Vehicle control method, storage medium, steering system and vehicle

Abstract

The present application provides a vehicle control method, storage medium, steering system and vehicle. The method includes: obtaining a left wheel speed signal, a right wheel speed signal, a yaw rate signal and a steering wheel hand force signal during the driving process of the vehicle; performing steering zero position straight-ahead learning based on the left wheel speed signal, the right wheel speed signal, the yaw rate signal and the steering wheel hand force signal to obtain the straight-ahead middle direction; after successfully learning the straight-ahead middle direction, when the vehicle is judged to be deviating based on the left wheel speed signal, the right wheel speed signal and the steering wheel hand force signal, the vehicle is controlled to return to the straight-ahead middle direction. The present application can realize the function of simultaneously detecting torque and angle signals when the steering has only a torque sensor, and realize the active return function.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a vehicle control method, a storage medium, a steering system and a vehicle. Background Art

[0002] At present, the configuration rate of EPS (Electric Power Steering) systems in commercial vehicles and passenger vehicles is increasing year by year. Currently, all newly developed vehicle models are equipped with EPS systems. The normal operation of EPS systems requires torque sensors and angle sensors. Most sensors use TAS (Torque Angle Sensor, torque and angle sensor integrated solution) to obtain vehicle steering angle signals. This solution is relatively expensive and requires steering center calibration. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a vehicle control method, storage medium, steering system and vehicle, which can realize the function of simultaneously detecting torque and angle signals when there is only a torque sensor in the steering, and realize the active self-centering function.

[0004] One aspect of an embodiment of the present application provides a vehicle control method. The method includes: during the driving process of the vehicle, obtaining a left wheel speed signal, a right wheel speed signal, a yaw rate signal, and a steering wheel hand force signal; performing steering zero position straight-ahead learning based on the left wheel speed signal, the right wheel speed signal, the yaw rate signal, and the steering wheel hand force signal to obtain a straight-ahead middle direction; after successfully learning the straight-ahead middle direction, when it is determined that the vehicle is deviating based on the left wheel speed signal, the right wheel speed signal, and the steering wheel hand force signal, controlling the vehicle to return to the straight-ahead middle direction.

[0005] Further, the steering zero position straight-ahead learning based on the left wheel speed signal, the right wheel speed signal, the yaw rate signal and the steering wheel hand force signal to obtain the straight-ahead median direction includes: when the difference between the left wheel speed signal and the right wheel speed signal is lower than a set speed threshold, the value of the yaw rate signal is lower than a set yaw rate threshold, and the value of the steering wheel hand force signal is lower than a set hand force threshold, it is determined that the vehicle is in a straight-ahead state, and the rack position of the steering gear in the straight-ahead state is recorded as the straight-ahead median direction.

[0006] Furthermore, the method also includes: identifying the left limit position of the steering wheel when turning left to the limit and the right limit position of the steering wheel when turning right to the limit based on the steering wheel hand force signal; identifying the middle position of the steering gear based on the left limit position and the right limit position; when the difference between the straight-ahead middle direction and the middle position of the steering gear is within a predetermined threshold, it is determined that the straight-ahead middle direction learning is successful.

[0007] Furthermore, the method also includes: when the difference between the straight-ahead neutral direction and the middle position of the steering gear exceeds the predetermined threshold, a fault message is sent to the vehicle-mounted large screen.

[0008] Furthermore, the method also includes: obtaining a maximum steering wheel angle by converting according to a steering gear line angle transmission ratio and a rack stroke; obtaining an actual maximum vehicle angle based on the maximum steering wheel angle and a difference between the straight-ahead median direction and a middle position of the steering gear; obtaining a full-stroke steering angle based on the actual maximum vehicle angle, and dividing the full-stroke steering angle into equal parts in advance through a motor position sensor to obtain a corresponding relationship between the position of the motor and the angle within the steering stroke; obtaining an actual operating position of the motor through a motor position sensor; and obtaining and outputting an actual steering wheel angle based on the actual operating position of the motor and the corresponding relationship.

[0009] Furthermore, the method of judging the vehicle deviation based on the left wheel speed signal, the right wheel speed signal and the steering wheel hand force signal includes: when the difference between the left wheel speed signal and the right wheel speed signal exceeds a set speed threshold, and the value of the steering wheel hand force signal is lower than a set hand force threshold, then judging the vehicle deviation.

