Steering system

Abstract

To provide a steering system that can enhance presence of a game that is given to a user, when using an operation member in playing the game.SOLUTION: The steering system is a steer-by-wire type steering system that comprises an operation device 2 including an operation member 20 and a reaction force applying device 25, a turning device 3 that turns wheels 11 and 12 in accordance with control currents, and a controller 4, which is configured to be switchable between a normal mode in which the wheels 11 and 12 are turned based on an operation signal and a virtual mode in which a virtual moving body 8a created as a video is steered based on an operation signal. The controller 4 is configured to set the control currents to current values at which the wheels 11 and 12 are not turned, without depending on the operation signal, and to set operation reaction force on the basis of predetermined vibrational components of a signal received from the turning device 3.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Recently, in a steer-by-wire type steering system in which an operation member and a steering device are mechanically separated, a steering system has been developed that is configured to allow a user to play a game using the operation member. For example, Japanese Patent Application Laid-Open No. 2022-1925 discloses a vehicle capable of switching an operation target by an operation unit of a steering device between a vehicle and a virtual moving body in a game. That is, such a steering system is configured to be able to switch between a normal mode in which the vehicle is an operation target and a game mode in which a virtual moving body is an operation target.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a steer-by-wire type steering system, when an operation member is operated by a user, a reaction force applying device is configured to apply a reaction force (operation reaction force) to the operation member according to the operation of the operation member. Further, in the normal mode, the vehicle acquires information on the driving road surface, and based on the road surface information, the reaction force applying device applies an operation reaction force to the operation member. Since the detected value of the control current supplied to the electric motor of the steering device that steers the wheels may change depending on the road surface condition because the steering load changes according to the road surface condition, the road surface condition can be estimated by detecting the current value of the control current input to the electric motor. By using this estimation, in the normal mode, the reaction force applying device can reflect the road surface condition in the operation reaction force.

[0005] However, in the game mode, the magnitude of the control current of the electric motor of the steering device does not correspond to the road surface conditions in the game. Furthermore, in the game mode, since the vehicle is not actually traveling on the road surface, information on the road surface conditions cannot be obtained from the control current of the electric motor. Therefore, in the game mode, an operating reaction force that does not reflect the road surface conditions is applied to the operating member. With an operating reaction force that does not reflect the road surface conditions, it becomes difficult to give a high sense of presence to the user who operates the operating member.

[0006] Thus, there is room for improvement in the conventional steering system in terms of enhancing the sense of presence in the game. An object of the present invention is to provide a steering system capable of improving the sense of presence given to the user when the operating member is used in a game.

Means for Solving the Problems

[0007] The steering system according to the first aspect of the present invention includes an operating device including an operating member for a steering operation by a user and a reaction force applying device that applies an operating reaction force to the operating member, a steering device that is mechanically separated from the operating device and steers wheels according to a supplied control current, and a controller that controls the steering device and the reaction force applying device based on an operation signal regarding the operation of the operating member received from the operating device. The steering system is a steer-by-wire type steering system configured to be switchable between a normal mode in which the wheels are steered 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. Hereinafter, this configuration is also referred to as the "basic configuration of the first aspect". The controller according to the first aspect is configured to set the control current to a current value at which the wheels do not steer regardless of the operation signal in the virtual mode, and to set the operating reaction force based on a predetermined vibration component among the signals received from the steering device.

[0008] The steering system according to the second aspect of the present invention is a steer-by-wire type steering system having the same basic configuration as that of the first aspect, and in the virtual mode, the controller supplies the control current to the steering device so that the wheels repeatedly steer left and right regardless of the operation signal.

[0009] The steering system according to the third aspect of the present invention is a steer-by-wire type steering system having the same basic configuration as that of the first aspect, and the controller is configured to receive an accelerator signal related to the operation of an accelerator operation member for accelerator operation provided in the vehicle and a brake signal related to the operation of a brake operation member for brake operation provided in the vehicle. Further, in the virtual mode, the controller sets the control current to a current value at which the wheels do not steer regardless of the operation signal, and is configured to set the operation reaction force based on the operation signal and the accelerator signal or the brake signal.

Advantages of the Invention

[0010] According to the first aspect of the present invention, in the virtual mode, the control current supplied to the steering device is set to a value at which the wheels do not steer (for example, 0). Therefore, unnecessary steering of the wheels due to the operation of the operation member is suppressed. In addition, signals transmitted from the steering device (for example, detection signals of the control current) often contain noise. The noise includes waves of a certain frequency, that is, vibration components. By reflecting the vibration components in the operation reaction force by the controller, the road surface condition (roughness) can be pseudo-transmitted to the user through the operation reaction force. That is, according to the first aspect, the reality of the game can be improved, and the sense of presence given to the user in the game can be enhanced.

