A method, apparatus, vehicle and storage medium for determining a turning angle of a vehicle

Abstract

The application provides a method and device for determining a vehicle turning angle, a vehicle and a storage medium. The method is applied to the field of vehicle steering control and includes the following steps: in the case of an abnormal steering wheel turning angle signal, determining a target turning angle difference between a current time and a previous time according to an actual wheel speed of a target front wheel and a predicted wheel speed of the target front wheel; the target front wheel is a front wheel capable of keeping the vehicle in a safe driving state among a left front wheel and a right front wheel; determining a target steering wheel turning angle at the current time according to the target turning angle difference, a first predicted front wheel turning angle at the current time and a previous front wheel turning angle at the previous time; the first predicted front wheel turning angle is a front wheel turning angle predicted based on the running state of the vehicle at the current time; and controlling the vehicle to run based on the target steering wheel turning angle. The method can control the vehicle to run through the estimated steering wheel turning angle when the steering wheel turning angle signal is lost during the running of the vehicle, thereby avoiding the safety risks caused by the uncontrollable vehicle.

Description

Technical Field

[0001] This application relates to the field of vehicle steering control, and more specifically, to a method, apparatus, vehicle, and storage medium for determining the steering angle of a vehicle in the field of vehicle steering control. Background Technology

[0002] During vehicle operation, the steering wheel angle plays a crucial role in the vehicle's movement. For example, in Active Rear Steering (ARS), the ARS system adjusts the rear wheel angle based on the steering wheel angle (i.e., the driver's steering intention) and other vehicle dynamic parameters (such as vehicle speed and yaw rate).

[0003] Due to various factors, the steering wheel angle signal may be lost during transmission while the vehicle is in motion. For the aforementioned ARS system, the loss of the steering wheel angle signal may prevent the ARS system from recognizing the driver's steering intentions, causing the vehicle to become uncontrollable and produce an unexpected driving trajectory, threatening the driver's life safety.

[0004] Therefore, how to reasonably control the vehicle when the steering wheel angle signal is lost has become an urgent problem to be solved. Summary of the Invention

[0005] This application provides a method, apparatus, vehicle, and storage medium for determining vehicle steering angle. The method can control vehicle operation by estimating the steering wheel angle when the steering wheel angle signal is lost during vehicle operation, thereby avoiding safety risks caused by uncontrolled vehicle operation.

[0006] In a first aspect, a method for determining a vehicle steering angle is provided. The method includes: in the event of an abnormal steering wheel angle signal, determining a target steering angle difference between the current moment and the previous moment based on the actual wheel speed of the target front wheel and the predicted wheel speed of the target front wheel; the target front wheel being either the left front wheel or the right front wheel that enables the vehicle to be in a safe driving state; determining a target steering wheel angle at the current moment based on the target steering angle difference, a first predicted front wheel angle at the current moment, and the previous front wheel angle at the previous moment, wherein the first predicted front wheel angle is a front wheel angle predicted based on the vehicle's current operating state; and controlling the vehicle's operation based on the target steering wheel angle.

[0007] In the above technical solution, if the steering wheel signal is lost during vehicle operation, this application proposes a method for determining the vehicle's steering angle. Specifically, when the vehicle detects an abnormality (loss) in the steering wheel angle signal, the difference between the current and previous moments is determined by using the actual wheel speed and the predicted wheel speed of the target front wheel. The target front wheel is either the left or right front wheel, the one that ensures the vehicle is in a safe driving state. This estimation process prioritizes vehicle driving safety. The actual and predicted wheel speeds reflect the difference between the wheel speed during vehicle operation and the ideal wheel speed. By determining the target steering angle difference using these two wheel speeds and further obtaining the steering wheel angle, the actual wheel speed during vehicle operation becomes closer to the predicted wheel speed. Therefore, by estimating the target steering wheel angle when the steering wheel signal is abnormal, the vehicle can still steer normally, optimizing the vehicle's steering response and accuracy, ensuring continuity during driving, preventing user anxiety, and enhancing the reliability of vehicle fault handling.

[0008] In conjunction with the first aspect, in some possible implementations, determining the target steering wheel angle at the current moment based on the target steering angle difference, the first predicted front wheel angle at the current moment, and the previous front wheel angle at the previous moment includes: determining the second predicted front wheel angle at the current moment as the sum of the target steering angle difference and the previous front wheel angle; determining the target front wheel angle as the smaller of the first predicted front wheel angle and the second predicted front wheel angle; and determining the target steering wheel angle based on the target front wheel angle and a preset steering ratio.

[0009] In the above technical solution, a certain rotation ratio relationship exists between the steering wheel angle and the front wheel angle. When determining the target steering wheel angle, the vehicle can first determine the target front wheel angle at the current moment, and then determine the target steering wheel angle based on the rotation ratio. The first predicted front wheel angle is the front wheel angle predicted by the vehicle based on the current dynamics model and current state, and is only related to the current state of the vehicle. By summing the difference between the previous front wheel angle and the target angle, the second predicted front wheel angle at the current moment is obtained. The second predicted front wheel angle takes into account the angle changes between the current moment and the previous moment. By selecting the smaller front wheel angle from the first and second predicted front wheel angles as the target front wheel angle, the vehicle's steering safety can be ensured, and oversteering can be avoided.

[0010] In conjunction with the first aspect and the above implementation methods, in some possible implementation methods, the method further includes: determining the target front wheel based on the vehicle's operating parameters at the current moment, the operating parameters being used to represent the vehicle's operating state; and determining the predicted wheel speed based on the operating parameters at the current moment, the vehicle's operating parameters at the previous moment, and the time difference between the current moment and the previous moment.

[0011] In conjunction with the first aspect and the above implementation methods, in some possible implementation methods, the operating parameters at the current moment include the driving condition, the actual wheel speed of the left front wheel, and the actual wheel speed of the right front wheel. Determining the target front wheel based on the vehicle's operating parameters at the current moment includes: determining the target front wheel as the left front wheel when the actual wheel speed of the left front wheel is normal and the actual wheel speed of the right front wheel is abnormal; determining the target front wheel as the right front wheel when the actual wheel speed of the left front wheel is abnormal and the actual wheel speed of the right front wheel is normal; when the actual wheel speeds of the left and right front wheels are normal, if the driving condition is a driving condition, determining the target front wheel as the front wheel corresponding to the smaller of the actual wheel speeds of the left and right front wheels; if the driving condition is a braking condition, determining the target front wheel as the front wheel corresponding to the larger of the actual wheel speeds of the left and right front wheels.

[0012] In the above technical solution, when determining the target front wheel, the vehicle first checks whether the actual wheel speeds of the left and right front wheels are normal. If the actual wheel speed of one of the front wheels is abnormal, control is achieved by relying on the actual wheel speed of the other front wheel, thus providing reliability and accuracy in determining the target front wheel. Furthermore, when both front wheels have normal actual wheel speeds, under driving conditions, one front wheel may slip, resulting in an excessively high wheel speed relative to the other normally moving front wheel. By selecting the front wheel with the lower wheel speed, the vehicle can achieve safe control during normal turning. When the vehicle is braking, if one front wheel has good braking performance, its wheel speed is lower compared to the other front wheel. By selecting the front wheel with the higher wheel speed, the reliability of turning during braking is increased, thus enhancing vehicle safety.

[0013] In conjunction with the first aspect and the above implementation methods, in some possible implementation methods, determining the predicted wheel speed based on the operating parameters at the current moment, the operating parameters of the vehicle at the previous moment, and the time difference between the current moment and the previous moment includes: determining the target predicted lateral speed and the target predicted longitudinal speed at the current moment based on the operating parameters at the current moment, the operating parameters at the previous moment, and the time difference; and determining the predicted wheel speed based on the target predicted lateral speed, the target predicted longitudinal speed, the operating parameters at the current moment, and the operating parameters at the previous moment.

[0014] In conjunction with the first aspect and the above implementation methods, in some possible implementation methods, the operating parameters at the current moment include yaw rate, lateral acceleration, longitudinal acceleration, left rear wheel speed, and right rear wheel speed; the operating parameters at the previous moment include the previous longitudinal speed, previous lateral speed, and previous front wheel steering angle; determining the target predicted lateral speed and target predicted longitudinal speed at the current moment based on the operating parameters at the current moment, the operating parameters at the previous moment, and the time difference includes: determining the product of the longitudinal acceleration and the time difference; determining the first predicted longitudinal speed based on the previous longitudinal speed and the product; determining the second predicted longitudinal speed as the average wheel speed of the left rear wheel speed and the right rear wheel speed; and determining the target predicted longitudinal speed as the first predicted longitudinal speed. The longitudinal vehicle speed with the smaller value among the vehicle speed and the second predicted longitudinal vehicle speed; the target predicted lateral vehicle speed is determined based on the previous lateral vehicle speed, the lateral acceleration, the yaw acceleration, the target predicted longitudinal vehicle speed, and the time difference; and the predicted wheel speed is determined based on the target predicted lateral vehicle speed, the target predicted longitudinal vehicle speed, the current operating parameters, and the previous operating parameters, including: determining the sine and cosine values ​​of the previous front wheel steering angle; determining a first predicted wheel speed component based on the cosine value, the target predicted longitudinal vehicle speed, and the yaw rate; determining a second predicted wheel speed component based on the sine value, the target predicted lateral vehicle speed, and the yaw rate; and determining the predicted wheel speed as the sum of the first predicted wheel speed component and the second predicted wheel speed component.

