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 Unexamined Patent Application Publication No. 2022-1925 discloses a vehicle that can switch 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 a 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 game mode, the magnitude of the control current of the steering device's electric motor does not correspond to the road surface conditions in the game. Furthermore, since the vehicle is not actually traveling on the road in game mode, it is not possible to obtain information about the road surface conditions from the electric motor's control current. Therefore, in game mode, the control components are subjected to operating forces that do not reflect the road surface conditions. With operating forces that do not reflect the road surface conditions, it becomes difficult to give the user operating the control components a high level of realism.

[0006] Thus, conventional steering systems have room for improvement in terms of enhancing the sense of realism in games. The object of the present invention is to provide a steering system that can improve the sense of realism given to the user when the operating member is used in a game. [Means for solving the problem]

[0007] A steering system according to a first embodiment of the present invention is a steer-by-wire steering system comprising: an operating device including an operating member for steering operation by a user and a reaction force applying device for applying an operating reaction force to the operating member; a steering device mechanically separated from the operating device and steering the wheels in accordance with 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 operating member received from the operating device, wherein the system is 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 a video is steered based on the operation signal. Hereinafter, this configuration will also be referred to as the "basic configuration of the first embodiment." In the virtual mode, the controller of the first embodiment is configured to set the control current to a current value in which the wheels are not steered, regardless of the operation signal, and to set the operating reaction force based on a predetermined vibration component of the signal received from the steering device.

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

[0009] A steering system according to a third embodiment of the present invention is a steer-by-wire steering system having the same basic configuration as the first embodiment, wherein the controller is configured to receive an accelerator signal relating to the operation of an accelerator operating member for accelerator operation provided on the vehicle, and a brake signal relating to the operation of a brake operating member for brake operation provided on the vehicle. Furthermore, in the virtual mode, the controller is configured to set the control current to a current value that does not cause the wheels to steer, regardless of the operation signal, and to set the operating reaction force based on the operation signal and the accelerator signal or the brake signal. [Effects of the Invention]

[0010] According to the first embodiment of the present invention, in virtual mode, the control current supplied to the steering device is set to a value that does not cause the wheels to steer (e.g., 0). This suppresses unnecessary steering of the wheels caused by the operation of the operating member. Furthermore, the signals transmitted from the steering device (e.g., the control current detection signal) often contain noise. This noise contains waves of a certain frequency, i.e., vibration components. By reflecting these vibration components in the operating reaction force, the controller can convey the road surface conditions (roughness) to the user in a simulated manner through the operating reaction force. In other words, according to the first embodiment, the realism of the game is increased, and the sense of immersion given to the user in the game can be improved.

[0011] According to the second embodiment of the present invention, in virtual mode, the wheels can be made to vibrate slightly from side to side regardless of the operation of the operating member. This makes it possible to generate simulated vibrations in the vehicle that resemble vibrations of a moving vehicle, such as engine vibrations or vibrations caused by uneven road surfaces. According to the second embodiment, the realism of the game can be increased, and the sense of immersion given to the user in the game can be improved.

[0012] According to the third embodiment of the present invention, the effect of accelerator or brake operation on the wheels can be reflected in the operating reaction force. For example, when accelerator or brake operation is performed, the pitch angle of the vehicle changes, and the force (load) applied to the wheels also changes. In a configuration in which the operating member and the steering device are mechanically connected, when the force applied to the steering wheel changes, the feel of operating the operating member (steering force) also changes. According to the third embodiment, the change in the feel of operation due to the change in the force applied to the wheels can be expressed in the operating reaction force. In other words, according to the third embodiment, the realism of the game can be increased, and the sense of immersion given to the user in the game can be improved. [Brief explanation of the drawing]

[0013] [Figure 1] This is a diagram showing the configuration of the steering system of this embodiment. [Figure 2] This is a diagram illustrating the road surface simulation control of this embodiment. [Figure 3] This flowchart shows an example of road surface simulation control according to this embodiment. [Figure 4] This is a diagram illustrating the vehicle vibration control of this embodiment. [Figure 5] This flowchart shows an example of vehicle vibration control according to this embodiment. [Figure 6] This flowchart shows an example of pitch reaction force control according to this embodiment. [Figure 7] This is a conceptual diagram illustrating the signal flow of the steering system in this embodiment. [Modes for carrying out the invention]

[0014] Hereinafter, a steering system 1, which is one 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 embodiments described below. The steering system 1 of this embodiment is installed in an electric vehicle, for example. In-vehicle communication is performed, for example, by CAN (car area network or controllable area network), FlexRay, or Ethernet.