[0011] According to the second aspect of the present invention, in the virtual mode, the wheels can be slightly vibrated left and right regardless of the operation of the operation member. Thereby, it is possible to generate a pseudo-vibration similar to the vibration of a running vehicle, for example, the vibration caused by the vibration of the engine or the unevenness of the road surface, in the vehicle. According to the second aspect, the reality of the game can be enhanced, and the sense of presence given to the user in the game can be improved.

[0012] According to the third aspect of the present invention, the influence on the wheels due to the accelerator operation or the brake operation can be reflected in the operation reaction force. For example, when the accelerator operation or the brake operation is performed, the pitch angle of the vehicle changes, and the force (load) applied to the wheels also changes. In a configuration where the operation member and the steering device are mechanically connected, when the force applied to the steered wheels changes, the operation feeling (steering force) of the operation member also changes. According to the third aspect, the change in the operation feeling due to the change in the force applied to the wheels can be expressed by the operation reaction force. That is, according to the third aspect, the reality of the game can be enhanced, and the sense of presence given to the user in the game can be improved.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0014] Hereinafter, as a mode for carrying out the present invention, a steering system 1 which is an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art in addition to the following examples. The steering system 1 of the present embodiment is mounted on an electric vehicle as an example. Communication inside the vehicle is performed by, for example, CAN (car area network or controllable area network), FlexRay, or Ethernet.

[0015] As shown in FIG. 1, the steering system 1 includes an operation device 2, a steering 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.

[0016] The operation member 20 is a handle member for a steering operation by the user. The operation member 20 is, for example, a steering wheel. Note that 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 square shape. The operation member 20 can also be said to be a steering operation member. The operation member 20 is fixed to the tip of the steering shaft 21. The operation member 20 and the steering shaft 21 are rotatably held by the steering column 22 in the instrument panel reinforcement.

[0017] 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 incorporated in the steering shaft 21.

[0018] The reaction force applying device 25 is a device that applies an operating reaction force to the operating member 20. The reaction force applying device 25 includes a reaction force motor 26 which is 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 operating reaction force for steering operation to the operating member 20 via the steering shaft 21. The reaction force applying device 25 has a general structure including a speed reducer and the like. A rotation angle sensor 26a is provided on the reaction force motor 26.

[0019] The steering device 3 is a device that steers the wheels 11, 12 (front wheels or steered wheels). The steering device 3 is mechanically separated from the operating device 2. The steering device 3 includes a steering motor 35 which is an electric motor as a drive source, and a current sensor 351 that detects the current value of the control current input to the steering motor 35. More specifically, the steering device 3 includes a steering rod 31, a housing 32, a rod moving mechanism 33, a steering motor 35, a current sensor 351, a rotation angle sensor 352, and a steering angle sensor 36.

[0020] The steering rod 31 is a member whose both ends are respectively connected to the left and right steering knuckles 90 via tie rods 34. The housing 32 is a member that supports the steering rod 31 so as to be movable left and right and is fixedly held by the vehicle body.

[0021] The rod moving mechanism 33 is a mechanism for moving the steering rod 31 left and right using the steering motor 35 as a drive source. The steering motor 35 is an electric motor that steers the wheels 11, 12. The rod moving mechanism 33 mainly consists of a ball screw mechanism constituted by a ball groove screwed on the steering rod 31 and a nut that engages with the ball groove via bearing balls and is rotated by the steering motor 35. Since it has a general structure, a detailed description of the rod moving mechanism 33 will be omitted.

[0022] The current sensor 351 is a sensor that detects the current (control current) input to the steering motor 35. The rotation angle sensor 352 is a sensor that detects the rotation angle of the steering motor 35. The steering angle sensor 36 is a sensor that detects the steering angle (steering amount) of the wheels 11 and 12. The steering angle sensor 36 detects the amount of movement of the steering rod 31 to the left and right from the neutral position.

