virtual moving body.

[0022] Based on the steering system according to the third aspect of the present invention, the controller may also be configured to, in the virtual mode, increase the operation reaction force according to the braking signal during the forward movement of the virtual moving body.

[0023] According to the first aspect of the present invention, in the virtual mode, the control current supplied to the deflection device is set to a value at which the wheel does not deflect (for example, 0). Therefore, unnecessary deflection of the wheel caused by the operation of the operation member is suppressed. In addition, in most cases, the signal (for example, the detection signal of the control current) sent from the deflection device contains noise. The noise contains waves of a certain frequency, that is, vibration components. The controller can convey the road surface condition (roughness) to the user analogously through the operation reaction force by making the operation reaction force reflect the vibration components. That is, according to the first aspect, the realism of the game is improved, and the sense of presence felt by the user in the game can be improved.

[0024] According to the second aspect of the present invention, in the virtual mode, the wheel can be made to vibrate slightly left and right regardless of the operation of the operation member. As a result, the vehicle can generate a simulated vibration that simulates the vibration of a running vehicle, such as the vibration of an engine or the vibration caused by road surface unevenness. According to the second aspect, the realism of the game is improved, and the sense of presence felt by the user in the game can be improved.

[0025] According to the third aspect of the present invention, it is possible to make the operating reaction force reflect the influence of the acceleration operation or the braking operation on the wheels. For example, when an acceleration operation or a braking operation is performed, the pitch angle of the vehicle changes, and the force (load) applied to the wheels also changes. In a structure where the operating member is mechanically connected to the deflection device, if the force applied to the deflection wheel changes, the operating feeling (steering force) of the operating member also changes. According to the third aspect, it is possible to represent the change in the operating feeling caused by the change in the force applied to the wheels with the operating reaction force. That is, according to the third aspect, the realism of the game is improved, and it is possible to enhance the sense of presence felt by the user in the game.

[0026] Hereinafter, with reference to the accompanying drawings, the features, advantages, and technical and industrial significance of the exemplary embodiments of the present invention will be described. In the drawings, the same reference numerals denote the same elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural diagram of the steering system of the present embodiment.

[0028] Figure 2 It is a structural diagram for explaining the road surface simulation control of the present embodiment.

[0029] Figure 3 It is a flowchart showing an example of the road surface simulation control of the present embodiment.

[0030] Figure 4 It is a structural diagram for explaining the vehicle vibration control of the present embodiment.

[0031] Figure 5 It is a flowchart showing an example of the vehicle vibration control of the present embodiment.

[0032] Figure 6 It is a flowchart showing an example of the pitch reflection control of the present embodiment.

[0033] Figure 7 It is a schematic diagram showing the signal flow of the steering system of the present embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] Hereinafter, as a mode for carrying out the present invention, the steering system 1 as an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In addition, the present invention can be implemented in various modes in which various changes and improvements have been made based on the knowledge of those skilled in the art, in addition to the following embodiments. As an example, the steering system 1 of the present embodiment is mounted on a battery electric vehicle. Communication inside the vehicle is performed, for example, by Controller Area Network (CAN), FlexRay, or Ethernet.

[0035] As Figure 1 shown, the steering system 1 includes an operation device 2, a deflection device 3, and a controller 4. The operation device 2 of the present embodiment includes an operation member 20, a steering shaft 21, a steering column 22, an operation amount sensor 23, an operation torque sensor 24, and a reaction force applying device 25.

[0036] The operation member 20 is a handle member that allows a user to perform a steering operation. The operation member 20 is, for example, a steering wheel. In addition, the shape of the operation member 20 is not limited to a circular shape such as a steering wheel, and may be a polygonal shape such as a quadrilateral shape, for example. The operation member 20 can also be said to be a steering operation member. The operation member 20 is fixed to the front end of the steering shaft 21. The operation member 20 and the steering shaft 21 are rotatably held by the instrument panel via the steering column 22.

[0037] The operation amount sensor 23 is a sensor that detects the operation amount (operation angle) of the operation member 20. The operation torque sensor 24 is a sensor that detects the operation torque of the operation member 20. The operation torque can also be said to be the operation force applied by the user to the operation member 20. The operation torque sensor 24 detects, for example, the amount of twist of a torsion bar 27 provided on the steering shaft 21.

[0038] The reaction force applying device 25 is a device that applies an operation reaction force to the operation member 20. The reaction force applying device 25 includes a reaction force motor 26 as an electric motor. The reaction force applying device 25 uses the reaction force motor 26 supported by the steering column 22 as a power source, and applies an operation reaction force relative to the steering operation to the operation member 20 via the steering shaft 21. The reaction force applying device 25 is a device having a general structure including a speed reducer and the like. A rotation angle sensor 26a is provided on the reaction force motor 26.

