Low-temperature compensation method and device for electric power steering system

Abstract

The invention is suitable for the technical field of automobile electric power steering, and provides a low-temperature compensation method and device for an electric power steering system, and the method comprises the steps: S100, obtaining temperature sensor data of a key part of a target vehicle, and judging whether the temperature of the key part of the target vehicle is greater than a threshold value or not; s200, if the temperature of the key part of the target vehicle is larger than a threshold value, an electric power steering system of the target vehicle enters a low-temperature compensation mode; and S300, after the electric power steering system of the target vehicle enters the low-temperature compensation mode, motor current control parameters are adjusted, and torque friction compensation is adjusted. By introducing a multi-dimensional weighted low-temperature compensation strategy and smooth transition control of a temperature transition interval, the response speed and compensation precision of the EPS system in a low-temperature environment are remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of automotive electric power steering, and particularly relates to a method and device for low-temperature compensation of an electric power steering system. Background Art

[0002] With the development of automotive intelligence, the EPS system has gradually replaced the traditional hydraulic power steering system and become a standard configuration for modern vehicles. The EPS system provides steering assistance through an electric motor to improve the sensitivity of vehicle control and driving comfort. However, in a low-temperature environment, the performance of the electric motor, sensors, lubricating grease, and mechanical components is affected, resulting in changes in the system response speed, the accuracy of assistance output, and the steering feel, seriously affecting driving safety and comfort. In the prior art, the quickest method is to replace the lubricating grease with low viscosity at low temperature, but this lubricating grease is expensive and the effect is not very ideal. There is also a temperature compensation strategy that corrects the performance of the EPS system in a low-temperature environment by simply fixed temperature gain look-up tables.

[0003] However, these existing methods have problems such as insufficient compensation accuracy, overly simplified compensation algorithms, and uneven compensation during the transition from low temperature to normal temperature, and cannot precisely adjust the assistance output under various working conditions. Therefore, designing an accurate method that can perform low-temperature compensation, weighted compensation under different working conditions, and smooth transition has become the key to solving the problems of the prior art. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and device for low-temperature compensation of an electric power steering system, aiming to solve the problems proposed in the background art.

[0005] The present invention is implemented as follows. A method for low-temperature compensation of an electric power steering system, the method includes the following steps: Step S100, obtain the temperature sensor data of the key parts of the target vehicle, and determine whether the temperature of the key parts of the target vehicle is greater than a threshold value; Step S200, if the temperature of the key parts of the target vehicle is greater than the threshold value, make the electric power steering system of the target vehicle enter the low-temperature compensation mode; Step S300, after the electric power steering system of the target vehicle enters the low-temperature compensation mode, adjust the motor current control parameters and adjust the torque friction compensation; Step S400, monitor the vehicle speed, steering angle, and torque of the target vehicle, and dynamically adjust the compensation coefficient in combination with the temperature sensor data; Step S500, determine whether the temperature of the key components of the target vehicle has risen to normal. If so, gradually reduce the compensation until the low-temperature compensation mode ends.

[0006] As a further limitation of the technical solution of the embodiment of the present invention, the key parts of the target vehicle are the motor, the torque sensor, and the friction part, and in step S100, the acquisition frequency of the temperature sensor data of the key parts of the target vehicle is 10 times per second.

[0007] As a further limitation of the technical solution of the embodiment of the present invention, the threshold value is 0°C, and in step S200, if the temperature of the key parts of the target vehicle is not greater than the threshold value, the electric power steering system of the target vehicle is made to enter the normal mode without any compensation.

[0008] As a further limitation of the technical solution of the embodiment of the present invention, in step S400, when it is determined that the target vehicle is in a low-speed driving state, the electric power steering system of the target vehicle should increase the weight of the low-temperature compensation, and when it is determined that the target vehicle is in a high-speed driving state, the compensation weight is correspondingly reduced.

[0009] As a further limitation of the technical solution of the embodiment of the present invention, in step S500, the electric power steering system of the target vehicle is provided with a temperature buffer zone. When the key parts of the target vehicle are within this temperature buffer zone, the electric power steering system gradually weakens the low-temperature compensation intensity; The temperature buffer zone is 0°C - 20°C.