[0023] The controller 4 is configured to control the steering device 3 and the reaction force applying device 25 based on an operation signal regarding the operation of the operation member 20 received from the operation device 2. The controller 4 is a computer including one or more processors 41 and one or more memories 42. The 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 steering device 3. The operation device 2 and the steering device 3 are electrically connected via the controller. That is, the steering system 1 is a steer-by-wire type steering system that steers the vehicle by converting the mechanical operation of the operation member 20 by the user into an electrical signal and transmitting the electrical signal to the steering device 3 mechanically separated from the operation member 20. Note that the controller 4 may be composed of two or more communicably connected computers. For example, the controller 4 may be composed of a controller (computer) of the operation device 2 and a controller (computer) of the steering device 3.

[0024] (Control Mode) The steering system 1 is configured to be switchable between a normal mode in which the wheels 11 and 12 are steered based on an operation signal and a virtual mode in which a virtual moving body 8a created as an image 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 a virtual moving body 8a (for example, an image of a vehicle) represented as an image in a game is operated by the operation member 20. The virtual moving body 8a is created as an image viewable inside the vehicle. The normal mode can also be referred to as, for example, the first mode, the main mode, or the real mode. The virtual mode can also be referred to as, for example, the second mode, the sub mode, or the game mode.

[0025] A display device 80 is arranged inside the vehicle. Examples of the display device 80 include an in-panel display, a display of a navigation system, a front glass on which an image or the like is projected, a display of a portable terminal, AR glasses, or a head-mounted display. The game machine 8 may be arranged inside the vehicle or may be arranged outside the vehicle by being connected to the vehicle by wireless communication. 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 and the controller 4 are connected so as to be able to communicate only with respect to predetermined information.

[0026] In the virtual mode, the game machine 8 displays the virtual moving body 8a on the display device 80. The controller 4 transmits operation information readable from the operation signal to the game machine 8, and the game machine 8 creates a display image of the virtual moving body 8a on the display device 80 based on the operation information and displays on the display device 80 a situation in which the virtual moving body 8a is steered. 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.

[0027] Based on the user's operation (instruction), the controller 4 switches between the normal mode and the virtual mode. For example, when the user performs a button operation to select the virtual mode on the mode selection means (such as an operation panel) provided in the vehicle, the controller 4 checks that the predetermined conditions are satisfied and then switches the control mode of the vehicle from the normal mode to the virtual mode. Similarly, the controller 4 switches the control mode from the virtual mode to the normal mode based on the operation of the operation panel or the like by the user. When the user selects the virtual mode and the predetermined conditions are satisfied, the controller 4 turns on the change permission flag. When the user does not select the virtual mode or the predetermined conditions are not satisfied, the change permission flag remains off. The virtual mode is a control mode assumed for the user to play a game using the operation member 20 when the vehicle is in a stopped state, such as when the battery of an electric vehicle is being charged.

[0028] (Details of the normal mode) In the normal mode, the controller 4 controls the steering motor 35 based on the detection value (detection signal) of the operation amount sensor 23. The controller 4 calculates the target steering angle from 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 steering angle and the actual steering angle (detection value of the steering angle sensor 36). The controller 4 supplies the set control current to the steering motor 35.

[0029] In the normal mode, the controller 4 sets the operation reaction force on 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 (also referred to as a reaction force current) corresponding to the set operation reaction force to the reaction force motor 26.

[0030] Based on the detected values of the vehicle speed and the steering angle sensor 36, the controller 4 calculates the lateral acceleration of the vehicle. The vehicle speed is calculated, for example, based on the detected values of wheel speed sensors (not shown) provided on each wheel. The controller 4 calculates the self-aligning torque of the wheels based on the detected value of the steering angle sensor 36. It can also be said that the controller 4 estimates a force equivalent to the self-aligning torque based on the steering angle of the wheels. The various forces acting on the wheels may change according to the vehicle speed. Therefore, in the normal mode, the controller 4 reflects, for example, the vehicle speed, the lateral acceleration, and the self-aligning torque in the operating reaction force. Also, an operating reaction force corresponding to the resistance of the road surface to the steering of the wheels is set as a basic reaction force in the controller 4.

[0031] Based on the detected value of the operation torque sensor 24, the controller 4 sets the operating reaction force. In order to keep the user's operation torque within a predetermined range, a force for assisting the operation of the user's operation member 20 is required according to the magnitude of the operation torque. Therefore, the controller 4 reduces the operating reaction force as the detected value of the operation torque sensor 24 is larger so that the operation torque is maintained within the predetermined 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, for example, the self-aligning torque and the assist force as an example, is also referred to as "first reaction force control".

