A control method and device for electric power steering and a vehicle

Abstract

This invention provides a control method for electric power steering, comprising: acquiring first torque data of the driver within a preset time period; determining a target torque feature vector based on the first torque data; determining a target personalized power steering characteristic map of the driver based on the target torque feature vector; determining a target power steering torque based on the current driving parameters of the vehicle and the target personalized power steering characteristic map during vehicle operation; thus, when the vehicle starts, extracting the driver's target feature vector through guidance information, and matching a personalized power steering characteristic map for the driver based on the target feature vector, so that the vehicle's power steering system conforms to the driver's operating characteristics during the start-up phase; and correcting the target personalized power steering characteristic map based on real-time driving parameters during vehicle operation, adaptively adjusting the power steering torque to ensure that the power steering output is more adapted to the driver's needs and improve the vehicle's steering control safety.

Description

Technical Field

[0001] This invention relates to the field of vehicle control technology, and in particular to a control method, device and vehicle for electric power steering. Background Technology

[0002] Electric power steering (EPS) is a key component of a car chassis. Existing EPS systems mainly rely on sensors that collect operating data such as vehicle speed, steering torque, and steering angle, and then use pre-calibrated power steering characteristic curves to calculate the power steering torque.

[0003] However, the relevant technologies all use pre-calibrated universal power steering characteristic curves, which can only adapt to standardized driver characteristics and cannot achieve differentiated matching for different drivers' physical conditions, steering habits, and steering feel preferences. In actual driving, it is very easy for the power steering output to mismatch with the driver's needs: for example, when the power steering is too strong, the steering wheel feels too light and the road feel is lacking; when the power steering is too weak, the steering load is too high and the handling is difficult, which increases the driver's operating burden, increases fatigue during long-term driving, and is not conducive to ensuring steering safety.

[0004] Therefore, there is an urgent need for an adaptive control method for electric power steering to solve the above-mentioned technical problems. Summary of the Invention

[0005] To address the problems existing in the prior art, embodiments of the present invention provide a control method, device, and vehicle for electric power steering, in order to solve or partially solve the technical problem that the steering operation characteristics of different drivers cannot be adapted, the power steering torque is difficult to be adjusted in a personalized and adaptive manner, resulting in the steering power output not matching the driver's needs, and thus affecting the safety of vehicle steering and handling.

[0006] A first aspect of the present invention provides a control method for electric power steering, the method comprising: When the vehicle is running, the driver’s first torque data within a preset time period is extracted based on driving guidance information, and a target torque feature vector is determined based on the first torque data to characterize the driver’s steering habits. The driver's target personalized power assist characteristic map is determined based on the target torque feature vector; During vehicle operation, a target assist torque is determined based on the vehicle's current driving parameters and the target personalized assist characteristic map; the target assist torque is used to control the motor to provide corresponding steering assistance.

[0007] In the above scheme, the vehicle being in the starting state is determined by the following steps: When the vehicle is powered on, determine whether the vehicle speed is 0. If the vehicle speed is 0, continue to determine whether the gear is the target gear, which is either Parking (P) or Neutral (N). If the gear is the target gear, the vehicle is determined to be in the starting state.

[0008] In the above scheme, determining the target torque feature vector characterizing the driver's steering habits based on the first torque data includes: Determine the peak torque and average torque from the first torque data; A first torque threshold and a second torque threshold are determined based on the peak torque, and the torque rise rate is determined based on the first torque threshold and the second torque threshold. The torque fluctuation variance is determined based on the first torque data; The peak torque, the average torque, the torque rise rate, and the torque fluctuation variance are concatenated to obtain the target torque feature vector.

[0009] In the above scheme, determining the driver's target personalized power assist characteristic map based on the target torque feature vector includes: If the driver is the historical user, then the driver's historical personalized assistance characteristic map is retrieved from the database and the historical personalized assistance characteristic map is determined as the target personalized assistance characteristic map; If the driver is a new user, determine the Euclidean distance between the target torque feature vector and each driver template feature vector in the database; The driver template feature vector corresponding to the minimum Euclidean distance is determined as the target template feature vector, and the corresponding target personalized power assist characteristic map is searched from the database based on the target template feature vector; the database stores the correspondence between driver template feature vectors and personalized power assist characteristic maps.