[0010] Furthermore, the method also includes: when controlling the vehicle to return to the center position, real-time monitoring of the left wheel speed signal and the right wheel speed signal until the difference between the left wheel speed signal and the right wheel speed signal is lower than a set speed threshold; if the difference between the left wheel speed signal and the right wheel speed signal exceeds the set speed threshold, re-performing steering zero position straight-ahead learning.

[0011] Another aspect of an embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the vehicle control method as described above are implemented.

[0012] Another aspect of the embodiment of the present application provides a steering system. The steering system includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the vehicle control method described above when executing the computer program.

[0013] Another aspect of the embodiments of the present application provides a vehicle, wherein the vehicle comprises the steering system as described above.

[0014] The vehicle control method of the present application can monitor the left wheel speed signal, the right wheel speed signal, the yaw rate signal and the steering wheel hand force signal through monitoring. Through the internal algorithm, the TAS (torque and angle sensor) can simultaneously detect the torque and angle signals, providing the whole vehicle with steering zero-position straight-ahead learning and realizing the active self-centering function without the need for steering center position calibration, and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the interaction between the steering system and vehicle signals according to an embodiment of the present application.

[0016] Figure 2 This is a flow chart of a vehicle control method according to an embodiment of the present application.

[0017] Figure 3 This is a flowchart for implementing steering zero position straight-ahead learning according to one embodiment of the present application.

[0018] Figure 4 This is a flowchart for implementing vehicle deviation compensation according to an embodiment of the present application.

[0019] Figure 5 A schematic block diagram of a steering system according to an embodiment of the present application. DETAILED DESCRIPTION

[0020] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are merely examples of devices consistent with some aspects of the present application as detailed in the appended claims.

[0021] The vehicle control method, storage medium, steering system and vehicle of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the features of the following embodiments and implementations can be combined with each other.

[0022] Figure 1 The following is a schematic diagram of the interaction between the steering system and the vehicle signal according to an embodiment of the present application. Figure 1As shown, the vehicle of the present application includes a steering system, for example, an electric power steering (EPS) system 100. The EPS system 100 can communicate with the PMS (power controller) system 200, the EHB (Electronic Hydraulic Brake) system 300 and the vehicle-mounted display screen 400 through a CAN network. The KL15 (Klemme, connector) of the vehicle and the EPS system 100 can be connected by a hard line. After the KL15 (Klemme, connector) of the vehicle is connected, the EPS system 100 receives the ready signal sent by the PMS system 200, and the EPS system 100 enters the working mode. The EPS system 100 monitors in real time the vehicle speed signal PMS_VehicleSpeed, the invalid vehicle speed signal PMS_VehicleSpeedInvalid, the yaw rate signal EHB_YawrateStatus, the invalid yaw rate signal EHB_YawrateStatusInvalid, and the steering wheel hand force signal Steeringtorqe applied to the steering wheel sent by the PMS system 200. The vehicle speed signal PMS_VehicleSpeed ​​indicates the signal sent by the PMS system 200 to the EPS system 100 when it can reflect the current actual vehicle speed of the vehicle; the invalid vehicle speed signal indicates the signal sent by the PMS system 200 to the EPS system 100 when the acquired vehicle speed data is abnormal and cannot represent the current actual vehicle speed of the vehicle. The yaw rate signal EHB_YawrateStatus indicates a signal sent by the PMS system 200 to the EPS system 100 when it can reflect the current actual yaw rate of the vehicle; the invalid yaw rate signal EHB_YawrateStatusInvalid indicates a signal sent by the PMS system 200 to the EPS system 100 when the acquired yaw rate data is abnormal and cannot represent the current actual yaw rate of the vehicle. The steering wheel hand force signal indicates a signal that can reflect the force applied to the steering wheel by the driver when turning the steering wheel.

[0023] If the EPS system 100 receives at least one invalid signal of the invalid vehicle speed signal PMS_VehicleSpeedInvalid and the invalid yaw rate signal EHB_YawrateStatusInvalid sent by the PMS system 200, that is, as long as one of the vehicle speed and the yaw rate is invalid, the EPS system 100 determines that the vehicle speed signal is abnormal at this time and cannot perform related functions. If the EPS system 100 receives the vehicle speed signal PMS_VehicleSpeedInvalid and the yaw rate signal EHB_YawrateStatusInvalid sent by the PMS system 200, that is, the vehicle speed and the yaw rate are both valid, the EPS system 100 can perform related control of the vehicle, such as performing the steering zero position straight-ahead learning, deviation compensation and other functions to be introduced below.