[0032] The control current is set according to the difference between the target steering angle and the actual steering angle (hereinafter also referred to as the angle difference). The control current can also be referred to as the steering current or the steering command value. When the controller 4 supplies the control current corresponding to the angle difference to the steering motor 35 and the angle difference does not decrease due to the road surface condition (for example, unevenness), the controller 4 further increases the control current to increase the driving force of the steering motor 35. Depending on the road surface condition, there may be a case where only the control current fluctuates without the angle difference fluctuating. That is, the fluctuation of the control current may be caused by the road surface condition. The controller 4 can detect this fluctuation of the control current and transmit the road surface condition to the user by reflecting the fluctuation of the control current on the operating reaction force. Hereinafter, the reaction force control based on the fluctuation of 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".

[0033] 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 and the steering device 3 are mechanically connected. In the normal mode, the controller 4 executes 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 applying device 25. The self-aligning torque is a force that acts in the direction of reducing the slip angle of the tire, and in the mechanically connected system, it is a force that tries to return the operated operating member 20 to its original position. The self-aligning torque increases, for example, in accordance with the increase in the steering angle until the steering angles of the wheels 11 and 12 reach a predetermined angle. The controller 4 increases the operating reaction force, for example, in accordance with the increase in the steering angle until the steering angle reaches a predetermined angle.

[0034] (Details of the virtual mode) In the virtual mode, the controller 4 sets the control current to a current value at which the wheels 11 and 12 do not steer, regardless of the operation signal (regardless of the operation of the operation member 20). This control is also referred to as "steering prevention control". It can also be said that the controller 4 sets the absolute value of the control current to be equal to or less than a predetermined value. As an example of the steering prevention control, in the virtual mode, the controller 4 sets the control current to 0 regardless of the operation signal. That is, in the virtual mode, the controller 4 is configured not to supply a control current to the steering motor 35 in principle. As a result, the steering motor 35 does not operate and the wheels 11 and 12 are not steered. The current value of the control current at which the wheels 11 and 12 do not steer can be calculated in advance by experiments, simulations, etc., assuming driving on a general paved road or an unpaved road, for example.

[0035] In the virtual mode, the controller 4 sets an operation 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, in the virtual mode, the controller 4 executes first reaction force control on the reaction force applying device 25. For example, based on the detection value of the operation amount sensor 23, the controller 4 calculates a self-aligning torque and reflects the calculated self-aligning torque in the operation reaction force. As a result, the greater the self-aligning torque, the greater the operation reaction force.

[0036] (1) Road surface simulation control in the virtual mode In the virtual mode, unlike the normal mode, the vehicle does not actually drive on the road surface. Therefore, the road surface condition does not fluctuate and there is no fluctuation in the control current according to the road surface condition. As a result, in the virtual mode, the controller 4 cannot execute the second reaction force control and the third reaction force control as in the normal mode.

[0037] Therefore, the controller 4 is configured to set an operating reaction force based on a predetermined vibration component among the signals received from the steering device 3. The controller 4 of the present embodiment is configured to reflect a predetermined vibration component among the signals received from the steering device 3 with respect to the operating reaction force set based on the operation signal, that is, the operating reaction force set by the first reaction force control.

[0038] Hereinafter, the control for reflecting a predetermined vibration component of the signal from the steering device 3 with respect to the set operating reaction force is also referred to as "road surface simulation control". Although various signals can be considered as the signal received by the controller 4 from the steering device 3, 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 fluctuates (in a wave shape) at a certain frequency in the time series data of the magnitude of the value indicated by the signal.

[0039] The detection value of the current sensor 351 includes a random noise component. In the present embodiment, the control current corresponding to the steering command value from the controller 4 to the steering motor 35 is set to 0. However, noise has entered the circuit in the steering device 3 due to its configuration, and the detection value of the current sensor 351 fluctuates slightly instead of the set value (0). The controller 4 uses this fine fluctuation of the detection value of the current sensor 351, that is, the noise component, as a vibration component for reaction force control.

[0040] In the virtual mode, the controller 4 is configured to extract a predetermined frequency component as a vibration component from the signal related to the detected value received from the current sensor 351. As shown in FIG. 2, the detection signal of the current sensor 351 is extracted as a predetermined vibration component by passing through the band-pass filter 61 and the amplifier 62. The controller 4 reflects the signal extracted by the band-pass filter 61 and the amplifier 62 from the detection signal of the current sensor 351 as a vibration component in the operating reaction force. That is, the controller 4 varies the operating reaction force set in the first reaction force control according to the passage of time based on the vibration component. The controller 4 adds the value of the vibration component at that time to the operating reaction force set in the first reaction force control and resets the operating reaction force. The controller 4 controls the reaction force motor 26 based on the reset operating reaction force (reaction force current).