[0015] As shown in Figure 1, the steering system 1 comprises an operating device 2, a steering device 3, and a controller 4. In this embodiment, the operating device 2 comprises an operating member 20, a steering shaft 21, a steering column 22, an operating amount sensor 23, an operating torque sensor 24, and a reaction force applying device 25.

[0016] The operating member 20 is a steering wheel member for the user to operate the steering. The operating member 20 is, for example, a steering wheel. The shape of the operating member 20 is not limited to a circle like a steering wheel, but may also be a polygon, such as a square. The operating member 20 can also be called a steering operating member. The operating member 20 is fixed to the tip of the steering shaft 21. The operating member 20 and the steering shaft 21 are rotatably held in the instrument panel reinforcement by the steering column 22.

[0017] The operating amount sensor 23 is a sensor that detects the amount of operation (operating angle) of the operating member 20. The operating torque sensor 24 is a sensor that detects the operating torque of the operating member 20. The operating torque can also be described as the operating force applied by the user to the operating member 20. The operating torque sensor 24 detects, for example, the amount of twist of a torsion bar 27 incorporated into 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 to apply an operating reaction force for a 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 or the like. A rotation angle sensor 26a is provided in the reaction force motor 26.

[0019] The steering device 3 is a device that steers the wheels 11, 12 (front wheels or steering 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 a control current input to the steering motor 35. More specifically described, the steering device 3 includes a steering rod 31, a housing 32, a rod movement 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 movement 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 movement mechanism 33 mainly consists of a ball screw mechanism constituted by a ball groove screwed onto 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 movement mechanism 33 is 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 (amount of steering) 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 device 25 based on operation signals related to the operation of the operating member 20 received from the operating device 2. The controller 4 is a computer comprising one or more processors 41 and one or more memories 42. The computer can also be called an electronic control unit (ECU). The controller 4 is communicatively connected to the operating device 2 and the steering device 3. The operating device 2 and the steering device 3 are electrically connected via the controller. In other words, the steering system 1 is a steer-by-wire steering system that steers the vehicle by converting the mechanical operation of the operating member 20 by the user into electrical signals and transmitting these electrical signals to the steering device 3, which is mechanically separated from the operating member 20. Note that the controller 4 may consist of two or more communicatively connected computers. For example, the controller 4 may consist of a controller (computer) for the operating device 2 and a controller (computer) for the steering device 3.

[0024] (Control mode) The steering system 1 is configured to allow switching between a normal mode in which the wheels 11 and 12 are steered based on operation signals, and a virtual mode in which a virtual moving object 8a, created as a video, is steered based on operation signals. In other words, the steering system 1 has at least two control modes. The normal mode is a control mode for steering the vehicle based on the operation of the operating member 20. The virtual mode is a control mode in which a virtual moving object 8a (for example, a video of a vehicle) represented as a video in a game is operated by the operating member 20. The virtual moving object 8a is created as a video that can be viewed inside the vehicle. The normal mode can also be called, for example, the first mode, the main mode, or the real mode. The virtual mode can also be called, for example, the second mode, the sub-mode, or the game mode.

[0025] A display device 80 is located inside the vehicle. Examples of the display device 80 include an instrument panel display, a navigation system display, a windshield onto which images are projected, a mobile device display, AR glasses, or a head-mounted display. The game console 8 may be located inside the vehicle or may be located outside the vehicle by connecting to the vehicle via wireless communication. The game console 8 can be described as a computer equipped with one or more processors and one or more memories. The game console 8 and the controller 4 are connected so that they can communicate only predetermined information.

[0026] In virtual mode, the game console 8 displays a virtual mobile object 8a on the display device 80. The controller 4 transmits operation information read from the operation signals to the game console 8, and the game console 8 creates a display image of the virtual mobile object 8a on the display device 80 based on the operation information, and displays the steering status of the virtual mobile object 8a on the display device 80. In other words, in virtual mode, the user can steer the virtual mobile object 8a displayed on the display device 80 by operating the operation member 20.