[0024] The present application provides a vehicle control method. Figure 2 A flow chart of a vehicle control method according to an embodiment of the present application is disclosed. Figure 2 As shown, a vehicle control method according to an embodiment of the present application may include steps S11 to S15.

[0025] In step S11 , during the driving of the vehicle, the EPS system 100 can obtain the left wheel speed signal PMS_VehicleSpeedleft, the right wheel speed signal PMS_VehicleSpeedright, the yaw rate signal EHB_YawrateStatus and the steering wheel hand force signal Steeringtorqe in real time.

[0026] In step S12 , the EPS system 100 may perform steering zero position straight driving learning based on the left wheel speed signal PMS_VehicleSpeedleft, the right wheel speed signal PMS_VehicleSpeedright, the yaw rate signal EHB_YawrateStatus and the steering wheel hand force signal Steeringtorqe to obtain the straight driving neutral direction.

[0027] In step S13, the straight-ahead median direction L_vehimid is learned successfully.

[0028] In step S14, after successfully learning the straight-ahead neutral direction L_vehimid, the EPS system 100 can determine whether the vehicle is running off the road based on the left wheel speed signal PMS_VehicleSpeedleft, the right wheel speed signal PMS_VehicleSpeedright and the steering wheel hand force signal Steeringtorqe. When the result of the judgment is "yes", the process proceeds to step S15. Otherwise, the process returns to step S14 to continue the subsequent running off judgment.

[0029] In step S15, when the EPS system 100 determines that the vehicle is running off the track based on the left wheel speed signal PMS_VehicleSpeedleft, the right wheel speed signal PMS_VehicleSpeedright and the steering wheel hand force signal Steeringtorqe, the EPS can use the straight-ahead mid direction L_vehimid as the target steering position for the vehicle to return to the straight-ahead mid direction L_vehimid by applying torque to the motor.

[0030] The vehicle control method of the present application can monitor the left wheel speed signal, the right wheel speed signal, the yaw rate signal and the steering wheel hand force signal PMS_VehicleSpeedleft, the right wheel speed signal PMS_VehicleSpeedright, the yaw rate signal EHB_YawrateStatus and the steering wheel hand force signal Steeringtorqe when only TOS (Torque Only Sensor) is needed for steering. The function of simultaneously detecting the torque and angle information of TAS (torque and angle sensor) is realized through an internal algorithm, and the whole vehicle is provided with steering zero position straight-ahead learning and active self-centering function without the need for steering center position calibration, which is low in cost.

[0031] In some embodiments, the vehicle control method of the present application may further include step S16.

[0032] In step S16, the successfully learned straight middle direction L_vehimid is stored in a non-volatile memory (NVM), so that the value of the straight middle direction L_vehimid will not be lost when the vehicle is powered on and off again or the software is updated.

[0033] Combine the following Figure 3 To explain in detail how this application performs the zero-position straight-ahead learning.

[0034] Figure 3 The present invention discloses a flowchart for implementing the zero-position straight-ahead learning of an embodiment of the present invention. Figure 3 As shown, the EPS system 100 monitors the left wheel speed signal PMS_VehicleSpeedleft, the right wheel speed signal PMS_VehicleSpeedright, the yaw rate signal EHB_YawrateStatus and the steering wheel hand force signal Steeringtorqe in real time. The EPS system 100 can perform steering zero position straight driving learning based on the left wheel speed signal PMS_VehicleSpeedleft, the right wheel speed signal PMS_VehicleSpeedright, the yaw rate signal EHB_YawrateStatus and the steering wheel hand force signal Steeringtorqe. In step S321, if the difference between the left wheel speed signal PMS_VehicleSpeedleft and the right wheel speed signal PMS_VehicleSpeedright is lower than the set speed threshold, the value of the yaw rate signal EHB_YawrateStatus is lower than the set yaw rate threshold, and the value of the steering wheel hand force signal Steeringtorqe is lower than the set hand force threshold, the EPS system 100 determines that the vehicle is in a straight-ahead state at this time, and the EPS system 100 automatically marks the rack position of the steering gear in this state as the straight-ahead middle direction L_vehimid. Among them, the set speed threshold, the set yaw rate threshold, and the set hand force threshold can be pre-calibrated. In step 22, the left limit position of the steering wheel turning to the left and the right limit position of the steering wheel turning to the right are identified based on the steering wheel hand force signal Steeringtorqe, and then the steering gear middle position L_steermid can be identified based on the left limit position and the right limit position. In step S23, the difference between the straight-ahead middle direction L_vehimid and the steering gear middle position L_steermid is calculated. In step S24, when the difference between the straight-ahead median direction L_vehimid and the middle position of the steering gear L_steermid is within a predetermined threshold, it is determined that the straight-ahead median direction L_vehimid is successfully learned. In step S25, when the difference between the straight-ahead median direction L_vehimid and the middle position of the steering gear L_steermid exceeds a predetermined threshold, the EPS system 100 determines that there is a large deviation in the hard points of the vehicle or the steering wheel installation position, and it is necessary to check the vehicle parts or reinstall the steering wheel for four-wheel alignment. At this time, the EPS system 100 will send a fault message to the vehicle-mounted large screen 400 to prompt the driver.