[0041] The band-pass filter 61 is a filter circuit that allows only signals in a predetermined frequency band (hereinafter also referred to as the permitted frequency band) to pass through. The band-pass filter 61 is configured to be adjustable in 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.

[0042] The amplifier 62 is a circuit that amplifies the magnitude of a signal, and amplifies and outputs the 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 signal (vibration component) to be extracted according to the control mode. The band-pass filter 61 and the amplifier 62 are each used in both the normal mode and the virtual mode.

[0043] As an example of control, as shown in FIG. 3, the controller 4 receives a change permission flag at a predetermined timing (S11). The predetermined timing may be, for example, periodic, or may be after a user changes the 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 steering command value to 0, sets the allowable frequency band of the band-pass filter 61 to a value for the virtual mode, and sets the gain of the amplifier 62 to a value for the virtual mode (S13).

[0044] 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 allowable frequency band of the band-pass filter 61 to a value for the normal mode, and sets the gain of the amplifier 62 to a value for the normal mode (S14).

[0045] According to the above configuration, in the virtual mode, by the steering prevention control, the control current is set to a current value at which the wheels 11 and 12 do not steer (here, 0). Therefore, unnecessary steering of the wheels 11 and 12 due to the operation of the operation member 20 is suppressed. Thereby, deterioration of the tire and increase in power consumption are suppressed. Further, the signal transmitted from the steering device 3 (for example, the detected value of the control current) often contains noise. The noise contains waves of a certain frequency, that is, vibration components. By reflecting the vibration component by the controller 4 in the operation reaction force, the road surface condition (roughness) can be pseudo-transmitted to the user through the operation reaction force. That is, according to the road surface simulation control, the reality of the game can be improved, and the sense of presence given to the user in the game can be enhanced.

[0046] Further, when executing road surface simulation control, the controller 4 can utilize the configuration (such as the band - pass filter 61 and the amplifier 62) used in the normal mode. Therefore, it is possible to suppress an increase in manufacturing cost and to efficiently utilize the configuration. Note that the above - mentioned steering system 1 is configured to use 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 include, for example, a normal route including a band - pass filter and an amplifier for the normal mode, and a virtual route including a band - pass filter and an amplifier for the virtual mode. In this case, the controller 4 selects the route through which the signal passes according to the control mode.

[0047] Note that the controller 4 may execute road surface simulation control for the operating reaction force set by a method other than the operating reaction force set by the first reaction force control. 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, steering prevention control, the first reaction force control, and road surface simulation control in the virtual mode.

[0048] (2) Vehicle vibration control in the virtual mode In the virtual mode, the controller 4 may supply a control current to the steering device 3 so that the wheels 11, 12 repeatedly steer left and right 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, similar to the steering prevention control, the relevance between the operation signal and the control current is lost, and the control current is set so that the wheels 11, 12 perform a predetermined operation. According to the vehicle vibration control, in the virtual mode, the wheels 11, 12 can be slightly vibrated left and right. Thereby, it is possible to generate a pseudo - vibration similar to the vibration of the traveling vehicle, for example, the vibration of the engine or the vibration due to the unevenness of the road surface, in the vehicle. According to this configuration, the reality of the game can be enhanced, and the sense of presence given to the user in the game can be improved.

[0049] In the virtual mode, the controller 4 is configured to supply a control current that increases and decreases at a predetermined frequency to the steering device 3 (steering motor 35). The controller 4 executes, for example, vehicle vibration control while executing first reaction force control.

[0050] When the controller 4 executes vehicle vibration control while executing steering prevention control, a correction control current obtained by adding an additional current value that increases and decreases at a predetermined frequency to the control current set in the steering prevention control is supplied to the steering device 3 so that the wheels 11 and 12 repeatedly steer left and right regardless of the operation signal. As shown in FIG. 4, in the normal mode, a target steering angle is calculated from the operation signal, and a steering command value (current value of the control current) is set based on the difference between the target steering angle and the actual steering angle. In the steering prevention control in the virtual mode, the current value of the control current, which is this steering 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 predetermined frequency is added to the current value of the control current set as the steering command value. As a result, the current value of the correction control current for swinging the wheels 11 and 12 left and right is set, and the correction control current is supplied to the steering motor 35.

[0051] As an example of the control, as shown in FIG. 5, the controller 4 receives a change permission flag at a predetermined timing (S21). When the change permission flag is on (S22: Yes), the controller 4 sets the control mode to the virtual mode and executes 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 vehicle vibration control (S24).

