EPS deviation compensation control method, device, system and automobile

Abstract

The embodiment of the present invention provides an EPS deviation compensation control method, an EPS deviation compensation control device, an EPS deviation compensation control system and an automobile, and relates to the field of EPS control technology. The method comprises: when it is determined that the vehicle is in a straight-line driving state, obtaining the historical compensation torque of the EPS motor; when it is determined that the vehicle is in a deviation state according to the historical compensation torque and the current operating parameters of the vehicle, controlling the output torque of the EPS motor according to the historical compensation torque and the current steering torque of the steering wheel. When the present invention determines that the vehicle is in a straight-line driving state, when it is determined that the current vehicle is in a deviation state according to the steering torque of the steering wheel, the output torque of the EPS motor can be adjusted according to the real-time steering torque of the steering wheel and the historical compensation torque, so that the vehicle can be kept in a straight-line driving state through the compensation torque output by the EPS motor without the driver correcting the steering wheel.

Description

Technical Field

[0001] The present invention relates to the field of EPS control technology, and in particular to an EPS running deviation compensation control method, an EPS running deviation compensation control device, an EPS running deviation compensation control system and a vehicle. Background Art

[0002] Normal vehicles can keep driving in a straight line without the steering wheel moving. However, due to crosswind, high road surface on one side, unstable tire pressure, deformation of vehicle suspension and other problems, if the steering wheel is freely placed in the middle position, the vehicle will automatically deviate to a certain direction during driving, and the driver needs to maintain a certain hand force for a long time to keep the car driving in a straight line. However, the existing automobile EPS system cannot keep the vehicle driving in a straight line without the driver correcting the steering wheel after the vehicle has the above-mentioned deviation problem, and does not affect driving in non-straight driving conditions. At the same time, when the vehicle is in a non-straight driving state, the existing EPS system cannot quickly identify the working condition, resulting in the driver's feel being affected by the deviation compensation torque in the non-straight driving state. If the lateral acceleration signal and yaw rate signal are used to identify whether the vehicle is in a straight driving state, for some vehicles, corresponding controllers and sensors need to be added, resulting in an increase in the cost of the entire vehicle. Summary of the invention

[0003] The purpose of the embodiments of the present invention is to provide an EPS deviation compensation control method, device, system and automobile to solve the problem that the existing EPS system cannot automatically maintain the vehicle running in a straight line after the vehicle deviates.

[0004] In order to achieve the above object, in a first aspect of the present invention, an EPS deviation compensation control method is provided, which is applied to an EPS system, wherein the EPS system includes an EPS motor, and the EPS motor is used to provide a compensation torque to a steering wheel. The method includes:

[0005] When it is determined that the vehicle is in a straight-line driving state, obtaining a historical compensation torque of the EPS motor;

[0006] When it is determined that the vehicle is in a deviation state based on the historical compensation torque and the current operating parameters of the vehicle, the compensation torque output by the EPS motor is controlled based on the historical compensation torque and the current steering torque of the steering wheel.

[0007] Optionally, controlling the compensation torque output by the EPS motor according to the historical compensation torque and the current steering torque of the steering wheel includes:

[0008] When it is determined based on the current steering torque that the steering wheel rotation direction is consistent with the steering wheel rotation direction corresponding to the historical compensation torque, the historical compensation torque is used as the initial compensation torque of the EPS motor, and the compensation torque output by the EPS motor is adjusted based on the current steering torque until the current steering torque is not greater than a first threshold value, and the compensation torque output by the EPS motor corresponding to the current steering torque being not greater than the first threshold value is maintained;

[0009] When the steering wheel rotation direction determined based on the current steering torque is opposite to the steering wheel rotation direction corresponding to the historical compensation torque, the historical compensation torque is cleared, and the compensation torque output by the EPS motor is controlled based on the current steering torque until the current steering torque is no greater than a first threshold, and the compensation torque output by the EPS motor corresponding to the current steering torque being no greater than the first threshold is maintained.

[0010] Optionally, using the historical compensation torque as the initial compensation torque of the EPS motor includes:

[0011] The compensation torque output by the EPS motor is controlled according to a preset compensation torque output slope until the compensation torque output by the EPS motor reaches the historical compensation torque.