[0010] As a further limitation of the technical solution of the embodiment of the present invention, in step S500, if the temperature of the key components of the target vehicle does not rise back to normal, the low-temperature compensation mode is continuously carried out, that is, step S300 is entered again.

[0011] An electric power steering system low-temperature compensation device, the device includes a temperature data acquisition module, a low-temperature compensation mode entry module, a data compensation module, a compensation coefficient dynamic adjustment module, and a temperature rise judgment module, where: The temperature data acquisition module is used to acquire the temperature sensor data of the key parts of the target vehicle and judge whether the temperature of the key parts of the target vehicle is greater than the threshold value; The low-temperature compensation mode entry module is used to make the electric power steering system of the target vehicle enter the low-temperature compensation mode if the temperature of the key parts of the target vehicle is greater than the threshold value; The data compensation module is used to adjust the motor current control parameters and adjust the torque friction compensation after the electric power steering system of the target vehicle enters the low-temperature compensation mode; The compensation coefficient dynamic adjustment module is used to monitor the vehicle speed, steering angle, and torque of the target vehicle and dynamically adjust the compensation coefficient in combination with the temperature sensor data; The temperature rise judgment module is used to judge whether the temperature of the key components of the target vehicle has risen back to normal. If so, the compensation is gradually reduced until the low-temperature compensation mode ends.

[0012] Compared with the prior art, the present invention significantly improves the response speed and compensation accuracy of the EPS system in a low-temperature environment by introducing a multi-dimensional weighted low-temperature compensation strategy and smooth transition control in the temperature transition interval. The specific effects include: Precise compensation: In extreme low-temperature working conditions, the compensation algorithm can precisely adjust the output characteristics of the motor and sensors to ensure the stability and accuracy of the steering feel.

[0013] Smooth transition: By using a temperature buffer during the transition from low temperature to normal temperature, it ensures a smooth compensation process without abruptness and reduces the discomfort of the driver.

[0014] Adaptive control: The combination of closed-loop control and adaptive compensation can correct the compensation parameters in real time to ensure the stable performance of the system under various working conditions. Description of the Drawings

[0015] Figure 1 It is the overall architecture diagram of the EPS system with low-temperature compensation provided by the embodiment of the present invention; Figure 2 It is the flowchart of the low-temperature compensation method provided by the embodiment of the present invention; Figure 3 It is the compensation weight curve diagram under different working conditions provided by the embodiment of the present invention. Detailed Embodiment

[0016] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0017] Figure 1 It shows the flowchart of the method provided by the embodiment of the present invention.

[0018] Specifically, a low-temperature compensation method for an electric power steering system, the method specifically includes the following steps: Step S100, obtain the temperature sensor data of the key parts of the target vehicle, and judge whether the temperature of the key parts of the target vehicle is greater than the threshold.

[0019] The key parts of the target vehicle are the motor, torque sensor, and friction parts, and in step S100, the acquisition frequency of the temperature sensor data of the key parts of the target vehicle is 10 times per second.

[0020] In the embodiment of the present invention, the working temperature of the key components (such as the motor, torque sensor, friction parts, etc.) of the EPS system is monitored in real time by the temperature sensors installed in the EPS system. The temperature sensor data is transmitted to the EPS motor controller through the CAN bus.

[0021] By setting the temperature sampling frequency to 10 times per second, it can be ensured that the electric power steering system can quickly respond to changes in the ambient temperature to determine whether the electric power steering system needs to activate the compensation mechanism.

[0022] Furthermore, the low-temperature compensation method for the electric power steering system further includes the following steps: Step S200, if the temperature of the key parts of the target vehicle is greater than the threshold value, make the electric power steering system of the target vehicle enter the low-temperature compensation mode.

[0023] Step S300, after the electric power steering system of the target vehicle enters the low-temperature compensation mode, adjust the motor current control parameters and adjust the torque friction compensation.

[0024] The threshold value is 0°C, and in step S200, if the temperature of the key parts of the target vehicle is not greater than the threshold value, make the electric power steering system of the target vehicle enter the normal mode without any compensation.