[0052] Note that the controller 4 may be configured to execute vehicle vibration control only at a predetermined vibration timing. Examples of the vibration timing include, 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 accelerator operation member 71 is operated, or the timing when the brake operation member 72 is operated.

[0053] The controller 4 is configured to receive an accelerator signal related to the operation of an accelerator operation member 71 for accelerator operation provided in the vehicle, and a brake signal related to the operation of a brake operation member 72 for brake operation provided in the vehicle. The accelerator signal corresponds to, for example, the detection value of a sensor (not shown) that detects the operation amount of the accelerator operation member 71. The brake signal corresponds to, for example, the detection value of a sensor (not shown) that detects the operation amount of the brake operation member 72. The controller 4 may be configured to set an additional current value based on the accelerator signal or the brake signal in the virtual mode. Thereby, the vibration state of the vehicle can be changed according to the degree of the user's accelerator operation or the degree of the brake operation.

[0054] The controller 4 may increase the additional current value according to the accelerator signal or the brake signal. The controller 4 may change the frequency of the additional current value according to the accelerator signal or the brake signal. The controller 4 may set the additional current value to 0 when no accelerator operation or brake operation is being performed. The accelerator operation member 71 is, for example, an accelerator pedal, and the brake operation member 72 is, for example, a brake pedal. Note that the accelerator operation member 71 and the brake operation member 72 may be members (such as lever members or pedal members) provided on the operation member 20.

[0055] In the virtual mode, the controller 4 executes, for example, steering prevention control, first reaction force control, and vehicle vibration control. In addition to this, the controller 4 may further execute road surface simulation control in the virtual mode.

[0056] (3) Pitch reflection control in the virtual mode In the virtual mode, the controller 4 may be configured to set an operation reaction force based on the operation signal and the accelerator signal or the brake signal. The control of setting the operation reaction force based on the accelerator signal or the brake signal is also referred to as "pitch reflection control". By reflecting the accelerator operation and the brake operation by the user in the operation reaction force in the virtual mode, the reality of the game is enhanced and the sense of presence is improved.

[0057] According to this configuration, the influence on the wheels 11 and 12 due to the accelerator operation or the brake operation can be reflected in the operating reaction force. For example, when an accelerator operation or a brake 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 operating feeling of the operating member 20 also changes. According to this configuration, the change in the operating feeling due to the change in the load can be expressed by the operating reaction force. The controller 4 can execute pitch reflection control together with steering prevention control, road surface simulation control, and vehicle vibration control.

[0058] In the virtual mode, the controller 4 is configured to reduce the operating reaction force in response to an accelerator signal corresponding to the forward movement of the virtual moving body 8a. When the vehicle moves forward by an accelerator operation, the pitch angle of the vehicle changes to an upward pitch, and the downward force applied to the front wheels 11 and 12 decreases. In this situation, in a mechanically connected system, since the resistance of the road surface to the steering of the wheels 11 and 12 decreases, the force required for the operation of the operating member 20 decreases. In order to express this situation by the operating reaction force, the controller 4 reduces the operating reaction force in response to the forward accelerator signal.

[0059] In the virtual mode, the controller 4 is configured to increase the operating reaction force in response to a brake signal during the forward movement of the virtual moving body 8a. When a brake operation is performed while the vehicle is moving forward, the pitch angle of the vehicle changes to a downward pitch, and the downward force applied to the front wheels 11 and 12 increases. In this situation, in a mechanically connected system, since the resistance of the road surface to the steering of the wheels 11 and 12 increases, the force required for the operation of the operating member 20 increases. In order to express this situation by the operating reaction force, the controller 4 increases the operating reaction force in response to the brake signal during forward movement.

[0060] The controller 4 executes a front wheel load calculation for estimating the front wheel load based on an accelerator signal or a brake signal. The controller 4 reflects the calculation result of the front wheel load calculation on the operating reaction force set by the first reaction force control. For example, the controller 4 increases the operating reaction force as the front wheel load increases and decreases the operating reaction force as the front wheel load decreases.

[0061] In the game, in most cases, the virtual moving body 8a is configured to move forward by an accelerator operation. Therefore, in the virtual mode, the controller 4 may regard the accelerator signal as acceleration of the virtual moving body 8a forward and the brake signal as deceleration during the forward movement of the virtual moving body 8a, and execute the above reaction force control. That is, the controller 4 does not have to determine whether it is moving forward or whether it is moving forward.