[0012] Optionally, the current operating parameters of the vehicle include a steering angle of a steering wheel and a current speed of the vehicle; determining that the vehicle is in a deviation state based on the historical compensation torque and the current operating parameters of the vehicle includes:

[0013] If the historical compensation torque is not 0, it is determined that the vehicle is in a deviation state; or

[0014] If the historical compensation torque is 0, it is determined that the vehicle is in a deviation state when the following conditions are met simultaneously within the first preset duration period:

[0015] The current steering torque belongs to a first steering torque range;

[0016] The steering angle of the steering wheel is less than a second threshold;

[0017] The current vehicle speed of the vehicle is within a first preset speed range.

[0018] Optionally, the vehicle is determined to be in a straight-line driving state when the following conditions are met simultaneously during the second preset duration period:

[0019] The current steering torque belongs to a second steering torque range, the steering angle of the steering wheel is less than a third threshold, and the current vehicle speed of the vehicle is within a second preset speed range.

[0020] Optionally, the method further comprises:

[0021] When it is determined that the vehicle is in a non-straight driving state based on the current steering torque, the steering angle of the steering wheel and the current speed of the vehicle, the EPS motor is controlled to stop outputting the compensation torque, and the compensation torque that the EPS motor stops outputting when it is determined that the vehicle is in a non-straight driving state is used as the historical compensation torque of the EPS motor.

[0022] Optionally, if the following conditions are met during the third preset duration, it is determined that the vehicle is in a non-straight-line driving state:

[0023] If the current steering torque is greater than the fourth threshold, or the steering angle of the steering wheel is greater than the fifth threshold, or the current vehicle speed is less than the sixth threshold.

[0024] In a second aspect of the present invention, an EPS deviation compensation control device is provided, comprising:

[0025] a processing module configured to obtain a historical compensation torque of the EPS motor when it is determined that the vehicle is in a straight-line driving state;

[0026] The control module is configured to control the torque output by the EPS motor according to the historical compensation torque and the current steering torque of the steering wheel when it is determined that the vehicle is in a deviation state according to the historical compensation torque and the current operating parameters of the vehicle.

[0027] In a third aspect of the present invention, an EPS deviation compensation control system is provided, comprising:

[0028] The EPS deviation compensation control device mentioned above; and

[0029] The torque sensor is configured to collect current steering torque of the steering wheel.

[0030] In a fourth aspect of the present invention, a vehicle is provided, comprising the EPS deviation compensation control system described above.

[0031] The above technical solution of the present invention can determine the current deviation state of the vehicle according to the steering torque of the steering wheel obtained in real time when it is determined that the vehicle is in a straight-line driving state. If it is determined that the vehicle is in a straight-line driving state without deviation, the EPS motor does not provide deviation compensation to ensure that the vehicle can maintain straight-line driving when the steering wheel does not move. If it is determined that the vehicle is in a straight-line driving state, the output torque of the EPS motor is adjusted according to the real-time steering torque of the steering wheel and the historical compensation torque, so that after the vehicle has a deviation problem, the corresponding torque compensation can be performed according to the current deviation state of the vehicle, thereby achieving the compensation torque output by the EPS motor to maintain the vehicle's straight-line driving when the driver does not correct the steering wheel.

[0032] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings:

[0034] Figure 1 It is a method flow chart of an EPS deviation compensation control method provided by a preferred embodiment of the present invention;

[0035] Figure 2 Schematic diagram of the EPS system structure provided by the preferred embodiment of the present invention;

[0036] Figure 3 It is a schematic diagram of the deviation compensation state of the EPS system provided by the preferred embodiment of the present invention;

[0037] Figure 4 This is a flow chart of EPS deviation compensation control provided by a preferred embodiment of the present invention;

[0038] Figure 5 It is a schematic block diagram of an EPS deviation compensation control device provided in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0039] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0040] like Figure 1 As shown, in a first aspect of this embodiment, an EPS deviation compensation control method is provided, which is applied to an EPS system, wherein the EPS system includes an EPS motor, and the EPS motor is used to provide a compensation torque to a steering wheel. The method includes:

[0041] When it is determined that the vehicle is in a straight-line driving state, the historical compensation torque of the EPS motor is obtained;

[0042] When it is determined that the vehicle is in a deviation state based on the historical compensation torque and the current operating parameters of the vehicle, the compensation torque output by the EPS motor is controlled based on the historical compensation torque and the current steering torque of the steering wheel.