[0010] In the above scheme, the current driving parameters include: the vehicle's current speed and the current steering wheel input torque; determining the target assist torque based on the vehicle's current driving parameters and the target personalized assist characteristic map includes: Based on the current speed and the current steering wheel input torque, the corresponding basic assist current is found in the target personalized assist characteristic map; The base assist current is adaptively corrected based on the current steering angular velocity and the current driving mode to obtain the corrected assist current. Under the condition that the current road surface is in a severe condition, the damping current is determined, and the target assist current is determined based on the damping current and the corrected assist current. The target assist current is converted into the target assist torque using the motor torque coefficient.

[0011] In the above scheme, the adaptive correction of the base assist current based on the current steering angle and the current driving mode to obtain the corrected assist current includes: The current compensation amount is determined based on the current steering angular velocity, and the basic assist current and the first current compensation amount are superimposed to obtain the compensation current; The current compensation coefficient is determined based on the current driving mode, the product of the compensation current and the current compensation coefficient is determined, and the product is determined as the corrected assist current.

[0012] In the above scheme, determining the target assist current based on the damping current and the corrected assist current includes: The current difference between the corrected assist current and the damping current is determined, and the current difference is determined as the target assist current.

[0013] In the above scheme, after determining the target assist torque based on the vehicle's current driving parameters and the target personalized assist characteristic map, the method further includes: In response to preset data analysis trigger conditions, valid historical driving parameters within the target historical time period are obtained; the valid historical driving parameters include valid historical vehicle speed, valid historical steering wheel input torque, valid historical steering angular velocity, and target power assist current; The system divides the grid into different working conditions based on vehicle speed and steering wheel input torque. The steering angular velocity and target power assist current in each working condition grid are analyzed to obtain the power assist deviation analysis results. Based on the results of the assist deviation analysis, the basic assist current of the corresponding working point in the target personalized assist characteristic spectrum is smoothly updated to obtain the updated target personalized assist characteristic spectrum.

[0014] A second aspect of the present invention provides a control device for electric power steering, the device comprising: The first determining unit is used to extract the first torque data of the driver within a preset time period based on driving guidance information when the vehicle is in the starting state, and to extract a target torque feature vector to characterize the driver's steering habits based on the first torque data. The second determining unit is used to determine the driver's target personalized power assist characteristic map based on the target torque feature vector; The third determining unit is used to determine the target assist torque based on the vehicle's current driving parameters and the target personalized assist characteristic map during vehicle operation; the target assist torque is used to control the motor to provide corresponding steering assistance.

[0015] A third aspect of the present invention provides a vehicle including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the steps of the method described in any of the first aspects.

[0016] This invention provides a control method, device, and vehicle for electric power steering. The method includes: when the vehicle is in a running state, extracting first torque data of the driver within a preset time period based on driving guidance information; determining a target torque feature vector characterizing the driver's steering habits based on the first torque data; determining a target personalized power steering characteristic map of the driver based on the target torque feature vector; and determining a target power steering torque based on the vehicle's current driving parameters and the target personalized power steering characteristic map during vehicle operation. The target power steering torque is used to control the motor to provide corresponding steering assistance. Thus, when the vehicle starts, the driver's target feature vector is extracted through simple driving guidance information, and a target personalized power steering characteristic map that closely matches the driver's steering habits is quickly matched based on the target feature vector, so that the vehicle's power steering system conforms to the driver's steering operation characteristics from the start-up stage. During vehicle operation, the target personalized power steering characteristic map is corrected based on real-time driving parameters, and the power steering torque is adaptively adjusted to ensure that the power steering output is more adapted to the driver's needs, thereby improving the vehicle's steering control safety. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A schematic flowchart of an electric power steering control method according to an embodiment of the present invention is shown; Figure 2 A schematic diagram of the control device structure for electric power steering according to an embodiment of the present invention is shown. Detailed Implementation

[0018] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0019] To better understand the technical solution of this invention, the Electric Power Steering (EPS) system is first introduced here. The system includes: a steering wheel assembly, a torque sensor, a steering angle sensor, a vehicle speed sensor, a power steering motor and a reduction mechanism, an electronic control unit, a human-machine interface, and vehicle status sensors; wherein... The steering wheel assembly carries the steering wheel and steering column to achieve mechanical steering transmission, and the torque sensor is used to monitor the steering wheel input torque applied by the driver. The steering angle sensor is used to collect steering wheel angle signals in real time; the vehicle speed sensor is used to monitor vehicle speed. The assist motor and reduction mechanism output assist torque; the assist motor can be a brushless DC motor. The electronic control unit is equipped with a processor and memory. The memory is used to store personalized assist feature maps (MAPs) and adaptive learning algorithms.