[0015] In combination with the first aspect and the above implementation methods, in some possible implementation methods, the step of determining the first predicted front wheel steering angle includes: obtaining the actual longitudinal speed, rear wheel steering angle and yaw rate of the vehicle at the current moment; and determining the first predicted front wheel steering angle based on the actual longitudinal speed, the rear wheel steering angle and the yaw rate.

[0016] Secondly, an apparatus for determining vehicle steering angle is provided. The apparatus includes: a difference determination module, used to determine a target steering angle difference between the current moment and the previous moment based on the actual wheel speed of the target front wheel and the predicted wheel speed of the target front wheel when the steering wheel angle signal is abnormal; the target front wheel is the left front wheel or the right front wheel that can keep the vehicle in a safe driving state; an angle determination module, used to determine the target steering wheel angle at the current moment based on the target steering angle difference, the first predicted front wheel angle at the current moment, and the previous front wheel angle at the previous moment; the first predicted front wheel angle is the front wheel angle predicted based on the current operating state of the vehicle; and a control module, used to control the operation of the vehicle based on the target steering wheel angle.

[0017] In conjunction with the second aspect, in some possible implementations, the steering angle determination module is specifically used to: determine the second predicted front wheel steering angle at the current moment as the sum of the target steering angle difference and the previous front wheel steering angle; determine the target front wheel steering angle as the smaller of the first predicted front wheel steering angle and the second predicted front wheel steering angle; and determine the target steering wheel angle based on the target front wheel steering angle and the preset steering ratio.

[0018] In conjunction with the second aspect and the above-described implementation, in some possible implementations, the device further includes: a wheel speed determination module, used to determine the target front wheel based on the vehicle's operating parameters at the current moment, the operating parameters being used to represent the vehicle's operating state; and to determine the predicted wheel speed based on the operating parameters at the current moment, the vehicle's operating parameters at the previous moment, and the time difference between the current moment and the previous moment.

[0019] In conjunction with the second aspect and the above implementation methods, in some possible implementation methods, the operating parameters at the current moment include the driving condition, the actual wheel speed of the left front wheel, and the actual wheel speed of the right front wheel. The wheel speed determination module is specifically used to: determine the target front wheel as the left front wheel when the actual wheel speed of the left front wheel is normal and the actual wheel speed of the right front wheel is abnormal; determine the target front wheel as the right front wheel when the actual wheel speed of the left front wheel is abnormal and the actual wheel speed of the right front wheel is normal; when the actual wheel speed of the left front wheel is normal and the actual wheel speed of the right front wheel is normal, if the driving condition is a driving condition, determine the target front wheel as the front wheel corresponding to the wheel speed with the smaller value between the actual wheel speed of the left front wheel and the actual wheel speed of the right front wheel; if the driving condition is a braking condition, determine the target front wheel as the front wheel corresponding to the wheel speed with the larger value between the actual wheel speed of the left front wheel and the actual wheel speed of the right front wheel.

[0020] In conjunction with the second aspect and the above implementation methods, in some possible implementation methods, the wheel speed determination module is further configured to: determine the target predicted lateral speed and the target predicted longitudinal speed at the current moment based on the operating parameters at the current moment, the operating parameters at the previous moment, and the time difference; and determine the predicted wheel speed based on the target predicted lateral speed, the target predicted longitudinal speed, the operating parameters at the current moment, and the operating parameters at the previous moment.

[0021] In conjunction with the second aspect and the above implementation methods, in some possible implementation methods, the operating parameters at the current moment include yaw rate, lateral acceleration, longitudinal acceleration, left rear wheel speed, and right rear wheel speed; the operating parameters at the previous moment include the previous longitudinal speed, the previous lateral speed, and the previous front wheel steering angle; the wheel speed determination module is further used to: determine the product of the longitudinal acceleration and the time difference; determine a first predicted longitudinal speed based on the previous longitudinal speed and the product; determine a second predicted longitudinal speed as the average wheel speed of the left rear wheel speed and the right rear wheel speed; and determine the target predicted longitudinal speed as the first predicted longitudinal speed. The wheel speed determination module is further configured to: determine the longitudinal speed with the smaller value between the previous lateral speed and the second predicted longitudinal speed; determine the target predicted lateral speed based on the previous lateral speed, the lateral acceleration, the yaw acceleration, the target predicted longitudinal speed, and the time difference; and determine the wheel speed determination module is also configured to: determine the sine and cosine values ​​of the previous front wheel steering angle; determine the first predicted wheel speed component based on the cosine value, the target predicted longitudinal speed, and the yaw rate; determine the second predicted wheel speed component based on the sine value, the target predicted lateral speed, and the yaw rate; and determine the predicted wheel speed as the sum of the first predicted wheel speed component and the second predicted wheel speed component.

[0022] In conjunction with the second aspect and the above implementation methods, in some possible implementation methods, the device further includes: a steering angle prediction module, used to acquire the actual longitudinal speed, rear wheel steering angle and yaw rate of the vehicle at the current moment; and to determine the first predicted front wheel steering angle based on the actual longitudinal speed, the rear wheel steering angle and the yaw rate.

[0023] Thirdly, a vehicle is provided, including a memory and a processor. The memory is used to store executable program code, and the processor is used to call and run the executable program code from the memory, causing the vehicle to perform the methods described in the first aspect or any possible implementation thereof.

[0024] Fourthly, a computer program product is provided, comprising: computer program code, which, when run on a computer, causes the computer to perform the methods described in the first aspect or any possible implementation thereof.

[0025] Fifthly, a computer-readable storage medium is provided that stores computer program code, which, when executed on a computer, causes the computer to perform the methods described in the first aspect or any possible implementation thereof. Attached Figure Description

[0026] Figure 1 This is a schematic flowchart illustrating a method for determining the turning angle of a vehicle according to an embodiment of this application;

[0027] Figure 2 This is a schematic flowchart illustrating a method for determining a target angle difference provided in an embodiment of this application;

[0028] Figure 3 This is a schematic flowchart illustrating a method for determining the steering wheel angle provided in an embodiment of this application;

[0029] Figure 4 This is a schematic diagram of a device for determining the turning angle of a vehicle provided in an embodiment of this application;

[0030] Figure 5 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application. Detailed Implementation

[0031] The technical solutions in this application will be clearly and thoroughly described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more than two.

[0032] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0033] Before introducing the methods of the embodiments of this application, the technical terms that may be involved in the embodiments of this application will be explained.

[0034] ARS (Advanced Vehicle Dynamics Control) is an advanced vehicle dynamics control system that actively adjusts the steering angle of the rear wheels based on vehicle speed, steering wheel angle, and other sensor data to improve vehicle handling and stability. Active rear-wheel steering can reduce the turning radius of the vehicle by turning the rear wheels a small angle in the opposite direction to the front wheels when the vehicle is traveling at low speeds or stationary; and improve straight-line stability when the vehicle is traveling at high speeds by turning the rear wheels a small angle in the same direction as the front wheels.

[0035] Steering ratio: The ratio between the angle the steering wheel turns and the actual angle the front wheels turn.

[0036] Electronic Stability Program (ESP), also known as Electronic Stability Control, is an active safety system designed to prevent vehicles from skidding or losing control in emergency situations. It maintains vehicle stability by detecting and reducing oversteer or understeer.

[0037] Traction Control System (TCS): Prevents the drive wheels from spinning and slipping when the vehicle is driving on wet or slippery surfaces, ensuring optimal traction for the vehicle under various driving conditions.

[0038] Adaptive Cruise Control (ACC): An intelligent cruise control system that automatically adjusts the vehicle speed within a set speed range to maintain a safe distance from the vehicle in front.

[0039] Electric Power Steering (EPS) system: A system that uses an electric motor to provide steering assistance, replacing the traditional hydraulic power steering system. EPS systems can provide appropriate assistance based on vehicle speed and steering angle, making steering easier.

[0040] The application scenarios of the embodiments of this application are described below.

[0041] Currently, with the gradual development of intelligent technology, vehicles are equipped with a variety of functions. During vehicle operation, these functions can be activated as needed to ensure driving safety and driver safety.

