Steering wheel control method and system for steer-by-wire and vehicle

Abstract

The invention relates to a steering wheel control method and system for steer-by-wire and a vehicle, and the method comprises the steps that the driving intention of a driver is obtained, the driving intention comprises auxiliary driving and getting-on and getting-off assistance, and a preset driving mode is started based on the driving intention; based on steering wheel data, preset locking torque is obtained, a force sense feedback driving motor is controlled to apply the preset locking torque to a steering wheel so as to lock the steering wheel, and the steering wheel data comprises the rotating angle of the steering wheel when the preset driving mode is started; when the driving intention is aided driving, the preset driving mode is an aided driving mode, and the preset locking moment is a first locking moment; when the driving intention is getting-on and getting-off assistance, the preset driving mode is a getting-on and getting-off assistance mode, and the preset locking moment is a second locking moment; the first locking moment is smaller than the second locking moment. The problems that the overall layout of a cockpit is affected and the occupied space and the cost are increased due to the fact that the steering wheel is locked by adding an additional mechanical structure in the prior art can be solved.

Description

Technical Field

[0001] The present application relates to the technical field of wire-controlled steering, and in particular to a steering wheel control method, system and vehicle for wire-controlled steering. Background Art

[0002] With the advancement of vehicle chassis technology, steer-by-wire (SWI) has also begun to be used in vehicles. In steer-by-wire vehicles, the steering wheel and steering wheel are connected only by communication lines, with no physical mechanical connection. When a steering command is issued through the steering wheel, the steering wheel angle is converted into a steering wheel angle and then transmitted via communication lines to the steering wheel actuator mechanism to complete the steering action. This execution method allows for more flexible control strategies and diverse driving modes.

[0003] Historically, traditional steering wheels have provided support to the driver through mechanical connections. This support is derived from wheel-ground friction. Because traditional steering wheels are mechanically connected, the upward rotation (steering wheel) completely follows the downward rotation (steering wheel), transferring the friction generated by wheel-ground friction to the steering wheel through the mechanical structure. This additional support helps drivers enter and exit the vehicle more effectively.

[0004] However, the steer-by-wire system lacks a mechanical connection. If the driver still holds the steering wheel when getting in and out of the vehicle, an angle difference between the steering wheel and the steering wheel will inadvertently appear, causing uncertainty in the driver's response to the vehicle and the position of the steering wheel.

[0005] For the driver, under the wire-controlled steering structure, the steering wheel is allowed to remain independent and not rotate in the assisted driving state, that is, it does not rotate with the steering wheel. However, since there is no mechanical connection mechanism, it is also necessary to ensure that the steering wheel does not shake abnormally at a small angle to avoid negative impacts on the driver due to steering wheel deflection or shaking during the assisted driving process.

[0006] Considering the above two scenarios, when getting on and off the vehicle, the steering wheel needs to be provided with a larger locking support torque so that the steering wheel can assist the driver in getting on and off the vehicle. When assisting driving, the steering wheel needs to be provided with a smaller locking fixing torque to prevent the steering wheel from deflecting or shaking and causing negative effects on the driver, so as to improve user confidence.

[0007] A currently mature solution uses a mechanical locking mechanism, restricting the steering wheel from locking via a mechanical latch and locking mechanism. However, this solution typically requires additional mechanical structure, which impacts the overall cockpit layout and requires high material requirements, increasing costs. Another solution involves a brake motor gripping the upper motor rotor to increase rotational friction, while providing support through a mechanical connection between the upper motor and the steering wheel. This solution also requires additional mechanical structure, resulting in an excessively large force feedback unit. Summary of the Invention

[0008] Embodiments of the present application provide a steering wheel control method, system, and vehicle for steer-by-wire to address the problem in related technologies of adding additional mechanical structures to lock the steering wheel, which affects the overall layout of the cockpit and increases space occupancy and costs.

[0009] In a first aspect, a steering wheel control method for steer-by-wire is provided, comprising: Obtaining a driver's driving intention and activating a preset driving mode based on the driving intention, wherein the driving intention includes assisted driving and vehicle entry and exit assistance; Based on steering wheel data, obtaining a preset locking torque, and controlling a force feedback drive motor to apply the preset locking torque to the steering wheel to lock the steering wheel, wherein the steering wheel data includes a steering angle of the steering wheel when a preset driving mode is activated; Wherein, when the driving intention is assisted driving, the preset driving mode is the assisted driving mode, and the preset locking torque is the first locking torque; When the driving intention is to assist in getting on and off the vehicle, the preset driving mode is the getting on and off assist mode, and the preset locking torque is the second locking torque; the first locking torque is smaller than the second locking torque.

[0010] In some embodiments, obtaining the driver's driving intention specifically includes: Receive driving signals, including assisted driving switch status, assisted driving wake-up voice, assisted driving wake-up gesture, ready signal, main driving door switch status, gear status and vehicle speed; If the driving signal includes one or more of the following: the assisted driving switch is in the on state, the assisted driving wake-up voice, and the assisted driving wake-up gesture, then the driving intention is assisted driving; If the driving signal includes a Ready signal in the stop state, a main driving door changing from closed to open, a gear in the P gear and a vehicle speed of 0, then the driving intention is to assist in getting on and off the vehicle.