[0025] In the embodiment of the present invention, the electric power steering system pre-sets a low-temperature threshold value (for example, below 0°C). When the ambient temperature is lower than this threshold value, the electric power steering system enters the low-temperature compensation mode. In the low-temperature mode, a pre-calibrated low-temperature compensation algorithm is used to compensate the motor output characteristics.

[0026] The low-temperature compensation strategy ensures that the assist force output by the EPS system is consistent with the driver's steering input at low temperatures by adjusting the motor current control parameters, friction compensation parameters, etc.

[0027] If the temperature is higher than the threshold value, the electric power steering system will enter the normal mode without any compensation.

[0028] Furthermore, the low-temperature compensation method for the electric power steering system further includes the following steps: Step S400, monitor the vehicle speed, steering angle and torque of the target vehicle, and dynamically adjust the compensation coefficient in combination with the temperature sensor data.

[0029] When it is determined that the target vehicle is in a low-speed driving state, the electric power steering system of the target vehicle should increase the weight of low-temperature compensation, and when it is determined that the target vehicle is in a high-speed driving state, the compensation weight is correspondingly reduced.

[0030] In the embodiment of the present invention, the electric power steering system of the target vehicle performs multi-dimensional weighted compensation according to the current working conditions of the target vehicle (such as vehicle speed, steering angle, steering hand force, etc.). Real-time data is obtained through the vehicle speed sensor, torque angle sensor and steering wheel angle sensor, and the compensation coefficient is dynamically adjusted in combination with the temperature data.

[0031] For low speeds, the electric power steering system increases the weight of low-temperature compensation to ensure the smoothness and accuracy of the assist output during low-speed steering; while under high-speed conditions, the compensation weight is correspondingly reduced to improve steering stability and road feel feedback.

[0032] Furthermore, the low-temperature compensation method of the electric power steering system further includes the following steps: Step S500, determine whether the temperature of the key components of the target vehicle has risen to normal. If so, gradually reduce the compensation until the low-temperature compensation mode ends.

[0033] The electric power steering system of the target vehicle is provided with a temperature buffer zone. When the key parts of the target vehicle are within this temperature buffer zone, the electric power steering system gradually weakens the low-temperature compensation intensity; The temperature buffer zone is 0°C - 20°C.

[0034] In the embodiment of the present invention, the electric power steering system sets a temperature buffer zone (for example, 0°C to 20°C). Within this temperature range, the system gradually weakens the low-temperature compensation intensity to ensure a smooth transition of the assist output when transitioning from low temperature to normal temperature and avoid abrupt assist changes.

[0035] Within the buffer zone, the compensation coefficient changes linearly according to the temperature. Specifically, when the temperature gradually rises, the low-temperature compensation weight gradually decreases, and the normal-temperature compensation gradually takes over the system control.

[0036] If the temperature of the key components of the target vehicle has not risen to normal, the low-temperature compensation mode is continuously performed, that is, step S300 is entered again.

[0037] Furthermore, the low-temperature compensation method of the electric power steering system further includes the following processing procedures: Compensation accuracy control: An adaptive control algorithm is adopted to perform real-time correction on the steering feedback of the EPS system. Through a closed-loop control method, the feedback error (that is, the deviation between the desired output and the actual output) is used to adjust the low-temperature compensation parameters to ensure the accuracy of the compensation.

[0038] In extremely low-temperature situations (such as below -30°C), the system increases the correction of the motor starting current and response time, and at the same time considers the influence of low-temperature lubrication to make a greater correction to the friction torque to ensure the accuracy of the assist output.

[0039] A dynamic weighting mechanism is adopted, including assigning different weights to different working conditions according to driving conditions and real-time sensor data. The compensation algorithm calculates and finally outputs according to the input weights to ensure an appropriate assist level to adapt to various driving situations.

[0040] The system can calculate the final compensation value using the following formula ( ):

[0041] wherein, , , , are the dynamic weights of the temperature, vehicle speed, torque, and steering angle factors respectively. , , , are the compensation values for each factor calculated based on the sensor input, and each weight value can be dynamically adjusted according to the real-time data of the system sensors. For example: The temperature compensation weight can be adjusted as follows: At lower temperatures, the system compensates by increasing the motor output, and the weight increases as the temperature drops, indicating that more compensation is required. When , the weight value reaches the maximum (1.0) for full compensation.

