Vehicle steering wheel aligning method and device, computer equipment and storage medium

Abstract

The invention relates to the technical field of automatic parking, in particular to a vehicle steering wheel aligning method and device, computer equipment and a storage medium, and the method comprises the steps that when a steering wheel aligning instruction is received, a first angle of a steering wheel of a vehicle at a first moment is obtained; a first error between the first angle and a target request angle is obtained, the first error is analyzed to determine whether the steering wheel is located in an aligning position interval, the target request angle is the angle of the steering wheel at the aligning position, and the aligning position interval is determined according to the aligning position of the steering wheel and a preset threshold value; if the steering wheel is located in the aligning position interval, the real-time torque of the vehicle is obtained; and obtaining a comparison result between the real-time torque and a torque threshold value, obtaining a target rotation angle based on the real-time torque under the condition that the comparison result does not meet a preset condition, and controlling the steering wheel to reversely rotate by utilizing the target rotation angle until the steering wheel is in a return position. The steering wheel aligning accuracy can be improved, and the adjusting frequency is reduced.

Description

Technical Field

[0001] The present disclosure relates to the technical field of automatic parking, and particularly to a method, an apparatus, a computer device, and a storage medium for straightening a vehicle steering wheel. Background Art

[0002] With the rapid development of automotive technologies, autonomous driving assistance technologies have become increasingly popular, including functions such as assisted cruise control, assisted braking, and assisted parking. Among them, the automatic parking assistance system helps the vehicle enter the target parking space by controlling the rotation of the steering wheel. However, after the vehicle enters the target parking space, the automatic parking assistance system exits control. At this time, due to the incomplete release of the tire stress, the steering wheel may deflect, resulting in poor vehicle stability and a bad user experience.

[0003] Existing steering wheel straightening control schemes rely on preset values (i.e., auxiliary parameters for the vehicle to complete steering wheel straightening). However, the numerical settings of these preset values may not be adaptable to all vehicle and road surface types because different tires may have different deformation degrees on the same road surface type, and the same wheel may also have different deformation degrees on different road surface types. Fixing an increase in a certain value may cause the steering wheel to be over-adjusted or under-adjusted, resulting in inaccurate adjustment and even more adjustment times, thereby affecting efficiency and effect. Therefore, how to improve the accuracy of steering wheel straightening has become an urgent problem to be solved. Summary of the Invention

[0004] In view of this, the present disclosure provides a method, an apparatus, a computer device, and a storage medium for straightening a vehicle steering wheel to solve the problem that the steering wheel cannot be accurately straightened currently.

[0005] In a first aspect, the present disclosure provides a method for straightening a vehicle steering wheel, the method comprising:

[0006] When receiving a steering wheel straightening instruction, obtaining a first angle of the vehicle's steering wheel at a first moment;

[0007] Obtaining a first error between the first angle and a target request angle, and analyzing the first error to determine whether the steering wheel is located in a straightening position interval, where the target request angle is the angle at which the steering wheel is in a straightening position, and the straightening position interval is determined according to the straightening position of the steering wheel and a preset threshold;

[0008] If the steering wheel is located in the straightening position interval, obtaining the real-time torque of the vehicle;

[0009] Obtain the comparison result between the real-time torque and the torque threshold. When the comparison result does not meet the preset condition, obtain the target steering angle based on the real-time torque, and use the target steering angle to control the steering wheel to rotate in the reverse direction until the steering wheel is in the straight-ahead position, where the preset condition is that the real-time torque is less than the torque threshold.

[0010] Further, analyzing the first error to determine whether the steering wheel is in the straight-ahead position interval includes:

[0011] If the first error falls within the numerical range corresponding to the straight-ahead position interval, it is determined that the steering wheel is in the straight-ahead position interval;

[0012] If the first error does not fall within the numerical range corresponding to the straight-ahead position interval, it is determined that the steering wheel is not in the straight-ahead position interval.

[0013] Further, if the steering wheel is in the straight-ahead position interval, obtaining the real-time torque of the vehicle includes:

[0014] When the steering wheel is in the straight-ahead position interval, obtain the vehicle driving condition data of the vehicle;

[0015] Determine the preset duration based on the vehicle driving condition data, where the preset duration is the duration to wait from the first moment until obtaining the real-time torque of the steering assist motor of the vehicle;

[0016] After waiting for the preset duration, obtain the real-time torque of the vehicle.

[0017] Further, determining the preset duration based on the vehicle driving condition data includes:

[0018] Based on the vehicle driving condition data and the real-time steering system model, obtain the first change curve of the torque of the steering assist motor of the vehicle as time moves backward and the second change curve of the steering wheel angle as time moves backward, where the real-time steering system model is used to evaluate the steering fluctuation state of the vehicle;

[0019] Determine the preset duration based on the first change curve and the second change curve.

[0020] Further, determining the preset duration based on the first change curve and the second change curve includes:

[0021] Obtain the first change rate based on the first change curve and the second change rate based on the second change curve;

[0022] Compare the first change rate with the corresponding first change rate threshold and compare the second change rate with the corresponding second change rate threshold;

[0023] When the first change rate is less than the first change rate threshold and the second change rate is less than the second change rate threshold, obtain the current second moment;

[0024] Based on the first moment and the second moment, a preset duration is obtained.