[0011] In some embodiments, obtaining a preset locking torque based on steering wheel data specifically includes: using the steering wheel angle when the preset driving mode is activated as a target steering wheel angle when the steering wheel is locked, and obtaining an angle difference between the actual steering wheel angle and the target steering wheel angle; The preset locking torque is obtained based on the rotation angle difference.

[0012] In some embodiments,

[0013] in, For the The preset locking torque applied to the steering wheel at a certain moment, =1, 2....; For The proportionality coefficient related to the error; For the The angle difference between the actual steering wheel angle at a certain moment and the target angle; Shielding coefficient to shield noise and reduce overshoot recovery time; For The integral coefficient related to the historical accumulation of errors; For The differential coefficient associated with the change in error.

[0014] In some embodiments, when hour, =1, when hour, =0; and / or when When it is less than the set dead zone, =0; and / or when hour, =0.

[0015] In some embodiments, the steering wheel data further includes steering wheel speed; The method further comprises: The preset locking torque is corrected based on the steering wheel speed, and the corrected preset locking torque is used as the preset locking torque that is finally output.

[0016] In some embodiments,

[0017] in, is the preset locking torque of the final output, is the steering wheel speed gain value in the preset driving mode, For the The speed of the steering wheel at that moment.

[0018] In some embodiments, when the preset driving mode is the vehicle entry and exit assist mode, the steering wheel data further includes log data for steering wheel failure, and the log data includes one or more of a steering wheel angle log and a steering wheel speed log; Based on the steering wheel data, the preset locking torque is obtained, including: receiving and reading the log data; determining whether a temporary steering wheel failure occurs based on the log data; If no temporary steering wheel failure occurs, the steering wheel angle at which the preset driving mode is activated is used as the target steering wheel angle for locking the steering wheel, and the angle difference between the actual steering wheel angle and the target steering wheel angle is obtained; and the preset locking torque is obtained based on the angle difference; If a temporary steering wheel failure occurs, a basic locking torque is obtained based on the steering wheel hand torque, and the basic locking torque is used as the preset locking torque.

[0019] In some embodiments,

[0020] in, is the basic locking torque, is the steering wheel hand torque gain value when a temporary steering wheel failure occurs, is the steering wheel hand torque.

[0021] In some embodiments, the preset driving mode is an assisted driving mode. After starting the preset driving mode, the method further includes: Receive driving signals; If the driving signal includes an assisted driving exit signal or an emergency takeover signal, the assisted driving mode is exited and the steering wheel is unlocked.

[0022] In some embodiments, the preset driving mode is a vehicle entry and exit assistance mode. After activating the preset driving mode, the method further includes: Receive driving signals; If the driving signal includes that the driver's seat is empty, the driver's door is closed and remains closed for a preset period of time, or a vehicle lock signal is received, the vehicle entry and exit assistance mode is exited and the steering wheel is unlocked.

[0023] In some embodiments, the preset driving mode is a vehicle entry and exit assistance mode. After activating the preset driving mode, the method further includes: Receive driving signals; If the driving signal includes that the driver's seat is occupied and the driver's door changes from open to closed, the boarding and exiting assist mode is exited and the steering wheel is unlocked.

[0024] In some embodiments, the preset driving mode is a vehicle entry and exit assistance mode. After activating the preset driving mode, the method further includes: If the driving signal further includes at least one of the gear position not being P, the vehicle speed not being 0, and the Ready signal not being in the stop state, the vehicle entry and exit assist mode is exited and the steering wheel is unlocked.

[0025] In a second aspect, a steering wheel control system for steer-by-wire is provided, comprising: A driving intention acquisition module, which is used to: acquire the driver's driving intention and activate a preset driving mode based on the driving intention, wherein the driving intention includes assisted driving and boarding and exiting assistance; a torque control module configured to obtain a preset locking torque based on steering wheel data, and control a force feedback drive motor to apply the preset locking torque to the steering wheel to lock the steering wheel, wherein the steering wheel data includes a steering wheel angle when a preset driving mode is activated; Wherein, when the driving intention is assisted driving, the preset driving mode is the assisted driving mode, and the preset locking torque is the first locking torque; When the driving intention is to assist in getting on and off the vehicle, the preset driving mode is the getting on and off assist mode, and the preset locking torque is the second locking torque; the first locking torque is smaller than the second locking torque.

[0026] According to a third aspect, a vehicle is provided, comprising the steering wheel control system for steer-by-wire as described above.