[0042]

[0043] wherein, is the current temperature measured by the system, is the lowest threshold temperature for full compensation (e.g., -30°C), is the temperature at which no compensation is required (e.g., 20°C).

[0044] The vehicle speed compensation weight can be adjusted as follows: At lower vehicle speeds, since the natural feedback force of the tires is less, more steering assistance is usually required for steering. The system compensates by increasing the motor torque to make steering easier, and the calculation of the weight is inversely proportional to the vehicle speed. At very low vehicle speeds (close to 0 km / h), this weight approaches its maximum value, and as the vehicle speed increases, the weight decreases, thereby reducing the compensation. This ensures that at high speeds, for stability and better road feel, the system can reduce the compensation to provide the least amount of steering assistance.

[0045]

[0046] wherein, is the current vehicle speed, is the highest vehicle speed threshold at which no compensation is required.

[0047] The torque compensation weight can be adjusted as follows: When the driver applies high steering torque, such as during a sharp turn or when parking, more assistance is required, and the torque weight It increases with the increase of the driver's input. At high torque levels, the weight will increase, which means more compensation is needed to help the driver turn the wheel smoothly.

[0048]

[0049] Among them, is the current steering torque applied by the driver, is the maximum steering threshold.

[0050] The steering angle compensation weight can be adjusted with reference to the following: The steering angle is the angle by which the steering wheel rotates relative to the center (straight line) position. Larger steering angle operations generally occur during significant turns (such as parking or sharp turns), while smaller steering angle operations usually occur during straight driving or minor direction corrections. At small steering angles, since the driver makes small adjustments and the relative resistance is also relatively low, less compensation is required. While at larger steering angles, the driver needs more assistance because the system has to overcome greater mechanical resistance, and the corresponding compensation also needs to be increased.

[0051] To consider the influence of the steering angle on the overall compensation, the steering angle weight is introduced. This weight can be calculated based on the absolute value of the current steering angle and the maximum steering angle supported by the EPS system:

[0052] Among them, is the steering angle weight, is the current steering angle, is the maximum steering angle. This weight varies between 0 (at 0° steering, which means no additional compensation is needed) and 1 (at the maximum steering angle, which means full compensation is needed).

[0053] The following are the key conditions for the system to dynamically adjust the weight: Low-speed, high-torque working conditions (such as parking) Weight of temperature: High, because low temperature will significantly increase friction and system stiffness at low speeds, and strong compensation is required.

[0054] Weight of vehicle speed: Medium, because the vehicle speed is low, but small adjustments may still be needed according to the steering input.

[0055] Weight of torque: High, because the large steering input by the driver during sharp turns requires high compensation to ensure smooth and easy steering.

[0056] In this case, the system uses strong compensation to offset the additional resistance from the cold.

[0057] b. High-speed, low-torque conditions (e.g., highway driving) Weight of temperature: Medium. Because temperature is still important, but at high speeds, the driver needs less assistance, so the weight is reduced.

[0058] Weight of vehicle speed: Low. Because at high speeds, too much compensation will make the steering overly sensitive, which will have a negative impact on handling and stability.

[0059] Weight of torque: Low. Since the driver is making small steering corrections, the required compensation is minimal.

[0060] Here, the system applies the minimum compensation to ensure high-speed stability and road feel.

[0061] c. Transition from low temperature to normal temperature As the temperature rises from low to normal, the weight of temperature gradually decreases, which allows the system to smoothly reduce compensation over time without suddenly changing the steering feel.

[0062] Other weights (vehicle speed and torque) are still adjusted according to real-time conditions, but have less impact on compensation when the system returns to normal operation.

[0063] Establish a compensation table or MAP (2D / 3D look-up table) In some systems, look-up tables are used to define how to adjust weights based on specific input values. This can be a 2D or 3D MAP that correlates temperature, vehicle speed, and torque with predefined compensation values. The system references this map during operation and inserts the appropriate compensation for a given condition.