[0027] Controller 4 switches between normal mode and virtual mode based on user operation (instructions). For example, if the user selects virtual mode using a mode selection means (e.g., an operation panel) provided in the vehicle, Controller 4 confirms that predetermined conditions are met and then switches the vehicle's control mode from normal mode to virtual mode. Similarly, Controller 4 switches the control mode from virtual mode to normal mode based on user operation of the operation panel, etc. Controller 4 turns on the change permission flag if the user has selected virtual mode and predetermined conditions are met. If the user has not selected virtual mode or predetermined conditions are not met, the change permission flag remains off. Virtual mode is a control mode intended for use when the vehicle is stationary, such as while the battery of an electric vehicle is charging, and the user is expected to play a game using the operating member 20.

[0028] (Details of normal mode) In normal mode, the controller 4 controls the steering motor 35 based on the detected value (detection signal) of the maneuver amount sensor 23. The controller 4 calculates the target steering angle from the detected value of the maneuver 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 normal mode, the controller 4 sets the operating reaction force on the operating member 20 based on the detected values ​​of the operating amount sensor 23 and the operating torque sensor 24, and controls the reaction force motor 26. The controller 4 supplies the reaction force motor 26 with a current (also called a reaction force current) corresponding to the set operating reaction force.

[0030] The controller 4 calculates the vehicle's lateral acceleration based on the vehicle speed and the values ​​detected by the steering angle sensor 36. The vehicle speed is calculated, for example, based on the values ​​detected by wheel speed sensors (not shown) provided on each wheel. The controller 4 calculates the wheel's self-aligning torque based on the values ​​detected by 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 wheel's steering angle. Various forces acting on the wheels may change depending on the vehicle speed. Therefore, in normal mode, the controller 4 reflects, for example, the vehicle speed, lateral acceleration, and self-aligning torque in the operating reaction force. The controller 4 also has an operating reaction force equivalent to the road surface resistance to wheel steering set as a basic reaction force.

[0031] The controller 4 sets the operating reaction force based on the value detected by the operating torque sensor 24. In order to keep the user's operating torque within a predetermined range, a force is required to assist the user's operation of the operating member 20, depending on the magnitude of the operating torque. Therefore, the controller 4 reduces the operating reaction force as the value detected by the operating torque sensor 24 increases, so that the operating torque is maintained within a predetermined range. Hereinafter, reaction force control based on the amount of operation of the operating member 20 and the operating torque, that is, reaction force control that takes into account self-aligning torque and assist force as an example, will also be 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 called the steering current or steering command value. If the angle difference does not decrease due to road surface conditions (e.g., unevenness) even after supplying the steering motor 35 with a control current corresponding to the angle difference, the controller 4 further increases the control current to increase the driving force of the steering motor 35. Depending on the road surface conditions, there may be cases where only the control current changes, while the angle difference does not change. In other words, fluctuations in the control current may be caused by road surface conditions. The controller 4 can detect these fluctuations in the control current and convey the road surface conditions to the user by reflecting the fluctuations in the control current in the operating reaction force. Hereinafter, reaction force control based on fluctuations in the control current, that is, reaction force control that takes road surface conditions (road noise) into consideration as an example, will also be referred to as "second reaction force control".

[0033] Thus, in normal mode, the controller 4 sets the operating reaction force of the operating member 20 so as to simulate 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 normal mode, the controller 4 performs first reaction force control, second reaction force control, and reaction force control (hereinafter also referred to as third reaction force control) that takes into account the vehicle speed and lateral acceleration on the reaction force applying device 25. Self-aligning torque is a force that acts in the direction of reducing the slip angle of the tire, and in a mechanically connected system, it is a force that tries to return the operated operating member 20 to its original position. Self-aligning torque increases in proportion to the increase in steering angle until the steering angle of the wheels 11 and 12 reaches a predetermined angle. For example, the controller 4 increases the operating reaction force in proportion to the increase in steering angle until the steering angle reaches a predetermined angle.

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

[0035] In virtual mode, the controller 4 sets the operating reaction force based on the operating signal. The operating signal is a signal relating to the detected value of the operating quantity sensor 23 and / or the detected value of the operating torque sensor 24. In other words, in virtual mode, the controller 4 performs first reaction force control on the reaction force applying device 25. For example, the controller 4 calculates the self-aligning torque based on the detected value of the operating quantity sensor 23 and reflects the calculated self-aligning torque in the operating reaction force. As a result, the larger the self-aligning torque, the larger the operating reaction force.