[0027] The beneficial effects of the technical solution provided by this application include: The embodiments of the present application provide a steering wheel control method, system and vehicle for wire-controlled steering. The present application is optimized at the software level. After activating the preset driving mode, the required locking torque is obtained based on the steering wheel angle when the preset driving mode is started, and the locking torque is applied to the steering wheel by controlling the force feedback drive motor to meet the steering wheel locking requirements of wire-controlled steering vehicles in assisted driving and boarding and exiting assistance scenarios. This solves the problem in related technologies of adding additional mechanical structures to lock the steering wheel, which affects the overall layout of the cockpit and increases space occupancy and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0029] Figure 1 A flow chart of a steering wheel control method for steer-by-wire provided in an embodiment of the present application; Figure 2 A schematic diagram of the steering wheel angle PID closed-loop control provided in an embodiment of the present application; Figure 3 A schematic diagram of mode switching provided in an embodiment of the present application; Figure 4 A block diagram of a steering wheel control system for steer-by-wire provided in an embodiment of the present application. DETAILED DESCRIPTION

[0030] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0031] See also Figure 1 As shown, an embodiment of the present application provides a steering wheel control method for steer-by-wire, which includes the following steps: 101: Obtain the driver's driving intention, and start a preset driving mode based on the driving intention.

[0032] In this application, the driver's driving intention mainly includes assisted driving and on-and-off assistance. Correspondingly, when the driving intention is assisted driving, the preset driving mode is the assisted driving mode, and when it is determined that the driver needs assisted driving, the assisted driving mode is started.

[0033] When the driving intention is to assist in getting on and off the vehicle, the preset driving mode is the getting on and off assist mode. Similarly, when it is determined that the driver needs to perform getting on and off assistance, the getting on and off assist mode is activated.

[0034] By judging the driving intention, the function of the corresponding driving mode is activated.

[0035] It is understandable that with the rapid development of intelligent connected vehicle technology, assisted driving has become an important development direction for the automotive industry. According to internationally recognized standards, autonomous driving can be divided into six levels: L0 to L5, with higher levels indicating a higher degree of automation. In this application, assisted driving is achieved based on the advanced driver assistance system (ADAS) installed on the vehicle. In this application, the advanced driver assistance system (ADAS) can achieve at least L1 level assisted driving, but it does not rule out that the advanced driver assistance system (ADAS) in this application can achieve L2 level or even higher level assisted driving.

[0036] 102: Based on the steering wheel data, a preset locking torque is obtained, and the force feedback drive motor is controlled to apply the preset locking torque to the steering wheel to lock the steering wheel, wherein the steering wheel data includes the steering wheel angle when the preset driving mode is started; wherein, when in the assisted driving mode, a first locking torque is applied to the steering wheel; when in the boarding and exiting assist mode, a second locking torque is applied to the steering wheel, and the first locking torque is less than the second locking torque.

[0037] In an embodiment of the present application, by obtaining the driver's driving intention, it is first determined whether the driver requires assisted driving or entry and exit assistance. For different preset driving modes, the required locking force is calculated based on the steering wheel angle when the preset driving mode is activated. Finally, the corresponding locking force is applied to the steering column of the steering wheel via a force feedback drive motor, thereby locking the steering wheel. During the steering wheel locking period, the steering wheel in the assisted driving mode is in a silent locking state and does not deflect or vibrate with the steering wheel, effectively reducing the negative impact of steering wheel deflection or vibration on the driver during assisted driving and optimizing the driver's riding experience. The steering wheel in the entry and exit assistance mode is in an auxiliary locking state, effectively preventing the steering wheel from accidentally rotating under external forces, providing support for the driver when entering and exiting the vehicle, and better assisting the driver in entering and exiting the cockpit.

[0038] At the same time, because the assisted driving mode also involves an emergency takeover situation, it is necessary to ensure that the driver can turn the steering wheel in this situation. Therefore, in the embodiment of the present application, the first locking torque applied to the steering wheel in the assisted driving mode is smaller than the second locking torque applied to the steering wheel in the vehicle entry and exit assistance mode. During vehicle entry and exit assistance, a larger locking support torque is provided to the steering wheel to enable the steering wheel to assist the driver in getting on and off the vehicle. However, during assisted driving, a smaller locking fixed torque is provided to the steering wheel to prevent steering wheel deflection or vibration from negatively impacting the driver, while also ensuring that the driver can turn the steering wheel in an emergency takeover situation, thereby enhancing user confidence.

[0039] It can be seen that the present application is optimized at the software level. After activating the preset driving mode, the required locking torque is obtained based on the steering wheel angle when the preset driving mode is started, and the locking torque is applied to the steering wheel by controlling the force feedback drive motor to meet the steering wheel locking requirements of the wire-controlled steering vehicle in assisted driving and boarding and exiting assistance scenarios. It solves the problem in the related technology that locking the steering wheel by adding additional mechanical structures will affect the overall layout of the cockpit and increase space occupancy and cost.

[0040] The driver's driving intention can be determined based on the driving signal. For example, obtaining the driver's driving intention specifically includes the following steps: 201: Receive a driving signal, where the driving signal includes an assisted driving switch status, an assisted driving wake-up voice, an assisted driving wake-up gesture, a ready signal, a main driving door switch status, a gear status, and a vehicle speed.