[0064] The following shows an example of a simplified 2D look-up table (temperature vs. vehicle speed): Temperature (°C) Vehicle speed (km / h) Compensation weight -30 0 High -20 20 Medium -10 50 Low 0 80 Minimum When the system reads temperature and vehicle speed data, it retrieves the appropriate compensation weights from this table to ensure accurate adjustment in real time.

[0065] Gradual adaptation and smoothness: To avoid sudden changes in the amount of compensation, it is necessary to ensure that the weights are gradually adjusted over time. For example, if the vehicle transitions from a cold environment to a warm environment, the compensation will decrease smoothly, maintaining a consistent and predictable steering feel for the driver.

[0066] When the temperature rises back to normal (e.g., from -20°C to 0°C), it can be achieved through linear interpolation between the weights at different temperature points.

[0067] For example, when the temperature approaches the normal operating range, the system uses a linear formula to gradually reduce

[0068] This ensures that the transition from full compensation at very low temperatures to no compensation at normal temperatures is smooth and gradual, preventing any sudden changes in the steering behavior from affecting vehicle stability and road feel.

[0069] Final compensation Acts on the EPS motor by adjusting the following parameters: Motor current: Increase the current to overcome friction or stiffness.

[0070] Torque control: Adjust the amount of torque assist provided to the driver.

[0071] For example, if the current temperature is -20°C, the vehicle speed is 30 km / h, the driver applies a steering torque of 2 Nm, and the steering angle is 30°, the system will calculate:

[0072]

[0073]

[0074]

[0075] Substitute these values into the compensation formula:

[0076] Then, the system will calculate the final compensation , thereby determining how much additional torque or current needs to be applied to the motor to maintain smooth steering. Of course, for fine-tuning in different environments, different vehicles or operating environments may require different compensation strategies. For example: Cold regions: Temperature compensation may be given priority.

[0077] Urban driving: Low-speed torque adjustment may be emphasized more frequently.

[0078] Highway driving: The weight of vehicle speed compensation can be reduced to enhance stability.

[0079] In these cases, the weighted algorithm can be fine-tuned according to the expected usage environment of the vehicle.

[0080] Storage and calibration module: The system stores the compensation parameters and calibration data for different operating conditions through the EEPROM or Flash memory. After each adjustment of the compensation parameters, the system records these parameters for automatic loading during future operations.

[0081] The system supports remote calibration via the CAN interface, ensuring flexible adjustment of the compensation strategy in different climate environments.

[0082] This invention patent provides a vehicle, which includes an electric drive assembly with the above-mentioned electric power steering system (or device) with low-temperature compensation or a computer device (or electronic equipment). Specifically, the vehicle can be a private car, such as a sedan, SUV, MPV or pickup truck, etc. The vehicle can also be an operating vehicle, such as a minibus, bus, small truck or large trailer, etc. The vehicle can be a traditional fuel vehicle or a new energy vehicle. When the vehicle is a new energy vehicle, it can be a plug-in hybrid vehicle or an extended-range hybrid vehicle, etc., or it can also be a pure electric vehicle.

[0083] This invention patent provides an electric power steering system, which includes a system arranged in the cabin and a system arranged on the chassis. Specifically, this system can be a column electric power steering (CEPS) system, or a rack and pinion electric power steering (DPEPS, SPEPS, REPS) system, and can also be a steer-by-wire (SBW) or even a rear-wheel steering (RWS) system.

[0084] The following are the specific implementation manners of the technical solutions mentioned in the present invention: Temperature monitoring and compensation start: The EPS controller monitors the temperature signals of the motor, torque sensor and friction parts in real time. When the temperature is lower than the set threshold, the system enters the low-temperature compensation mode. The controller first adjusts the response current of the motor to reduce the problem of insufficient assist output caused by difficult motor startup at low temperatures.

[0085] Implementation of weighted compensation: Combining signals such as vehicle speed, hand torque and steering angle, the system adjusts the compensation weight according to real-time data. Under low-speed working conditions, the compensation algorithm increases the compensation intensity for frictional torque to ensure stable assist output during low-speed steering; under high-speed working conditions, the compensation weight is reduced to enhance the road feel.