[0042] The steering wheel angle plays a crucial role in the operation of various vehicle functions. Below are examples of how the steering wheel angle is used in various vehicle functions.

[0043] For example, the ARS system adjusts the angle of the rear wheels based on the steering wheel angle (i.e., the driver's steering intention) and other vehicle dynamic parameters (such as vehicle speed, yaw rate, etc.).

[0044] During the operation of the ESP system, steering wheel angle is one of the important input signals. The ESP system can determine whether the vehicle has deviated from the expected path based on the steering wheel angle, combined with data from other sensors (such as vehicle speed and yaw rate), thereby controlling the vehicle to maintain a stable driving state.

[0045] During the operation of the TSC system, the system can determine whether the vehicle is turning based on the steering wheel angle and determine the braking force that needs to be applied to ensure normal vehicle control.

[0046] During the operation of the ACC system, the ACC system can determine whether the driver intends to change lanes or turn based on the steering wheel angle, and thus decide whether to continue to keep the ACC function active or deactivate it.

[0047] During the operation of the EPS system, the EPS system can dynamically adjust the magnitude and direction of the power assist provided by the electric motor according to the change of steering wheel angle, so as to ensure that the vehicle steering operation is both light and precise.

[0048] Due to various factors, the steering wheel angle signal may be lost during vehicle operation, causing the vehicle to be unable to acquire the steering wheel angle. Common signal loss scenarios include, but are not limited to, the following:

[0049] (1) Sensor failure

[0050] When the steering wheel angle sensor itself suffers physical damage, such as a broken wire, loose connection, or failure of internal components, it may be unable to collect the steering wheel angle, resulting in the loss of the steering wheel angle signal.

[0051] (2) Power supply problem

[0052] The steering wheel angle sensor requires a stable power supply to function properly. If the power supply voltage is unstable or there is a power outage, the steering wheel angle sensor will not function properly.

[0053] (3) Communication failure

[0054] Sensor signals typically communicate with the Electronic Control Unit (ECU) via a communication bus (e.g., Controller Area Network (CAN) bus). When the communication bus malfunctions, signal loss may occur.

[0055] Based on the role of steering wheel angle in various vehicle functions, the loss of steering wheel angle signal will affect the normal operation of various vehicle functions.

[0056] Specifically, if the steering wheel angle signal is lost, the ARS system cannot obtain the driver's steering intention, causing the vehicle to become uncontrollable and produce an unexpected driving trajectory, threatening the driver's life safety.

[0057] The ESP system will be unable to accurately determine the driver's intentions, which may lead to incorrect intervention or complete failure, increasing the risk of losing vehicle control.

[0058] The TSC system cannot accurately assess the vehicle's direction of travel and the driver's steering intentions, resulting in the application of unnecessary braking or power limitation to the vehicle, affecting the driving experience and safety.

[0059] The ACC system cannot recognize whether the driver is changing lanes or performing other steering operations, leading to misjudgment and taking inappropriate deceleration or acceleration measures.

[0060] The EPS system fails to provide adequate assistance based on the current steering angle, resulting in heavy or unstable steering.

[0061] Based on the aforementioned problem of vehicle uncontrollability when the steering wheel angle signal is lost, this application provides a method for determining the vehicle's steering angle. This method can control the vehicle's operation by estimating the steering wheel angle when the steering wheel angle signal is lost during vehicle operation, thereby avoiding the safety risks caused by the vehicle being out of control.

[0062] The following describes a method for determining the turning angle of a vehicle, provided by an embodiment of this application.

[0063] Figure 1 This is a schematic flowchart illustrating a method for determining the turning angle of a vehicle according to an embodiment of this application. It should be understood that this method can be applied to any ECU in the vehicle, and this embodiment of the application does not limit the ECU that executes the method.

[0064] For example, such as Figure 1 As shown, the method 100 includes:

[0065] 101. In the event of an abnormal steering wheel angle signal, determine the target angle difference between the current moment and the previous moment based on the actual wheel speed of the target front wheel and the predicted wheel speed of the target front wheel; the target front wheel is the front wheel that can keep the vehicle in a safe driving state between the left front wheel and the right front wheel.

[0066] The aforementioned abnormal steering wheel angle signal refers to the loss of the steering wheel angle signal.

[0067] It should be understood that most vehicles are now equipped with a variety of vehicle functions (e.g., various intelligent driving functions). During vehicle operation, in order to ensure the safety of the vehicle and its occupants, the ECU can control the operation of various vehicle functions according to the vehicle's operating status.

[0068] Optional features include, but are not limited to, ACC, TSC, EPS, Lane Keeping Assist (LKA), etc.

[0069] During vehicle operation, steering wheel angle signals represent the driver's steering intentions. Therefore, steering wheel angle signals play a crucial role in the operation of vehicle functions.

[0070] During vehicle operation, various factors (such as sensor inaccuracy or communication bus malfunctions) can cause the steering wheel angle signal to be lost, preventing the ECU from acquiring it and thus affecting the normal control and operation of various vehicle functions. Therefore, the ECU needs to constantly monitor whether the steering wheel angle signal is being transmitted normally while the vehicle is in motion.

[0071] The following are several methods for determining whether the steering wheel angle signal is lost, provided in the embodiments of this application.

[0072] The first method involves a sampling period when the steering angle sensor collects the steering wheel angle signal. That is, the steering angle sensor typically collects the steering wheel angle signal at fixed time intervals. Therefore, in this embodiment, the technician can preset the maximum response time of the steering wheel angle signal based on the sampling period of the steering angle sensor. Each time the ECU receives a steering wheel angle signal, it updates a timer. If the ECU does not receive a new steering wheel angle signal within the maximum response time, it is determined that the steering wheel angle signal has been lost; conversely, if the ECU receives a new steering wheel angle signal within the maximum response time, it is determined that the steering wheel angle signal has not been lost.

[0073] The second method involves the vehicle controlling the ECU used to send steering wheel angle signals to the ECU executing this method at regular intervals. If the ECU executing this method does not receive a heartbeat signal within a preset time period, it is confirmed that the steering wheel angle signal has been lost; if the ECU executing this method receives a heartbeat signal within the preset time period, it is confirmed that the steering wheel angle signal has not been lost.

[0074] Therefore, regardless of which method is used, when the ECU determines that the steering wheel angle signal is lost, the method of this application embodiment can be used to estimate the current steering wheel angle using the vehicle's driving parameters.

[0075] It should be understood that the steering wheel angle and the front wheel angle are directly related during vehicle operation. Therefore, when estimating the steering wheel angle, it can be indirectly obtained by estimating the front wheel angle. When determining the front wheel angle, the ECU can first determine the target steering angle difference between the current moment and the previous moment, i.e., the required compensation angle between the current moment and the previous moment.

[0076] Specifically, when calculating the target steering angle difference, the ECU can select the target front wheel from the vehicle's left and right front wheels to ensure safe driving. Then, based on the actual wheel speed and the predicted wheel speed of the target front wheel, the target steering angle difference is determined. The actual wheel speed refers to the wheel speed collected by the wheel speed sensor of the target front wheel; the predicted wheel speed is the theoretical wheel speed of the target front wheel estimated by the ECU based on the vehicle's operating parameters.

[0077] The following describes the process of determining the target front wheel and the predicted wheel speed of the target front wheel in an embodiment of this application.

[0078] One possible implementation method also includes:

[0079] Based on the vehicle's operating parameters at the current moment, the target front wheel is determined. The operating parameters are used to represent the vehicle's operating status.

[0080] The predicted wheel speed is determined based on the current operating parameters, the vehicle's operating parameters at the previous moment, and the time difference between the current moment and the previous moment.

[0081] Specifically, the ECU can combine the vehicle's operating parameters at the current moment with the operating parameters at the previous moment to determine the predicted wheel speed.

[0082] During vehicle operation, the ECU can acquire the vehicle's operating parameters at any given moment through various sensors within the vehicle. These operating parameters represent the vehicle's operating status. Therefore, the ECU can obtain the operating parameters at the current moment and the operating parameters from the previous moment.

[0083] For the target front wheel at the current moment, the ECU can determine the target front wheel from the vehicle's left and right front wheels based on the current operating parameters. The target front wheel is the one that ensures the vehicle remains in a safe driving state, either the left or right front wheel.

[0084] When identifying the target front wheel, its wheel speed plays a crucial role in the prediction process. Therefore, the ECU must first ensure that the actual wheel speed of the target front wheel is accurate and reliable. Specifically, the ECU can do this by checking for any abnormalities in the wheel speeds of the two front wheels. Secondly, since the two front wheels operate differently under various driving conditions, the ECU also needs to consider the vehicle's driving conditions.