[0020] The human-machine interface can output driving guidance prompts to the driver during the calibration process; Vehicle status sensors are used to detect vehicle gear position and power status information, thereby determining whether the vehicle is in the starting state.

[0021] Based on the above system, embodiments of the present invention provide a control method for electric power steering, such as... Figure 1 As shown, the method mainly includes the following steps: S110, when the vehicle is in the starting state, extract the first torque data of the driver within a preset time period based on the driving guidance information, and determine the target torque feature vector to characterize the driver's steering habits based on the first torque data.

[0022] In order to quickly determine the driver's steering habits, the driver is guided to complete the prescribed steering operation during the vehicle start-up phase to carry out calibration. Data such as initial torque and steering angular velocity are collected to construct feature vectors and match them with the appropriate power assist characteristic map, providing benchmark data for subsequent long-term adaptive learning.

[0023] Therefore, when the vehicle is in the starting state, this embodiment of the invention extracts the driver's first torque data within a preset time period based on driving guidance information, and determines the target torque feature vector to characterize the driver's steering habits based on the first torque data.

[0024] In one implementation, the vehicle being in the started state is determined by the following steps: When the vehicle is powered on, determine if the vehicle speed is 0. If the vehicle speed is 0, continue to determine if the gear is the target gear. The target gear is either Park (P) or Neutral (N). If the gear is the target gear, the vehicle is confirmed to be in the starting state.

[0025] Specifically, if the vehicle is in the accessory energization (ACC) position or the all-vehicle energization (ON) position, then the vehicle is considered to be powered on. In ACC mode, only in-vehicle accessories such as the audio-visual system, central control screen, and cigarette lighter are powered; the engine, vehicle power system, and EPS power assist main circuit are not powered. In ON mode, the entire vehicle electronic control system is powered, the in-vehicle controller, EPS motor, and various sensors are all powered and ready, and the engine is in a standby state.

[0026] Then, it continues to determine whether the vehicle speed is 0. If so, it continues to determine whether the vehicle is in P or N gear. If so, the driver torque characteristic calibration process can be triggered.

[0027] Before calibration, the current ignition key ID, cockpit facial recognition results, steering wheel fingerprint information, etc. can be read to determine whether the current driver is a new driver; If the corresponding ignition key ID is not matched, the cockpit facial recognition result is a recognition failure, or the corresponding steering wheel fingerprint is not matched, the current driver is determined to be a new driver, and driving guidance information can be issued via the central control screen or voice. Driving guidance information may include "Please turn the steering wheel slightly (left or right) about 15 degrees and then straighten it", "Please turn the steering wheel to the right at a constant speed, with an angle not exceeding 30 degrees", and "Please hold the steering wheel naturally with both hands, without deliberately exerting force", etc.

[0028] During the steering wheel rotation, the torque input torque of a complete steering event can be sampled by a torque sensor at a preset frequency (e.g., 100Hz) within a preset time period to obtain the first torque data within the preset time period. The rotation angle corresponding to a complete steering event is -10° to -20° or 10° to 20°.

[0029] After obtaining the first torque data, a target torque feature vector can be determined based on the first torque data to characterize the driver's steering habits, including: Determine the peak torque and average torque from the initial torque data; A first torque threshold and a second torque threshold are determined based on the peak torque, and the torque rise rate is determined based on the first torque threshold and the second torque threshold. The torque fluctuation variance is determined based on the first torque data; The peak torque, average torque, torque rise rate, and torque fluctuation variance are concatenated to obtain the torque feature vector.

[0030] For example, for a certain steering event, suppose the peak torque determined from the first torque data is 2 N·m and the average torque is 0.9 N·m.

