Steering wheel angle estimation methods, devices, storage media, and vehicles

Abstract

This application provides a steering wheel angle estimation method, device, storage medium, and vehicle, belonging to the field of data processing technology. The method includes: monitoring the vehicle's driving parameters and fault status when the vehicle's steering wheel angle sensor malfunctions; estimating the real-time steering angle of the vehicle's steering wheel based on the driving parameters and the vehicle's attribute information when the vehicle's driving parameters are valid and the vehicle is in a non-faulty state; and performing gain compensation on the real-time steering angle of the vehicle's steering wheel to obtain the current steering angle of the vehicle's steering wheel, so that the electric power steering system can provide assistance based on the current steering angle. This application aims to improve user safety when using a vehicle.

Description

Technical Field

[0001] This application relates to the field of data processing technology, and more specifically, to a steering wheel angle estimation method, device, storage medium, and vehicle. Background Technology

[0002] With the development of technology, people are pursuing higher and higher vehicle safety and comfort. As a major component of chassis control, the electric power steering system (EPS) not only affects the ease of handling when driving a car, but is also an important part of ensuring driving safety.

[0003] However, when the steering wheel angle sensor in the EPS system malfunctions, the reliability of the electric power steering system (EPS) will decrease, which will seriously affect the safety of the user when using the vehicle. Summary of the Invention

[0004] This application provides a steering wheel angle estimation method, device, storage medium, and vehicle, aiming to improve user safety when using the vehicle.

[0005] In a first aspect, embodiments of this application provide a steering wheel angle estimation method, applied to a vehicle, the method comprising:

[0006] In the event of a malfunction in the vehicle's steering wheel angle sensor, monitor the vehicle's driving parameters and the vehicle's malfunction status.

[0007] When the vehicle's driving parameters are valid and the vehicle is in a non-faulty state, the real-time steering angle of the vehicle's steering wheel is estimated based on the vehicle's driving parameters and the vehicle's attribute information.

[0008] Gain compensation is applied to the real-time steering angle of the vehicle's steering wheel to obtain the current steering angle of the vehicle's steering wheel, so that the electric power steering system can provide assistance based on the current steering angle.

[0009] Optionally, monitoring the vehicle's driving parameters and the vehicle's fault status includes:

[0010] The vehicle's driving parameters are obtained and judged. If the driving parameters are within the calibration range within a first preset time period, the vehicle's driving parameters are determined to be valid.

[0011] If the vehicle's fault code continuously indicates that the vehicle is fault-free or the fault does not exceed the preset fault state during the second preset time period, and the vehicle's electric power steering system is continuously fault-free during the second preset time period, then the vehicle's fault state is determined to be a non-fault state.

[0012] Optionally, when the vehicle's driving parameters are valid and the vehicle is in a non-faulty state, the real-time steering angle of the vehicle's steering wheel is estimated based on the vehicle's driving parameters and the vehicle's attribute information, including:

[0013] When the vehicle's driving parameters are valid and the vehicle is in a non-faulty state, the real-time steering angle of the vehicle's steering wheel is estimated based on the state equation of the two-degree-of-freedom dynamic model. The formula for calculating the real-time steering angle of the vehicle's steering wheel is as follows:

[0014]

[0015] In the formula, δ Hw This refers to the real-time steering angle of the steering wheel; C αf C represents the front wheel lateral stiffness. αr Rear wheel lateral stiffness; l f The distance from the vehicle's center of gravity to the front axle; r denoted as ρ, where m is the distance from the vehicle's center of gravity to the rear axle; ρ is the vehicle's curb weight; and v is the vehicle speed. α is the yaw rate; α is the lateral acceleration; ξ is the steering system gear ratio; α f The vehicle's center of gravity sideslip angle.

[0016] Optionally, gain compensation is performed on the real-time steering angle of the vehicle steering wheel to obtain the current steering angle of the vehicle steering wheel, including:

[0017] Obtain the load of the vehicle and determine the vehicle load gain compensation based on the vehicle load;

[0018] The current steering angle of the vehicle steering wheel is calculated based on the real-time steering angle of the vehicle steering wheel and the vehicle load gain compensation.