[0025] Further, the method further includes:

[0026] After determining that the steering wheel is not in the straight-ahead position interval, a steering wheel straightening instruction is sent, and preset rotation parameters corresponding to the steering wheel are obtained, where the preset rotation parameters are used for information on gradually returning the steering wheel from the current position to the straight-ahead position;

[0027] Control the steering wheel to adjust the angle based on the preset rotation parameters until the steering wheel is in the straight-ahead position interval.

[0028] Further, obtaining a target rotation angle based on the real-time torque and using the target rotation angle to control the steering wheel to rotate in the reverse direction until the steering wheel is in the straight-ahead position includes:

[0029] Obtain a target rotation angle based on the real-time torque, use the target rotation angle to control the steering wheel to rotate in the reverse direction to obtain a second angle of the steering wheel, and use the second angle as the first angle. Start looping from obtaining the first error between the first angle and the target request angle until the comparison result meets the preset condition to determine that the steering wheel is in the straight-ahead position.

[0030] In a second aspect, the present disclosure provides a device for straightening a vehicle steering wheel, and the device includes:

[0031] A first acquisition module, configured to acquire a first angle of the vehicle's steering wheel at a first moment when receiving a steering wheel straightening instruction;

[0032] A second acquisition module, configured to acquire a first error between the first angle and the target request angle, and analyze the first error to determine whether the steering wheel is in the straight-ahead position interval, where the target request angle is the angle when the steering wheel is in the straight-ahead position, and the straight-ahead position interval is determined according to the straight-ahead position of the steering wheel and a preset threshold;

[0033] A third acquisition module, configured to acquire the real-time torque of the vehicle if the steering wheel is in the straight-ahead position interval;

[0034] A control module, configured to obtain a comparison result between the real-time torque and a torque threshold, and when the comparison result does not meet the preset condition, obtain a target rotation angle based on the real-time torque and use the target rotation angle to control the steering wheel to rotate in the reverse direction until the steering wheel is in the straight-ahead position, where the preset condition is that the real-time torque is less than the torque threshold.

[0035] In a third aspect, the present disclosure provides a computer device, including: a memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to execute the method for straightening the vehicle steering wheel according to the first aspect or any corresponding embodiment thereof.

[0036] In a fourth aspect, the present disclosure provides a computer-readable storage medium, on which computer instructions are stored, and the computer instructions are used to cause a computer to execute the method for straightening the vehicle steering wheel according to the first aspect or any corresponding embodiment thereof.

[0037] When the method provided by the embodiment of the present application receives a steering wheel straightening instruction, it obtains the first angle of the vehicle steering wheel at the first moment, and then compares the first angle with the target request angle when the steering wheel is in the straightening position to obtain the first error. Then, based on the first error, it determines whether the steering wheel is in the straightening position interval, and further obtains the real-time torque of the vehicle. Then, based on the comparison result between the real-time torque and the torque threshold, it obtains the target rotation angle, and uses the target rotation angle to control the reverse rotation of the steering wheel until the steering wheel is in the straightening position. Since the real-time torque can reflect the road surface type and the rebound angle of the steering wheel after unlocking, by dynamically calculating the target rotation angle of the steering wheel through this algorithm and using the target rotation angle to control the reverse rotation of the steering wheel, the accuracy of steering wheel straightening can be improved, the number of adjustments can be reduced, the system can be prevented from entering an infinite loop or being unable to complete straightening, and the straightening accuracy and user experience are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific embodiments of the present disclosure or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0039] Figure 1 is a flowchart of the method for straightening the vehicle steering wheel according to the embodiment of the present application;

[0040] Figure 2 is a schematic diagram of the straightening position interval for straightening the vehicle steering wheel according to the embodiment of the present application;

[0041] Figure 3 is a schematic diagram of the change of the target rotation angle according to the embodiment of the present application;

[0042] Figure 4 is a complete flowchart of the method for straightening the vehicle steering wheel according to the embodiment of the present application;

[0043] Figure 5A structural block diagram of an apparatus for a method of straightening a vehicle steering wheel according to an embodiment of the present application;

[0044] Figure 6 A schematic diagram of the hardware structure of a computer device according to an embodiment of the present application. Detailed implementation manners

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present disclosure. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.

[0046] According to an embodiment of the present application, there is provided a method, an apparatus, a computer device, and a storage medium for straightening a vehicle steering wheel. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. And although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0047] In this embodiment, there is provided a method for straightening a vehicle steering wheel, Figure 1 which is a flowchart of the method for straightening a vehicle steering wheel according to an embodiment of the present application. As Figure 1 shown, this method can be applied to a steering system. The method flow includes the following steps:

[0048] Step S101: When a steering wheel straightening instruction is received, obtain a first angle of the vehicle's steering wheel at a first moment.

[0049] In an embodiment of the present application, the vehicle's automatic parking system sends a steering wheel straightening request to the steering system through CAN (Controller Area Network) or other vehicle-mounted communication interfaces. A highly integrated electronic control unit (ECU) is built inside the vehicle's steering system, which is like the "intelligent brain" of the entire steering system. Once a steering wheel straightening instruction is generated, the instruction signal will be transmitted to this electronic control unit through the vehicle-mounted network at an extremely fast speed.