[0031] The first torque threshold is 10% of the peak torque, and the second torque threshold is 90% of the peak torque. That is, the first torque threshold is 0.2 Nm and the second torque threshold is 1.8 Nm. Assuming that it takes 0.4 s to rise from the first torque threshold to the second torque threshold, then the torque rise rate is: (1.8-0.2) / 0.4=4 N.m / s.

[0032] The torque fluctuation variance is calculated as follows: Assuming five torque sampling points were collected: 0.8 Nm, 0.9 Nm, 0.95 Nm, and 0.85 Nm; and the average torque is 0.9 Nm, then the torque fluctuation variance is... for: Therefore, the torque eigenvector is: [2, 0.9, 4, 0.003].

[0033] If there is only one steering event, then the torque feature vector [2, 0.9, 4, 0.003] is determined as the final target torque feature vector; if there are multiple steering events, the torque feature vector corresponding to each steering event can be obtained, and finally the average value of each dimension of multiple torque feature vectors is determined as the target torque feature vector.

[0034] This yields the driver's personalized torque feature vector.

[0035] S111, determine the driver's target personalized assist characteristic map based on the target torque feature vector.

[0036] After determining the driver's target torque feature vector, the driver's target personalized power assist characteristic profile can be determined based on the target torque feature vector, including: If the driver is a historical user, the driver's historical personalized assistance feature map is retrieved from the database and used as the target personalized assistance feature map. If the driver is a new user, determine the Euclidean distance between the target torque feature vector and the feature vector of each driver template in the database; The driver template feature vector corresponding to the minimum Euclidean distance is determined as the target template feature vector. Based on the target template feature vector, the corresponding target personalized power assist feature map is searched from the database. The database stores the correspondence between the driver template feature vector and the personalized power assist feature map.

[0037] Specifically, if the current ignition key ID, cockpit facial recognition result, and steering wheel fingerprint information can all successfully match a historical user, it indicates that the driver is a historical user. The driver's historical personalized power steering characteristic map is then directly retrieved from the data and designated as the target personalized power steering characteristic map. The x-axis of the power steering characteristic map represents vehicle speed, the Y-axis represents steering wheel input torque, and the Z-axis represents power steering current.

[0038] If the driver is a new user, after obtaining the driver's target torque feature vector, it can be compared with all driver template feature vectors in the feature library to determine the Euclidean distance between the target torque feature vector and each template feature vector. The driver template feature vector corresponding to the smallest Euclidean distance is determined as the target template feature vector. Then, the personalized power assist characteristic map corresponding to the target template feature vector is searched from the database, and the personalized power assist characteristic map corresponding to the target template feature vector is used as the driver's target personalized power assist characteristic map. The database stores the correspondence between driver template feature vectors and personalized power assist characteristic maps of historical users, ensuring a correspondence between them.

[0039] For example, assuming the target torque feature vector is [1.5, 0.85, 3.9, 0.021], and a driver template feature vector is [1.6, 0.9, 4.2, 0.025], then the Euclidean distance is: .

[0040] S112, During vehicle operation, a target assist torque is determined based on the vehicle's current driving parameters and the target personalized assist characteristic map; the target assist torque is used to control the motor to provide corresponding steering assistance.

[0041] After determining the target personalized power steering characteristic map, during vehicle operation, the target power steering torque is determined based on the vehicle's current driving parameters and the target personalized power steering characteristic map. This means that the base power steering torque is adaptively corrected to obtain the target power steering torque. The target power steering torque is used to control the motor to provide corresponding steering assistance.

[0042] Specifically, for new users, the target personalized power steering characteristic map only closely resembles their steering habits and cannot yet perfectly match them. For experienced users, the original personalized power steering characteristic map may exhibit adaptation deviations due to driving conditions and scenarios. Therefore, during vehicle operation, it is necessary to adaptively correct the base power steering torque based on the vehicle's current driving parameters and the target personalized power steering characteristic map, periodically iterating and updating the personalized power steering characteristic map to ensure it continuously aligns with the driver's real-time steering habits.

[0043] In one implementation, the current driving parameters include: the vehicle's current speed and the current steering wheel input torque; the base assist torque is adaptively corrected based on the vehicle's current driving parameters and the target personalized assist characteristic map to obtain the target assist torque, including: Based on the current speed and current steering wheel input torque, find the corresponding basic assist current in the target personalized power assist characteristic map; The base assist current is adaptively corrected based on the current steering angular velocity and the current driving mode to obtain the corrected assist current. Given that the current road surface condition is a severe road surface condition, determine the damping current, and then determine the target assist current based on the damping current and the correction assist current. The target assist current is converted into the target assist torque by utilizing the motor torque coefficient.