[0019] Optionally, gain compensation is performed on the real-time steering angle of the vehicle steering wheel to obtain the current steering angle of the vehicle steering wheel, including:

[0020] Obtain the vehicle's load and speed;

[0021] Determine the vehicle load gain compensation based on the vehicle's load;

[0022] Based on the vehicle's load and speed, determine the tire lateral stiffness gain compensation;

[0023] The current steering angle of the vehicle steering wheel is calculated based on the real-time steering angle of the vehicle steering wheel, the vehicle load gain compensation, and the tire lateral stiffness gain compensation.

[0024] Optionally, after performing gain compensation on the real-time steering angle of the vehicle steering wheel to obtain the current steering angle of the vehicle steering wheel, the method further includes:

[0025] The steering wheel center position is read from a pre-stored steering wheel center position table, and the current steering angle is corrected according to the steering wheel center position to obtain the corrected current steering angle, so that the electric power steering system can provide assistance according to the corrected current steering angle;

[0026] The steering wheel center position is the steering wheel center position when the vehicle is normally in a straight-line driving state.

[0027] Optionally, the method further includes:

[0028] The number of times the vehicle is in a normal straight-line driving state is accumulated;

[0029] When the preset number of times is accumulated, the current steering wheel center position is obtained, and the obtained current steering wheel center position is stored as a new steering wheel center position parameter in the steering wheel center position table.

[0030] Secondly, embodiments of this application provide a steering wheel angle estimation device, the device comprising:

[0031] The monitoring module is used to monitor the vehicle's driving parameters and the vehicle's fault status in the event of a malfunction in the vehicle's steering wheel angle sensor.

[0032] The steering angle estimation module is used to estimate the real-time steering angle of the vehicle's steering wheel based on the vehicle's driving parameters and attribute information, provided that the vehicle's driving parameters are valid and the vehicle is in a non-faulty state.

[0033] The gain compensation module is used to compensate for the real-time steering angle of the vehicle steering wheel to obtain the current steering angle of the vehicle steering wheel, so that the electric power steering system can provide assistance according to the current steering angle.

[0034] Thirdly, this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steering wheel angle estimation method as described in the first aspect of the embodiment.

[0035] Fourthly, this application provides a vehicle equipped with the device described in the second aspect of the embodiment, the device performing the steering wheel angle estimation method described in the first aspect of the embodiment.

[0036] Beneficial effects:

[0037] In the event of a malfunction in the vehicle's steering wheel angle sensor, the vehicle's driving parameters and malfunction status are monitored. If the vehicle's driving parameters are valid and the vehicle is in a non-malfunctioning state, the real-time steering angle of the vehicle's steering wheel is estimated based on the vehicle's driving parameters and vehicle attribute information. Gain compensation is then applied to the real-time steering angle of the vehicle's steering wheel to obtain the current steering angle of the vehicle's steering wheel, so that the electric power steering system can provide assistance based on the current steering angle.

[0038] Even in the event of a steering wheel angle sensor malfunction, this method can determine the current steering angle through estimation and gain compensation. The electric power steering system can continue to provide assistance based on the current steering angle, thereby reducing the weakening of the electric power steering system's assistance effect due to steering wheel angle sensor failure and improving the safety of the user when using the vehicle. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a flowchart of the steps of a steering wheel angle estimation method proposed in an embodiment of this application;

[0041] Figure 2 This is a flowchart for determining the fault status of a vehicle according to an embodiment of this application;

[0042] Figure 3 This is a flowchart of the steps of a steering wheel angle estimation method proposed in an embodiment of this application;

[0043] Figure 4 This is a functional block diagram of a steering wheel angle estimation device according to an embodiment of this application;

[0044] Figure 5 This is a functional block diagram of a steering wheel angle estimation device proposed in an embodiment of this application. Detailed Implementation

[0045] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0046] A vehicle's steering wheel angle sensor detects the steering wheel's rotation angle and direction of turn, providing steering control for the electric power steering system to assist the user in steering. Compared to relying solely on mechanical steering, this significantly reduces effort and improves safety during steering. However, if the steering wheel angle sensor malfunctions or fails to function properly for other reasons, it will affect the assistance effect of the electric power steering system, thereby reducing driving safety. Therefore, this application provides a method for calculating the steering wheel angle in the event of a steering wheel angle sensor malfunction. By adding redundancy, even when the steering wheel angle sensor malfunctions, the system can still provide the steering wheel rotation angle for the electric power steering system without adding other hardware, thereby improving the reliability and safety of the vehicle for the user.