[0041] 202: If the driving signal includes one or more of the assisted driving switch being on, the assisted driving wake-up voice, and the assisted driving wake-up gesture, then the driving intention is assisted driving.

[0042] For example, as an example, the driving signal determined to be in assisted driving mode may be an instruction actively triggered by the driver. The driving signal includes the assisted driving switch status, assisted driving wake-up voice or assisted driving wake-up gesture. For example, the driver can trigger the above-mentioned assisted driving signal by triggering the assisted driving switch to turn on the assisted driving switch.

[0043] Alternatively, the driver can also trigger the assisted driving signal by issuing an assisted driving wake-up voice or drawing an assisted driving wake-up gesture or other forms with his hand at a preset location (such as the central control screen).

[0044] The above driving signals are sent by the host computer or the auxiliary driving module and can thus be directly obtained.

[0045] 203: If the driving signal includes the Ready signal being in the stop state, the main driving door being opened from closed, the gear being in the P gear and the vehicle speed being 0, then the driving intention is to assist in getting on and off the vehicle.

[0046] For example, as an example, the determination of the boarding and exiting assist mode is obtained by pre-set conditions, and the pre-set conditions include a Ready signal, a main vehicle door switch state, a gear state, a vehicle speed, and the like.

[0047] When the Ready signal is in the stop state, the main driving door is opened from closed to open, the gear is in P gear and the vehicle speed is 0, the driving intention is determined to be boarding and exiting assistance.

[0048] Understandably, the Ready sign typically appears on new energy or hybrid vehicles. It's located in the instrument cluster, typically above the tachometer. This is a startup status light unique to new energy electric vehicles. The Ready signal indicates whether the main battery (i.e., the power battery) is powered and operational. When the Ready signal is in the "stop" state, it indicates the main battery is not powered. When the Ready signal is in the "running" state, it indicates the main battery is powered, indicating that the vehicle is fully prepared, has successfully started, and is ready to go.

[0049] It is understandable that the door switch status can be monitored by a door sensor, the gear position status can be monitored by a gear position sensor, and the vehicle speed can be monitored by a vehicle speed sensor.

[0050] When entering the assisted driving mode or the vehicle entry and exit assistance mode, the present application performs PID closed-loop control through the steering wheel angle. Specifically, based on the steering wheel data, the preset locking torque is obtained, including the following steps: 301: Using the steering wheel angle when the preset driving mode is activated as the target steering wheel angle when the steering wheel is locked, and obtaining the steering wheel angle difference between the actual steering wheel angle and the target steering wheel angle.

[0051] 302: Obtain the preset locking torque based on the rotation angle difference.

[0052] In this embodiment, the steering wheel angle when the preset driving mode is started is used as the target angle when the steering wheel is locked, the preset locking torque is calculated in real time, and the PID closed-loop control method is used to ensure that the steering wheel is always at the target angle during the preset driving mode, thereby meeting the steering wheel locking requirements of steer-by-wire vehicles in assisted driving and boarding and exiting assistance scenarios. In addition, it should be noted that this application uses the steering wheel angle when the preset driving mode is started as the target angle when the steering wheel is locked, and focuses on keeping the steering wheel stable, so that the driver's safety can be guaranteed regardless of assisted driving or boarding and exiting assistance.

[0053] Specifically, see Figure 2 As shown, the preset locking torque is calculated by PID closed-loop control, which can be seen in the following formula (1): (1) in, For the The preset locking torque applied to the steering wheel at a certain moment, in N·m, =1, 2....; For The proportionality coefficient related to the error is in N·m / °; For the The steering wheel angle can be monitored by an angle sensor.

[0054] The shielding coefficient is dimensionless, which is used to shield noise and reduce overshoot recovery time. For The integral coefficient related to the historical accumulation of error, the unit is N·m / °; For The differential coefficient related to the change in error, in N·m / °.

[0055] The above-mentioned coefficients are all custom values obtained through experience during the debugging process.

[0056] Among them, when hour, =1, when hour, =0, by Assigning values is used to effectively avoid overshoot caused by excessive integration. Customize values based on experience gained during debugging. While the car is parked, you can adjust parameters by pulling the steering wheel to control the steering range and speed. While driving, observe the steering wheel's behavior over bumpy roads and other road conditions, adjusting parameters to control steering wheel wobbling.

[0057] At the same time, the integral part is controlled by dead zone, overshoot integral is cleared and saturation is controlled to avoid abnormal integral caused by noise, which in turn causes the integral part to output abnormal values. When it is less than the set dead zone, = 0. By setting it to 0, you can avoid the integral part from outputting abnormal values.

[0058] To reduce the overshoot recovery time, hour, =0. That is, when The symbol and When the signs of are opposite, Set to 0 to speed up the reset after overshoot.

[0059] The above-mentioned dead zone setting is an empirically customized value during the debugging process.