[0050] After that, the electronic control unit will obtain the first angle of the vehicle's steering wheel at the first moment in real time. Herein, the first moment refers to the moment when the electronic control unit of the vehicle receives the steering wheel return-to-center command. Specifically, since high-precision angle sensors are equipped in the steering system of the steering wheel, these sensors are closely connected to the rotating shaft of the steering wheel. When the steering wheel is in a rotating state, the sensors will, according to their unique working principles, convert the rotation angle of the steering wheel into corresponding electrical signals or digital signals, and then, based on the electrical signals or digital signals, perform corresponding angle signal conversions to obtain the first angle of the vehicle's steering wheel at the first moment.

[0051] Step S102: Obtain the first error between the first angle and the target request angle, and analyze the first error to determine whether the steering wheel is located within the return-to-center position interval. Herein, the target request angle is the angle at which the steering wheel is in the return-to-center position, and the return-to-center position interval is determined according to the return-to-center position of the steering wheel and a preset threshold.

[0052] In the embodiment of the present application, the target request angle A is set to 0°, which is the angle to ensure that the steering wheel returns to the return-to-center position. At this time, the first error between the first angle and the target request angle A (that is, the numerical difference between the first angle and the target request angle A) can be obtained, and based on this first error, it can be determined whether the steering wheel is located within the return-to-center position interval. It should be noted that the return-to-center position interval here is determined according to the return-to-center position of the steering wheel and a preset threshold. Among them, the return-to-center position of the steering wheel (see Figure 2 ) is known. That is, during the vehicle production and manufacturing process, engineers will perform precise design and debugging on the steering system to determine the return-to-center position of the steering wheel. This position is determined by comprehensively considering factors such as the overall layout of the vehicle, the geometric parameters of the steering mechanism, and the four-wheel alignment, so as to ensure that when the vehicle is driving straight, the steering wheel is in a specific intermediate position, enabling the vehicle to maintain a stable straight driving state.

[0053] In addition, in order to determine that the steering wheel is close to or approaching the return-to-center position at the first moment, a predetermined interval is obtained based on the preset threshold. As shown in Figure 2 , deviation angles are provided on both the left and right sides of the return-to-center position. This angle is the preset threshold, such as 3°. At this time, the return-to-center position interval is [-3°, 3°].

[0054] It should be noted that the return-to-center position range is an angular range used to measure whether the steering wheel is in a reasonable middle position. Taking the return-to-center position of the steering wheel determined through precise design and debugging during the vehicle manufacturing process as the core reference, this position comprehensively considers factors such as the overall vehicle layout, geometric parameters of the steering mechanism, and four-wheel alignment, and is a key setting to ensure the straight-line driving stability of the vehicle. On this basis, a certain angle is extended to the left and right sides around the return-to-center position, and this angle is the preset threshold. For example, taking the return-to-center position as the origin and extending 3° to the left and right respectively, the formed [-3°, 3°] range is a typical return-to-center position range. When the first error between the calculated first angle of the steering wheel and the target request angle A (0°, that is, the ideal angle for the steering wheel to return to the return-to-center position) falls within this range, it can be determined that the steering wheel is within the return-to-center position range in the current state, indicating that its angle is close to or in the ideal return-to-center state, which helps to maintain the smoothness of the vehicle's straight-line driving; otherwise, it means that the steering wheel is deviated.

[0055] In the embodiment of the present application, analyzing the first error to determine whether the steering wheel is located in the return-to-center position range includes the following steps A1 - A2:

[0056] Step A1, if the first error falls within the numerical range corresponding to the return-to-center position range, it is determined that the steering wheel is located in the return-to-center position range.

[0057] Specifically, in the embodiment of the present application, the return-to-center position range corresponds to a numerical range, such as the above [-3°, 3°]. When the first error falls within this numerical range, it is considered that the steering wheel is located in the return-to-center position range, that is, it is considered that the steering wheel is relatively close to the return-to-center position and is infinitely close to the return-to-center position.

[0058] Step A2, if the first error does not fall within the numerical range corresponding to the return-to-center position range, it is determined that the steering wheel is not located in the return-to-center position range.

[0059] Specifically, in the embodiment of the present application, the return-to-center position range corresponds to a numerical range, such as the above [-3°, 3°]. When the first error does not fall within this numerical range, it is considered that the steering wheel is not located in the return-to-center position range, that is, it is considered that the steering wheel is relatively far from the return-to-center position, and at this time, the steering wheel still needs to be brought closer to the return-to-center position to proceed to the next step.

[0060] In the embodiment of the present application, after determining that the steering wheel is not located in the return-to-center position range, the following steps A3 - step A4 are further included:

[0061] Step A3, receive the steering wheel return-to-center command and obtain the preset rotation parameters corresponding to the steering wheel, where the preset rotation parameters are information used to gradually return the steering wheel from the current position to the return-to-center position.

[0062] Specifically, when the automatic parking system detects that the steering wheel deviates from the straight-ahead position range and is far from the straight-ahead position, it will immediately issue a steering wheel straightening command. The steering system receives this command through a dedicated communication interface, which can transmit from the automatic parking system to the steering system.