[0047] Reference Figure 1 The diagram illustrates a flowchart of a steering wheel angle estimation method according to an embodiment of the present invention. The method is applied to a terminal with the client installed, and the method may specifically include the following steps:

[0048] S101: In the event of a malfunction in the vehicle's steering wheel angle sensor, monitor the vehicle's driving parameters and the vehicle's fault status.

[0049] In this step, when the vehicle's steering wheel angle sensor malfunctions, the vehicle's driving parameters and status are monitored. By comparing the vehicle's current driving parameters with the presence of a malfunction, it can be determined whether to begin estimating the steering wheel angle.

[0050] Vehicle driving parameters can include vehicle speed, lateral acceleration, yaw rate, and sideslip angle. These parameters can be read through the vehicle's Controller Area Network (CAN).

[0051] In one implementation, monitoring the vehicle's driving parameters and its fault status includes the following sub-steps:

[0052] A1: Obtain the driving parameters of the vehicle, judge the driving parameters, and determine that the driving parameters of the vehicle are valid if the driving parameters are within the calibration range within a first preset time period.

[0053] When the vehicle's steering wheel angle sensor malfunctions, the vehicle's driving parameters are acquired, and it is then determined whether the driving parameters are within the calibration range. If the driving parameters are within the calibration range for a first preset time period, the vehicle's driving parameters are deemed valid; otherwise, the vehicle's driving parameters are deemed invalid. The calibration range and the first preset time period can be customized according to actual conditions.

[0054] In practice, when the vehicle's driving parameters are determined to be valid, a valid driving parameter flag can be output to the vehicle's ECU; when the vehicle's driving parameters are determined to be invalid, an invalid driving parameter flag can be output to the vehicle's ECU.

[0055] A2: If the vehicle's fault code continuously indicates that the vehicle is fault-free or the fault does not exceed the preset fault state within the second preset time period, and the vehicle's electric power steering system is continuously fault-free within the second preset time period, then the vehicle's fault state is determined to be a non-fault state.

[0056] Reference Figure 2 A flowchart illustrating the determination of a vehicle's fault state in one implementation is shown, such as... Figure 2 The method for determining the vehicle fault status includes the following two conditions:

[0057] The first condition is: read the vehicle's fault codes. The vehicle's fault codes indicate that the vehicle has no faults or that the faults have not exceeded the preset fault state.

[0058] The second condition is that the electric power steering system is in a non-faulty state;

[0059] When both of the above conditions are met, the fault timer starts counting. If the above two conditions are met continuously within the second preset time period, the vehicle's fault status is determined to be a non-fault status. If only one of the above two conditions is met within the second preset time period, the fault timer is reset, the fault status judgment is exited, and the vehicle's fault status is determined to be a fault status.

[0060] In other embodiments, the vehicle fault status determination method can be set to other determination conditions, and when the vehicle fault status is a non-fault status, the vehicle fault status flag bit can be output to the vehicle's on-board computer ECU as valid; when the vehicle fault status is a fault status, the vehicle fault status flag bit can be output to the vehicle's on-board computer ECU as invalid.

[0061] S102: When the vehicle's driving parameters are valid and the vehicle is in a non-faulty state, estimate the real-time steering angle of the vehicle's steering wheel based on the vehicle's driving parameters and the vehicle's attribute information.

[0062] In practice, the vehicle ECU can determine to enter the steering angle estimation mode when it receives a valid driving parameter flag and a valid vehicle fault status flag.

[0063] In another implementation, when the vehicle ECU receives a valid driving parameter flag and a valid vehicle fault status flag, it obtains a selection signal from the user to enter the steering angle estimation mode. For example, the vehicle ECU controls the vehicle to display on the touch screen whether to enter the steering angle estimation mode, and the user can make the selection through the touch screen. If the vehicle ECU receives an invalid driving parameter flag or an invalid vehicle fault status flag, the vehicle ECU controls the vehicle to provide a prompt message to remind the user that the steering angle estimation mode is currently in effect.