[0086] Smooth transition from low temperature to normal temperature: When the vehicle gradually enters the normal temperature from a low-temperature environment, the system linearly reduces the low-temperature compensation intensity according to the temperature and gradually and smoothly transitions to the normal-temperature compensation mode. During this process, the system monitors the output curve of the steering assist to avoid discontinuous assist changes caused by compensation transition.

[0087] Through the implementation of the present invention, the assist compensation accuracy of the EPS system under low-temperature working conditions has been significantly improved, especially realizing smooth and continuous compensation output during the transition from low temperature to normal temperature. At the same time, the multi-dimensional weighted compensation strategy adopted can accurately control the assist output under different vehicle working conditions, improving the stability of the system and driving safety.

[0088] This invention patent designs a device for low - temperature compensation, which is specifically implemented through both hardware and software to ensure that the EPS system can work effectively in a low - temperature environment. The low - temperature compensation device covers aspects such as hardware components, device logic, and software - hardware interaction, as follows: Composition of the Low - Temperature Compensation Device This device mainly consists of the following parts: Temperature Sensor Module It is mainly used to detect the temperature of key components of the EPS system in real - time, including the temperature information of components such as motors, torque sensors, friction components, and steering shafts.

[0089] The temperature sensors are installed on the motor controller and the friction part, and transmit temperature data through the CAN bus or SENT signal to ensure the real - time nature of compensation.

[0090] Motor Control Unit (MCU) The motor control unit is responsible for adjusting the output characteristics of the motor according to the real - time temperature data provided by the temperature sensor. Under low - temperature conditions, the MCU ensures that the motor can quickly respond to steering demands in a cold environment by controlling the starting current and operating current of the motor.

[0091] After receiving the instructions from the low - temperature compensation module, the MCU controls the current and torque output of the motor by adjusting the PWM (Pulse - Width Modulation) signal, and smoothly executes the low - temperature compensation algorithm.

[0092] Compensation Control Module This module is responsible for torque and friction compensation of the EPS system in a low - temperature environment. The compensation control module is embedded with low - temperature compensation algorithms, including temperature - current compensation curves, temperature - friction torque compensation curves, and steering torque adjustment strategies at low temperatures.

[0093] This module can quickly calculate the optimal compensation parameters according to signals such as real - time temperature, steering angular velocity, and torque through an interpolation table or a calibration table, and transmit the compensated signal to the motor control unit for execution.

[0094] Working Logic of the Low - Temperature Compensation Device Temperature Detection and Startup Conditions When the temperature sensor detects that the temperature is lower than the set low - temperature threshold (such as 0°C or - 10°C), the system enters the low - temperature compensation mode.

[0095] The compensation control module reads the data of each sensor (temperature, torque, vehicle speed, steering angular velocity, etc.), and combines the current driving conditions to start the corresponding compensation algorithm.

[0096] Motor Response Optimization By adjusting the starting current and running current of the motor, the compensation device ensures that the response speed of the motor is not affected in low-temperature environments. At the same time, according to the actual steering demand, it adjusts the maximum output torque of the motor to prevent insufficient output or response lag of the steering system under low-temperature conditions.

[0097] The system dynamically adjusts the operating characteristics of the motor according to real-time temperature changes. When the temperature rises close to room temperature, the low-temperature compensation intensity gradually decreases to ensure a smooth transition of the system at different temperatures.

[0098] Friction Compensation and Weighted Control Low temperature increases the frictional resistance of mechanical components. The compensation device dynamically adjusts the assist output through the frictional torque compensation module to ensure smooth steering operation.

[0099] Under different working conditions (such as low speed and large steering angle, parking and turning in place, high speed and small angle correction, etc.), the compensation module adjusts the proportion of friction compensation according to the weighting coefficient to ensure consistent steering feel and prevent over-compensation or under-compensation.

[0100] Adaptive Compensation Adjustment The system uses a closed-loop control method to continuously monitor the error between the driver's steering operation and the actual assist output. When a large deviation in assist output is detected, the compensation device automatically adjusts the compensation coefficient to optimize the compensation effect.