[0035] In some embodiments, the vehicle control method of the present application may further include steps S31 to S35.

[0036] In step S31, the maximum steering wheel angle can be calculated based on the steering gear line angle transmission ratio C and the rack travel L. , as shown below:

[0037]

[0038] In step S32, after obtaining the maximum steering wheel angle After that, we can further calculate the maximum steering wheel angle based on The actual maximum turning angle of the vehicle is obtained by taking the difference between the straight-ahead median direction L_vehimid and the steering gear middle position L_steermid , as shown below:

[0039]

[0040] In step S33, the actual maximum turning angle of the vehicle can be The full-stroke steering angle is obtained, and the full-stroke steering angle is divided equally in advance by a motor position sensor to obtain a corresponding relationship between the position of the motor and the steering angle within the steering stroke.

[0041] In step S34, the actual running position of the motor may be acquired through a motor position sensor.

[0042] In step S35, the actual steering wheel angle is obtained and output based on the actual operating position of the motor and the corresponding relationship.

[0043] The following will be combined Figure 4 The following describes in detail how the present application determines vehicle deviation based on the wheel speed signal PMS_VehicleSpeedleft, the right wheel speed signal PMS_VehicleSpeedright and the steering wheel hand force signal Steeringtorqe.

[0044] Figure 4 The following is a flowchart of the implementation of vehicle deviation compensation according to an embodiment of the present application. Figure 4As shown, in step S41, the difference between the left wheel speed signal PMS_VehicleSpeedleft and the right wheel speed signal PMS_VehicleSpeedright is calculated. In step S42, the steering wheel hand force signal Steeringtorqe is obtained. In step S43, when the difference between the left wheel speed signal PMS_VehicleSpeedleft and the right wheel speed signal PMS_VehicleSpeedright exceeds the set speed threshold, and the value of the steering wheel hand force signal Steeringtorqe is higher than the set hand force threshold, it is determined that the driver intends to perform steering. In step S44, when the difference between the left wheel speed signal PMS_VehicleSpeedleft and the right wheel speed signal PMS_VehicleSpeedright exceeds the set speed threshold, and the value of the steering wheel hand force signal Steeringtorqe is lower than the set hand force threshold, it is determined that the driver does not intend to perform steering, and it is judged that the vehicle is running off the track at this time.

[0045] In some embodiments, in step S44: when controlling the vehicle to return to the center position, PMS_VehicleSpeedleft and the right wheel speed signal PMS_VehicleSpeedright are also monitored in real time until the difference between PMS_VehicleSpeedleft and the right wheel speed signal PMS_VehicleSpeedright is lower than the set speed threshold; if the difference between PMS_VehicleSpeedleft and the right wheel speed signal PMS_VehicleSpeedright exceeds the set speed threshold, it is necessary to re-perform steering zero position straight-ahead learning.

[0046] The present application also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the vehicle control method described above are implemented.

[0047] The present application also provides a steering system, for example, an electric power steering (EPS) system 100 . Figure 5 A schematic block diagram of an EPS system 100 according to an embodiment of the present application is disclosed. Figure 5As shown, the EPS system 100 of one embodiment of the present application includes a processor 101, an internal bus 102, a network interface 103, a memory 104 and a non-volatile memory 105, and may also include hardware required for other services. The processor 101 can read the corresponding computer program from the non-volatile memory 105 into the memory 104 and then run it to implement the steps of the vehicle control method as described above. Of course, in addition to the software implementation, the present application does not exclude other implementation methods, such as logic devices or a combination of software and hardware, etc., that is to say, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic components.