[0036] (1) Road surface simulation control in virtual mode In virtual mode, unlike normal mode, the vehicle does not actually travel on the road surface. Therefore, the road surface conditions do not change, and there are no fluctuations in the control current in response to the road surface conditions. As a result, the controller 4 cannot perform the second reaction force control and third reaction force control in virtual mode as it does in normal mode.

[0037] Therefore, the controller 4 is configured to set the operating reaction force based on a predetermined vibration component of the signal received from the steering device 3. The controller 4 in this embodiment is configured to reflect a predetermined vibration component of the signal received from the steering device 3 to the operating reaction force set based on the operating signal, that is, the operating reaction force set in the first reaction force control.

[0038] Hereinafter, the control that reflects a predetermined vibration component of the signal from the steering device 3 in response to the set operating reaction force will also be referred to as "road surface simulation control." The signal that the controller 4 receives from the steering device 3 can be various signals, but in this embodiment, it is the detected value (detection signal) of the current sensor 351. The vibration component can be described as the part of the time-series data of the magnitude of the value indicated by the signal where the value fluctuates (waveformly) at a certain frequency.

[0039] The value detected by the current sensor 351 contains random noise components. In this embodiment, the control current corresponding to the steering command value from the controller 4 to the steering motor 35 is set to 0. However, due to its configuration, noise is introduced into the circuit within the steering device 3, and the value detected by the current sensor 351 fluctuates slightly rather than remaining at the set value (0). The controller 4 utilizes these fine fluctuations in the value detected by the current sensor 351, i.e., the noise components, as vibration components for reaction force control.

[0040] In virtual mode, the controller 4 is configured to extract predetermined frequency components as vibration components from the signal related to the detected value received from the current sensor 351. As shown in Figure 2, the detection signal from the current sensor 351 is extracted as predetermined vibration components by passing through the bandpass filter 61 and the amplifier 62. The controller 4 reflects the signal extracted from the detection signal from the current sensor 351 by the bandpass filter 61 and the amplifier 62 as vibration components in the operating reaction force. In other words, 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 components. The controller 4 adds the value of the vibration components 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 bandpass filter 61 is a filter circuit that allows only signals within a predetermined frequency band (hereinafter also referred to as the permitted frequency band) to pass through. The bandpass filter 61 is configured to allow adjustment of the permitted frequency band. The controller 4 changes the permitted frequency band of the bandpass filter 61 according to the control mode so that the permitted frequency bands are different for 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] Amplifier 62 is a circuit that amplifies the magnitude of a signal, amplifying the input signal according to the set gain and outputting it. Controller 4 adjusts the gain of amplifier 62 according to the control mode so that the gains are different for normal mode and virtual mode. Controller 4 stores the gains for normal mode and virtual mode. In this way, controller 4 switches the parameter values ​​related to the signal (oscillating component) to be extracted according to the control mode. The bandpass filter 61 and amplifier 62 are used for both normal mode and virtual mode, respectively.

[0043] As an example of control, as shown in Figure 3, the controller 4 receives a change permission flag at a predetermined timing (S11). The predetermined timing may be, for example, periodic, or it may be after the user has performed an operation to change from normal mode to virtual mode. If the change permission flag is on (S12: Yes), the controller 4 sets the control mode to virtual mode. That is, the controller 4 sets the control current corresponding to the steering command value to 0, sets the permission frequency band of the bandpass filter 61 to a value for virtual mode, and sets the gain of the amplifier 62 to a value for virtual mode (S13).

[0044] If the change permission flag is off (S12: No), the controller 4 sets the control mode to normal mode. That is, the controller 4 sets the control current according to the operation signal, sets the permission frequency band of the bandpass filter 61 to the value for normal mode, and sets the gain of the amplifier 62 to the value for normal mode (S14).

[0045] According to the above configuration, in virtual mode, the steering prevention control sets the control current to a value (in this case, 0) that prevents the wheels 11 and 12 from steering. Therefore, unnecessary steering of the wheels 11 and 12 caused by the operation of the operating member 20 is suppressed. This suppresses tire deterioration and increased power consumption. In addition, the signal transmitted from the steering device 3 (for example, the detected value of the control current) often contains noise. Noise contains waves of a certain frequency, i.e., vibration components. The controller 4 reflects these vibration components in the operating reaction force, thereby simulating the road surface conditions (roughness) to the user through the operating reaction force. In other words, road surface simulation control can increase the realism of the game and improve the sense of immersion given to the user in the game.