[0101] The system can predict the compensation strategy based on the temperature change trend (such as rapid cooling or heating) and adjust the motor and friction compensation parameters in advance to reduce steering lag and assist sudden changes.

[0102] Compensation and Transition to Room Temperature When the vehicle enters the room temperature environment from a low-temperature environment, the compensation device controls the gradual weakening of the compensation intensity through a temperature buffer zone. When the temperature approaches room temperature, the friction compensation and motor compensation gradually decrease and finally return to the calibration value at room temperature.

[0103] The change in compensation intensity during the transition process is smoothly adjusted through a linear interpolation table to avoid inconsistent steering feel caused by sudden compensation changes.

[0104] Device Storage and Calibration Storage Medium The low-temperature compensation device is built-in with an EEPROM or Flash memory to store compensation curves and calibration data at different temperatures. Each time the system performs compensation, the storage medium records the current compensation parameters to ensure the system's adaptive learning ability.

[0105] The storage medium also supports remote calibration and upgrade through an external CAN bus interface. The system can be customized and calibrated according to different regions and climate conditions to adapt to different global climate environments.

[0106] Calibration and Adjustment The compensation device supports dynamic calibration. Engineers can adjust the compensation coefficient and compensation curve during vehicle operation through the calibration tool and store the calibration results in the EEPROM.

[0107] The calibration data of the system at normal temperature and low temperature are stored separately. Different calibration curves are selected through temperature detection to ensure the accuracy of the compensation effect.

[0108] Installation and Interfaces of the Device Hardware Interfaces The device communicates with other control units of the vehicle through the CAN bus, obtains signals such as vehicle speed, steering angle, torque, temperature, etc. in real time, and feeds back the compensated signals to the motor control unit (MCU).

[0109] The system also reserves a diagnostic interface to support the OBD (On-Board Diagnostic) device to monitor the status and troubleshoot faults of the low-temperature compensation system.

[0110] Installation Location The compensation control module is integrated into the EPS control unit, and the temperature sensor is installed around the motor and friction components to ensure accurate monitoring of the working temperature of the system.

[0111] Advantages of the Compensation Device High-precision Compensation: Provide adaptive compensation for different temperatures and working conditions to ensure accurate power assist output of the EPS system at low temperatures.

[0112] Smooth Transition: During the transition from low temperature to normal temperature, the compensation device can dynamically adjust the compensation coefficient to ensure a smooth transition of the power assist output and avoid obvious power assist mutations perceived by the driver.

[0113] Adaptive Learning: The compensation device has adaptive capabilities and can automatically adjust compensation parameters according to actual driving conditions to enhance the intelligence of the system.

[0114] Through these hardware and software modules, the low-temperature compensation device can effectively improve the performance of the EPS system in low-temperature environments and ensure a smooth transition from low temperature to normal temperature. The design of these devices ensures the high precision and reliability of the system.

[0115] Furthermore, in another preferred embodiment provided by the present invention, a low-temperature compensation device for an electric power steering system, the device includes a temperature data acquisition module, a low-temperature compensation mode entry module, a data compensation module, a compensation coefficient dynamic adjustment module, and a temperature rise judgment module, wherein: The temperature data acquisition module is used to acquire the temperature sensor data of key parts of the target vehicle and determine whether the temperature of the key parts of the target vehicle is greater than the threshold; A low-temperature compensation mode entry module, configured to, if the temperature of a key part of a target vehicle is greater than a threshold value, cause the electric power steering system of the target vehicle to enter a low-temperature compensation mode; A data compensation module, configured to, after the electric power steering system of the target vehicle enters the low-temperature compensation mode, adjust motor current control parameters and adjust torque friction compensation; A compensation coefficient dynamic adjustment module, configured to monitor the vehicle speed, steering angle, and torque of the target vehicle, and dynamically adjust the compensation coefficient in combination with temperature sensor data; A temperature rise judgment module, configured to judge whether the temperature of a key component of the target vehicle has risen to normal, and if so, gradually reduce the compensation until the low-temperature compensation mode ends.