[0085] Therefore, when determining the target front wheel, the current operating parameters include the driving conditions, the actual wheel speed of the left front wheel, and the actual wheel speed of the right front wheel. The specific process and principle of determining the target front wheel based on the above parameters at the current moment are explained below.

[0086] One possible implementation involves determining the target front wheel based on the vehicle's current operating parameters, including:

[0087] If the actual wheel speed of the left front wheel is normal and the actual wheel speed of the right front wheel is abnormal, the target front wheel is determined to be the left front wheel;

[0088] If the actual wheel speed of the left front wheel is abnormal while the actual wheel speed of the right front wheel is normal, the target front wheel is determined to be the right front wheel.

[0089] If the actual wheel speeds of the left and right front wheels are both normal, and the driving condition is a drive condition, the target front wheel is determined as the front wheel corresponding to the smaller of the actual wheel speeds of the left and right front wheels. If the driving condition is a braking condition, the target front wheel is determined as the front wheel corresponding to the larger of the actual wheel speeds of the left and right front wheels.

[0090] For example, the ECU can obtain the actual wheel speed of the left front wheel through the wheel speed sensor of the left front wheel, and obtain the actual wheel speed of the right front wheel through the wheel speed sensor of the right front wheel.

[0091] Regarding driving conditions, the engine speed varies depending on the driving conditions. Therefore, in this embodiment, the technician can preset engine speed ranges corresponding to different driving conditions based on the actual driving scenario of the vehicle, and store these ranges in the ECU. When obtaining the current driving condition, the ECU can obtain the current engine speed and match it with the preset engine speed ranges for different driving conditions to obtain the driving condition.

[0092] Optionally, the driving conditions include driving conditions and braking conditions.

[0093] To ensure the accuracy and effectiveness of determining the actual wheel speed of the target front wheels, the ECU needs to first determine whether the actual wheel speeds of the left and right front wheels are normal, in order to determine whether the actual wheel speeds of the left and right front wheels are available at the current moment.

[0094] The question of whether the actual wheel speed of the left front wheel or the actual wheel speed of the right front wheel is normal has two meanings: first, whether the wheel speed signal of the left front wheel or the signal of the right front wheel is lost; and second, whether the actual wheel speed of the left front wheel or the actual wheel speed of the right front wheel is within a reasonable wheel speed range.

[0095] Therefore, when the ECU determines whether the actual wheel speed of the left front wheel is normal, it first determines whether it can acquire the actual wheel speed signal sent by the wheel speed sensor of the left front wheel. Specifically, based on the above description, the ECU can also determine whether it can acquire the actual wheel speed signal of the left front wheel by setting a preset response time or sending a heartbeat signal.

[0096] When the ECU cannot obtain the actual wheel speed signal of the left front wheel, it determines that the actual wheel speed of the left front wheel is abnormal. When the ECU can obtain the actual wheel speed signal of the left front wheel, it needs to further determine whether the actual wheel speed of the left front wheel is within a reasonable wheel speed range. If the actual wheel speed of the left front wheel is within a reasonable wheel speed range, the ECU determines that the actual wheel speed of the left front wheel is normal; if the actual wheel speed of the left front wheel is outside a reasonable wheel speed range, the ECU determines that the actual wheel speed of the left front wheel is abnormal.

[0097] Similarly, based on the same principle, the ECU can also determine whether the actual wheel speed of the right front wheel is normal.

[0098] When the ECU determines that the actual wheel speed of the left front wheel is normal, but the actual wheel speed of the right front wheel is abnormal, it means that the actual wheel speed of the right front wheel is invalid. Therefore, the ECU determines that the target front wheel is the left front wheel.

[0099] When the ECU determines that the actual wheel speed of the right front wheel is normal, but the actual wheel speed of the left front wheel is abnormal, it means that the actual wheel speed of the left front wheel is invalid. Therefore, the ECU determines that the target front wheel is the right front wheel.

[0100] In other words, regardless of the vehicle's driving conditions, if the actual wheel speed of one front wheel is abnormal, the ECU will directly identify the other front wheel as the target front wheel.

[0101] When the ECU determines that the actual wheel speed of the left front wheel is abnormal and the actual wheel speed of the right front wheel is abnormal, it cannot continue to execute the solution of this application embodiment and can generate abnormal alarm information to prompt the user to handle it in time.

[0102] When the ECU determines that the actual wheel speeds of both the right and left front wheels are normal, the rotation of the front wheels varies under different driving conditions. Therefore, the ECU can specifically determine the target front wheel based on the different driving conditions.

[0103] In one scenario, if the current driving condition is under traction, road surface and weather factors can cause the vehicle to slip, resulting in inconsistent wheel speeds between the two front wheels. For example, when a vehicle is traveling on a wet surface and one front wheel slips, that front wheel has a higher actual wheel speed, while the other front wheel rolls normally. The actual wheel speed of the slipping front wheel is larger than that of the non-slipping front wheel. Therefore, under traction conditions, the ECU needs to select the safer, non-slipping front wheel (i.e., the front wheel with the lower actual wheel speed) as the target front wheel to achieve stable vehicle control.

[0104] In another scenario, if the current driving condition is braking, during vehicle braking, one front wheel may have locked due to good braking performance, resulting in a lower actual wheel speed, while the other front wheel, due to poor braking performance, maintains a higher actual wheel speed. Therefore, to ensure vehicle safety and enable sufficient braking, the ECU can select the front wheel with the higher actual wheel speed as the target front wheel in this situation.

[0105] Through the above process, the ECU selects the target front wheel from the left and right front wheels that can enable the vehicle to be in a safe driving state.

[0106] In the above technical solution, when determining the target front wheel, the vehicle first checks whether the actual wheel speeds of the left and right front wheels are normal. If the actual wheel speed of one of the front wheels is abnormal, control is achieved by relying on the actual wheel speed of the other front wheel, thus providing reliability and accuracy in determining the target front wheel. Furthermore, when both front wheels have normal actual wheel speeds, under driving conditions, one front wheel may slip, resulting in an excessively high wheel speed relative to the other normally moving front wheel. By selecting the front wheel with the lower wheel speed, the vehicle can achieve safe control during normal turning. When the vehicle is braking, if one front wheel has good braking performance, its wheel speed is lower compared to the other front wheel. By selecting the front wheel with the higher wheel speed, the reliability of turning during braking is increased, thus enhancing vehicle safety.

[0107] Once the target front wheel is identified, the ECU can obtain its actual wheel speed. Further, the ECU needs to determine the predicted wheel speed of the target front wheel based on the current operating parameters, the operating parameters from the previous moment, and the time difference between the two moments.

[0108] One possible implementation involves determining the predicted wheel speed based on the current operating parameters, the vehicle's operating parameters at the previous moment, and the time difference between the current and previous moments, including:

[0109] Based on the current operating parameters, the previous operating parameters, and the time difference, determine the target predicted lateral speed and the target predicted longitudinal speed at the current moment.

[0110] The predicted wheel speed is determined based on the target predicted lateral speed, the target predicted longitudinal speed, the current operating parameters, and the operating parameters from the previous moment.

[0111] Specifically, the ECU primarily estimates wheel speeds based on vehicle dynamics models and data from various sensors. Since lateral and longitudinal vehicle speeds are fundamental data describing the vehicle's motion during operation, they directly impact the predicted wheel speeds. Therefore, in determining the predicted wheel speeds, the ECU first needs to determine the target predicted lateral and longitudinal vehicle speeds at the current moment based on the current operating parameters, the operating parameters from the previous moment, and the time difference.

[0112] It should be understood that, for longitudinal vehicle speed, longitudinal acceleration directly reflects the vehicle's acceleration in the forward direction during vehicle operation. Furthermore, during vehicle operation, especially under stable driving conditions, the rear wheels are less affected by steering, and their speed is a better indicator of the vehicle's longitudinal speed. Therefore, the ECU can determine the target predicted longitudinal vehicle speed using the vehicle's longitudinal acceleration, left rear wheel speed, and right rear wheel speed.

[0113] For a vehicle's lateral speed, during vehicle movement, there are corresponding lateral acceleration and yaw rate. Furthermore, when the vehicle is turning, the yaw rate introduces an additional lateral velocity component, which is related to the longitudinal speed. When predicting the lateral speed at the current moment, it is also necessary to consider the lateral velocity component generated by the longitudinal speed due to turning.

[0114] Therefore, the vehicle can combine the previous lateral speed, the previous longitudinal speed, and the vehicle's current lateral acceleration and yaw rate to obtain the target predicted lateral speed.

[0115] The following is the specific prediction process for the target's lateral speed and longitudinal speed.

[0116] In one possible implementation, the predicted lateral speed and predicted longitudinal speed of the target at the current moment are determined based on the operating parameters at the current moment, the operating parameters at the previous moment, and the time difference, including:

[0117] Determine the product of longitudinal acceleration and time difference; determine the first predicted longitudinal speed based on the previous longitudinal speed and the product; determine the second predicted longitudinal speed as the average wheel speed of the left rear wheel and the right rear wheel; determine the target predicted longitudinal speed as the longitudinal speed with the smaller value between the first and second predicted longitudinal speeds.