[0063] After receiving the command, the steering system starts the parameter acquisition process. It will access the vehicle's on-board database, which stores a large number of preset rotation parameters for different initial steering wheel positions and vehicle driving states. The steering system first reads the actual position information of the current steering wheel. Then, based on this position information and the current driving speed, direction and other state data of the vehicle, it filters out the matching preset rotation parameters from the database. This parameter includes the rotation direction (clockwise or counterclockwise) and rotation angle required to gradually return the steering wheel from the current position to the straight-ahead position.

[0064] Step A4, control the steering wheel to adjust the angle based on the preset rotation parameters until the steering wheel is within the straight-ahead position range.

[0065] Specifically, after successfully obtaining the preset rotation parameters, the steering system adjusts the angle of the steering wheel. First, it controls the rotation direction of the steering motor according to the rotation direction parameter. If the rotation direction is clockwise, the steering system sends a clockwise rotation control signal to the motor, and the motor starts to drive the steering wheel to rotate clockwise; if it is counterclockwise, a counterclockwise rotation signal is sent.

[0066] During the rotation process, the steering system continuously receives the real-time angle information feedback from the steering wheel angle sensor. At the same time, it compares the current actual rotation angle with the preset rotation angle in real time. As the steering wheel rotates, when the actual rotation angle gradually approaches the preset rotation angle, the steering system gradually reduces the motor speed to achieve precise angle adjustment. Once the actual rotation angle reaches the preset rotation angle and the steering wheel position is detected to be within the straight-ahead position range, the steering system immediately stops sending the drive signal to the motor, and the motor stops running, thus completing the angle adjustment of the steering wheel and making it stably within the straight-ahead position range.

[0067] Step S103, if the steering wheel is within the straight-ahead position range, obtain the real-time torque of the vehicle.

[0068] In the embodiment of the present application, if the steering wheel is within the straight-ahead position range, obtaining the real-time torque of the vehicle includes the following steps B1 - B3:

[0069] Step B1, when the steering wheel is within the straight-ahead position range, obtain the vehicle driving condition data of the vehicle.

[0070] Specifically, if the steering wheel is in the range of the straight-ahead position, it is considered that the steering wheel is close to the straight-ahead position. At this time, a period of time can be waited to obtain the current real-time torque of the vehicle, or the current real-time torque of the vehicle can be directly obtained.

[0071] In the embodiment of the present application, taking the example of obtaining the real-time torque of the vehicle after waiting for a preset time period for illustration. Specifically, various sensors deployed on the vehicle, such as a vehicle speed sensor, an acceleration sensor, a steering wheel angle sensor, etc., collect vehicle driving condition data in real time through the sensors. The driving condition data includes information such as vehicle speed, acceleration, vehicle body attitude, and initial steering wheel angle.

[0072] Step B2, determine a preset time period based on the vehicle driving condition data, where the preset time period is the time period that needs to be waited from the first moment until the real-time torque of the steering assist motor of the vehicle is obtained.

[0073] In the embodiment of the present application, determining the preset time period based on the vehicle driving condition data includes the following steps B21 - B22:

[0074] Step B21, based on the vehicle driving condition data and the real-time steering system model, obtain a first change curve of the torque of the steering assist motor of the vehicle as time moves backward and a second change curve of the steering wheel angle as time moves backward, where the real-time steering system model is used to evaluate the steering fluctuation state of the vehicle.

[0075] Specifically, the real-time steering system model runs in the ECU. This model is constructed based on the mechanical structure characteristics, dynamics principles of the vehicle steering system, and a large amount of actual test data, and can accurately evaluate the steering fluctuation state of the vehicle under different working conditions.

[0076] When calculating the first change curve of the torque of the steering assist motor as time moves backward, first input the collected driving condition data into the real-time steering system model. The model will calculate based on these data, combined with parameters such as the mechanical transmission relationship of the steering system and the characteristic curve of the assist motor. For example, when the vehicle is driving at a low speed, the model will calculate a relatively large assist motor torque required to provide a suitable steering feel according to the vehicle speed and the steering wheel angle; while when driving at a high speed, the assist motor torque will be correspondingly reduced. As time goes by, the model will continuously receive new working condition data and continuously update the calculation, so as to obtain a series of torque values of the steering assist motor corresponding to different moments. Arranging these values in chronological order forms the first change curve of the torque of the steering assist motor as time moves backward.

[0077] For the second variation curve in which the steering wheel angle moves backward over time, it is also based on the collected vehicle driving condition data. The steering wheel angle sensor will detect the rotation angle of the steering wheel in real time and transmit the angle data to the ECU. The ECU records these real-time angle data in chronological order, and at the same time, combines the evaluation results of the real-time model of the steering system on the vehicle steering fluctuation state to correct and optimize the angle data. For example, when the model detects slight steering fluctuations during vehicle driving, it will appropriately adjust the steering wheel angle data to more accurately reflect the actual effective rotation angle of the steering wheel. As time goes on, the ECU continuously collects and processes new steering wheel angle data, and finally forms the second variation curve in which the steering wheel angle moves backward over time, thus presenting the change of the steering wheel angle at different moments.

[0078] Step B22, determine a preset duration based on the first variation curve and the second variation curve.

[0079] In the embodiment of the present application, determining the preset duration based on the first variation curve and the second variation curve includes the following steps B221 - step B224:

[0080] Step B221, obtain a first variation rate based on the first variation curve and a second variation rate based on the second variation curve.