[0044] In one implementation, the base power assist current is adaptively corrected based on the current steering angular velocity and the current driving mode to obtain a corrected power assist current, including: The current compensation amount is determined based on the current steering angular velocity. The basic assist current and the first current compensation amount are then superimposed to obtain the compensation current. Determine the current compensation coefficient based on the current driving mode, determine the product of the compensation current and the current compensation coefficient, and use the product as the correction assist current.

[0045] In one implementation, determining the target assist current based on the damping current and the corrected assist current includes: Determine the current difference between the corrected assist current and the damping current, and use this current difference as the target assist current.

[0046] Specifically, during vehicle operation, the system continuously collects the vehicle's current speed and steering wheel input torque, and then searches for the corresponding base assist current in the target personalized power steering characteristic map based on these data. .

[0047] Get the current steering wheel angle, according to the formula Determine the current steering angular velocity of the steering wheel. The base power assist current is adaptively corrected based on the current steering angular velocity and the current driving mode to obtain the corrected power assist current. .

[0048] For example, suppose the current steering angular velocity is greater than a preset angular velocity threshold, indicating that the driver is making a rapid turn, therefore the base assist current needs to be increased. Overlay a with Positively correlated compensation amount To obtain the compensation current , that is .

[0049] Among them, compensation amount It can be determined based on a pre-calibrated compensation table, for example, a portion of the compensation table can be shown in Table 1: Table 1

[0050] As shown in Table 1, the compensation table records the correspondence between steering angular velocity and compensation amount. If the current steering angular velocity is in the compensation table, the corresponding compensation amount can be directly found based on the current steering angular velocity; if the current steering angular velocity is not in the compensation table, the compensation amount corresponding to the current angular velocity can be determined by using the linear interpolation method.

[0051] Considering that different driving modes also affect steering assist requirements, vehicles are mostly used in low-speed, congested road conditions, where drivers prefer a lighter steering feel. Therefore, a coefficient greater than 1 is used to amplify the assist output. In Standard mode, the steering feel is adapted to general family driving scenarios, and the assist does not require adjustment of the multiplier; the assist value calculated adaptively is used directly. In Sport mode, because drivers seek stronger road feedback and more stable steering characteristics, they do not want the steering wheel to be too light and sensitive. If the conventional adaptive output assist current is used, the steering assist will be too large and the road feel will be too weak, failing to meet the demands of sporty handling. Therefore, it is necessary to further adjust the compensation current according to the current driving mode to obtain the corrected assist current.

[0052] Specifically, the corresponding current compensation coefficient needs to be determined based on the current driving mode. For example, if the current driving mode is standard mode, the current compensation coefficient can be 1; if the current driving mode is economy mode, the current compensation coefficient can be greater than 1, such as 1.2; if the current driving mode is sport mode, the current compensation coefficient can be less than 1, such as 0.8.

[0053] After determining the current compensation coefficient, it is necessary to determine the compensation current and the current compensation coefficient. K The product of these two factors is used to determine the corrected boost current. , that is .

[0054] Furthermore, considering that road impacts under adverse road conditions can be transmitted in reverse through the wheels to the steering wheel, causing steering wheel vibration and hand-kickback, which interferes with the driver's normal steering operation, it is also necessary to determine the damping current under adverse road conditions and apply reverse assist torque to the EPS motor to suppress steering wheel vibration and ensure steering stability.

[0055] Therefore, if the current road surface condition is a severe road surface condition, the damping current is determined. The target assist current is determined based on the damping current and the corrected assist current. That is, it can be determined according to the formula. .

[0056] The damping current is determined as follows: The fluctuation range of the EPS motor output current is continuously monitored, and the variance of the current fluctuation within a short time window (e.g., 10 minutes) is statistically analyzed. If the variance of the current fluctuation is less than or equal to the preset variance threshold, the current road surface condition is determined to be a smooth paved road surface. If the variance of the current fluctuation is greater than the preset variance threshold and the duration is greater than the preset duration threshold (e.g., 1 second), the current road surface condition is determined to be a severe road surface condition, and a damping current needs to be applied.