[0064] In the steering angle estimation mode of this embodiment, the real-time steering angle is estimated using the state equations of a two-degree-of-freedom dynamic model. Based on the state equations of the two-degree-of-freedom dynamic model, the formula for calculating the rate of change of vehicle displacement in the lateral position is as follows:

[0065]

[0066] In the formula, C represents the rate of change of lateral position. αf C represents the front wheel lateral stiffness. αr ρ is the rear wheel lateral stiffness; m is the vehicle's curb weight; v x Let l be the vehicle velocity along the x-axis of the vehicle body coordinate system. f The distance from the vehicle's center of gravity to the front axle; r This is the distance from the vehicle's center of gravity to the rear axle. δ is the yaw rate; Whl The turning angle of the wheel.

[0067] Based on the above formula for calculating the rate of change of displacement in the lateral position, a formula for estimating the real-time steering angle of the vehicle can be derived:

[0068]

[0069] In the formula, δ Hw This refers to the real-time steering angle of the steering wheel; C αf C represents the front wheel lateral stiffness. αr Rear wheel lateral stiffness; l f The distance from the vehicle's center of gravity to the front axle; r denoted as ρ, where m is the distance from the vehicle's center of gravity to the rear axle; ρ is the vehicle's curb weight; and v is the vehicle speed. α is the yaw rate; α is the lateral acceleration; ξ is the steering system gear ratio; α f The vehicle's center of gravity sideslip angle.

[0070] S103: Perform gain compensation on the real-time steering angle of the vehicle steering wheel to obtain the current steering angle of the vehicle steering wheel, so that the electric power steering system can provide assistance according to the current steering angle.

[0071] Because the formula for calculating the real-time steering angle includes the vehicle's curb weight m and the front wheel lateral stiffness C... αf and rear wheel lateral stiffness C αr It is a known fixed value, but the vehicle load changes during actual use, such as load variation, and the tire lateral stiffness is also affected by vehicle speed and load. Therefore, in order to improve the accuracy of the steering angle estimation results, this method also performs gain compensation on the real-time steering angle.

[0072] In one embodiment, the load of the vehicle is obtained, and a vehicle load gain compensation G1 is determined based on the vehicle load using a pre-set algorithm. The calculated vehicle load gain compensation G1 is positively correlated with the vehicle load, that is, the greater the vehicle load, the greater the vehicle load gain compensation G1, and the value of vehicle load gain compensation G1 ranges from 0 to ±1. The current steering angle of the vehicle steering wheel can be obtained by multiplying the estimated real-time steering angle with the vehicle load gain compensation.

[0073] In another implementation, the vehicle's load and speed are obtained, and a pre-set algorithm is used to determine the vehicle load gain compensation G1 based on the vehicle's load, and the tire lateral stiffness gain compensation G2 based on the vehicle's load and speed.

[0074] Vehicle load gain compensation G1 is positively correlated with vehicle load, meaning the greater the vehicle load, the greater the vehicle load gain compensation G1, and the value range of vehicle load gain compensation G1 is 0 to ±1. For the same vehicle and at the same speed, tire side stiffness gain compensation G2 is positively correlated with vehicle load, meaning the greater the vehicle load, the greater the tire side stiffness gain compensation G2. For the same vehicle and at the same load, tire side stiffness gain compensation G2 is negatively correlated with vehicle speed, meaning the greater the vehicle speed, the smaller the tire side stiffness gain compensation G2, and the value range of tire side stiffness gain compensation G2 is 0 to ±1. The estimated real-time steering angle of the vehicle steering wheel, the vehicle load gain compensation G1, and the tire side stiffness gain compensation G2 are multiplied, and the result of the multiplication is used as the current steering angle of the vehicle steering wheel.

[0075] Even in the event of a steering wheel angle sensor malfunction, this method can determine the current steering angle through estimation and gain compensation. The electric power steering system can continue to provide assistance based on the current steering angle, thereby reducing the degree to which the assistance effect of the electric power steering system weakens due to steering wheel angle sensor failure and improving the safety of the user when using the vehicle.

[0076] Reference Figure 3The flowchart of another implementation of the steering wheel angle estimation method is shown. This method also includes the following steps:

[0077] S104: Read the steering wheel center position from the pre-stored steering wheel center position table, and correct the current steering angle according to the steering wheel center position to obtain the corrected current steering angle, so that the electric power steering system can provide assistance according to the corrected current steering angle; wherein, the steering wheel center position is the steering wheel center position when the vehicle is normally in a straight driving state.