[0048] The EPS system 100 of the present application can have beneficial technical effects similar to the vehicle control method described above, so it will not be described in detail here.

[0049] The above is a detailed introduction to the vehicle control method, storage medium, EPS system and vehicle provided in the embodiments of the present application. Specific examples are used herein to illustrate the vehicle control method, storage medium, EPS system and vehicle in the embodiments of the present application. The description of the above embodiments is only used to help understand the core idea of ​​the present application and is not intended to limit the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the spirit and principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications should also fall within the scope of protection of the claims attached to the present application.

Claims

1. A vehicle control method, characterized in that: The method is applicable to a vehicle having only a torque sensor, and comprises: During the driving process of the vehicle, a left wheel speed signal, a right wheel speed signal, a yaw rate signal and a steering wheel hand force signal are obtained; Performing steering zero position straight-ahead learning based on the left wheel speed signal, the right wheel speed signal, the yaw rate signal and the steering wheel hand force signal to obtain a straight-ahead neutral direction; After successfully learning the straight-ahead neutral direction, when it is determined that the vehicle is deviating based on the left wheel speed signal, the right wheel speed signal and the steering wheel hand force signal, the vehicle is controlled to return to the straight-ahead neutral direction.

2. The method according to claim 1, characterized in that The performing steering zero position straight-ahead learning based on the left wheel speed signal, the right wheel speed signal, the yaw rate signal and the steering wheel hand force signal to obtain the straight-ahead middle direction includes: When the difference between the left wheel speed signal and the right wheel speed signal is lower than a set speed threshold, the value of the yaw rate signal is lower than a set yaw rate threshold, and the value of the steering wheel hand force signal is lower than a set hand force threshold, it is determined that the vehicle is in a straight-ahead state, and the rack position of the steering gear in the straight-ahead state is recorded as the straight-ahead neutral direction.

3. The method according to claim 2, characterized in that Also includes: Based on the steering wheel hand force signal, identifying a left limit position of the steering wheel when the steering wheel is turned to the left and a right limit position of the steering wheel when the steering wheel is turned to the right; identifying a steering gear intermediate position based on the left extreme position and the right extreme position; When the difference between the straight-ahead mid-position and the middle position of the steering gear is within a predetermined threshold, it is determined that the straight-ahead mid-position learning is successful.

4. The method according to claim 3, characterized in that Also includes: When the difference between the straight-ahead neutral direction and the middle position of the steering gear exceeds the predetermined threshold, a fault message is sent to the vehicle-mounted large screen.

5. The method according to claim 3, characterized in that Also includes: The maximum steering wheel angle is calculated based on the steering gear line angle transmission ratio and rack travel; Obtaining an actual maximum turning angle of the vehicle based on the maximum turning angle of the steering wheel and the difference between the straight-ahead neutral direction and the middle position of the steering gear; Obtaining a full-stroke steering angle based on the actual maximum steering angle of the vehicle, and dividing the full-stroke steering angle into equal parts in advance by a motor position sensor to obtain a corresponding relationship between the position of the motor and the steering angle within the steering stroke; The actual running position of the motor is obtained through the motor position sensor; The actual steering wheel angle is obtained and output based on the actual operating position of the motor and the corresponding relationship.

6. The method according to claim 1, characterized in that The determining of vehicle deviation based on the left wheel speed signal, the right wheel speed signal and the steering wheel hand force signal comprises: When the difference between the left wheel speed signal and the right wheel speed signal exceeds a set speed threshold, and the value of the steering wheel hand force signal is lower than a set hand force threshold, it is determined that the vehicle is running off the track.

7. The method according to claim 1, characterized in that Also includes: When controlling the vehicle to return to the center position, the left wheel speed signal and the right wheel speed signal are monitored in real time until the difference between the left wheel speed signal and the right wheel speed signal is lower than a set speed threshold; If the difference between the left wheel speed signal and the right wheel speed signal exceeds the set speed threshold, the steering zero position straight driving learning is performed again.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the vehicle control method as described in any one of claims 1 to 7 are implemented.

9. A steering system, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the vehicle control method as described in any one of claims 1 to 7 when executing the computer program.

10. A vehicle, characterized in that: Comprising a steering system as claimed in claim 9.

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