[0081] Step B222, compare the first variation rate with the corresponding first variation rate threshold, and compare the second variation rate with the corresponding second variation rate threshold.

[0082] Step B223, when the first variation rate is less than the first variation rate threshold and the second variation rate is less than the second variation rate threshold, obtain the current second moment.

[0083] Step B224, obtain the preset duration based on the first moment and the second moment.

[0084] In the embodiment of the present application, if both the first variation curve and the second variation curve can be represented by the mathematical function y = f(x), then the variation rate of these curves at a certain point is the derivative f′(x) of the function. By differentiating the function according to the differentiation formula and rules, the corresponding curve variation rate can be obtained.

[0085] After that, compare the first variation rate with the corresponding first variation rate threshold, and compare the second variation rate with the corresponding second variation rate threshold. For example, the first variation rate threshold is 0.1 N·m / s, and the second variation rate threshold is 0.5° / s. If the first variation rate is less than 0.1 N·m / s and the second variation rate is less than 0.5° / s, it is considered that the steering system reaches a stable state. According to the simulation process, determine the time required from the current moment (i.e., the first moment) to the moment in the stable state (i.e., the second moment) to obtain the preset duration.

[0086] Example: When the vehicle speed is stable at 20 km / h and the vehicle is traveling along a left-turn path, the acceleration is 0.5 m / s 2 , and the steering wheel rotates uniformly from 0° to 90° in 3 seconds, that is, the steering angle change rate is 30° / s. At the same time, based on historical data and system identification algorithms, a real-time model of the steering system is established.

[0087] Data such as the collected vehicle speed, acceleration, and steering angle change rate are input into the real-time model of the steering system for numerical simulation. During the simulation process, the model calculates and outputs the changes in the steering assist motor torque and the steering wheel angle over time based on its own model parameters and input data.

[0088] Based on the model output results, curves of the steering assist motor torque and the steering wheel angle are constructed. When the simulation reaches the 5th second, after calculation, the torque change rate drops to 0.08 N·m / s, which is less than the first change rate threshold of 0.1 N·m / s; the steering wheel angle change rate drops to 0.3° / s, which is less than the second change rate threshold of 0.5° / s. It can be judged from this that the steering system reaches a stable state at this time.

[0089] It can be seen from the simulation process that it takes a total of 5 seconds from the start of the left-turn operation of the vehicle (the 0th second) to the steering system reaching a stable state. This result provides an important basis for the vehicle control system, and the steering system can wait for 5 seconds accordingly.

[0090] On the one hand, the curve constructed by the real-time model and multi-dimensional data in the embodiment of the present application can accurately capture the dynamic changes of the steering system and provide a data basis for analyzing the performance of the steering system; on the other hand, by setting change rate thresholds and making comparison judgments, abnormal fluctuation states of the steering system can be accurately identified. When both the first change rate and the second change rate are less than the thresholds, it indicates that the steering system is in a stable operation state. At this time, the obtained preset duration can be used to quantitatively evaluate the stability of the steering system, so as to optimize the control strategy of the steering system and improve the smoothness of vehicle steering in the future.

[0091] Step B3, after waiting for the preset duration, obtain the real-time torque of the vehicle.

[0092] Specifically, after the steering system waits for a preset duration, such as 5 seconds, the current real-time torque of the vehicle can be obtained by installing torque sensors in the vehicle's transmission system, such as at the drive shaft, transmission output shaft, or engine crankshaft. These sensors use principles such as strain gauges, magnetoelectric effects, and photoelectric effects to convert torque signals into electrical signals, thereby measuring the magnitude of the transmitted torque in real time. The engine output torque can also be calculated through a pre-set engine torque model. For example, the electronic control unit determines the basic torque based on the throttle opening and engine speed, and then corrects it according to parameters such as intake air volume and water temperature to obtain the real-time engine torque value.

[0093] Step S104: Obtain the comparison result between the real-time torque and the torque threshold, and when the comparison result does not meet the preset condition, obtain the target steering angle based on the real-time torque, and use the target steering angle to control the steering wheel to rotate in the reverse direction until the steering wheel is in the centered position, where the preset condition is that the real-time torque is less than the torque threshold.

[0094] In the embodiment of the present application, obtaining the target steering angle based on the real-time torque and using the target steering angle to control the steering wheel to rotate in the reverse direction until the steering wheel is in the centered position includes step C1:

[0095] Step C1: Obtain the target steering angle based on the real-time torque, and use the target steering angle to control the steering wheel to rotate in the reverse direction to obtain the second angle of the steering wheel, and use the second angle as the first angle, and start to loop from obtaining the first error between the first angle and the target request angle until the comparison result meets the preset condition, and determine that the steering wheel is in the centered position.

[0096] Specifically, in the embodiment of the present application, set the preset condition for the vehicle to complete the steering wheel centering: the real-time torque is less than the torque threshold (such as 0.3 N·m). Only when the calculated real-time torque of the vehicle meets this preset condition, the automatic parking system exits the control. Otherwise, it is necessary to obtain the target steering angle B based on the real-time torque. n :

[0097]

[0098] In the formula, T m is the real-time torque of the nth sampling, and k eps is the steering system stiffness.