[0062] The controller 4 executes a steering prevention control, a first reaction force control, and a pitch reaction force control in the virtual mode. In addition to this, the controller 4 may further execute a road surface simulation control and / or a vehicle vibration control in the virtual mode.

[0063] The pitch reflection control may also be executed in the normal mode. In this case, the controller 4 may 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 fluctuation range of the calculation result (front wheel load) in the front wheel load calculation.

[0064] As an example of control, as shown in FIG. 6, the controller 4 receives a change permission flag at a predetermined timing (S31). When the change permission flag is on (S32: Yes), the control mode is set to the virtual mode, the gain of the front wheel load calculation is changed to a value for the virtual mode, and 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, the gain of the front wheel load calculation is changed to a value for the normal mode, and 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). Note that the gain of the front wheel load calculation may be changed according to the accelerator operation amount and the brake operation amount.

[0065] (Summary) As shown in FIG. 7, in the virtual mode, the controller 4 transmits operation information regarding the operation amount of the operation member 20, accelerator information regarding the operation amount of the accelerator operation member 71, and brake information regarding the operation amount of the brake operation member 72 to the game machine 8 based on the input operation signal, accelerator signal, and brake signal. The game machine 8 displays the virtual moving body 8a on the display device 80 so as to reflect the various types of information received from the controller 4. Further, in any control mode, the controller 4 sets an operation reaction force based on the input various signals and supplies a reaction force current corresponding to the operation reaction force to the reaction force motor 26. In the steering system 1, the setting of the operation reaction force differs depending on the control mode as described above. Also, in any control mode, the controller 4 sets a control current or a corrected control current based on the input various signals and supplies the control current or the corrected control current to the steering motor 35. In the steering system 1, the setting of the control current or the corrected control current differs depending on the control mode as described above.

[0066] In the virtual mode, the controller 4 can execute, for example, the first reaction force control, the steering prevention control, the road surface simulation control, the vehicle vibration control, and the pitch reflection control simultaneously or independently. Thus, the various controls of the present disclosure can be combined with each other as appropriate. The steering system 1 of the present embodiment includes, in the virtual mode, at least one of the following configurations: (1) a configuration that executes the steering prevention control and the road surface simulation control; (2) a configuration that executes the vehicle vibration control; and (3) a configuration that executes the steering prevention control, the first reaction force control, and the pitch reflection control. Note that when the controller 4 can acquire the speed information of the virtual moving body 8a in the game from the game machine 8, the controller 4 may set the operation reaction force based on the vehicle speed information, that is, execute the third reaction force control. The game machine 8 may function as a simulator for driving training, for example. Further, 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 predetermined information with each other.

Explanation of Signs

[0067] 1... Steering system, 11, 12... Wheels, 2... Operating device, 20... Operating member, 23... Operation amount sensor, 25... Reaction force applying device, 3... Steering device, 35... Steering motor, 351... Current sensor, 4... Controller, 61... Band-pass filter, 62... Amplifier, 71... Accelerator operating member, 72... Brake operating member, 8a... Virtual moving body.

Claims

1. An operating device including an operating member for a steering operation by a user and a reaction force applying device for applying a reaction force to the operating member, a steering device that is mechanically separated from the operating device and steers wheels according to a supplied control current, a controller that controls the steering device and the reaction force applying device based on an operation signal regarding the operation of the operating member received from the operating device, A steer-by-wire type steering system including a normal mode of steering wheels based on the operation signal and a virtual mode of steering a virtual moving body created as an image based on the operation signal, and the normal mode and the virtual mode are configured to be switchable, wherein the controller, in the virtual mode, sets the control current to a current value at which the wheels do not steer regardless of the operation signal, and is configured to set the operation reaction force based on a predetermined vibration component among the signals received from the steering device. Steering system.

2. The steering system according to claim 1, wherein the controller is configured to reflect the vibration component with respect to the operation reaction force set based on the operation signal in the virtual mode. The steering system according to claim 1.

3. The steering device includes an electric motor for steering wheels and a current sensor for detecting a current value of the control current input to the electric motor, and the controller is configured to extract a predetermined frequency component as the vibration component from a signal regarding the detection value received from the current sensor in the virtual mode. The steering system according to claim 1 or 2.

4. A band-pass filter that allows only signals in a predetermined allowable frequency band to pass through, an amplifier that amplifies the signal that has passed through the band-pass filter, further comprising, and the controller is 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 vibration component. The steering system according to claim 3.