[0118] The target predicted lateral speed is determined based on the previous lateral speed, lateral acceleration, yaw acceleration, target predicted longitudinal speed, and time difference.

[0119] Optionally, when predicting lateral vehicle speed, the operating parameters include the previous lateral vehicle speed, lateral acceleration, and yaw rate at the previous moment. When predicting longitudinal vehicle speed, the operating parameters include longitudinal acceleration, left rear wheel speed, and right rear wheel speed. Here, both left and right rear wheel speeds refer to the actual wheel speeds.

[0120] It should be understood that when the steering wheel angle signal is lost, the ECU records a timeframe for the previous lateral speed and the previous longitudinal speed at the previous moment. This timeframe is designated as the "signal loss time." During the prediction of the lateral speed, if the current time in this embodiment is specifically the time following the signal loss time, the previous lateral speed is the actual lateral speed of the vehicle at the signal loss time. Similarly, the previous longitudinal speed is the actual longitudinal speed of the vehicle at the signal loss time.

[0121] If the current time in this embodiment is any time after the moment the signal is lost, the previous lateral vehicle speed is the lateral vehicle speed obtained from the previous prediction. The previous longitudinal vehicle speed is the longitudinal vehicle speed obtained from the previous prediction. Based on this, the ECU can directly obtain the previous longitudinal vehicle speed and the previous lateral vehicle speed at the previous moment.

[0122] For example, the ECU can obtain the actual wheel speed of the left rear wheel through the wheel speed sensor of the left rear wheel; and obtain the actual wheel speed of the right rear wheel through the wheel speed sensor of the right rear wheel.

[0123] For example, the ECU can obtain the current yaw rate through the vehicle's yaw rate sensor; obtain the current lateral acceleration through the vehicle's lateral acceleration sensor; and obtain the current longitudinal acceleration through the vehicle's longitudinal acceleration sensor.

[0124] Specifically, based on the above operating parameters, the ECU can calculate the target predicted longitudinal vehicle speed using the following formula (1).

[0125] V x(t) =min{V x(t-1) +a x(t) ·d t ,(V (t)RL +V (t)RR ) / 2} Formula (1)

[0126] In formula (1):

[0127] V x(t) The predicted longitudinal speed of the target vehicle at the current time t, in kilometers per hour (km / h);

[0128] V x(t-1)The previous longitudinal speed at time t-1, in kilometers per hour (km / h);

[0129] a x(t) Longitudinal acceleration at the current time t, unit: meters per square second (m / s²) 2 );

[0130] V ( t )RL : The speed of the left rear wheel at the current time t, in kilometers per hour (km / h);

[0131] V ( t )RR : The speed of the right rear wheel at the current time t, in kilometers per hour (km / h);

[0132] dt: The time difference between the current moment and the previous moment, in seconds (s).

[0133] In determining the target predicted longitudinal vehicle speed, it is assumed that the vehicle's longitudinal acceleration remains constant within the time interval dt. The longitudinal acceleration a at the current moment is used. x(t) Multiplying the longitudinal speed by the time difference dt allows us to estimate the change in longitudinal speed within the time interval dt. Adding this to the previous longitudinal acceleration gives us the first predicted longitudinal speed estimated using the first method.

[0134] Furthermore, the speed of the rear wheels of a vehicle is a better indicator of the vehicle's longitudinal speed. Therefore, by averaging the actual wheel speeds of the left and right rear wheels, the second predicted longitudinal speed estimated in the second method is obtained.

[0135] Finally, to ensure vehicle safety, the ECU selects the longitudinal speed with the smaller value from the two estimation methods mentioned above as the final target predicted longitudinal speed.

[0136] Specifically, based on the target predicted longitudinal vehicle speed and the above-mentioned operating parameters, the ECU can calculate the target predicted lateral vehicle speed using the following formula (2).

[0137]

[0138] In formula (2):

[0139] V y(t) : Predicted lateral speed at current time t, in kilometers per hour (km / h);

[0140] V y(t-1) : The previous lateral speed at the previous moment t-1, in kilometers per hour (km / h);

[0141] d Vy(t): Rate of change of lateral velocity of the vehicle, unit: meters per square second (m / s) 2 );

[0142] a y(t) : Lateral acceleration at the current time t, unit: meters per square second (m / s²) 2 );

[0143] YawRate (t) : The yaw rate at the current time t, in radians per second (rad / s);

[0144] V x(t) The predicted longitudinal speed of the target vehicle at the current time t, in kilometers per hour (km / h);

[0145] dt: The time difference between the current moment and the previous moment, in seconds (s).

[0146] YawRate (t) ˙V x(t) To account for the fact that during a vehicle's cornering, its center of gravity moves not only along the tangent of the curve (i.e., longitudinal velocity) but also experiences lateral displacement due to yaw rate, the additional lateral velocity component caused by vehicle rotation is obtained by multiplying the yaw rate and longitudinal velocity. Lateral acceleration primarily reflects the effect of lateral forces on the vehicle during cornering. Therefore, by adding the vehicle's lateral acceleration to the additional lateral velocity component, the accurate rate of change of lateral velocity can be obtained.

[0147] Based on the obtained lateral velocity change rate, assuming that the lateral velocity change rate of the vehicle is constant during time dt, the change in lateral velocity during time dt can be obtained by formula (2). Then, it is added to the previous lateral velocity at the previous moment to obtain the target predicted lateral velocity.

[0148] After obtaining the target's predicted lateral velocity and target's predicted longitudinal velocity, the ECU can calculate the predicted wheel speed of the target's front wheels.

[0149] It should be understood that the front wheel angle directly affects the vehicle's steering behavior. During a turn, due to the front wheel angle, the front wheel speed can be divided into longitudinal and lateral components, both of which are closely related to the front wheel angle. Therefore, when calculating the predicted wheel speed of the target front wheels, it is necessary to consider the front wheel angle.

[0150] During vehicle operation, there is a fixed rotation ratio between the steering wheel angle and the front wheel angle. In the event of a lost steering wheel angle signal, this embodiment specifically estimates the front wheel angle at the current moment to obtain the estimated steering wheel angle. Since the estimated front wheel angle is based on the actual wheel speed and the predicted wheel speed of the target front wheel at the current moment, the ECU cannot obtain the current front wheel angle during the calculation of the predicted wheel speed. During normal vehicle operation, the front wheel angle generally changes slowly or remains constant, meaning the angle change between adjacent moments is not significant. Therefore, the ECU can obtain the predicted wheel speed by combining the previous front wheel angle, the predicted lateral speed, the predicted longitudinal speed, and the vehicle's current operating parameters.

[0151] In one possible implementation, the predicted wheel speed is determined based on the target predicted lateral speed, the target predicted longitudinal speed, the current operating parameters, and the previous operating parameters, including:

[0152] Determine the sine and cosine values ​​of the previous front wheel steering angle;

[0153] The first predicted wheel speed component is determined based on the cosine value, the target predicted longitudinal vehicle speed, and the yaw rate.

[0154] The second predicted wheel speed component is determined based on the sine value, the target predicted lateral vehicle speed, and the yaw rate.

[0155] The predicted wheel speed is determined as the sum of the first predicted wheel speed component and the second predicted wheel speed component.

[0156] Among them, the operating parameters of the previous moment include the previous front wheel steering angle.

[0157] For example, for the previous front wheel angle, if the current time in this embodiment is specifically the time after the signal loss time, the previous front wheel angle is the actual front wheel angle of the vehicle at the time of signal loss.

[0158] Specifically, during vehicle operation, if the steering wheel angle signal is normal, the front wheel angles will also be normal. Generally, the angles of the left and right front wheels are not significantly different. The ECU can obtain the left front wheel angle from the left front wheel angle sensor as the front wheel angle at each sampling time. Alternatively, the ECU can obtain the right front wheel angle from the right front wheel angle sensor. Or, the ECU can use the smaller of the left and right front wheel angles as the front wheel angle at each sampling time. Or, the ECU can use the average of the left and right front wheel angles as the front wheel angle at each sampling time.

[0159] Based on this, if the current moment is the moment after the moment the signal was lost, the ECU can obtain the previous front wheel steering angle.

[0160] If the current time in this embodiment is any time after the moment the signal is lost, the previous front wheel angle is the front wheel angle predicted in the previous calculation. The ECU can directly obtain the front wheel angle predicted in the previous calculation.

[0161] Specifically, the ECU can calculate the predicted wheel speed of the target front wheel using the following formula (3).