[0099] At the same time, the steering system will use the target steering angle to control the steering wheel to rotate in the reverse direction to compensate for the steering wheel deflection problem caused by tire deformation, excessive steering wheel rotation, or other factors, so that the steering wheel gradually returns to the centered position. In addition, when the steering wheel rotates in the reverse direction based on the target steering angle, since the real-time torque obtained by each sampling is constantly changing, the obtained target steering angle will also change. For example Figure 3As shown, the target steering angle calculated based on the real-time torque of the first sampling is B1, and then the steering wheel is commanded to turn towards the middle, approaching the target request angle A (0°).

[0100] After turning, before the steering wheel fully returns to the middle, another target steering angle B2 is calculated based on the new real-time torque (i.e., the real-time torque obtained from the second sampling). Add the previous B1 and the current B2 together, and then let the steering wheel continue to adjust in the reverse direction, and then approach the target request angle A (0°).

[0101] During this process, as time goes by, the target steering angle will fluctuate as shown in Figure 3 As shown. And during the process of the steering wheel continuously adjusting based on the target steering angle, the second angle of the steering wheel will be obtained multiple times. Then, using the second angle as the first angle, start to loop from obtaining the first error between the first angle and the target request angle until the real-time torque is less than the torque threshold, then it is determined that the vehicle has completed the steering wheel return to the straight position, and the automatic parking system exits the control.

[0102] When the method provided by the embodiment of the present application receives the steering wheel return-to-straight instruction, it obtains the first angle of the vehicle's steering wheel at the first moment, and then compares the first angle with the target request angle when the steering wheel is in the return-to-straight position to obtain the first error. Then, based on the first error, it determines whether the steering wheel is located in the return-to-straight position interval, thereby obtaining the real-time torque of the vehicle. Then, based on the comparison result between the real-time torque and the torque threshold, it obtains the target steering angle, and uses the target steering angle to control the steering wheel to rotate in the reverse direction until the steering wheel is in the return-to-straight position. Since the real-time torque can reflect the road surface type and the rebound angle of the steering wheel after the control is released, by dynamically calculating the target steering angle of the steering wheel through this algorithm and using the target steering angle to control the steering wheel to rotate in the reverse direction, the accuracy of the steering wheel return to the straight position can be improved, the number of adjustments can be reduced, the system can be prevented from entering an infinite loop or being unable to complete the return to the straight position, and the return-to-straight accuracy and user experience are improved.

[0103] Figure 4 is the complete flow diagram of the method for returning the vehicle's steering wheel to the straight position according to the embodiment of the present application. The specific process is as follows:

[0104] Step S1. The automatic parking system sends a steering wheel return-to-straight request to the steering system and sets the target request angle to 0° to ensure that the steering wheel returns to the return-to-straight position.

[0105] Step S2. The automatic parking system monitors the current angle of the steering wheel in real time through the steering wheel angle sensor and calculates the error between the current angle and the target request angle (0°).

[0106] Step S3. Determine whether the error is less than a preset threshold (e.g., 3°). If the error is less than the preset threshold, execute Step S4. The system confirms that the steering wheel is approaching the straight-ahead position and enters Step S5. Otherwise, the automatic parking system will continue to send a steering wheel straightening request until the error is less than the preset threshold.

[0107] Step S5. Start timing. After waiting for a preset duration, obtain the real-time torque of the power steering motor.

[0108] Step S6. Determine whether the real-time torque is less than the torque threshold. If the real-time torque is less than the torque threshold, then in Step S7, it is determined that the vehicle has completed steering wheel straightening and the automatic parking system exits the control. If the condition is not met, enter Step S8.

[0109] Step S8. Calculate the target steering angle based on the real-time torque.

[0110] Step S9. The automatic parking system sends a target steering angle request to the steering system according to the calculated target steering angle, and controls the steering wheel to rotate in the opposite direction of the current deflection direction to compensate for the steering wheel deflection problem caused by tire deformation or other factors.

[0111] Step S10. Calculate the error between the current angle of the steering wheel and the target requested angle, and repeat Steps S3 to S10 until the real-time torque is less than the torque threshold. Then execute Step S7, the vehicle completes steering wheel straightening, and the automatic parking system exits the control.

[0112] The method for straightening the vehicle steering wheel proposed in the embodiment of the present application calculates the target steering angle of the steering wheel using the real-time torque of the steering wheel. Since the real-time torque can reflect the road surface type and the rebound angle of the steering wheel after unlocking, the reverse rotation of the steering wheel based on the target steering angle can improve the accuracy of steering wheel straightening, reduce the number of adjustments, and prevent the system from entering an infinite loop or being unable to complete straightening.

[0113] In this embodiment, a device for straightening the vehicle steering wheel is also provided. This device is used to implement the above embodiments and preferred implementation manners, and those that have been described will not be repeated. As used below, the term "module" can be a combination of software and / or hardware that can achieve a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware is also possible and contemplated.