[0043] In this way, when the present embodiment determines that the vehicle is in a straight-line driving state, the current deviation state of the vehicle can be determined based on the steering torque of the steering wheel obtained in real time. If it is determined that the vehicle is in a straight-line driving state without deviation, the EPS motor does not enter the deviation compensation mode, so as to ensure that the vehicle can maintain straight-line driving when the steering wheel does not move. If it is determined that the vehicle is in a straight-line driving state with deviation, the output torque of the EPS motor is adjusted according to the real-time steering torque of the steering wheel and the historical compensation torque, so that after the vehicle has a deviation problem, corresponding torque compensation can be performed according to the current deviation state of the vehicle. When the steering torque of the steering wheel is less than or equal to a certain threshold, the output compensation torque of the EPS motor is maintained at this time, thereby achieving the goal of maintaining the vehicle's straight-line driving through the compensation torque output by the EPS motor when the driver does not correct the steering wheel.

[0044] Specifically, Figure 2 As shown, EPS is Electric Power Steering, an electric power steering system. In this embodiment, the EPS system includes a controller, an EPS motor and a reduction mechanism, the controller is connected to the EPS motor, the EPS motor is connected to the reduction mechanism, and the reduction mechanism is connected to the rack and pinion assembly. The controller is used to control the output torque of the EPS motor, the torque output by the EPS motor is transmitted to the reduction mechanism, and the wheels are driven to rotate through the connecting rod connected to the rack and pinion assembly. The steering wheel is connected to the rack and pinion assembly, so that the steering torque generated by the rotation of the steering wheel drives the wheels to rotate through the connecting rod connected to the rack and pinion assembly. Among them, a torque sensor is provided on the connecting shaft between the steering wheel and the rack and pinion assembly, the output end of the torque sensor is connected to the input end of the controller, and is used to collect the steering torque of the steering wheel. The controller can be an ECU. When the driver drives a vehicle that is running off the track at different speeds, he often needs to maintain different hand forces to keep driving in a straight line. Here, the driver's hand force is manifested as the steering torque of the steering wheel.

[0045] like Figure 3 As shown, the EPS motor is initially in a non-compensated state, and the actual deviation compensation torque provided is 0; when it is determined that the vehicle is in a straight-line driving state, the historical compensation torque of the EPS motor is obtained. When it is determined that the vehicle is in a deviation state based on the historical compensation torque and the current operating parameters of the vehicle, the EPS motor is controlled to enter a compensation state, and the output torque of the EPS motor is adjusted according to the real-time steering torque of the steering wheel and the historical compensation torque, so that after the vehicle has a deviation problem, corresponding torque compensation can be performed according to the current deviation state of the vehicle; when it is determined that the vehicle is in a non-straight-line driving state, the EPS motor is controlled to enter a non-compensated state, and the EPS motor is controlled to stop outputting the compensation torque according to the set compensation torque output slope, so as to eliminate the influence of the EPS deviation compensation torque on the driver's feel in the non-straight-line driving state.