5. The band-pass filter and the amplifier are each used in both the normal mode and the virtual mode, and the controller, in the normal mode, sets the allowable frequency band of the band-pass filter and the gain of the amplifier to values for the normal mode, respectively. configured to set the allowable frequency band of the band-pass filter and the gain of the amplifier to values for the virtual mode, respectively, in the virtual mode The steering system according to claim 4. **Claim 6** configured such that the controller sets the control current to 0 regardless of the operation signal in the virtual mode The steering system according to claim 1 or 2. **Claim 7** configured such that the controller supplies, to the steering device, a corrected control current obtained by adding an additional current value that increases and decreases at a predetermined frequency to the control current so that the wheels repeatedly steer left and right regardless of the operation signal in the virtual mode The steering system according to claim 1. **Claim 8** The controller is configured to receive an accelerator signal related to the operation of an accelerator operation member for an accelerator operation provided in the vehicle and a brake signal related to the operation of a brake operation member for a brake operation provided in the vehicle and sets the additional current value based on the accelerator signal or the brake signal in the virtual mode The steering system according to claim 7. **Claim 9** The controller is configured to receive an accelerator signal related to the operation of an accelerator operation member for an accelerator operation provided in the vehicle and a brake signal related to the operation of a brake operation member for a brake operation provided in the vehicle and is configured to set the operation reaction force based on the operation signal and the accelerator signal or the brake signal in the virtual mode The steering system according to claim 1, 2, 7, or 8. **Claim 10** configured such that the controller reduces the operation reaction force according to the accelerator signal corresponding to the forward movement of the virtual moving body in the virtual mode The steering system according to claim 9. **Claim 11** configured such that the controller increases the operation reaction force according to the brake signal during the forward movement of the virtual moving body in the virtual mode The steering system according to claim 9. **Claim 12** An operating device including an operating member for a steering operation by a user and a reaction force applying device that applies an operation reaction force to the operating member a steering device that is mechanically separated from the operating device and steers wheels according to a supplied control current A controller that controls the steering 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; A steer-by-wire type steering system including: the operation device including an operation member for a steering operation by a user and a reaction force applying device that applies an operation reaction force to the operation member; a steering device that is mechanically separated from the operation device and steers wheels according to a supplied control current; and a controller that controls the steering 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, and is configured to be able to switch between a normal mode of steering wheels based on the operation signal and a virtual mode of steering a virtual moving body created as an image based on the operation signal. In the virtual mode, the controller supplies the control current to the steering device so that the wheels repeatedly steer left and right regardless of the operation signal. In the virtual mode, the controller supplies the control current to the steering device so that the wheels repeatedly steer left and right regardless of the operation signal. Steering system.

13. In the virtual mode, the controller is configured to supply the control current to the steering device, which increases and decreases at a predetermined frequency. The steering system according to claim 12.

14. The controller is configured to: Receive an accelerator signal related to the operation of an accelerator operation member for an accelerator operation provided in the vehicle and a brake signal related to the operation of a brake operation member for a brake operation provided in the vehicle; In the virtual mode, supply the control current to the steering device so that the wheels repeatedly steer left and right based on the accelerator signal or the brake signal. The steering system according to claim 12 or 13.

15. An operation device including an operation member for a steering operation by a user and a reaction force applying device that applies an operation reaction force to the operation member; A steering device that is mechanically separated from the operation device and steers wheels according to a supplied control current; A controller that controls the steering 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; A steer-by-wire type steering system including: the operation device including an operation member for a steering operation by a user and a reaction force applying device that applies an operation reaction force to the operation member; a steering device that is mechanically separated from the operation device and steers wheels according to a supplied control current; and a controller that controls the steering 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, and is configured to be able to switch between a normal mode of steering wheels based on the operation signal and a virtual mode of steering a virtual moving body created as an image based on the operation signal. In the virtual mode, the controller is configured to: The controller is configured to: Receive an accelerator signal related to the operation of an accelerator operation member for an accelerator operation provided in the vehicle and a brake signal related to the operation of a brake operation member for a brake operation provided in the vehicle; In the virtual mode, Set the control current to a current value at which the wheels do not steer regardless of the operation signal. A steering system configured to set the operating reaction force based on the operation signal and the accelerator signal or the brake signal. Steering system.

16. The controller is configured to reduce the operating reaction force according to the accelerator signal corresponding to the forward movement of the virtual moving body in the virtual mode. The steering system according to claim 15.

17. The controller is configured to increase the operating reaction force according to the brake signal during the forward movement of the virtual moving body in the virtual mode. The steering system according to claim 15 or 16.

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