[0046] Furthermore, when executing road surface simulation control, the controller 4 can utilize the configuration used in normal mode (for example, the bandpass filter 61 and amplifier 62). This allows for the suppression of increased manufacturing costs and the efficient use of the configuration. The steering system 1 described above is configured to use a common bandpass filter 61 and a common amplifier 62 in both normal mode and virtual mode. On the other hand, the steering system 1 may also include, for example, a normal route including a bandpass filter and amplifier for normal mode, and a virtual route including a bandpass filter and amplifier for virtual mode. In this case, the controller 4 selects the route through which the signal passes according to the control mode.

[0047] Furthermore, the controller 4 may perform road surface simulation control for an operating reaction force set by a method other than the operating reaction force set in the first reaction force control. In normal mode, the controller 4 performs the first reaction force control, the second reaction force control, and the third reaction force control. In virtual mode, the controller 4 performs, for example, steering prevention control, the first reaction force control, and road surface simulation control.

[0048] (2) Vehicle vibration control in virtual mode Controller 4 may supply a control current to the steering device 3 in virtual mode so that the wheels 11 and 12 repeatedly steer left and right, regardless of the operation signal (regardless of the operation of the operating member 20). This control is also called "vehicle vibration control". When vehicle vibration control is performed, similar to steering prevention control, the relationship between the operation signal and the control current is eliminated, and the control current is set so that the wheels 11 and 12 perform a predetermined operation. With vehicle vibration control, the wheels 11 and 12 can be made to vibrate slightly from side to side in virtual mode. This makes it possible to generate simulated vibrations in the vehicle that resemble vibrations of a moving vehicle, such as engine vibrations or vibrations caused by uneven road surfaces. With this configuration, the realism of the game can be increased, and the sense of immersion given to the user in the game can be improved.

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

[0050] When the controller 4 performs vehicle vibration control while performing steering prevention control, it supplies a corrective control current to the steering device 3, which is the control current set in the steering prevention control plus an additional current value that increases or decreases at a predetermined frequency, so that the wheels 11 and 12 repeatedly steer left and right regardless of the operation signal. As shown in Figure 4, in normal mode, the target steering angle is calculated from the operation signal, and the steering command value (current value of the control current) is set from the difference between the target steering angle and the actual steering angle. In the virtual mode steering prevention control, the current value of the control current, which is this steering command value, is set to 0. In the virtual mode vehicle vibration control, an additional current value that increases or 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 corrective control current that causes the wheels 11 and 12 to swing left and right is set, and the corrective control current is supplied to the steering motor 35.

[0051] As an example of control, as shown in Figure 5, the controller 4 receives a change permission flag at a predetermined timing (S21). If the change permission flag is on (S22: Yes), the controller 4 sets the control mode to virtual mode and performs vehicle vibration control (S23). If the change permission flag is off (S22: No), the controller 4 sets the control mode to normal mode and does not perform vehicle vibration control (S24).

[0052] The controller 4 may be configured to perform vehicle vibration control only at predetermined vibration timings. Examples of vibration timings in the virtual mode include the timing when the game actually starts, the timing when the virtual mobile body 8a is displayed on the display device 80, the timing when the accelerator operating member 71 is operated, or the timing when the brake operating member 72 is operated.

[0053] Controller 4 is configured to receive an accelerator signal relating to the operation of an accelerator operating member 71 provided in the vehicle for accelerator operation, and a brake signal relating to the operation of a brake operating member 72 provided in the vehicle for brake operation. The accelerator signal corresponds to, for example, the detected value of a sensor (not shown) that detects the amount of operation of the accelerator operating member 71. The brake signal corresponds to, for example, the detected value of a sensor (not shown) that detects the amount of operation of the brake operating member 72. In virtual mode, Controller 4 may be configured to set an additional current value based on the accelerator signal or the brake signal. This makes it possible to change the degree of vibration of the vehicle according to the degree of the user's accelerator operation or brake operation.

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

[0055] In virtual mode, the controller 4 performs, for example, steering prevention control, first reaction force control, and vehicle vibration control. In addition, the controller 4 may also perform road surface simulation control in virtual mode.