[0057] The damping current can be calculated using the formula... Sure, The damping coefficient is preset, for example, 20; This represents the variance of the current fluctuation.

[0058] Once the target assist current is determined, it is converted into a target assist torque using the motor torque coefficient. The target assist torque is then used to control the motor to provide corresponding steering assistance. In other words, a motor control signal is generated based on the target assist torque, driving the power steering motor to output a corresponding amount of auxiliary torque. This provides real-time steering assistance to the steering system, adapting to the operating conditions and reducing the hand force required for the driver to operate the steering wheel.

[0059] In addition, to ensure that the target personalized power assist characteristic map can keep pace with the driver's dynamically changing steering habits over the long term, this embodiment of the invention will continuously collect operating data such as steering wheel input torque, steering angular velocity, and vehicle speed during daily driving, and statistically analyze the deviation between the driver's actual power assist needs and the output value of the target personalized power assist characteristic map. Under the premise of meeting safety constraints such as update threshold and single adjustment range limit, the power assist parameters of the corresponding working condition grid points in the target personalized power assist characteristic map will be iteratively updated in a small manner, so that the power assist characteristics can be continuously adapted and optimized as the driver's force application habits and driving state change.

[0060] In one implementation, after determining the target assist torque based on the vehicle's current driving parameters and the target personalized assist characteristic map, the method further includes: In response to preset data analysis trigger conditions, the system acquires valid historical driving parameters within the target historical time period. Valid historical driving parameters include valid historical vehicle speed, valid historical steering wheel input torque, valid historical steering angular velocity, and target power assist current. The system divides the grid into different working conditions based on vehicle speed and steering wheel input torque. The steering angular velocity and target power assist current in each working condition grid are analyzed to obtain the power assist deviation analysis results. Based on the results of the assist deviation analysis, the basic assist torque of the corresponding working point in the target personalized assist characteristic map is smoothly updated to obtain the updated target personalized assist characteristic map.

[0061] Specifically, when the vehicle is driving normally, it can continuously record driving parameters for each steering event: vehicle speed, steering wheel input torque, steering angular velocity, and the final output target assist current, and store these driving parameters in a database.

[0062] When the driving mileage or driving time conditions are met, the data analysis trigger condition is determined to be met, and data analysis is started.

[0063] Invalid driving parameters in the database are removed to obtain valid historical vehicle speed, valid historical steering wheel input torque, valid historical steering angular velocity, and target assist current.

[0064] Different operating condition grids are divided according to vehicle speed and steering wheel input torque (for example, a vehicle speed of less than 30 km / h and steering wheel input torque of less than 1 N·m can be considered as an operating condition grid). For each operating condition grid, the steering angular velocity of each steering event within that grid and the final output target assist current are statistically analyzed. If, under that operating condition grid, the steering angular velocity is generally too high (habitually quick and light steering wheel turns), but the basic assist current obtained from the original target personalized assist characteristic map is too low, real-time compensation and additional current are required to obtain the target assist current adapted to the driver. This indicates that the basic assist current setting of that operating condition grid in the target personalized assist characteristic map is too low, that is, the assist deviation analysis result is that the assist current setting is too low.

[0065] Once the target assist current required for the current operating condition grid is statistically determined, the original parameters are not immediately overwritten. The system adjusts the base assist current by 1% to 2% in each effective update cycle, gradually smoothing the adjustment and converging it towards the target assist current. After the grid parameters for this operating condition stabilize, the updated parameters are entered into the assist characteristic map (MAP), completing the iterative update of the corresponding grid points in the personalized assist characteristic map, thus obtaining the updated target personalized assist characteristic map. By continuously updating the power steering characteristic map in small increments, it can adapt to the driver's dynamic changes in steering force application habits as fatigue level, grip posture, and driving experience change. On the other hand, a single adjustment of only 1% to 2% can achieve a smooth transition of parameters, avoiding abrupt changes in steering wheel feel caused by sudden changes in power steering characteristics, thus balancing driving comfort and driving safety.