[0162] V wheel(model) =(V x(t) -B·YawRate (t) ·cosα F(t-1) +(V y(t) +L·YawRate (t) ·sinα F(t-1) Formula (3)

[0163] In formula (3):

[0164] V wheel(model) : The predicted wheel speed of the target front wheel at the current time t, in kilometers per hour (km / h);

[0165] V x(t) The predicted longitudinal speed of the target vehicle at the current time t, in kilometers per hour (km / h);

[0166] V y(t) : Target predicted lateral vehicle speed at current time t, unit: km / h;

[0167] YawRate ( t ) : The yaw rate at the current time t, in radians per second (rad / s);

[0168] α F(t-1) : The previous front wheel rotation angle at the previous time t-1, in degrees (°);

[0169] B: Half track, which is the distance from the vehicle's center of gravity to one of the front wheels, in millimeters (mm);

[0170] L: Wheelbase, which is the distance between the front and rear axles of a vehicle, in millimeters (mm).

[0171] As can be seen from formula (3), the predicted wheel speed is mainly composed of two parts. The first part is the longitudinal speed component caused by the longitudinal vehicle speed and the yaw rate, which is the first predicted wheel speed component. The second part is the lateral speed component caused by the lateral vehicle speed and the yaw rate, which is the second predicted wheel speed component.

[0172] Among them, the B˙YawRate in the first part ( t ) It is a lateral displacement velocity component caused by the yaw rate. cosα F(t-1) This represents the steering effect caused by the front wheel rotation angle, reflecting the influence of steering on longitudinal speed. Part 1 (Vx) (t )-B˙YawRate (t) )˙cos F α (t-1) Specifically, it takes into account the yaw rate and the longitudinal velocity component after the front wheel turns.

[0173] L˙YawRate in Part Two ( t ) This is an additional lateral velocity component caused by the yaw rate. F( t- 1) This indicates the steering effect caused by the front wheel rotation angle, reflecting the impact of steering on lateral speed. Part Two (V) y(t )+L˙YawRate (t) )˙sinα F(t-1) The yaw rate and the lateral velocity component after the front wheel turns are taken into account.

[0174] Through the above process, the ECU can obtain the actual wheel speed and predicted wheel speed of the target front wheel.

[0175] It should be understood that the predicted wheel speed is the target front wheel speed predicted based on the vehicle's dynamics model and sensor characteristics. Regardless of whether the target front wheel is the left or right front wheel, the corresponding dynamics model and sensor characteristics are the same. In other words, the calculated predicted wheel speed is the same regardless of whether the target front wheel is the left or right front wheel.

[0176] Specifically, when determining the target steering angle difference between the current moment and the previous moment based on the actual and predicted wheel speeds of the target's front wheels, a proportional-integral (PI) controller is mainly used.

[0177] The expression for the PI controller is shown in formula (4) below.

[0178]

[0179] In formula (4):

[0180] u (t) The output signal of the PI controller, in this embodiment of the application, is specifically the target angle difference Δα. F ;

[0181] K p : Proportional gain, which is a preset constant in this embodiment;

[0182] K i Integral gain, in this embodiment of the application, is a preset constant;

[0183] e(t): The deviation between the actual wheel speed and the predicted wheel speed of the target front wheel, which is the input signal of the PI controller.

[0184] Using the above formula (4), the difference between the actual wheel speed of the target front wheel and the predicted wheel speed of the target front wheel can be used as input by the PI controller to obtain the target steering angle difference.

[0185] The reason why the target steering angle difference can be determined by comparing the actual and predicted wheel speeds of the target front wheels at the current moment is that the deviation between the actual and predicted wheel speeds reflects the difference between the current vehicle state and the expected state. Through a PI controller, the ECU can convert the error between the actual and predicted wheel speeds into an increment in the front wheel steering angle, thereby adjusting the vehicle's direction to gradually bring the actual wheel speed closer to the predicted wheel speed.

[0186] To facilitate understanding of the calculation process for the target angle difference in the embodiments of this application, the following is a summary. Figure 2 The above calculation process will be explained.

[0187] Figure 2 This is a schematic flowchart illustrating a method for determining the target angle difference provided in an embodiment of this application.

[0188] For example, such as Figure 2 As shown, the method 200 includes:

[0189] 201. Based on the current driving conditions, the actual wheel speed of the left front wheel, and the actual wheel speed of the right front wheel, determine the target front wheel.

[0190] 202. Determine the product of longitudinal acceleration and time difference; based on the previous longitudinal speed and the product, determine the first predicted longitudinal speed.

[0191] 203, the second predicted longitudinal speed is determined as the average wheel speed of the left rear wheel and the right rear wheel.

[0192] 204. The target predicted longitudinal speed is determined as the longitudinal speed with the smaller value between the first predicted longitudinal speed and the second predicted longitudinal speed.

[0193] 205. Based on the previous lateral speed, lateral acceleration, yaw acceleration, target predicted longitudinal speed and time difference, determine the target predicted lateral speed.

[0194] 206. Based on the target predicted lateral speed, the target predicted longitudinal speed, the current yaw rate, and the previous front wheel rotation angle, determine the predicted wheel speed.

[0195] 207. Based on the actual wheel speed of the target front wheel and the predicted wheel speed of the target front wheel, determine the target turning angle difference between the current moment and the previous moment.

[0196] The steps 201-207 in method 200 have the same inventive concept as the steps for determining the target angle difference in method 100. Please refer to the description in method 200 for details, which will not be repeated here.

[0197] 102. Based on the target steering angle difference, the first predicted front wheel steering angle at the current moment and the previous front wheel steering angle at the previous moment, determine the target steering wheel angle at the current moment. The first predicted front wheel steering angle is the front wheel steering angle predicted based on the vehicle's current operating state.

[0198] The change in front wheel steering angle Δα between the previous moment and the current moment is obtained. F Subsequently, since the steering wheel angle and the vehicle's front wheel angle satisfy a preset rotation ratio relationship, the ECU can first determine the target front wheel angle at the current moment, and then obtain the target steering wheel angle based on the rotation ratio relationship.

[0199] Specifically, when determining the front wheel steering angle at the current moment, taking into account the vehicle's driving state, the ECU can first estimate the first predicted front wheel steering angle under the current driving state based on the vehicle's dynamic characteristics.

[0200] In one possible implementation, the step of determining the first predicted front wheel steering angle includes:

[0201] Obtain the vehicle's actual longitudinal speed, rear wheel steering angle, and yaw rate at the current moment;

[0202] The first predicted front wheel angle is determined based on the actual longitudinal vehicle speed, rear wheel steering angle, and yaw rate.

[0203] Specifically, the first predicted front wheel steering angle can be calculated using the following formula (5).

[0204] α Fdynamic(t) =YawRate (t) ·L / V xveh(t) -α R(t) Formula (5)

[0205] In formula (5):

[0206] α Fdynamic(t) : The dynamic front wheel steering angle of the vehicle at the current time t, in degrees (°);

[0207] YawRate(t): Yaw rate at time t, in radians per second (rad / s);

[0208] L: Wheelbase, unit: millimeters (mm);

[0209] V xveh(t) : The actual longitudinal speed of the vehicle at the current time t, in kilometers per hour (km / h);

[0210] α R( t ) : The rear wheel steering angle of the vehicle at the current time t, in degrees (°).

[0211] Specifically, the first predicted front wheel steering angle is obtained by the ECU based on the vehicle's dynamics model and current sensor parameters, and it can reflect the vehicle's real-time control requirements at the current moment.

[0212] The ECU obtains the vehicle's actual longitudinal speed at the current moment through the vehicle's longitudinal speed sensor; it obtains the rear wheel steering angle through the steering angle sensor on the rear wheels; and it obtains the yaw rate through the yaw rate sensor. The rear wheel steering angle can be either the steering angle of the left or right rear wheel, or it can be the average of the steering angles of the left and right rear wheels.

[0213] After obtaining the above parameters, the ECU can calculate the first predicted front wheel steering angle using the above formula (5).

[0214] It should be understood that in the aforementioned process, the ECU calculates the target steering angle difference. Based on the target steering angle difference and the previous front wheel steering angle, the ECU can also obtain a current predicted front wheel steering angle, referred to as the "second predicted front wheel steering angle." Furthermore, through the first and second predicted front wheel steering angles, the ECU can obtain the current target front wheel steering angle and, through the steering ratio, calculate the target steering wheel angle at the current moment.

[0215] In one possible implementation, the target steering wheel angle at the current moment is determined based on the target steering angle difference, the first predicted front wheel steering angle at the current moment, and the previous front wheel steering angle at the previous moment, including:

[0216] The second predicted front wheel angle at the current moment is determined as the sum of the target angle difference and the previous front wheel angle;

[0217] The target front wheel steering angle is determined as the smaller of the first and second predicted front wheel steering angles.