[0039] The deflection device 3 is a device that deflects the wheels 11, 12 (front wheels or deflection wheels). The deflection device 3 is mechanically separated from the operation device 2. The deflection device 3 includes an electric motor, i.e., a deflection motor 35, as a drive source, and a current sensor 351 that detects the current value of the control current input to the deflection motor 35. To explain in more detail, the deflection device 3 includes a steering rod 31, a housing 32, a rod movement mechanism 33, a deflection motor 35, a current sensor 351, a rotation angle sensor 352, and a deflection angle sensor 36.

[0040] The steering rod 31 is a component whose both ends are respectively connected to the left and right steering knuckles 90 via tie rods 34. The housing 32 is a component that supports the steering rod 31 so that it can move left and right and is fixedly held on the vehicle body.

[0041] The rod movement mechanism 33 is a mechanism for moving the steering rod 31 left and right using the deflection motor 35 as a drive source. The deflection motor 35 is an electric motor that deflects the wheels 11, 12. The rod movement mechanism 33 is mainly composed of a ball screw mechanism, and the ball screw mechanism is composed of a ball groove formed on the steering rod 31, a nut that is threadedly engaged with the ball groove via bearing balls and rotates by the deflection motor 35. Since it is a mechanism with a general structure, the detailed description of the rod movement mechanism 33 is omitted.

[0042] The current sensor 351 is a sensor that detects the current (control current) input to the deflection motor 35. The rotation angle sensor 352 is a sensor that detects the rotation angle of the deflection motor 35. The deflection angle sensor 36 is a sensor that detects the deflection angle (deflection amount) of the wheels 11, 12. The deflection angle sensor 36 detects the movement amounts of the steering rod 31 from the neutral position to the left and right respectively.

[0043] The controller 4 is configured to control the deflection device 3 and the reaction force applying device 25 based on the operation signal related to the operation of the operation member 20 received from the operation device 2. The controller 4 is a computer having one or more processors 41 and one or more memories 42. A computer can also be said to be an electronic control unit (ECU). The controller 4 is communicably connected to the operation device 2 and the deflection device 3. The operation device 2 and the deflection device 3 are electrically connected via the controller. That is, the steering system 1 is a steer-by-wire type steering system that converts the mechanical operation of the user on the operation member 20 into an electrical signal and transmits the electrical signal to the deflection device 3 that is mechanically separated from the operation member 20, thereby steering the vehicle. In addition, the controller 4 may be composed of two or more computers communicably connected. For example, the controller 4 may be composed of the controller (computer) of the operation device 2 and the controller (computer) of the deflection device 3.

[0044] Control mode

[0045] The steering system 1 is configured to be able to switch between a normal mode in which the wheels 11 and 12 are deflected based on an operation signal, and a virtual mode in which a virtual moving body 8a for image production is steered based on the operation signal. That is, at least two control modes are set in the steering system 1. The normal mode is a control mode for steering the vehicle based on the operation of the operation member 20. The virtual mode is, for example, a control mode in which the operation member 20 is used to operate a virtual moving body 8a (for example, an image of a vehicle) represented by an image in a game. The virtual moving body 8a is produced as an image that can be viewed and heard in the vehicle. The normal mode can also be said to be, for example, the first mode, the main mode, or the real mode. The virtual mode can also be said to be, for example, the second mode, the sub mode, or the game mode.

[0046] A display device 80 is arranged in the vehicle. Examples of the display device 80 include a display on the instrument panel, a display of a navigation system, a windshield for projecting an image, a display of a mobile terminal, AR glasses, or a head-mounted display. The game machine 8 can be arranged in the vehicle or can be connected to the vehicle by wireless communication and arranged outside the vehicle. The game machine 8 can be said to be a computer having one or more processors and one or more memories. The game machine 8 is connected to the controller 4 so as to be able to communicate only specified information.

[0047] In the virtual mode, the game machine 8 displays the virtual moving body 8a on the display device 80. The controller 4 sends operation information that can be read from the operation signal to the game machine 8, and the game machine 8 produces a display image of the virtual moving body 8a on the display device 80 based on the operation information and displays the state of steering the virtual moving body 8a on the display device 80. That is, in the virtual mode, the user can steer the virtual moving body 8a displayed on the display device 80 by operating the operation member 20.