[0046] like Figure 4As shown, when the driver is driving the vehicle, the controller obtains the steering torque of the steering wheel in real time through the torque sensor. When the controller determines that the vehicle is in a straight-line driving state, it obtains the current operating parameters of the vehicle in real time, such as the current steering torque of the steering wheel, the vehicle speed, the steering wheel angle, etc., and determines whether the vehicle is in a deviation state based on the current operating parameters of the vehicle. If the vehicle is determined to be in a deviation state, it enters the deviation compensation mode, first reads the historical compensation torque of the EPS motor, and determines the output torque of the EPS motor based on the read historical compensation torque and the steering torque of the steering wheel obtained in real time. Among them, the historical compensation torque of the EPS motor can be pre-set, and can also be updated according to the compensation torque output by the EPS motor. If the EPS motor's output deviation compensation torque is still determined based on the steering torque of the steering wheel obtained in real time when the vehicle is changing lanes, turning, making a U-turn or parking, unexpected assistance will be generated, thereby affecting the driver's control of the vehicle. At the same time, if the deviation compensation torque output by the EPS motor remains constant, the deviation compensation torque output by the EPS motor may interfere with the active return current of the EPS motor, causing the driver to frequently correct the deviation of the vehicle. Therefore, this embodiment controls the EPS motor to output the deviation compensation torque only when it is determined that the vehicle is in a straight-ahead deviation state; when the controller determines that the vehicle is in a straight-ahead state without deviation, the EPS motor does not enter the deviation compensation mode, and the actual deviation compensation torque provided is 0, to ensure that the vehicle can maintain straight-ahead driving without moving the steering wheel; when the controller determines that the vehicle is in a non-straight-ahead driving state, the deviation compensation mode is exited, and the EPS motor no longer outputs the deviation compensation torque, to eliminate the influence of the deviation compensation torque on the driver's feel in the non-straight-ahead driving state.Since the vehicle may be affected by the road surface flatness, tire pressure, vehicle suspension deformation and crosswind during driving, which may cause the vehicle's deviation direction to change, after obtaining the historical compensation torque, it is also necessary to control the deviation compensation torque output by the EPS motor according to the current steering torque of the steering wheel and the historical compensation torque. For example, if according to the historical compensation torque, the EPS motor needs to output 1Nm and control the deviation compensation torque of the steering wheel to turn left, but the controller determines that the vehicle is currently in a state of deviation to the left based on the current steering torque of the steering wheel obtained in real time, then the EPS motor needs to output the deviation compensation torque to control the steering wheel to deviate to the right. Since the vehicle enters the deviation compensation mode, when the hand force The direction is opposite to the historical compensation torque. If the historical compensation torque is still used as the initial compensation torque of the EPS motor, the compensation torque will be miscalculated and applied incorrectly. Therefore, the controller will clear the historical compensation torque to zero at this time, and use it as the initial compensation torque of the EPS motor preset algorithm. Then, according to the real-time steering torque of the steering wheel, the EPS motor is controlled to output the corresponding deviation compensation torque for controlling the steering wheel to deviate to the right according to the preset algorithm to offset the steering torque generated by the driver's correction of the steering wheel, until the deviation compensation torque output by the EPS motor completely replaces the driver's correction of the steering wheel, and then the EPS motor is controlled to maintain the current deviation compensation torque and output it to maintain the vehicle's straight driving state.

[0047] Among them, the output torque of the EPS motor is controlled according to the historical compensation torque and the current steering torque of the steering wheel, including:

[0048] When the steering direction of the steering wheel determined according to the current steering torque is consistent with the steering direction of the steering wheel corresponding to the historical compensation torque, the historical compensation torque is used as the initial compensation torque of the EPS motor, and the output torque of the EPS motor is adjusted according to the current steering torque until the current steering torque is not greater than the first threshold, and the compensation torque output by the EPS motor corresponding to the current steering torque reaching not greater than the first threshold is maintained;

[0049] When the steering wheel rotation direction determined based on the current steering torque is opposite to the steering wheel rotation direction corresponding to the historical compensation torque, the historical compensation torque is cleared, and the output torque of the EPS motor is controlled based on the current steering torque until the current steering torque is no greater than the first threshold, and the compensation torque output by the EPS motor corresponding to the steering torque reaching no more than the first threshold is maintained.