[0218] The target steering wheel angle is determined based on the target front wheel angle and the preset steering ratio.

[0219] Specifically, the process of determining the target front wheel steering angle can be expressed by the following formula (6).

[0220] α F(t) =min(Δα) F +α F(t-1) ,a F(dynamic) ) Formula (6)

[0221] In formula (6):

[0222] α Fdynamic(t) : The dynamic front wheel steering angle of the vehicle at the current time t, in degrees (°);

[0223] Δα F Target angle difference, unit: degrees (°);

[0224] α F( t- 1) : The previous front wheel steering angle at the previous time t-1, in degrees (°).

[0225] Where, Δα F +α F(t-1) This is the second predicted front wheel steering angle, α. Fdynamic(t) The first predicted front wheel steering angle is used as the target front wheel steering angle. To ensure vehicle steering safety, after the ECU calculates the first and second predicted front wheel steering angles, it can select the smaller front wheel steering angle as the target front wheel steering angle.

[0226] Finally, the ECU obtains the target steering wheel angle at the current moment through the preset rotation ratio between the front wheel angle and the steering wheel angle.

[0227] The following is through Figure 3 The process of calculating the steering wheel angle in the embodiments of this application is described.

[0228] Figure 3 This is a schematic flowchart illustrating a method for determining the steering wheel angle provided in an embodiment of this application.

[0229] For example, such as Figure 3 As shown, the method 300 includes:

[0230] 301. Based on the current driving conditions, the actual wheel speed of the left front wheel, and the actual wheel speed of the right front wheel, determine the target front wheel.

[0231] 302, determine the product of longitudinal acceleration and time difference; based on the previous longitudinal speed and the product, determine the first predicted longitudinal speed.

[0232] 303, the second predicted longitudinal speed is determined as the average wheel speed of the left rear wheel and the right rear wheel.

[0233] 304. The target predicted longitudinal speed is determined as the longitudinal speed with the smaller value between the first predicted longitudinal speed and the second predicted longitudinal speed.

[0234] 305. Based on the previous lateral speed, lateral acceleration, yaw acceleration, target predicted longitudinal speed, and time difference, determine the target predicted lateral speed.

[0235] 306. Based on the target predicted lateral speed, the target predicted longitudinal speed, the current yaw rate, and the previous front wheel rotation angle, determine the predicted wheel speed.

[0236] 307. Based on the actual wheel speed of the target front wheel and the predicted wheel speed of the target front wheel, determine the target turning angle difference between the current moment and the previous moment.

[0237] 308, the second predicted front wheel angle at the current moment is determined as the sum of the target angle difference and the previous front wheel angle.

[0238] 309. Based on the actual longitudinal vehicle speed, rear wheel steering angle, and yaw rate, determine the first predicted front wheel steering angle.

[0239] 310, The target front wheel steering angle is determined as the smaller of the first predicted front wheel steering angle and the second predicted front wheel steering angle;

[0240] 311. Determine the target steering wheel angle based on the target front wheel angle and the preset steering ratio.

[0241] The process of determining the target steering wheel angle in method 300 has the same inventive concept as the process of determining the target steering wheel angle in method 200. For details, please refer to the detailed description in method 200, which will not be repeated here.

[0242] 103. Control vehicle movement based on target steering wheel angle.

[0243] After obtaining the target steering wheel angle at the current moment, the ECU can control the operation of vehicle functions that rely on the steering wheel angle signal to ensure vehicle driving safety.

[0244] In summary, this application proposes a method for determining the vehicle's steering angle when the steering wheel signal is lost during vehicle operation. Specifically, when the vehicle detects an abnormality (loss) in the steering wheel angle signal, the target steering angle difference between the current moment and the previous moment is determined by using the actual wheel speed and the predicted wheel speed of the target front wheel. The target front wheel is the left or right front wheel, whichever ensures the vehicle remains in a safe driving state. This estimation process prioritizes vehicle driving safety. The actual and predicted wheel speeds reflect the difference between the wheel speed during vehicle operation and the ideal wheel speed. By determining the target steering angle difference using these two wheel speeds and further obtaining the steering wheel angle, the actual wheel speed during vehicle operation becomes closer to the predicted wheel speed. Therefore, by estimating the target steering wheel angle when the steering wheel signal is abnormal, the vehicle can still steer normally, optimizing the vehicle's steering response and accuracy, ensuring continuity during driving, reducing user anxiety, and enhancing the reliability of vehicle fault handling.

[0245] Figure 4 This is a schematic diagram of a device for determining the turning angle of a vehicle, provided in an embodiment of this application.

[0246] For example, such as Figure 4 As shown, the device 400 includes:

[0247] The difference determination module 401 is used to determine the target steering angle difference between the current moment and the previous moment based on the actual wheel speed of the target front wheel and the predicted wheel speed of the target front wheel when the steering wheel angle signal is abnormal; the target front wheel is the front wheel that can keep the vehicle in a safe driving state between the left front wheel and the right front wheel.

[0248] The steering angle determination module 402 is used to determine the target steering wheel angle at the current moment based on the target steering angle difference, the first predicted front wheel steering angle at the current moment and the previous front wheel steering angle at the previous moment. The first predicted front wheel steering angle is the front wheel steering angle predicted based on the current operating state of the vehicle.

[0249] The control module 403 is used to control the operation of the vehicle based on the target steering wheel angle.

[0250] In one possible implementation, the steering angle determination module 402 is specifically used to: determine the second predicted front wheel steering angle at the current moment as the sum of the target steering angle difference and the previous front wheel steering angle; determine the target front wheel steering angle as the front wheel steering angle with the smaller value between the first predicted front wheel steering angle and the second predicted front wheel steering angle; and determine the target steering wheel angle based on the target front wheel steering angle and the preset rotation ratio.

[0251] Optionally, the device further includes: a wheel speed determination module, used to determine the target front wheel based on the vehicle's operating parameters at the current moment, the operating parameters being used to represent the vehicle's operating state; and to determine the predicted wheel speed based on the operating parameters at the current moment, the vehicle's operating parameters at the previous moment, and the time difference between the current moment and the previous moment.

[0252] In one possible implementation, the operating parameters at the current moment include the driving condition, the actual wheel speed of the left front wheel, and the actual wheel speed of the right front wheel. The wheel speed determination module 401 is specifically used to: determine the target front wheel as the left front wheel when the actual wheel speed of the left front wheel is normal and the actual wheel speed of the right front wheel is abnormal; determine the target front wheel as the right front wheel when the actual wheel speed of the left front wheel is abnormal and the actual wheel speed of the right front wheel is normal; when the actual wheel speed of the left front wheel is normal and the actual wheel speed of the right front wheel is normal, if the driving condition is a driving condition, determine the target front wheel as the front wheel corresponding to the wheel speed with the smaller value between the actual wheel speed of the left front wheel and the actual wheel speed of the right front wheel; if the driving condition is a braking condition, determine the target front wheel as the front wheel corresponding to the wheel speed with the larger value between the actual wheel speed of the left front wheel and the actual wheel speed of the right front wheel.

[0253] In one possible implementation, the wheel speed determination module 401 is further configured to: determine the target predicted lateral speed and the target predicted longitudinal speed at the current moment based on the operating parameters at the current moment, the operating parameters at the previous moment, and the time difference; and determine the predicted wheel speed based on the target predicted lateral speed, the target predicted longitudinal speed, the operating parameters at the current moment, and the operating parameters at the previous moment.

[0254] In one possible implementation, the operating parameters at the current moment include yaw rate, lateral acceleration, longitudinal acceleration, left rear wheel speed, and right rear wheel speed; the operating parameters at the previous moment include the previous longitudinal speed, the previous lateral speed, and the previous front wheel steering angle. The wheel speed determination module 401 is further configured to: determine the product of the longitudinal acceleration and the time difference; determine a first predicted longitudinal speed based on the previous longitudinal speed and the product; determine a second predicted longitudinal speed as the average wheel speed of the left rear wheel speed and the right rear wheel speed; and determine the target predicted longitudinal speed as the average wheel speed of the first predicted longitudinal speed and the second predicted longitudinal speed. In measuring longitudinal vehicle speed, the longitudinal vehicle speed with the smaller value is selected; the target predicted lateral vehicle speed is determined based on the previous lateral vehicle speed, the lateral acceleration, the yaw acceleration, the target predicted longitudinal vehicle speed, and the time difference; and the wheel speed determination module is further used to: determine the sine and cosine values ​​of the previous front wheel steering angle; determine a first predicted wheel speed component based on the cosine value, the target predicted longitudinal vehicle speed, and the yaw rate; determine a second predicted wheel speed component based on the sine value, the target predicted lateral vehicle speed, and the yaw rate; and determine the predicted wheel speed as the sum of the first predicted wheel speed component and the second predicted wheel speed component.