[0048] The controller 4 switches between the normal mode and the virtual mode based on the operation (instruction) of the user. For example, when the user performs a button operation of selecting the virtual mode on a mode selection unit (for example, an operation panel) provided in the vehicle, the controller 4 switches the control mode of the vehicle from the normal mode to the virtual mode after confirming that a specified condition is satisfied. Similarly, the controller 4 switches the control mode from the virtual mode to the normal mode based on the operation of the user on the operation panel or the like. When the user selects the virtual mode and a specified condition is satisfied, the controller 4 turns on the change permission flag. When the user does not select the virtual mode or the specified condition is not satisfied, the change permission flag is maintained off. The virtual mode is, for example, a control mode in which the user plays a game using the operation member 20 assuming a parking state such as when the battery of an electric vehicle is being charged.

[0049] Details of the normal mode

[0050] In the normal mode, the controller 4 controls the deflection motor 35 based on the detection value (detection signal) of the operation amount sensor 23. The controller 4 calculates the target deflection angle according to the detection value of the operation amount sensor 23, and sets the current value of the control current based on the difference between the target deflection angle and the actual deflection angle (detection value of the deflection angle sensor 36). The controller 4 supplies the set control current to the deflection motor 35.

[0051] In the normal mode, the controller 4 sets the operation reaction force relative to the operation member 20 based on the detection values of the operation amount sensor 23 and the operation torque sensor 24, and controls the reaction force motor 26. The controller 4 supplies a current (which can also be said to be the reaction force current) corresponding to the set operation reaction force to the reaction force motor 26.

[0052] The controller 4 calculates the lateral acceleration of the vehicle based on the vehicle speed and the detection value of the deflection angle sensor 36. The vehicle speed is calculated, for example, based on the detection values of wheel speed sensors (not shown) provided on each wheel. The controller 4 calculates the self-aligning torque of the wheel based on the detection value of the deflection angle sensor 36. It can also be said that the controller 4 infers the force equivalent to the self-aligning torque based on the deflection angle of the wheel. There are also cases where various forces acting on the wheel change according to the vehicle speed. Therefore, in the normal mode, the controller 4 causes the operation reaction force to reflect, for example, the vehicle speed, the lateral acceleration, and the self-aligning torque. In addition, in the controller 4, an operation reaction force equivalent to the resistance of the road surface with respect to the deflection of the wheel is also set as the basic reaction force.

[0053] The controller 4 sets the operation reaction force based on the detection value of the operation torque sensor 24. In order to keep the operation torque of the user within a specified range, a force for assisting the operation of the operation member 20 is required according to the magnitude of the operation torque. Therefore, for the controller 4, the larger the detection value of the operation torque sensor 24, the smaller the operation reaction force is made so as to maintain the operation torque within the specified range. Hereinafter, the reaction force control based on the operation amount and the operation torque of the operation member 20, that is, the reaction force control considering the self-aligning torque and the assisting force as an example is also referred to as "first reaction force control".

[0054] The control current is set based on the difference between the target deflection angle and the actual deflection angle (hereinafter, also referred to as the angle difference). The control current can also be said to be the deflection current or the deflection command value. When a control current corresponding to the angle difference is supplied to the deflection motor 35 but the angle difference does not decrease due to the road surface condition (e.g., unevenness), the controller 4 makes the control current larger to increase the driving force of the deflection motor 35. Depending on the road surface condition, there may be a case where the angle difference does not change but only the control current changes. That is, there is a case where the control current changes due to the road surface condition. The controller 4 can convey the road surface condition to the user by detecting the change in the control current and making the operating reaction force reflect the change in the control current. Hereinafter, the reaction force control based on the change in the control current, that is, the reaction force control considering the road surface condition (road noise) as an example, is also referred to as "the second reaction force control".

[0055] In this way, in the normal mode, the controller 4 sets the operating reaction force of the operating member 20 so as to simulate, for example, a power steering type steering system (hereinafter, also referred to as a mechanically connected system) in which the operating member 20 is mechanically connected to the deflection device 3. In the normal mode, the controller 4 performs the first reaction force control, the second reaction force control, and the reaction force control considering the vehicle speed and the lateral acceleration (hereinafter, also referred to as the third reaction force control) on the reaction force imparting device 25. In addition, the self-aligning torque is a force acting in the direction to reduce the slip angle of the tire and is a force that attempts to return the operated operating member 20 to its original position in the mechanically connected system. The self-aligning torque increases, for example, as the deflection angle increases until the deflection angles of the wheels 11 and 12 become a specified angle. The controller 4, for example, makes the operating reaction force larger as the deflection angle increases until the deflection angle becomes the specified angle.