[0060] In order to avoid abnormal feel caused by steering wheel shaking and rotating too fast, the present application further corrects the preset locking torque. Specifically, the steering wheel data also includes the steering wheel speed; the method also includes: based on the steering wheel speed, correcting the preset locking torque, and using the corrected preset locking torque as the final output preset locking torque.

[0061] Specifically, the preset locking torque is corrected as shown in the following formula (2): (2) in, is the preset locking torque of the final output, in N·m. The steering wheel speed gain value in the preset driving mode is in N·m·s / °, which is the custom value experienced during the debugging process. For the The speed of the steering wheel at that moment, in degrees / s.

[0062] It is understandable that since the first locking torque corresponding to the assisted driving mode is smaller than the second locking torque corresponding to the vehicle entry and exit assist mode, and the two are obtained using the same formula, in order to achieve the first locking torque being smaller than the second locking torque, the assisted driving mode is 、 、 and With the entry and exit assist mode 、 、 and There is a difference in size, that is, using 、 、 and The locking torque in the assisted driving mode and the vehicle entry and exit assist mode is adjusted so that the first locking torque is smaller than the second locking torque.

[0063] A correction torque based on the steering wheel speed is added to the torque after PID control to avoid abnormal feel caused by steering wheel shaking and excessive speed.

[0064] The rotation speed of the steering wheel can be monitored using a rotation speed sensor.

[0065] Furthermore, when the preset driving mode is the vehicle entry and exit assist mode, the steering wheel data further includes log data for steering wheel failure, and the log data includes one or more of a steering wheel angle log and a steering wheel speed log; Based on the steering wheel data, the preset locking torque is obtained, including: 401: Receive and read the log data.

[0066] 402: Determine whether a temporary steering wheel failure occurs based on the log data.

[0067] The above log data can be represented by assignments. For example, if the steering wheel angle is valid, it indicates that the steering wheel angle sensor is functioning properly, and the steering wheel angle log is assigned a value of 1. If the steering wheel angle is invalid, it indicates that the steering wheel angle sensor is abnormal, and the steering wheel angle log is assigned a value of 0. Similarly, if the steering wheel speed is valid, it indicates that the steering wheel speed sensor is functioning properly, and the steering wheel speed log is assigned a value of 1. If the steering wheel speed is invalid, it indicates that the steering wheel speed sensor is abnormal, and the steering wheel speed log is assigned a value of 0. By reading the assignments of the steering wheel angle log and the steering wheel speed log, if at least one of the assignments is 0, the log data is invalid, and a temporary steering wheel failure can be assumed. Otherwise, no temporary steering wheel failure can be assumed.

[0068] 403: If no temporary steering wheel failure occurs, the steering wheel angle when the preset driving mode is activated is used as the target steering wheel angle for locking the steering wheel, and the angle difference between the actual steering wheel angle and the target steering wheel angle is obtained; based on the angle difference, the preset locking torque is obtained; 404: If a temporary steering wheel failure occurs, a basic locking torque is obtained based on the steering wheel hand torque, and the basic locking torque is used as the preset locking torque.

[0069] In steps 403-404, after entering the vehicle entry and exit assist mode, it is first determined whether a temporary steering wheel failure occurs, and different locking strategies are executed according to the determination result.

[0070] Specifically, in combination with the above formula (1) and formula (2), it can be seen that since the steering wheel angle and steering wheel speed are introduced when calculating the preset locking torque, the above angle and speed are valid when no temporary steering wheel failure occurs. Therefore, the steering wheel angle when the preset driving mode is started can be used as the target angle when the steering wheel is locked, and the angle difference between the actual steering wheel angle and the target angle is obtained; based on the angle difference, the preset locking torque is obtained.

[0071] However, in the event of a temporary steering wheel failure, the above-mentioned angle and speed are invalid, and the preset locking force cannot be calculated using the above-mentioned formulas (1) and (2). In this case, the preset locking torque can be obtained based on the steering wheel hand torque.

[0072] Specifically, see the following formula (3): (3) in, is the basic locking torque, in N·m, is the steering wheel hand torque gain value when a temporary steering wheel failure occurs. It is dimensionless and is an experience-defined value during the debugging process. is the steering wheel hand torque, in N·m.

[0073] The above-mentioned steering wheel hand torque can be monitored using a sensor.

[0074] By monitoring the steering wheel hand torque, the basic locking torque is calculated, and the basic locking torque is applied to the steering column of the steering wheel as the preset locking torque, thereby locking the steering wheel.

[0075] In this embodiment, when the boarding and exiting assistance mode is activated but a temporary fault occurs, the basic locking torque is calculated using the steering wheel hand torque to obtain a preset locking torque, and the steering wheel is locked as a transitional locking state to provide support for the driver to assist the driver in boarding and exiting the vehicle. It can be seen that this embodiment is actually a redundant backup for the steering wheel in the auxiliary locking state in the boarding and exiting assistance mode. By adding backup redundancy measures, the driver is avoided from physical injury.