[0078] The normal driving process of a vehicle includes the driving process before the steering wheel angle fails. During the normal driving process, it is necessary to determine whether the vehicle is in a straight-line driving state. The conditions used to determine the straight-line driving state of the vehicle are not restricted.

[0079] In this embodiment, the conditions for determining the straight-line driving state of the vehicle include the following eight conditions:

[0080] 1. The absolute value of the vehicle speed signal v is greater than the set minimum speed threshold v. min The minimum speed threshold is an arbitrary settable value, typically set to v. min =40km / h;

[0081] 2. Lateral acceleration G acc The absolute value of the signal is less than the set threshold for the lateral acceleration signal G. acc_max The threshold lateral acceleration signal is an arbitrary settable value, typically G. acc_max =0.5G;

[0082] 3. Yaw angular velocity ω θ_AOY <Set threshold yaw rate signal The threshold yaw rate is set to an arbitrary settable value, typically taking the value of [value missing]. Generally, the yaw rate threshold is related to the vehicle speed; the higher the vehicle speed, the smaller the threshold should be, showing a negative correlation.

[0083] 4. Gear rotation angle signal θ Pinion The absolute value of the angle is less than the set threshold angle θ. Pinion_max The threshold angle is set to an arbitrary settable value, typically θ. Pinion_max =8deg;

[0084] 5. Steering wheel torque signal T Hw The absolute value of the minimum torque signal T is less than the set threshold. Hw_max The minimum torque threshold signal is set to an arbitrary settable value, typically T. Hw_max =0.8 Nm;

[0085] 6. Gear speed signal v Pinion The absolute value of the velocity v is less than the set threshold. Pinion_max The set threshold speed can be any settable value, typically v. Pinion_max =10deg / s;

[0086] 7. Front wheel speed v Whl_fr v Whl_fl The absolute difference is less than the set threshold value v. Whl_max Rear wheel speed v Whl_rr v Whl_rl The absolute difference is less than the set threshold value v. Whl_max The threshold round number can be any settable value, typically v. Whl_max =1km / h;

[0087] 8. The steering wheel angle sensor is fault-free and the steering angle signal it sends is valid.

[0088] When all eight conditions are met, it indicates that the vehicle is in a straight-line driving state. The number of times the vehicle is in a normal straight-line driving state is accumulated, for example, the straight-line driving state counter is incremented by 1; otherwise, the straight-line driving state counter is cleared. When the straight-line driving state counter accumulates to a preset number, the straight-line driving flag is valid. The preset number of the straight-line driving state counter can be customized according to the actual situation. When the count meets the preset number, the current steering wheel center position is obtained and stored as a new steering wheel center position parameter in the steering wheel center position table. In actual implementation, the steering wheel center position table can be set in non-volatile memory.

[0089] In estimating the steering wheel angle, this method includes not only gain compensation for the real-time steering angle, but also self-learning the vehicle's steering wheel center position and using the steering wheel center position to correct the current steering angle. The correction method can be to add the current steering angle to the steering wheel center position to obtain the corrected current steering angle, thereby further improving the accuracy of the estimated steering angle and solving the problem of steering wheel center position angle drift caused by different vehicle characteristics and driving conditions.

[0090] This application has at least the following beneficial effects:

[0091] 1. Even in the event of a steering wheel angle sensor failure, this method can determine the current steering angle through estimation and gain compensation. The electric power steering system can continue to provide assistance based on the current steering angle, thereby reducing the degree to which the assistance effect of the electric power steering system weakens due to the failure of the steering wheel angle sensor and improving the safety of the user when using the vehicle.

[0092] 2. In addition to gain compensation for the real-time steering angle, it also includes self-learning the center position of the vehicle's steering wheel and using the center position of the steering wheel to correct the current steering angle, thereby further improving the accuracy of the estimated steering angle.

[0093] 3. This method provides a steering wheel angle estimation method for electronic power steering systems without increasing any hardware costs.

[0094] Reference Figure 4 The diagram illustrates a functional block diagram of a steering wheel angle estimation device according to an embodiment of the present invention, such as... Figure 4 The device includes:

[0095] The monitoring module 100 is used to monitor the vehicle's driving parameters and the vehicle's fault status in the event of a malfunction in the vehicle's steering wheel angle sensor.

[0096] The steering angle estimation module 200 is used to estimate the real-time steering angle of the vehicle's steering wheel based on the vehicle's driving parameters and the vehicle's attribute information, when the vehicle's driving parameters are valid and the vehicle is in a non-faulty state.