[0056] Details of the virtual mode

[0057] In the virtual mode, the controller 4 sets the control current to a current value at which the wheels 11 and 12 do not deflect regardless of the operation signal (regardless of the operation of the operating member 20). This control is also referred to as "deflection prevention control". It can also be said that the controller 4 sets the absolute value of the control current to be below a specified value. As an example of the deflection prevention control, the controller 4 sets the control current to 0 regardless of the operation signal in the virtual mode. That is, the controller 4 is configured to: in the virtual mode, in principle, no control current is supplied to the deflection motor 35. As a result, the deflection motor 35 does not operate and does not deflect the wheels 11 and 12. The current value of the control current at which the wheels 11 and 12 do not deflect can be, for example, assumed for driving on a general paved road or an unpaved road and can be pre-calculated through experiments, simulations, etc.

[0058] In the virtual mode, the controller 4 sets the operating reaction force based on the operation signal. The operation signal is a signal related to the detection value of the operation amount sensor 23 and / or the detection value of the operation torque sensor 24. That is, the controller 4 performs the first reaction force control on the reaction force imparting device 25 in the virtual mode. For example, the controller 4 calculates the self-aligning torque based on the detection value of the operation amount sensor 23 and causes the operating reaction force to reflect the calculated self-aligning torque. Thus, the greater the self-aligning torque, the greater the operating reaction force.

[0059] (1) Road surface simulation control in the virtual mode

[0060] In the virtual mode, different from the normal mode, the vehicle does not actually travel on the road surface. Therefore, the road surface condition does not change, and no change in the control current corresponding to the road surface condition occurs. Thus, in the virtual mode, the controller 4 cannot perform the second reaction force control and the third reaction force control as in the normal mode.

[0061] Therefore, the controller 4 is configured to set the operating reaction force based on a specified vibration component in the signal received from the deflection device 3. The controller 4 of the present embodiment is configured to cause the operating reaction force set based on the operation signal, that is, the operating reaction force set in the first reaction force control, to reflect the specified vibration component in the signal received from the deflection device 3.

[0062] Hereinafter, the control that causes the set operating reaction force to reflect the specified vibration component of the signal from the deflection device 3 is also referred to as "road surface simulation control". Regarding the signal received by the controller 4 from the deflection device 3, various signals can be considered, but in the present embodiment, it is the detection value (detection signal) of the current sensor 351. The vibration component can be said to be a part where the value varies (in a wave-like manner) at a certain frequency in the time series data of the magnitude of the value represented by the signal.

[0063] The detection value of the current sensor 351 contains a random noise component. In the present embodiment, the control current corresponding to the deflection command value sent from the controller 4 to the deflection motor 35 is set to 0. However, in the circuit within the deflection device 3, noise is structurally mixed, and the detection value of the current sensor 351 slightly varies from the set value (0). The controller 4 uses the slight variation of the detection value of the current sensor 351, that is, the noise component, as the vibration component for the reaction force control.

[0064] The controller 4 is configured to extract a specified frequency component as the vibration component from the signal related to the detection value received from the current sensor 351 in the virtual mode. As Figure 2As shown, through the band - pass filter 61 and the amplifier 62, the detection signal of the current sensor 351 is extracted as a specified vibration component. The controller 4 causes the signal extracted from the detection signal of the current sensor 351 by the band - pass filter 61 and the amplifier 62 to be reflected as a vibration component in the operating reaction force. That is, the controller 4 causes the operating reaction force set in the first reaction force control to change over time based on the vibration component. The controller 4 adds the value of the vibration component at each moment to the operating reaction force set in the first reaction force control to reset the operating reaction force. The controller 4 controls the reaction force motor 26 based on the reset operating reaction force (reaction force current).

[0065] The band - pass filter 61 is a filter circuit that allows only signals in a specified frequency band (hereinafter, also referred to as the permitted frequency band) to pass through. The band - pass filter 61 is configured to be able to adjust the permitted frequency band. The controller 4 changes the permitted frequency band of the band - pass filter 61 according to the control mode so that different permitted frequency bands are obtained in the normal mode and the virtual mode. The controller 4 stores the permitted frequency band for the normal mode and the permitted frequency band for the virtual mode.

[0066] The amplifier 62 is a circuit that amplifies the magnitude of a signal and outputs the amplified input signal according to a set gain. The controller 4 adjusts the gain of the amplifier 62 according to the control mode so that different gains are obtained in the normal mode and the virtual mode. The controller 4 stores the gain for the normal mode and the gain for the virtual mode. In this way, the controller 4 switches the parameter values related to the extracted signal (vibration component) according to the control mode. The band - pass filter 61 and the amplifier 62 are used in both the normal mode and the virtual mode.

[0067] As an example of the control, as Figure 3 shown, the controller 4 receives a change permission flag (S11) at a specified timing. The specified timing can be, for example, a periodic timing or after a user performs a change operation from the normal mode to the virtual mode. When the change permission flag is ON (S12: Yes), the controller 4 sets the control mode to the virtual mode. That is, the controller 4 sets the control current corresponding to the deflection command value to 0, sets the permitted frequency band of the band - pass filter 61 to the value for the virtual mode, and sets the gain of the amplifier 62 to the value for the virtual mode (S13).