[0076] It is understandable that the above-mentioned log data also includes a motor status log reflecting the status of the force feedback drive motor. After entering the boarding and exiting assistance mode, a motor status log reflecting the status of the force feedback drive motor will be received. If the force feedback drive motor is normal, the motor status log is assigned a value of 1. If the force feedback drive motor is mechanically damaged or burned, the motor status log is assigned a value of 0.

[0077] If the motor status log value is 1, the system proceeds to step 402. Alternatively, the system can choose to calculate the preset locking torque and execute locking according to step 403 until the vehicle entry and exit assistance is completed and the system exits normally. Alternatively, the system can choose to calculate the preset locking torque and execute locking according to step 404 until the vehicle entry and exit assistance is completed and the system exits normally. If the motor status log value is 0, the motor is mechanically damaged or burned out, resulting in a permanent fault and an unrecoverable error state. A prompt will be displayed indicating that hardware repair is required.

[0078] Similarly, in step 404, after entering the transitional locking state, if the motor status log value is 1, the preset locking torque is calculated and locked according to step 404 until the entry and exit assistance is completed and the vehicle exits normally. If the motor status log value is 0, the motor is mechanically damaged or burned out, resulting in a permanent fault and entering an unrecoverable error state, prompting a hardware repair request.

[0079] See also Figure 3 As shown, after initialization, log data will also be received and read, including vehicle speed status, vehicle speed, steering wheel torque status, seat signal, main driver door switch signal, gear signal, Ready signal, steering wheel speed status, steering wheel angle status, etc.

[0080] The above log data can be monitored by relevant sensors. If a temporary fault occurs, the corresponding log value is assigned to 0. If it is normal, the corresponding log value is assigned to 1.

[0081] By reading the log data, it is determined whether a temporary fault has occurred. If at least one log value is 0, it indicates that a temporary fault has occurred and the system enters a recoverable error state and can jump to a waiting state. If a permanent fault further occurs, the system enters an unrecoverable error state and prompts that hardware maintenance is required.

[0082] After initialization, if the status is judged to be normal, it enters the waiting state. If a permanent fault occurs in the waiting state, it enters the unrecoverable error state, and it will prompt that hardware maintenance is required. If a temporary fault occurs, it can enter the recoverable error state and jump to the waiting state again. Based on the above steps 101-102, the function is activated, jumping to the assisted driving mode or the boarding and exiting assist mode, and the corresponding locking strategy is performed.

[0083] After the corresponding function is activated, you can exit the function and enter the waiting state again.

[0084] Among them, the function exit of the assisted driving mode and the function exit of the boarding and exiting assistance mode are controlled by different strategies.

[0085] With respect to the assisted driving mode, specifically, the preset driving mode is the assisted driving mode. After starting the preset driving mode, the method further includes: 501: Receive driving signal.

[0086] 502: If the driving signal includes an assisted driving exit signal or an emergency takeover signal, exit the assisted driving mode and unlock the steering wheel.

[0087] For example, as an example, the assisted driving exit signal or emergency takeover signal for exiting the assisted driving mode function may be an instruction actively triggered by the driver. For example, the driver may trigger the above-mentioned assisted driving exit signal or emergency takeover signal by triggering the assisted driving switch to turn off the assisted driving switch.

[0088] Alternatively, the driver can also trigger the assisted driving exit signal or emergency takeover signal by issuing an assisted driving exit voice, drawing an assisted driving exit gesture with his hand at a preset location (such as the central control screen), or other forms.

[0089] After the assisted driving exit signal or the emergency takeover signal is triggered, the assisted driving exit signal or the emergency takeover signal is sent by the host computer or the assisted driving module, so that it can be directly obtained.

[0090] In addition, the above-mentioned emergency takeover signal can also be judged by the steering wheel hand torque, and the steering wheel hand torque is monitored by sensors. If it exceeds the preset torque value, it indicates that the driver has intervened. At this time, the emergency takeover signal is triggered and the assisted driving mode is automatically exited.

[0091] The entry and exit assistance mode can be further divided into entry assistance and exit assistance. Specifically, the preset driving mode is the entry and exit assistance mode. After the preset driving mode is activated, the method further includes: 601: Receive driving signal.

[0092] 602: If the driving signal includes that the driver's seat is empty, the driver's door is closed for a preset period of time, or a vehicle lock signal is received, then exit the vehicle entry and exit assistance mode and unlock the steering wheel.

[0093] When assisting with getting off the vehicle, it is necessary to determine whether the driver has completed the action of getting off the vehicle, and then exit the getting on and off assistance mode. There are many ways to determine whether the driver has completed the action of getting off the vehicle.

[0094] This embodiment provides two examples. First, if the driver's seat is unoccupied and the door remains closed for a preset period, indicating the driver has exited the vehicle, the ingress / egress assistance mode can be exited and the steering wheel unlocked. The preset period can be customized. Second, the ingress / egress assistance mode can be exited by receiving a key lock signal or an automatic lock signal. Upon receiving the key lock signal or the automatic lock signal, indicating the driver has exited the vehicle, the ingress / egress assistance mode can be exited and the steering wheel unlocked.