[0116] It should be understood that although the steps in the flowcharts of the embodiments of the present invention are shown in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least some of the steps in the embodiments may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed alternately or alternately with at least a part of other steps or sub-steps or stages of other steps. Those of ordinary skill in the art can understand that all or part of the processes of implementing the methods in the above embodiments can be completed by instructing relevant hardware through a computer program. The program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the embodiments provided in the present application can include non-volatile and / or volatile memories. Non-volatile memories can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memories can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0117] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as falling within the scope described in this specification.

[0118] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent for the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention shall be subject to the appended claims.

[0119] The foregoing is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A low temperature compensation method for an electric power steering system, characterized in that: The method comprises the following steps: Step S100, obtaining temperature sensor data of a key part of the target vehicle, and determining whether the temperature of the key part of the target vehicle is greater than a threshold; Step S200, if the temperature of the key part of the target vehicle is greater than the threshold, the electric power steering system of the target vehicle enters a low temperature compensation mode; Step S300, after the electric power steering system of the target vehicle enters the low temperature compensation mode, adjusting the motor current control parameters and adjusting the torque friction compensation; Step S400, monitoring the speed, turning angle and torque of the target vehicle, and dynamically adjusting the compensation coefficient in combination with the temperature sensor data; Step S500, determining whether the temperature of the key components of the target vehicle has returned to normal, and if so, gradually reducing the compensation until the low temperature compensation mode is terminated.

2. The low temperature compensation method for an electric power steering system according to claim 1, characterized in that: The key parts of the target vehicle are the motor, the torque sensor, and the friction parts, and in step S100, the frequency of acquiring the temperature sensor data of the key parts of the target vehicle is 10 times per second.

3. The low temperature compensation method for an electric power steering system according to claim 1, characterized in that: The threshold is 0° C., and in step S200 , if the temperature of the key part of the target vehicle is not greater than the threshold, the electric power steering system of the target vehicle enters a normal mode without any compensation.

4. The low temperature compensation method for an electric power steering system according to claim 1, characterized in that: In step S400, when it is determined that the target vehicle is in a low-speed driving state, the electric power steering system of the target vehicle should increase the weight of low-temperature compensation, and when it is determined that the target vehicle is in a high-speed driving state, the compensation weight is reduced accordingly.

5. The low temperature compensation method for an electric power steering system according to claim 1, characterized in that: In step S500, the electric power steering system of the target vehicle is provided with a temperature buffer zone, and when the key parts of the target vehicle are in the temperature buffer zone, the electric power steering system gradually weakens the low temperature compensation strength; The temperature buffer zone is 0°C-20°C.

6. The low temperature compensation method for an electric power steering system according to claim 1, characterized in that: In step S500, if the temperature of the key components of the target vehicle does not return to normal, the low temperature compensation mode is continuously performed, that is, the process enters step S300 again.

7. A low temperature compensation device for an electric power steering system, characterized in that: The device includes a temperature data acquisition module, a low temperature compensation mode entry module, a data compensation module, a compensation coefficient dynamic adjustment module and a temperature recovery judgment module, wherein: The temperature data acquisition module is used to obtain the temperature sensor data of the key parts of the target vehicle and determine whether the temperature of the key parts of the target vehicle is greater than a threshold; A low temperature compensation mode entry module is used to make the electric power steering system of the target vehicle enter a low temperature compensation mode if the temperature of a key part of the target vehicle is greater than a threshold value; A data compensation module, used to adjust motor current control parameters and adjust torque friction compensation after the electric power steering system of the target vehicle enters a low temperature compensation mode; A compensation coefficient dynamic adjustment module is used to monitor the speed, angle and torque of the target vehicle and dynamically adjust the compensation coefficient in combination with the temperature sensor data; The temperature recovery judgment module is used to judge whether the temperature of the key components of the target vehicle has returned to normal. If so, the compensation is gradually reduced until the low temperature compensation mode is ended.

8. A vehicle, characterized in that: The vehicle comprises the electric power steering system according to any one of claims 1 to 7.

9. A computer-readable storage medium, characterized in that: A low temperature compensation program is stored thereon, and when the low temperature compensation program is executed by the processor, the low temperature compensation method as described in any one of claims 1 to 7 is implemented.

Images