[0068] When the change permission flag is OFF (S12: No), the controller 4 sets the control mode to the normal mode. That is, the controller 4 sets the control current according to the operation signal, sets the permitted frequency band of the band - pass filter 61 to the value for the normal mode, and sets the gain of the amplifier 62 to the value for the normal mode (S14).

[0069] According to the above structure, in the virtual mode, through deflection prevention control, the control current is set to a current value (here, 0) that does not deflect the wheels 11 and 12. Thus, useless deflection of the wheels 11 and 12 caused by the operation of the operation member 20 is suppressed. Thereby, deterioration of the tires and an increase in power consumption are suppressed. In addition, in most cases, the signal (for example, the detected value of the control current) sent from the deflection device 3 contains noise. The noise contains waves of a certain frequency, that is, vibration components. The controller 4 causes the operation reaction force to reflect the vibration components, whereby the road surface condition (roughness) can be conveyed to the user analogously through the operation reaction force. That is, according to the road surface simulation control, the realism of the game is improved, and the sense of presence felt by the user in the game can be enhanced.

[0070] In addition, during the execution of the road surface simulation control, the controller 4 can utilize the structure (such as the band-pass filter 61 and the amplifier 62) used in the normal mode. Therefore, an increase in manufacturing cost can be suppressed and the structure can be utilized efficiently. Furthermore, the above-described steering system 1 has a structure that uses the common band-pass filter 61 and the common amplifier 62 in both the normal mode and the virtual mode. On the other hand, the steering system 1 may also include, for example, a normal path including a band-pass filter and an amplifier for the normal mode, and a virtual path including a band-pass filter and an amplifier for the virtual mode. In this case, the controller 4 selects the path through which the signal passes according to the control mode selection signal.

[0071] In addition, the controller 4 may perform road surface simulation control not on the operation reaction force set in the first reaction force control but on the operation reaction force set by other methods. The controller 4 executes the first reaction force control, the second reaction force control, and the third reaction force control in the normal mode. The controller 4 executes, for example, deflection prevention control, the first reaction force control, and road surface simulation control in the virtual mode.

[0072] (2) Vehicle vibration control in the virtual mode

[0073] The controller 4 may also supply a control current to the deflection device 3 in the virtual mode so that the wheels 11 and 12 deflect left and right repeatedly regardless of the operation signal (regardless of the operation of the operation member 20). This control is also referred to as "vehicle vibration control". When the vehicle vibration control is executed, as in the deflection prevention control, there is no longer a correlation between the operation signal and the control current, and the control current is set so that the wheels 11 and 12 perform a specified action. According to the vehicle vibration control, in the virtual mode, the wheels 11 and 12 can be made to vibrate slightly left and right. Thereby, the vehicle can be made to generate a simulated vibration that mimics the vibration of a moving vehicle, such as the vibration of an engine or the vibration caused by road surface irregularities. According to this structure, the realism of the game is improved, and the sense of presence felt by the user in the game can be enhanced.

[0074] The controller 4 is configured to supply a control current that increases and decreases at a prescribed frequency to the deflection device 3 (deflection motor 35) in the virtual mode. The controller 4, for example, executes the first reaction force control and executes vehicle vibration control.

[0075] When executing the deflection prevention control and the vehicle vibration control, the controller 4 supplies a corrected control current obtained by adding an additional current value that increases and decreases at a prescribed frequency to the control current set in the deflection prevention control to the deflection device 3, so that the wheels 11 and 12 deflect left and right repeatedly regardless of the operation signal. As Figure 4 shown, in the normal mode, the target deflection angle is calculated based on the operation signal, and the deflection command value (current value of the control current) is set based on the difference between the target deflection angle and the actual deflection angle. In the deflection prevention control in the virtual mode, the current value of the control current as the deflection command value is set to 0. In the vehicle vibration control in the virtual mode, an additional current value that increases and decreases at a prescribed frequency is added to the current value of the control current set as the deflection command value. Thereby, the current value of the corrected control current that causes the wheels 11 and 12 to swing left and right is set, and the corrected control current is supplied to the deflection motor 35.

[0076] As an example of the control, as Figure 5 shown, the controller 4 receives a change permission flag at a prescribed timing (S21). When the change permission flag is ON (S22: YES), the controller 4 sets the control mode to the virtual mode and executes the vehicle vibration control (S23). When the change permission flag is OFF (S22: NO), the controller 4 sets the control mode to the normal mode and does not execute the vehicle vibration control (S24).