[0066] Based on the same inventive concept as in the foregoing embodiments, this embodiment also provides a control device for electric power steering, such as... Figure 2 As shown, the device includes: The first determining unit 21 is used to extract the first torque data of the driver within a preset time period based on driving guidance information when the vehicle is in the starting state, and to extract a target torque feature vector to characterize the driver's steering habits based on the first torque data. The second determining unit 22 is used to determine the driver's target personalized power assist characteristic map based on the target torque feature vector; The third determining unit 23 is used to determine the target assist torque based on the vehicle's current driving parameters and the target personalized assist characteristic map during vehicle operation; the target assist torque is used to control the motor to provide corresponding steering assistance.

[0067] Since the apparatus described in the embodiments of this invention is used to implement the electric power steering control method of the embodiments of this invention, those skilled in the art can understand the specific structure and variations of the apparatus based on the method described in the embodiments of this invention, and therefore will not be described in detail here. All apparatuses used in the methods of the embodiments of this invention fall within the scope of protection of this invention.

[0068] Based on the same inventive concept, this embodiment provides a vehicle including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements any step of the method described above.

[0069] Through one or more embodiments of the present invention, the present invention has the following beneficial effects or advantages: This invention provides a control method, device, and vehicle for electric power steering. The method includes: when the vehicle is in a running state, extracting first torque data of the driver within a preset time period based on driving guidance information; determining a target torque feature vector characterizing the driver's steering habits based on the first torque data; determining a target personalized power steering characteristic map of the driver based on the target torque feature vector; and determining a target power steering torque based on the vehicle's current driving parameters and the target personalized power steering characteristic map during vehicle operation. The target power steering torque is used to control the motor to provide corresponding steering assistance. Thus, when the vehicle starts, the driver's target feature vector is extracted through simple driving guidance information, and a target personalized power steering characteristic map that closely matches the driver's steering habits is quickly matched based on the target feature vector, so that the vehicle's power steering system conforms to the driver's steering operation characteristics from the start-up stage. During vehicle operation, the target personalized power steering characteristic map is corrected based on real-time driving parameters, and the power steering torque is adaptively adjusted to ensure that the power steering output is more adapted to the driver's needs, thereby improving the vehicle's steering control safety.

[0070] The algorithms and displays provided herein are not inherently related to any particular computer, virtual system, or other device. Various general-purpose systems can also be used in conjunction with the teachings herein. The required structure for constructing such systems is apparent from the above description. Furthermore, this invention is not directed to any particular programming language. It should be understood that the contents of the invention described herein can be implemented using various programming languages, and the above description of specific languages ​​is for the purpose of disclosing the best mode of implementation of the invention.

[0071] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0072] Similarly, it should be understood that, in order to simplify this disclosure and aid in understanding one or more of the various aspects of the invention, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof. However, this method of disclosure should not be construed as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the following claims, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into this detailed description, wherein each claim itself is a separate embodiment of the invention.

[0073] Those skilled in the art will understand that modules in the device of the embodiments can be adaptively changed and placed in one or more devices different from that embodiment. Modules, units, or components in the embodiments can be combined into a single module, unit, or component, and further, they can be divided into multiple sub-modules, sub-units, or sub-components. Except where at least some of such features and / or processes or units are mutually exclusive, any combination can be used to combine all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or units of any method or device so disclosed. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that serves the same, equivalent, or similar purpose.

[0074] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0075] The various component embodiments of the present invention can be implemented in hardware, or as software modules running on one or more processors, or a combination thereof. Those skilled in the art will understand that microprocessors or digital signal processors (DSPs) can be used in practice to implement some or all of the functions of some or all of the components of the gateway, proxy server, or system according to embodiments of the present invention. The present invention can also be implemented as a device or apparatus program (e.g., a computer program and computer program product) for performing part or all of the methods described herein. Such programs implementing the present invention can be stored on a computer-readable medium or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.

[0076] It should be noted that the above embodiments are illustrative of the invention and not restrictive, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.

[0077] Although preferred embodiments of the invention 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 both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0078] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method for electric power steering, characterized in that, The method includes: When the vehicle is running, the driver’s first torque data within a preset time period is extracted based on driving guidance information, and a target torque feature vector is determined based on the first torque data to characterize the driver’s steering habits. The driver's target personalized power assist characteristic map is determined based on the target torque feature vector; During vehicle operation, a target assist torque is determined based on the vehicle's current driving parameters and the target personalized assist characteristic map; the target assist torque is used to control the motor to provide corresponding steering assistance.