[0097] The gain compensation module 300 is used to perform gain compensation on the real-time steering angle of the vehicle steering wheel to obtain the current steering angle of the vehicle steering wheel, so that the electric power steering system can provide assistance according to the current steering angle.

[0098] Optionally, the monitoring module includes:

[0099] The driving parameter monitoring unit is used to acquire the driving parameters of the vehicle, judge the driving parameters, and determine that the driving parameters of the vehicle are valid if the driving parameters are within the calibration range within a first preset time period.

[0100] The fault status monitoring unit is used to determine that the fault status of the vehicle is a non-fault status if the fault code of the vehicle continuously indicates that the vehicle is fault-free or the fault does not exceed the fault preset status within a second preset time period, and the electric power steering system of the vehicle is continuously fault-free within the second preset time period.

[0101] Optionally, the gain compensation module includes:

[0102] The first acquisition unit is used to acquire the load of the vehicle and determine the vehicle load gain compensation based on the load of the vehicle.

[0103] The first calculation unit is used to calculate the current steering angle of the vehicle steering wheel based on the real-time steering angle of the vehicle steering wheel and the vehicle load gain compensation.

[0104] Optionally, gain compensation is performed on the real-time steering angle of the vehicle steering wheel to obtain the current steering angle of the vehicle steering wheel, including:

[0105] The second acquisition unit is used to acquire the load and speed of the vehicle;

[0106] The second determining unit is used to determine vehicle load gain compensation based on the vehicle's load; and to determine tire lateral stiffness gain compensation based on the vehicle's load and speed.

[0107] The second calculation unit is used to calculate the current steering angle of the vehicle steering wheel based on the real-time steering angle of the vehicle steering wheel, the vehicle load gain compensation, and the tire lateral stiffness gain compensation.

[0108] Reference Figure 5 The diagram illustrates a functional block diagram of a steering wheel angle estimation device according to an embodiment of the present invention, such as... Figure 5 The device further includes:

[0109] The steering wheel center correction module 400 is used to read the steering wheel center position from a pre-stored steering wheel center position table, and correct the current steering angle according to the steering wheel center position to obtain the corrected current steering angle, so that the electric power steering system can provide assistance according to the corrected current steering angle; wherein, the steering wheel center position is the steering wheel center position when the vehicle is normally in a straight driving state.

[0110] Optionally, the device further includes:

[0111] The accumulation unit is used to accumulate the number of times the vehicle is in a normal straight-line driving state;

[0112] The update unit is used to obtain the current steering wheel center position when the number of times is accumulated to a preset number, and store the obtained current steering wheel center position as a new steering wheel center position parameter in the steering wheel center position table.

[0113] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steering wheel angle estimation method as described in the embodiments.

[0114] This application also provides a vehicle equipped with the device described in the embodiment, the device performing the steering wheel angle estimation method described in the embodiment.

[0115] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0116] Those skilled in the art will understand that embodiments of this application can be provided as methods, apparatus, or computer program products. Therefore, embodiments of this application can take the form of entirely hardware embodiments, entirely software embodiments, or embodiments combining software and hardware aspects. Furthermore, embodiments of this application can take the form of computer program products implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0117] This application describes embodiments with reference to flowchart illustrations and / or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing terminal device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal device, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0118] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing terminal device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0119] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal equipment, causing a series of operational steps to be performed on the computer or other programmable terminal equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable terminal equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0120] Although preferred embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.

[0121] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0122] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for estimating steering wheel angle, characterized in that, Applied to vehicles, the method includes: In the event of a malfunction in the vehicle's steering wheel angle sensor, the vehicle's driving parameters are acquired and evaluated. If the driving parameters are within the calibration range within a first preset time period, the vehicle's driving parameters are determined to be valid. If the vehicle's fault code continuously indicates that the vehicle is fault-free or the fault does not exceed the preset fault state during the second preset time period, and the vehicle's electric power steering system is fault-free during the second preset time period, then the vehicle's fault state is determined to be a non-fault state. When the vehicle's driving parameters are valid and the vehicle is in a non-faulty state, the real-time steering angle of the vehicle's steering wheel is estimated based on the vehicle's driving parameters and the vehicle's attribute information. Gain compensation is applied to the real-time steering angle of the vehicle's steering wheel to obtain the current steering angle of the vehicle's steering wheel, so that the electric power steering system can provide assistance based on the current steering angle.