[0077] In addition, the controller 4 may be configured to execute the vehicle vibration control only at a prescribed vibration timing. As the vibration timing, in the virtual mode, for example, the timing when the game actually starts, the timing when the virtual moving body 8a is displayed on the display device 80, the timing when the acceleration operation member 71 is operated, or the timing when the brake operation member 72 is operated can be cited.

[0078] The controller 4 is configured to receive an acceleration signal related to the operation of an acceleration operation component 71 for acceleration operation provided in the vehicle, and a braking signal related to the operation of a braking operation component 72 for braking operation provided in the vehicle. The acceleration signal is, for example, equivalent to the detection value of a sensor (not shown) that detects the operation amount of the acceleration operation component 71. The braking signal is, for example, equivalent to the detection value of a sensor (not shown) that detects the operation amount of the braking operation component 72. The controller 4 may also be configured to set an additional current value based on the acceleration signal or the braking signal in the virtual mode. Thereby, the vibration state of the vehicle can be changed according to the degree of the user's acceleration operation or braking operation.

[0079] The controller 4 may also increase the additional current value according to the acceleration signal or the braking signal. The controller 4 may also change the frequency of the additional current value according to the acceleration signal or the braking signal. When no acceleration operation or braking operation is performed, the controller 4 may set the additional current value to 0. The acceleration operation component 71 is, for example, an acceleration pedal, and the braking operation component 72 is, for example, a brake pedal. In addition, the acceleration operation component 71 and the braking operation component 72 may also be components provided on the operation component 20 (such as a lever component, a paddle component).

[0080] The controller 4 performs, for example, anti-deflection control, first reaction force control, and vehicle vibration control in the virtual mode. In addition to this, the controller 4 may also perform road surface simulation control in the virtual mode.

[0081] (3) Pitch reflection control in the virtual mode

[0082] The controller 4 may also be configured to set an operation reaction force based on the operation signal and the acceleration signal, or based on the operation signal and the braking signal in the virtual mode. The control of setting the operation reaction force based on the acceleration signal or the braking signal is also referred to as "pitch reflection control". By reflecting the acceleration operation and braking operation performed by the user to the operation reaction force in the virtual mode, the realism of the game is improved and the sense of presence is improved.

[0083] According to this structure, the influence of the acceleration operation or the braking operation on the wheels 11 and 12 can be reflected to the operation reaction force. For example, when an acceleration operation or a braking operation is performed, the pitch angle of the vehicle changes, and the downward force (load) applied to the wheels 11 and 12 also changes. In a mechanically connected system, if the load changes, the operation feeling of the operation component 20 also changes. According to this structure, the change in the operation feeling caused by the change in the load can be expressed by the operation reaction force. The controller 4 can perform pitch reflection control together with anti-deflection control, road surface simulation control, and vehicle vibration control.

[0084] The controller 4 is configured to reduce the operating reaction force according to the acceleration signal corresponding to the forward movement of the virtual moving body 8a in the virtual mode. When the vehicle moves forward by an acceleration operation, the pitch angle of the vehicle changes to an elevation angle, and the downward force applied to the front wheels 11 and 12 becomes smaller. In this situation, in the mechanically connected system, the resistance of the road surface against the deflection of the wheels 11 and 12 becomes smaller, so the force required to operate the operating member 20 becomes smaller. To represent this situation with the operating reaction force, the controller 4 reduces the operating reaction force according to the forward acceleration signal.

[0085] The controller 4 is configured to increase the operating reaction force according to the braking signal during the forward movement of the virtual moving body 8a in the virtual mode. If a braking operation is performed while the vehicle is moving forward, the pitch angle of the vehicle changes to a depression angle, and the downward force applied to the front wheels 11 and 12 becomes larger. In this situation, in the mechanically connected system, the resistance of the road surface against the deflection of the wheels 11 and 12 becomes larger, so the force required to operate the operating member 20 becomes larger. To represent this situation with the operating reaction force, the controller 4 increases the operating reaction force according to the braking signal during the forward movement.

[0086] The controller 4 performs a front-wheel load calculation for inferring the front-wheel load based on the acceleration signal or the braking signal. The controller 4 causes the calculation result of the front-wheel load calculation to be reflected in the operating reaction force set by the first reaction force control. For the controller 4, for example, the larger the front-wheel load, the larger the operating reaction force, and the smaller the front-wheel load, the smaller the operating reaction force.

[0087] In addition, in the game, in the vast majority of cases, it is configured that the virtual moving body 8a moves forward by an acceleration operation. Therefore, the controller 4 can also be configured to perform the above-mentioned reaction force control by regarding the acceleration signal as the acceleration of the virtual moving body 8a forward and the braking signal as the deceleration during the forward movement of the virtual moving body 8a in the virtual mode. That is, the controller 4 may not determine whether it is moving forward or during forward movement.