2. The method as described in claim 1, characterized in that, The vehicle is in the starting state as determined by the following steps: When the vehicle is powered on, determine whether the vehicle speed is 0. If the vehicle speed is 0, continue to determine whether the gear is the target gear, which is either Parking (P) or Neutral (N). If the gear is the target gear, the vehicle is determined to be in the starting state.

3. The method as described in claim 1, characterized in that, The step of determining the target torque feature vector characterizing the driver's steering habits based on the first torque data includes: Determine the peak torque and average torque from the first torque data; A first torque threshold and a second torque threshold are determined based on the peak torque, and the torque rise rate is determined based on the first torque threshold and the second torque threshold. The torque fluctuation variance is determined based on the first torque data; The peak torque, the average torque, the torque rise rate, and the torque fluctuation variance are concatenated to obtain the target torque feature vector.

4. The method as described in claim 1, characterized in that, Determining the driver's target personalized power assist characteristic map based on the target torque feature vector includes: If the driver is the historical user, then the driver's historical personalized assistance characteristic map is retrieved from the database and the historical personalized assistance characteristic map is determined as the target personalized assistance characteristic map; If the driver is a new user, determine the Euclidean distance between the target torque feature vector and each driver template feature vector in the database; The driver template feature vector corresponding to the minimum Euclidean distance is determined as the target template feature vector, and the corresponding target personalized power assist characteristic map is searched from the database based on the target template feature vector; the database stores the correspondence between driver template feature vectors and personalized power assist characteristic maps.

5. The method as described in claim 1, characterized in that, The current driving parameters include: the vehicle's current speed and the current steering wheel input torque; determining the target assist torque based on the vehicle's current driving parameters and the target personalized power assist characteristic map includes: Based on the current speed and the current steering wheel input torque, the corresponding basic assist current is found in the target personalized assist characteristic map; The base assist current is adaptively corrected based on the current steering angular velocity and the current driving mode to obtain the corrected assist current. Under the condition that the current road surface is in a severe condition, the damping current is determined, and the target assist current is determined based on the damping current and the corrected assist current. The target assist current is converted into the target assist torque using the motor torque coefficient.

6. The method as described in claim 5, characterized in that, The adaptive correction of the base assist current based on the current steering angle and current driving mode to obtain the corrected assist current includes: The current compensation amount is determined based on the current steering angular velocity, and the basic assist current and the first current compensation amount are superimposed to obtain the compensation current; The current compensation coefficient is determined based on the current driving mode, the product of the compensation current and the current compensation coefficient is determined, and the product is determined as the corrected assist current.

7. The method as described in claim 5, characterized in that, Determining the target assist current based on the damping current and the corrected assist current includes: The current difference between the corrected assist current and the damping current is determined, and the current difference is determined as the target assist current.

8. The method as described in claim 1, characterized in that, After determining the target assist torque based on the vehicle's current driving parameters and the target personalized assist characteristic map, the method further includes: In response to preset data analysis trigger conditions, valid historical driving parameters within the target historical time period are obtained; the valid historical driving parameters include valid historical vehicle speed, valid historical steering wheel input torque, valid historical steering angular velocity, and target power assist current; The system divides the grid into different working conditions based on vehicle speed and steering wheel input torque. The steering angular velocity and target power assist current in each working condition grid are analyzed to obtain the power assist deviation analysis results. Based on the results of the assist deviation analysis, the basic assist current of the corresponding working point in the target personalized assist characteristic spectrum is smoothly updated to obtain the updated target personalized assist characteristic spectrum.

9. A control device for electric power steering, characterized in that, The device includes: The first determining unit is used to extract the first torque data of the driver within a preset time period based on driving guidance information when the vehicle is in the starting state, and to extract a target torque feature vector to characterize the driver's steering habits based on the first torque data. The second determining unit is used to determine the driver's target personalized power assist characteristic map based on the target torque feature vector; The third determining unit is used to determine the target assist torque based on the vehicle's current driving parameters and the target personalized assist characteristic map during vehicle operation; the target assist torque is used to control the motor to provide corresponding steering assistance.

10. A vehicle comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the method according to any one of claims 1-8.

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