[0095] It is understandable that the above-mentioned determination of whether there is someone in the driver's seat can be monitored by a pressure sensor or the like.

[0096] Regarding the vehicle entry assistance, specifically, the preset driving mode is a vehicle entry and exit assistance mode. After the preset driving mode is activated, the method further includes: 701: Receive a driving signal.

[0097] 702: If the driving signal includes that the driver's seat is occupied and the driver's door changes from open to closed, exit the boarding and exiting assistance mode and unlock the steering wheel.

[0098] Usually, after the driver opens the car door and gets in, he will close the main driver's door. Therefore, when there is someone in the main driver's seat and the main driver's door changes from open to closed, it means that the driver has completed the getting in and out of the car. At this time, the getting in and out assist mode can be exited and the steering wheel can be unlocked to facilitate the driver to control the steering wheel.

[0099] Steps 701-702 are the logic for normal exit of the function after completing the boarding assistance in the boarding assistance mode.

[0100] However, there are still some special cases. For example, it is possible that a person gets into the vehicle not to start the ignition and drive, but to adjust the steering wheel or steering wheel and conduct a simple test drive of the vehicle. For example, a consumer is viewing and experiencing a car at a 4S dealership. In this case, the consumer usually does not close the door after opening the car door, getting in the car and sitting in the driver's seat. At this time, it is impossible to unlock the steering wheel based on steps 701-702. That is to say, the in-and-out assistance mode is not exited at this time, and the steering wheel is still in a locked state, making it impossible for the consumer to adjust the steering wheel. This makes it impossible to satisfy the intention of conducting a simple test drive of the vehicle.

[0101] For example, the car may slip right after the driver gets in and sits down. If the steering wheel is locked, the driver may not be able to avoid the risk by turning the steering wheel.

[0102] In order to cope with the above-mentioned special circumstances, the preset driving mode is the vehicle getting on and off assist mode. After starting the preset driving mode, the method further includes: if the driving signal also includes at least one of the gear position not being P gear, the vehicle speed not being 0, and the Ready signal not being in the stop state, then exiting the vehicle getting on and off assist mode and unlocking the steering wheel to facilitate the driver to control the steering wheel.

[0103] For example, after getting in the car, the driver does not close the door, steps on the brake to make the Ready signal not in the stop state, or shifts to N gear, thereby exiting the in-and-out assist mode and unlocking the steering wheel, making it easier for the driver to control the steering wheel.

[0104] For example, after getting in the car and the car is rolling, the driver can step on the brake to make the Ready signal not in the stop state. At the same time as braking, the in-and-out assist mode is exited and the steering wheel is unlocked, making it easier for the driver to control the steering wheel.

[0105] See also Figure 4 As shown, based on the technical concept of the above-mentioned steering wheel control method for wire-controlled steering, the embodiment of the present application further provides a steering wheel control system for wire-controlled steering, which includes: A driving intention acquisition module is used to: acquire the driver's driving intention, which includes assisted driving and boarding and exiting assistance; a torque control module configured to: activate a preset driving mode based on the driving intention, obtain a preset locking torque based on steering wheel data, and control a force feedback drive motor to apply the preset locking torque to the steering wheel to lock the steering wheel, wherein the steering wheel data includes a steering angle of the steering wheel when the preset driving mode is activated; Wherein, when the driving intention is assisted driving, the preset driving mode is the assisted driving mode, and the preset locking torque is the first locking torque; When the driving intention is to assist in getting on and off the vehicle, the preset driving mode is the getting on and off assist mode, and the preset locking torque is the second locking torque; the first locking torque is smaller than the second locking torque.

[0106] In the description of this application, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0107] It should be noted that, in this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0108] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A steering wheel control method for steer-by-wire, characterized in that: It includes: Obtaining a driver's driving intention and activating a preset driving mode based on the driving intention, wherein the driving intention includes assisted driving and vehicle entry and exit assistance; Based on steering wheel data, obtaining a preset locking torque, and controlling a force feedback drive motor to apply the preset locking torque to the steering wheel to lock the steering wheel, wherein the steering wheel data includes a steering angle of the steering wheel when a preset driving mode is activated; Wherein, when the driving intention is assisted driving, the preset driving mode is the assisted driving mode, and the preset locking torque is the first locking torque; When the driving intention is to assist in getting on and off the vehicle, the preset driving mode is the getting on and off assist mode, and the preset locking torque is the second locking torque; the first locking torque is smaller than the second locking torque.

2. The steering wheel control method for steer-by-wire according to claim 1, wherein: Obtain the driver's driving intention, including: Receive driving signals, including assisted driving switch status, assisted driving wake-up voice, assisted driving wake-up gesture, ready signal, main driving door switch status, gear status and vehicle speed; If the driving signal includes one or more of the following: the assisted driving switch is in the on state, the assisted driving wake-up voice, and the assisted driving wake-up gesture, then the driving intention is assisted driving; If the driving signal includes a Ready signal in the stop state, a main driving door changing from closed to open, a gear in the P gear and a vehicle speed of 0, then the driving intention is to assist in getting on and off the vehicle.