[0088] The controller 4 performs anti-deflection control, first reaction force control, and pitch reflection control in the virtual mode. In addition to this, the controller 4 may also perform road surface simulation control and / or vehicle vibration control in the virtual mode.

[0089] The pitch reflection control may also be performed in the normal mode. In this case, the controller 4 may also switch the gain of the front-wheel load calculation between the gain in the normal mode and the gain for the virtual mode according to the control mode. For example, the larger the gain, the larger the variation range of the calculation result (front-wheel load) in the front-wheel load calculation.

[0090] As Figure 6As shown in the figure, as an example of control, the controller 4 receives a change permission flag at a specified timing (S31). When the change permission flag is ON (S32: Yes), the control mode is set to the virtual mode, and the gain of the front wheel load calculation is changed to the value for the virtual mode. For example, the first reaction force control and the pitch reflection control are executed (S33). When the change permission flag is OFF (S32: No), the control mode is set to the normal mode, and the gain of the front wheel load calculation is changed to the value for the normal mode. For example, the first reaction force control, the second reaction force control, the third reaction force control, and the pitch reflection control are executed (S34). In addition, the gain of the front wheel load calculation may also be changed according to the acceleration operation amount and the braking operation amount.

[0091] Summary

[0092] As Figure 7 shown, in the virtual mode, the controller 4 sends operation information related to the operation amount of the operation unit 20, acceleration information related to the operation amount of the acceleration operation unit 71, and braking information related to the operation amount of the braking operation unit 72 to the game machine 8 based on the input operation signal, acceleration signal, and braking signal. The game machine 8 displays the virtual moving body 8a on the display device 80 in a manner that reflects the various types of information received from the controller 4. In addition, in any control mode, the controller 4 sets an operation reaction force based on the various types of signals input above, and supplies a reaction force current corresponding to the operation reaction force to the reaction force motor 26. In the steering system 1, as described above, the setting of the operation reaction force differs according to the control mode. In addition, in any control mode, the controller 4 sets a control current or a corrected control current based on the various types of signals input above, and supplies the control current or the corrected control current to the deflection motor 35. In the steering system 1, as described above, the setting of the control current or the corrected control current differs according to the control mode.

[0093] The controller 4 can execute the first reaction force control, the deflection prevention control, the road surface simulation control, the vehicle vibration control, and the pitch response control in a virtual mode, for example, simultaneously or independently of each other. Thus, various controls of the present disclosure can be appropriately combined with each other. The steering system 1 of the present embodiment includes at least one of the structures that (1) execute the deflection prevention control and the road surface simulation control, (2) execute the vehicle vibration control, and (3) execute the deflection prevention control, the first reaction force control, and the pitch response control in the virtual mode. Further, when the speed information of the virtual moving body 8a in the game can be obtained from the game machine 8, the controller 4 may also set the operation reaction force based on the vehicle speed information, that is, execute the third reaction force control. The game machine 8 can also function as a simulator for driving training, for example. In addition, the technology of the present disclosure can also be applied to moving bodies other than electric vehicles. The game machine 8 and the CAN (and / or the controller 4) can communicate with each other to specify information.

Claims

1. A steering system is a steer-by-wire steering system (1), characterized in that the steering system (1) comprises: an operating device including an operating member for a user to perform a steering operation and a reaction force imparting device configured to impart an operating reaction force to the operating member; a deflection device configured to be mechanically separated from the operating device and deflect a wheel according to a supplied control current; and a controller configured to control the deflection device and the reaction force imparting device based on an operation signal related to the action of the operating member received from the operating device, wherein the steering system is configured to switch between a normal mode of deflecting the wheel based on the operation signal and a virtual mode of steering a virtual moving body produced as an image based on the operation signal, the controller is configured to: in the virtual mode, set the control current to a current value at which the wheel does not deflect regardless of the operation signal, and set the operating reaction force based on a prescribed vibration component in a signal received from the deflection device.

2. The steering system according to claim 1, characterized in that the controller is configured to: in the virtual mode, cause the operating reaction force set based on the operation signal to reflect the prescribed vibration component.

3. The steering system according to claim 1 or 2, characterized in that the deflection device comprises an electric motor configured to deflect a wheel and a current sensor configured to detect a current value of the control current input to the electric motor, the controller is configured to: in the virtual mode, extract a prescribed frequency component from a signal related to a detection value received from the current sensor as the prescribed vibration component.

4. The steering system according to claim 3, characterized in that it further comprises: a band-pass filter configured to allow only signals in a prescribed permitted frequency band to pass through; and an amplifier configured to amplify the signal that has passed through the band-pass filter, wherein the controller is configured to: set the operating reaction force using the detection signal of the current sensor that has passed through the band-pass filter and the amplifier as the prescribed vibration component.