[0114] This embodiment provides a device for straightening the vehicle steering wheel, as Figure 5 shown, including:

[0115] The first acquisition module 501 is configured to obtain the first angle of the vehicle's steering wheel at the first moment when a steering wheel straightening instruction is received;

[0116] A second acquisition module 502, configured to acquire a first error between a first angle and a target request angle, and analyze the first error to determine whether the steering wheel is located within a returning-to-center position interval, where the target request angle is the angle at which the steering wheel is in the returning-to-center position, and the returning-to-center position interval is determined according to the returning-to-center position of the steering wheel and a preset threshold;

[0117] A third acquisition module 503, configured to acquire the real-time torque of the vehicle if the steering wheel is located within the returning-to-center position interval;

[0118] A control module 504, configured to acquire a comparison result between the real-time torque and a torque threshold, and in the case where the comparison result does not meet a preset condition, obtain a target rotation angle based on the real-time torque, and control the steering wheel to rotate in the reverse direction until the steering wheel is in the returning-to-center position, where the preset condition is that the real-time torque is less than the torque threshold.

[0119] In an embodiment of the present application, the second acquisition module 502 is configured to determine that the steering wheel is located within the returning-to-center position interval if the first error falls within a numerical range corresponding to the returning-to-center position interval. If the first error does not fall within the numerical range corresponding to the returning-to-center position interval, it is determined that the steering wheel is not located within the returning-to-center position interval.

[0120] In an embodiment of the present application, the third acquisition module 503 is configured to, when the steering wheel is located within the returning-to-center position interval, acquire vehicle driving condition data of the vehicle; determine a preset duration based on the vehicle driving condition data, where the preset duration is the duration to wait from a first moment until the real-time torque of the steering assist motor of the vehicle is acquired; and acquire the real-time torque of the vehicle after waiting for the preset duration.

[0121] In an embodiment of the present application, the third acquisition module 503 is configured to obtain a first change curve of the torque of the steering assist motor of the vehicle shifting with time and a second change curve of the steering wheel angle shifting with time based on the vehicle driving condition data and a real-time steering system model, where the real-time steering system model is used to evaluate the steering fluctuation state of the vehicle; and determine the preset duration based on the first change curve and the second change curve.

[0122] In an embodiment of the present application, the third acquisition module 503 is configured to obtain a first change rate based on the first change curve and a second change rate based on the second change curve; compare the first change rate with a corresponding first change rate threshold, and compare the second change rate with a corresponding second change rate threshold; in the case where the first change rate is less than the first change rate threshold and the second change rate is less than the second change rate threshold, acquire a current second moment; and obtain the preset duration based on the first moment and the second moment.

[0123] In an embodiment of the present application, the device further includes: after determining that the steering wheel is not in the straight-ahead position range, receiving a steering wheel straightening instruction and obtaining a preset rotation parameter corresponding to the steering wheel, where the preset rotation parameter is used to gradually return the steering wheel from the current position to the straight-ahead position; controlling the steering wheel to adjust the angle based on the preset rotation parameter until the steering wheel is in the straight-ahead position range.

[0124] In an embodiment of the present application, the control module 504 is configured to obtain a target rotation angle based on the real-time torque, control the steering wheel to rotate in the reverse direction by using the target rotation angle to obtain a second angle of the steering wheel, and use the second angle as the first angle, and start to loop from obtaining a first error between the first angle and the target request angle until the comparison result meets a preset condition to determine that the steering wheel is in the straight-ahead position.

[0125] The device for straightening the vehicle steering wheel in this embodiment is presented in the form of a functional unit. Here, the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and a memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0126] An embodiment of the present application further provides a computer device having the above Figure 5 shown device for straightening the vehicle steering wheel.

[0127] Please refer to Figure 6 , Figure 6 which is a schematic structural diagram of a computer device provided by an alternative embodiment of the present disclosure. As Figure 6 shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including a high-speed interface and a low-speed interface. Each component communicates with each other using different buses and can be installed on a common main board or installed in other ways as needed. The processor can process instructions executed within the computer device, including instructions stored in the memory or on the memory to display graphical information of the GUI on an external input / output device (such as a display device coupled to the interface). In some alternative embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (such as an array of servers, a set of blade servers, or a multi-processor system). Figure 6 In

[0128] The processor 10 may be a central processing unit, a network processor, or a combination thereof. Among them, the processor 10 may further include a hardware chip. The above-mentioned hardware chip may be an application-specific integrated circuit, a programmable logic device, or a combination thereof. The above-mentioned programmable logic device may be a complex programmable logic device, a field programmable gate array, a generic array logic, or any combination thereof.

[0129] Among them, the memory 20 stores instructions executable by at least one processor 10, so that at least one processor 10 executes the method shown in the above embodiments.

[0130] The memory 20 may include a program storage area and a data storage area. Among them, the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may further include a non-transitory memory, such as at least one magnetic disk storage device, a flash memory device, or other non-transitory solid-state storage devices. In some alternative embodiments, the memory 20 may optionally include a memory remotely provided with respect to the processor 10, and these remote memories may be connected to the computer device through a network. Examples of the above-mentioned network include but are not limited to the Internet, an enterprise intranet, a local area network, a mobile communication network, and combinations thereof.

[0131] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk, or a solid-state drive; the memory 20 may further include a combination of the above types of memories.

[0132] The electronic device further includes a communication interface 30 for the electronic device to communicate with other devices or communication networks.