[0056] (3) Pitch reflection control in virtual mode Controller 4 may be configured in virtual mode to set the operating force based on the operation signal and either the accelerator signal or the brake signal. Control that sets the operating force based on the accelerator signal or the brake signal is also called "pitch reflection control". In virtual mode, the realism of the game is enhanced and the sense of immersion is improved by reflecting the user's accelerator and brake operations in the operating force.

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

[0058] In virtual mode, the controller 4 is configured to reduce the operating reaction force in response to the accelerator signal corresponding to the forward movement of the virtual mobile body 8a. When the vehicle moves forward due to accelerator operation, the pitch angle of the vehicle changes to an upward-sloping front, and the downward force applied to the front wheels 11 and 12 decreases. In this situation, in a mechanically connected system, the resistance of the road surface to steering the wheels 11 and 12 decreases, so the force required to operate the operating member 20 decreases. To represent this situation with the operating reaction force, the controller 4 reduces the operating reaction force in response to the forward accelerator signal.

[0059] In virtual mode, the controller 4 is configured to increase the operating reaction force in response to a brake signal while the virtual mobile body 8a is moving forward. When the brakes are applied while the vehicle is moving forward, the pitch angle of the vehicle changes to a downward slope, and the downward force applied to the front wheels 11 and 12 increases. In this situation, in a mechanically connected system, the resistance of the road surface to steering the wheels 11 and 12 increases, so the force required to operate the operating member 20 increases. To represent this situation with the operating reaction force, the controller 4 increases the operating reaction force in response to a brake signal while the vehicle is moving forward.

[0060] Controller 4 performs a front wheel load calculation to estimate the front wheel load based on the accelerator signal or brake signal. Controller 4 reflects the calculation result of the front wheel load calculation in the operating reaction force set by the first reaction force control. For example, 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 games, the virtual mobile object 8a is almost always configured to move forward when the accelerator is pressed. Therefore, in virtual mode, the controller 4 may perform the above reaction force control by considering the accelerator signal as acceleration of the virtual mobile object 8a forward and the brake signal as deceleration while the virtual mobile object 8a is moving forward. In other words, the controller 4 does not need to determine whether it is moving forward or not, or whether it is moving forward or not.

[0062] In virtual mode, controller 4 performs steering prevention control, first reaction force control, and pitch reaction force control. In addition, controller 4 may also perform road surface simulation control and / or vehicle vibration control in virtual mode.

[0063] Pitch reflection control may also be performed in normal mode. In this case, the controller 4 may switch the gain for front wheel load calculation between the normal mode gain and the virtual mode gain according to the control mode. For example, the larger the gain, the larger the range of variation in the calculation result (front wheel load) in the front wheel load calculation.

[0064] As an example of control, as shown in Figure 6, the controller 4 receives a change permission flag at a predetermined timing (S31). If the change permission flag is on (S32: Yes), the control mode is set to virtual mode, the gain of the front wheel load calculation is changed to a value for virtual mode, and for example, the first reaction force control and pitch reflection control are executed (S33). If the change permission flag is off (S32: No), the control mode is set to normal mode, the gain of the front wheel load calculation is changed to a value for normal mode, and for example, the first reaction force control, second reaction force control, third reaction force control, and pitch reflection control are executed (S34). The gain of the front wheel load calculation may be changed according to the accelerator operation amount and brake operation amount.

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

[0066] In virtual mode, the controller 4 can simultaneously or independently perform, for example, first reaction force control, steering prevention control, road surface simulation control, vehicle vibration control, and pitch reflection control. Thus, the various controls of this disclosure can be combined with each other as appropriate. The steering system 1 of this embodiment has at least one configuration in virtual mode, which includes (1) a configuration for performing steering prevention control and road surface simulation control, (2) a configuration for performing vehicle vibration control, and (3) a configuration for performing steering prevention control, first reaction force control, and pitch reflection control. If the controller 4 can obtain speed information of the virtual mobile body 8a in the game from the game machine 8, it may set the operating reaction force based on that vehicle speed information, i.e., perform third reaction force control. The game machine 8 may function, for example, as a simulator for driving training. Furthermore, the technology of this disclosure can be applied to mobile bodies other than electric vehicles. The game machine 8 and CAN (and / or controller 4) can communicate predetermined information to each other. [Explanation of Symbols]

[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...Bandpass 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 steering operation by the user and a reaction force applying device for applying an operating reaction force to the operating member, A steering device, which is mechanically separated from the aforementioned operating device and steers the wheels in accordance with the 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 operating member received from the operating device, A steer-by-wire steering system comprising a normal mode in which the wheels are steered based on the operation signal and a virtual mode in which a virtual moving object created as a video is steered based on the operation signal, wherein the system is configured to be switchable between these modes, In the virtual mode, the controller Regardless of the aforementioned operation signal, the control current is set to a value such that the wheels do not steer. The system is configured to set the operating reaction force based on a predetermined vibration component among the signals received from the steering device. Steering system.