5. The steering system according to claim 4, characterized in that the band-pass filter and the amplifier are respectively used in both the normal mode and the virtual mode, the controller is configured to: in the normal mode, set the prescribed permitted frequency band of the band-pass filter and the gain of the amplifier to values for the normal mode respectively, in the virtual mode, set the prescribed permitted frequency band of the band-pass filter and the gain of the amplifier to values for the virtual mode respectively.

6. The steering system according to claim 1 or 2, characterized in that the controller is configured to: in the virtual mode, set the control current to 0 regardless of the operation signal.

7. The steering system according to claim 1, characterized in that The controller is configured to: in the virtual mode, supply a corrected control current obtained by adding an additional current value that increases and decreases at a specified frequency to the control current to the deflection device, so that the wheels deflect left and right repeatedly regardless of the operation signal.

8. The steering system according to claim 7, characterized in that the controller is configured to: receive an acceleration signal related to the operation of an acceleration operation member provided on the vehicle for acceleration operation, and a braking signal related to the operation of a braking operation member provided on the vehicle for braking operation, the controller is configured to: in the virtual mode, set the additional current value based on the acceleration signal or the braking signal.

9. The steering system according to claim 1, 2, 7 or 8, characterized in that the controller is configured to: receive an acceleration signal related to the operation of an acceleration operation member provided on the vehicle for acceleration operation, and a braking signal related to the operation of a braking operation member provided on the vehicle for braking operation, the controller is configured to: in the virtual mode, set the operation reaction force based on the operation signal and the acceleration signal, or based on the operation signal and the braking signal.

10. The steering system according to claim 9, characterized in that the controller is configured to: in the virtual mode, reduce the operation reaction force according to the acceleration signal corresponding to the forward movement of the virtual moving body.

11. The steering system according to claim 9, characterized in that the controller is configured to: in the virtual mode, increase the operation reaction force according to the braking signal during the forward movement of the virtual moving body.

12. A steering system, which is a steer-by-wire type steering system, characterized in that the steering system includes: an operation device including an operation member for the user to perform a steering operation, and a reaction force imparting device configured to impart an operation reaction force to the operation member; a deflection device configured to be mechanically separated from the operation device and deflect the wheels according to the supplied control current; and a controller configured to control the deflection device and the reaction force imparting device based on an operation signal related to the operation of the operation member received from the operation device, wherein the steering system is configured to switch between a normal mode in which the wheels are deflected based on the operation signal and a virtual mode in which a virtual moving body created as an image is steered based on the operation signal, the controller is configured to: in the virtual mode, supply the control current to the deflection device so that the wheels deflect left and right repeatedly regardless of the operation signal.

13. The steering system according to claim 12, characterized in that the controller is configured to: in the virtual mode, supply the control current that increases and decreases at a specified frequency to the deflection device.

14. The steering system according to claim 12 or 13, characterized in that The controller is configured to receive an acceleration signal related to the operation of an acceleration operation component for acceleration operation provided in the vehicle, and a braking signal related to the operation of a braking operation component for braking operation provided in the vehicle. The controller is configured to supply the control current to the deflection device in a manner that the wheels deflect left and right repeatedly based on the acceleration signal or the braking signal in the virtual mode.

15. A steering system, which is a steer-by-wire type steering system, characterized in that the steering system includes: an operation device, including an operation component for the user to perform a steering operation, and a reaction force applying device configured to apply an operation reaction force to the operation component; a deflection device, configured to be mechanically separated from the operation device and deflect the wheels according to the supplied control current; and a controller, configured to control the deflection device and the reaction force applying device based on an operation signal related to the operation of the operation component received from the operation device, wherein the steering system is configured to switch between a normal mode in which the wheels are deflected based on the operation signal, and a virtual mode in which a virtual moving body created as an image is steered based on the operation signal, the controller is configured to receive an acceleration signal related to the operation of an acceleration operation component for acceleration operation provided in the vehicle, and a braking signal related to the operation of a braking operation component for braking operation provided in the vehicle, the controller is configured to in the virtual mode, set the control current to a current value at which the wheels do not deflect regardless of the operation signal, set the operation reaction force based on the operation signal and the acceleration signal, or based on the operation signal and the braking signal.

16. The steering system according to claim 15, characterized in that the controller is configured to reduce the operation reaction force according to the acceleration signal corresponding to the advancement of the virtual moving body in the virtual mode.

17. The steering system according to claim 15 or 16, characterized in that the controller is configured to increase the operation reaction force according to the braking signal during the advancement of the virtual moving body in the virtual mode.

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