[0133] The embodiment of the present invention further provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or be implemented as computer code that can be recorded on a storage medium, or be implemented as computer code originally stored in a remote storage medium or a non-transitory machine-readable storage medium and downloaded through a network and to be stored in a local storage medium, so that the method described herein can be stored in such software processed on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium may be a magnetic disk, an optical disk, a read-only memory, a random access memory, a flash memory, a hard disk, or a solid-state drive, etc.; further, the storage medium may further include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by the computer, the processor, or the hardware, the method shown in the above embodiments is implemented.

[0134] While embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A method for returning a vehicle steering wheel to center, characterized in that: The method comprises: Upon receiving a steering wheel return command, obtaining a first angle of the steering wheel of the vehicle at a first moment; Obtaining a first error between the first angle and a target requested angle, and analyzing the first error to determine whether the steering wheel is located in a return-to-center position interval, wherein the target requested angle is an angle at which the steering wheel is in a return-to-center position, and the return-to-center position interval is determined according to the return-to-center position of the steering wheel and a preset threshold; If the steering wheel is in the return position interval, obtaining the real-time torque of the vehicle; Obtain a comparison result between the real-time torque and a torque threshold, and if the comparison result does not meet a preset condition, obtain a target angle based on the real-time torque, and use the target angle to control the steering wheel to rotate in the opposite direction until the steering wheel is in a return position, wherein the preset condition is that the real-time torque is less than the torque threshold.

2. The method according to claim 1, characterized in that The analyzing the first error to determine whether the steering wheel is located in a return-to-center position interval includes: If the first error falls within the numerical range corresponding to the return-to-center position interval, determining that the steering wheel is located in the return-to-center position interval; If the first error does not fall within the numerical range corresponding to the return-to-center position interval, it is determined that the steering wheel is not located in the return-to-center position interval.

3. The method according to claim 1, characterized in that If the steering wheel is in the return position interval, obtaining the real-time torque of the vehicle includes: When the steering wheel is located in the return-to-center position interval, obtaining vehicle driving condition data of the vehicle; Determining a preset time length based on the vehicle driving condition data, wherein the preset time length is the time length required to wait from the first moment to obtain the real-time torque of the steering power motor of the vehicle; After waiting for the preset time period, the real-time torque of the vehicle is obtained.

4. The method according to claim 3, characterized in that The determining the preset duration based on the vehicle driving condition data comprises: Based on the vehicle driving condition data and the real-time model of the steering system, a first variation curve of the steering power motor torque of the vehicle shifting backward with time and a second variation curve of the steering wheel angle shifting backward with time are obtained, wherein the real-time model of the steering system is used to evaluate the steering fluctuation state of the vehicle; The preset duration is determined based on the first change curve and the second change curve.

5. The method according to claim 4, characterized in that The determining the preset duration based on the first change curve and the second change curve includes: Obtain a first change rate based on the first change curve, and obtain a second change rate based on the second change curve; comparing the first change rate with a corresponding first change rate threshold, and comparing the second change rate with a corresponding second change rate threshold; When the first change rate is less than the first change rate threshold and the second change rate is less than the second change rate threshold, acquiring a current second moment; The preset duration is obtained based on the first moment and the second moment.

6. The method according to claim 2, characterized in that After determining that the steering wheel is not located in the return-to-center position interval, the method further includes: receiving the steering wheel return instruction, and acquiring the preset rotation parameters corresponding to the steering wheel, wherein the preset rotation parameters are used to gradually return the steering wheel from the current position to the return position; The steering wheel is controlled to adjust its angle based on the preset rotation parameter until the steering wheel is located in the return position interval.

7. The method according to claim 1, characterized in that The step of obtaining a target angle based on the real-time torque and controlling the steering wheel to rotate in the opposite direction by using the target angle until the steering wheel is in a return position comprises: A target angle is obtained based on the real-time torque, and the target angle is used to control the steering wheel to rotate in the opposite direction to obtain a second angle of the steering wheel. The second angle is used as the first angle, and the loop is executed starting from obtaining a first error between the first angle and the target requested angle until the comparison result meets the preset condition, and it is determined that the steering wheel is in the return position.

8. A device for returning the steering wheel of a vehicle to the center position, characterized in that: The device comprises: A first acquisition module is used to acquire a first angle of the steering wheel of the vehicle at a first moment when receiving a steering wheel return command; a second acquisition module, configured to acquire a first error between the first angle and a target requested angle, and analyze the first error to determine whether the steering wheel is located in a return-to-center position interval, wherein the target requested angle is an angle at which the steering wheel is in a return-to-center position, and the return-to-center position interval is determined according to the return-to-center position of the steering wheel and a preset threshold; A third acquisition module, configured to acquire the real-time torque of the vehicle if the steering wheel is located in the return-to-center position interval; A control module is used to obtain a comparison result between the real-time torque and a torque threshold, and when the comparison result does not meet a preset condition, obtain a target angle based on the real-time torque, and use the target angle to control the steering wheel to rotate in the opposite direction until the steering wheel is in a return position, wherein the preset condition is that the real-time torque is less than the torque threshold.

9. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method for returning the vehicle steering wheel to the center position as claimed in any one of claims 1 to 7 by executing the computer instructions.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the method for returning the vehicle steering wheel to center according to any one of claims 1 to 7.

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