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

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

4. A bandpass filter that allows only signals within a predetermined permitted frequency band to pass through, An amplifier that amplifies the signal that has passed through the bandpass filter, Furthermore, The controller is configured to set the operating reaction force using the detection signal from the current sensor, which has passed through the bandpass filter and the amplifier, as the vibration component. The steering system according to claim 3.

5. The bandpass filter and the amplifier are used in both the normal mode and the virtual mode, respectively. The aforementioned controller In the normal mode, the permitted frequency band of the bandpass filter and the gain of the amplifier are set to the values ​​for the normal mode, In the virtual mode, the allow frequency band of the bandpass filter and the gain of the amplifier are configured to be set to values ​​for the virtual mode, The steering system according to claim 4.

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

7. The controller supplies a corrective control current to the steering device, which is the control current plus an additional current value that increases or decreases at a predetermined frequency, so that the wheels repeatedly steer left and right in the virtual mode, regardless of the operation signal. The steering system according to claim 1.

8. The aforementioned controller It is configured to receive an accelerator signal relating to the operation of an accelerator operating member for operating the accelerator on the vehicle, and a brake signal relating to the operation of a brake operating member for operating the brakes on the vehicle. In the virtual mode, the additional current value is set based on the accelerator signal or the brake signal. The steering system according to claim 7.

9. The aforementioned controller It is configured to receive an accelerator signal relating to the operation of an accelerator operating member for operating the accelerator on the vehicle, and a brake signal relating to the operation of a brake operating member for operating the brakes on the vehicle. In the virtual mode, the operating reaction force is set based on the operating signal and the accelerator signal or the brake signal. The steering system according to claim 1, 2, 7, or 8.

10. The controller is configured to reduce the operating reaction force in the virtual mode in response to the accelerator signal corresponding to the forward movement of the virtual moving body. The steering system according to claim 9.

11. The controller is configured to increase the operating reaction force in the virtual mode in response to the brake signal while the virtual moving body is moving forward. The steering system according to claim 9.

12. An operating device including an operating member for steering operation by the user and a reaction force applying device for applying an operating reaction force to the operating member, A steering device, which is mechanically separated from the aforementioned operating device and steers the wheels in accordance with the 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 operating member received from the operating device, A steer-by-wire steering system comprising a normal mode in which the wheels are steered based on the operation signal and a virtual mode in which a virtual moving object created as a video is steered based on the operation signal, wherein the system is configured to be switchable between these modes, The controller supplies the control current to the steering device such that, in the virtual mode, the wheels repeatedly steer left and right regardless of the operation signal. Steering system.

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

14. The aforementioned controller It is configured to receive an accelerator signal relating to the operation of an accelerator operating member for operating the accelerator on the vehicle, and a brake signal relating to the operation of a brake operating member for operating the brakes on the vehicle. In the virtual mode, the control current is supplied 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 operating device including an operating member for steering operation by the user and a reaction force applying device for applying an operating reaction force to the operating member, A steering device, which is mechanically separated from the aforementioned operating device and steers the wheels in accordance with the 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 operating member received from the operating device, A steer-by-wire steering system comprising a normal mode in which the wheels are steered based on the operation signal and a virtual mode in which a virtual moving object created as a video is steered based on the operation signal, wherein the system is configured to be switchable between these modes, The aforementioned controller It is configured to receive an accelerator signal relating to the operation of an accelerator operating member for operating the accelerator on the vehicle, and a brake signal relating to the operation of a brake operating member for operating the brakes on the vehicle. In the aforementioned virtual mode, Regardless of the aforementioned operation signal, the control current is set to a value such that the wheels do not steer. The system is configured to set the operating reaction force based on the aforementioned operating signal and the accelerator signal or the brake signal. Steering system.

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

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

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