2. The method according to claim 1, characterized in that, When the vehicle's driving parameters are valid and the vehicle is in a non-faulty state, the real-time steering angle of the vehicle's steering wheel is estimated based on the vehicle's driving parameters and attribute information, including: When the vehicle's driving parameters are valid and the vehicle is in a non-faulty state, the real-time steering angle of the vehicle's steering wheel is estimated based on the state equation of the two-degree-of-freedom dynamic model. The formula for calculating the real-time steering angle of the vehicle's steering wheel is as follows: In the formula, δ Hw This refers to the real-time steering angle of the steering wheel; C αf C represents the front wheel lateral stiffness. αr Rear wheel lateral stiffness; l f The distance from the vehicle's center of gravity to the front axle; r denoted as ρ, where m is the distance from the vehicle's center of gravity to the rear axle; ρ is the vehicle's curb weight; and v is the vehicle speed. α is the yaw rate; α is the lateral acceleration; ξ is the steering system gear ratio; α f The vehicle's center of gravity sideslip angle.

3. The method according to any one of claims 1-2, characterized in that, Gain compensation is applied to the real-time steering angle of the vehicle's steering wheel to obtain the current steering angle of the vehicle's steering wheel, including: Obtain the load of the vehicle and determine the vehicle load gain compensation based on the vehicle load; The current steering angle of the vehicle steering wheel is calculated based on the real-time steering angle of the vehicle steering wheel and the vehicle load gain compensation.

4. The method according to any one of claims 1-2, characterized in that, Gain compensation is applied to the real-time steering angle of the vehicle's steering wheel to obtain the current steering angle of the vehicle's steering wheel, including: Obtain the vehicle's load and speed; Determine the vehicle load gain compensation based on the vehicle's load; Based on the vehicle's load and speed, determine the tire lateral stiffness gain compensation; The current steering angle of the vehicle steering wheel is calculated based on the real-time steering angle of the vehicle steering wheel, the vehicle load gain compensation, and the tire lateral stiffness gain compensation.

5. The method according to claim 1, characterized in that, After performing gain compensation on the real-time steering angle of the vehicle steering wheel to obtain the current steering angle of the vehicle steering wheel, the method further includes: The steering wheel center position is read from a pre-stored steering wheel center position table, and the current steering angle is corrected according to the steering wheel center position to obtain the corrected current steering angle, so that the electric power steering system can provide assistance according to the corrected current steering angle; The steering wheel center position is the steering wheel center position when the vehicle is normally in a straight-line driving state.

6. The method according to claim 5, characterized in that, The method further includes: The number of times the vehicle is in a normal straight-line driving state is accumulated; When the preset number of times is accumulated, the current steering wheel center position is obtained, and the obtained current steering wheel center position is stored as a new steering wheel center position parameter in the steering wheel center position table.

7. A steering wheel angle estimation device, characterized in that, Applied to vehicles, the device includes: The driving parameter monitoring unit is used to judge the driving parameters in the event of a malfunction of the vehicle's steering wheel angle sensor. If the driving parameters are within the calibration range within a first preset time period, the driving parameters of the vehicle are determined to be valid. The fault status monitoring unit is used to determine that the fault status of the vehicle is a non-fault status if the fault code of the vehicle continues to indicate that the vehicle is fault-free or the fault does not exceed the fault preset status during the second preset time period, and the electric power steering system of the vehicle is fault-free during the second preset time period. The steering angle estimation module is used to estimate the real-time steering angle of the vehicle's steering wheel based on the vehicle's driving parameters and attribute information, provided that the vehicle's driving parameters are valid and the vehicle is in a non-faulty state. The gain compensation module is used to compensate for the real-time steering angle of the vehicle steering wheel to obtain the current steering angle of the vehicle steering wheel, so that the electric power steering system can provide assistance according to the current steering angle.

8. A computer-readable storage medium, characterized in that, A computer program is stored on the computer-readable storage medium, which, when executed by a processor, implements the steering wheel angle estimation method as described in any one of claims 1 to 6.

9. A vehicle, characterized in that, The vehicle is equipped with the device as described in claim 7, which performs the steering wheel angle estimation method as described in any one of claims 1-6.

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