3. The steering wheel control method for steer-by-wire according to claim 1, wherein: Based on the steering wheel data, the preset locking torque is obtained, including: using the steering wheel angle when the preset driving mode is activated as a target steering wheel angle when the steering wheel is locked, and obtaining an angle difference between the actual steering wheel angle and the target steering wheel angle; The preset locking torque is obtained based on the rotation angle difference.

4. The steering wheel control method for steer-by-wire according to claim 3, wherein: in, For the The preset locking torque applied to the steering wheel at a certain moment, =1, 2....; For The proportionality coefficient related to the error; For the The angle difference between the actual steering wheel angle at a certain moment and the target angle; Shielding coefficient to shield noise and reduce overshoot recovery time; For The integral coefficient related to the historical accumulation of errors; For The differential coefficient associated with the change in error.

5. The steering wheel control method for steer-by-wire according to claim 4, characterized in that: when hour, =1, when hour, =0; and / or when When it is less than the set dead zone, =0; and / or when hour, =0.

6. The steering wheel control method for steer-by-wire according to claim 4, characterized in that: The steering wheel data also includes steering wheel speed; The method further comprises: The preset locking torque is corrected based on the steering wheel speed, and the corrected preset locking torque is used as the preset locking torque that is finally output.

7. The steering wheel control method for steer-by-wire according to claim 6, characterized in that: in, is the preset locking torque of the final output, is the steering wheel speed gain value in the preset driving mode, For the The speed of the steering wheel at that moment.

8. The steering wheel control method for steer-by-wire according to claim 1, wherein: When the preset driving mode is the vehicle entry and exit assist mode, the steering wheel data further includes log data for steering wheel failure, and the log data includes one or more of a steering wheel angle log and a steering wheel speed log; Based on the steering wheel data, the preset locking torque is obtained, including: receiving and reading the log data; determining whether a temporary steering wheel failure occurs based on the log data; If no temporary steering wheel failure occurs, the steering wheel angle at which the preset driving mode is activated is used as the target steering wheel angle for locking the steering wheel, and the angle difference between the actual steering wheel angle and the target steering wheel angle is obtained; and the preset locking torque is obtained based on the angle difference; If a temporary steering wheel failure occurs, a basic locking torque is obtained based on the steering wheel hand torque, and the basic locking torque is used as the preset locking torque.

9. The steering wheel control method for steer-by-wire according to claim 8, characterized in that: in, is the basic locking torque, is the steering wheel hand torque gain value when a temporary steering wheel failure occurs, is the steering wheel hand torque.

10. The steering wheel control method for steer-by-wire according to claim 1, wherein: The preset driving mode is an assisted driving mode. After starting the preset driving mode, the method further includes: Receive driving signals; If the driving signal includes an assisted driving exit signal or an emergency takeover signal, the assisted driving mode is exited and the steering wheel is unlocked.

11. The steering wheel control method for steer-by-wire according to claim 1, wherein: The preset driving mode is a vehicle entry and exit assist mode. After the preset driving mode is activated, the method further includes: Receive driving signals; If the driving signal includes that the driver's seat is empty, the driver's door is closed and remains closed for a preset period of time, or a vehicle lock signal is received, the vehicle entry and exit assistance mode is exited and the steering wheel is unlocked.

12. The steering wheel control method for steer-by-wire according to claim 1, wherein: The preset driving mode is a vehicle entry and exit assist mode. After the preset driving mode is activated, the method further includes: Receive driving signals; If the driving signal includes that the driver's seat is occupied and the driver's door changes from open to closed, the boarding and exiting assist mode is exited and the steering wheel is unlocked.

13. The steering wheel control method for steer-by-wire according to claim 1, wherein: The preset driving mode is a vehicle entry and exit assist mode. After the preset driving mode is activated, the method further includes: If the driving signal further includes at least one of the gear position not being P, the vehicle speed not being 0, and the Ready signal not being in the stop state, the vehicle entry and exit assist mode is exited and the steering wheel is unlocked.

14. A steering wheel control system for steer-by-wire, characterized in that: It includes: A driving intention acquisition module, which is used to: acquire the driver's driving intention and activate a preset driving mode based on the driving intention, wherein the driving intention includes assisted driving and boarding and exiting assistance; a torque control module configured to obtain a preset locking torque based on steering wheel data, and control a force feedback drive motor to apply the preset locking torque to the steering wheel to lock the steering wheel, wherein the steering wheel data includes a steering wheel angle when a preset driving mode is activated; Wherein, when the driving intention is assisted driving, the preset driving mode is the assisted driving mode, and the preset locking torque is the first locking torque; When the driving intention is to assist in getting on and off the vehicle, the preset driving mode is the getting on and off assist mode, and the preset locking torque is the second locking torque; the first locking torque is smaller than the second locking torque.

15. A vehicle, characterized in that: It includes the steering wheel control system for steer-by-wire according to claim 13.

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