[0255] Optionally, the device further includes: a steering angle prediction module, used to acquire the vehicle's actual longitudinal speed, rear wheel steering angle, and yaw rate at the current moment; and to determine the first predicted front wheel steering angle based on the actual longitudinal speed, the rear wheel steering angle, and the yaw rate.

[0256] Figure 5 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application.

[0257] For example, such as Figure 5 As shown, the vehicle 500 includes a memory 501 and a processor 502. The memory 501 stores executable program code 5011, and the processor 502 is used to call and execute the executable program code 5011 to perform a method for determining the turning angle of the vehicle.

[0258] Furthermore, embodiments of this application also protect an apparatus that may include a memory and a processor, wherein the memory stores executable program code, and the processor is used to call and execute the executable program code to perform a method for determining the turning angle of a vehicle provided in embodiments of this application.

[0259] This embodiment can divide the device into functional modules based on the above method example. For example, each module can correspond to a separate function, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0260] When each functional module is divided according to its corresponding function, the device may also include a difference determination module, a rotation angle determination module, and a control module. It should be noted that all relevant content regarding the steps involved in the above method embodiments can be referenced from the functional descriptions of the corresponding functional modules, and will not be repeated here.

[0261] It should be understood that the device provided in this embodiment is used to perform the above-described method for determining the turning angle of a vehicle, and therefore can achieve the same effect as the above-described implementation method.

[0262] When using an integrated unit, the device may include a processing module and a storage module. When the device is applied to a vehicle, the processing module can be used to control and manage the vehicle's movements. The storage module can be used to support the vehicle in executing relevant program code.

[0263] The processing module may be a processor or a controller, which can implement or execute various exemplary logic blocks, modules, and circuits shown in conjunction with the disclosure of this application. The processor may also be a combination of functions that implement computing capabilities, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc., and the storage module may be a memory.

[0264] In addition, the device provided in the embodiments of this application may specifically be a chip, component or module. The chip may include a connected processor and a memory. The memory is used to store instructions. When the processor calls and executes the instructions, the chip can execute a method for determining the turning angle of a vehicle provided in the above embodiments.

[0265] This embodiment also provides a computer-readable storage medium storing computer program code. When the computer program code is run on a computer, the computer executes the above-described related method steps to implement the method for determining the turning angle of a vehicle provided in the above embodiment.

[0266] This embodiment also provides a computer program product that, when run on a computer, causes the computer to perform the aforementioned steps to implement the method for determining the turning angle of a vehicle provided in the above embodiment.

[0267] In this embodiment, the device, computer-readable storage medium, computer program product, or chip are all used to execute the corresponding methods provided above. Therefore, the beneficial effects they can achieve can be referred to the beneficial effects in the corresponding methods provided above, and will not be repeated here.

[0268] Through the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0269] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0270] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for determining the turning angle of a vehicle, characterized in that, The method includes: In the event of an abnormal steering wheel angle signal, the target steering angle difference between the current moment and the previous moment is determined based on the actual wheel speed of the target front wheel and the predicted wheel speed of the target front wheel; the target front wheel is the front wheel that can keep the vehicle in a safe driving state, either the left front wheel or the right front wheel. The target steering wheel angle at the current moment is determined based on the target steering angle difference, the first predicted front wheel steering angle at the current moment, and the previous front wheel steering angle at the previous moment. The first predicted front wheel steering angle is the front wheel steering angle predicted based on the current operating state of the vehicle. Control the vehicle's movement based on the target steering wheel angle; The step of determining the target steering wheel angle at the current moment based on the target steering angle difference, the first predicted front wheel steering angle at the current moment, and the previous front wheel steering angle at the previous moment includes: The second predicted front wheel angle at the current moment is determined as the sum of the target angle difference and the previous front wheel angle; The target front wheel steering angle is determined to be the smaller of the first predicted front wheel steering angle and the second predicted front wheel steering angle; The target steering wheel angle is determined based on the target front wheel angle and the preset rotation ratio.

2. The method according to claim 1, characterized in that, The method further includes: The target front wheel is determined based on the vehicle's operating parameters at the current moment, whereby the operating parameters represent the vehicle's operating state. The predicted wheel speed is determined based on the operating parameters at the current moment, the operating parameters of the vehicle at the previous moment, and the time difference between the current moment and the previous moment.

3. The method according to claim 2, characterized in that, The current operating parameters include driving conditions, the actual wheel speed of the left front wheel, and the actual wheel speed of the right front wheel. Determining the target front wheel based on the vehicle's current operating parameters includes: If the actual wheel speed of the left front wheel is normal and the actual wheel speed of the right front wheel is abnormal, the target front wheel is determined to be the left front wheel. If the actual wheel speed of the left front wheel is abnormal and the actual wheel speed of the right front wheel is normal, the target front wheel is determined to be the right front wheel. When the actual wheel speed of the left front wheel is normal and the actual wheel speed of the right front wheel is normal, if the driving condition is a driving condition, the target front wheel is determined as the front wheel corresponding to the smaller wheel speed of the left front wheel and the actual wheel speed of the right front wheel; if the driving condition is a braking condition, the target front wheel is determined as the front wheel corresponding to the larger wheel speed of the left front wheel and the actual wheel speed of the right front wheel.

4. The method according to claim 2, characterized in that, Determining the predicted wheel speed based on the current operating parameters, the vehicle's operating parameters at the previous moment, and the time difference between the current moment and the previous moment includes: Based on the operating parameters at the current moment, the operating parameters at the previous moment, and the time difference, determine the target predicted lateral speed and the target predicted longitudinal speed at the current moment. The predicted wheel speed is determined based on the target predicted lateral speed, the target predicted longitudinal speed, the operating parameters at the current moment, and the operating parameters at the previous moment.

5. The method according to claim 4, characterized in that, The current operating parameters include yaw rate, lateral acceleration, longitudinal acceleration, left rear wheel speed, and right rear wheel speed. The previous operating parameters include the previous longitudinal speed, previous lateral speed, and previous front wheel steering angle. Determining the target predicted lateral speed and target predicted longitudinal speed at the current moment based on the current operating parameters, the previous operating parameters, and the time difference includes: Determine the product of the longitudinal acceleration and the time difference; determine the first predicted longitudinal speed based on the previous longitudinal speed and the product; determine the second predicted longitudinal speed as the average wheel speed of the left rear wheel and the right rear wheel; determine the target predicted longitudinal speed as the longitudinal speed with the smaller value between the first predicted longitudinal speed and the second predicted longitudinal speed. The target predicted lateral speed is determined based on the previous lateral speed, the lateral acceleration, the yaw rate, the target predicted longitudinal speed, and the time difference. And, determining the predicted wheel speed based on the target predicted lateral vehicle speed, the target predicted longitudinal vehicle speed, the operating parameters at the current moment, and the operating parameters at the previous moment includes: Determine the sine and cosine values ​​of the previous front wheel steering angle; The first predicted wheel speed component is determined based on the cosine value, the target predicted longitudinal vehicle speed, and the yaw rate. The second predicted wheel speed component is determined based on the sine value, the target predicted lateral vehicle speed, and the yaw rate. The predicted wheel speed is determined as the sum of the first predicted wheel speed component and the second predicted wheel speed component.

6. The method according to claim 1, characterized in that, The first step in determining the predicted front wheel steering angle includes: Obtain the vehicle's actual longitudinal speed, rear wheel steering angle, and yaw rate at the current moment; The first predicted front wheel angle is determined based on the actual longitudinal vehicle speed, the rear wheel steering angle, and the yaw rate.

7. A device for determining the turning angle of a vehicle, characterized in that, The device includes: The difference determination module is used to determine the target steering angle difference between the current moment and the previous moment based on the actual wheel speed of the target front wheel and the predicted wheel speed of the target front wheel when the steering wheel angle signal is abnormal; the target front wheel is the left front wheel or the right front wheel that can keep the vehicle in a safe driving state. Angle determination module is used to determine the target steering wheel angle at the current moment based on the target angle difference, the first predicted front wheel angle at the current moment, and the previous front wheel angle at the previous moment. The first predicted front wheel angle is the front wheel angle predicted based on the current operating state of the vehicle. The control module is used to control the vehicle's operation based on the target steering wheel angle; Specifically, the angle determination module is used for: The second predicted front wheel angle at the current moment is determined as the sum of the target angle difference and the previous front wheel angle; The target front wheel steering angle is determined to be the smaller of the first predicted front wheel steering angle and the second predicted front wheel steering angle; The target steering wheel angle is determined based on the target front wheel angle and the preset rotation ratio.

8. A vehicle, characterized in that, The vehicles include: Memory, used to store executable program code; A processor for calling and running the executable program code from the memory, causing the vehicle to perform the method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed, implements the method as described in any one of claims 1 to 6.

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