[0050] It can be understood that according to the direction of the historical compensation torque and the direction of the steering torque of the steering wheel, it is possible to accurately determine whether the vehicle's deviation direction corresponds to the vehicle deviation compensation direction provided by the historical compensation torque. For example, if it is determined according to the steering torque of the steering wheel that the current steering wheel is turning right, that is, it is determined that the vehicle is currently deviating to the left, and it is determined according to the historical compensation torque that the historical compensation torque provides an output torque for controlling the steering wheel to turn right, then the historical compensation torque is used as the initial compensation torque of the EPS motor preset algorithm, and the actual output compensation torque of the EPS motor is controlled to rise to the historical compensation torque of the EPS motor according to the preset compensation torque output slope, and then the EPS motor is controlled to update the output torque in real time according to the driver's hand force and direction according to the preset algorithm; conversely, if the driver's hand force direction at this moment is opposite to the steering wheel rotation direction provided by the historical compensation torque, the controller clears the historical compensation torque and uses it as the initial compensation torque of the EPS motor preset algorithm, and then controls the EPS motor to provide a deviation compensation torque that is updated in real time according to the driver's hand force and direction according to the preset algorithm. After the EPS motor provides the deviation compensation torque, the driver will inevitably adjust the correction amount of the steering wheel in time in order to maintain the vehicle's straight driving state. For example, after the EPS motor starts to provide the deviation compensation torque to control the steering wheel to deviate to the right, the driver will inevitably adaptively reduce the correction amount of the steering wheel to deviate to the right to maintain the vehicle's straight driving state. Then, when the current steering torque of the steering wheel corresponding to the driver's hand force is not greater than the first threshold, for example, less than or equal to 0.5Nm, it is considered that the driver no longer provides correction to the steering wheel. At this time, the deviation compensation torque provided by the EPS motor can maintain the vehicle's straight driving state without deviation.

[0051] In order to enable the EPS motor to quickly and accurately provide the vehicle with a deviation compensation torque, the controller needs to be able to memorize the deviation compensation torque output by the EPS motor last time. Therefore, the method of this embodiment further includes: using the output compensation torque of the EPS motor corresponding to when the EPS motor exits the deviation compensation mode as the historical compensation torque of the EPS motor. In this embodiment, when the controller determines to exit the deviation compensation mode, the deviation compensation torque provided by the EPS motor before exiting the deviation compensation mode is recorded, and the deviation compensation torque is used as the historical compensation torque when entering the deviation compensation mode next time.

[0052] For example, if the controller determines that the vehicle is in a straight-line driving state, and the historical compensation torque read is not 0, and the direction of the driver's hand force is the same as the steering wheel rotation direction provided by the historical compensation torque, the historical compensation torque is used as the initial compensation torque of the EPS motor preset algorithm, and the output torque of the EPS motor is controlled according to the preset compensation torque output slope to the historical compensation torque. Then, the deviation compensation torque output by the EPS motor is adjusted according to the real-time acquired steering wheel steering torque, until the deviation compensation torque finally output by the EPS motor offsets the driver's corrected hand force, that is, the current steering torque of the steering wheel is not greater than the first threshold. Among them, the EPS motor preset algorithm can be implemented using an existing algorithm. For example, let the first threshold be 0, and the compensation torque finally output by the EPS motor is the vector sum of the compensation torque currently output by the EPS motor and the current steering torque of the steering wheel. If the current compensation torque output by the EPS motor is 0.5Nm, the direction acting on the steering wheel is right, the driver's hand force is 0.2Nm, and the direction acting on the steering wheel is right, then the compensation torque finally output by the EPS motor is 0.7Nm, and the direction acting on the steering wheel is right; conversely, if the current compensation torque output by the EPS motor is 0.5Nm, the direction acting on the steering wheel is right, the driver's hand force is 0.2Nm, and the direction acting on the steering wheel is left, then the compensation torque finally output by the EPS motor is 0.3Nm, and the direction acting on the steering wheel is right. This embodiment does not specifically limit the EPS motor preset algorithm. It can be understood that if the controller initially reads a historical compensation torque of 0, and determines that the vehicle is in a non-deviation state according to the current operating parameters of the vehicle, it will not enter the deviation compensation mode, and the compensation torque output by the EPS motor is 0 at this time. If the EPS motor has entered the deviation compensation mode, before the deviation compensation torque output by the EPS motor completely offsets the driver's hand force, if the controller determines that the vehicle enters a turning, lane changing or parking road condition and exits the deviation compensation mode, the compensation torque currently output by the EPS motor will be used as the historical compensation torque when entering the deviation compensation mode next time. In this way, when the vehicle enters the straight deviation state again, the EPS motor can provide the corresponding deviation compensation torque to compensate the vehicle for deviation. If the deviated vehicle changes lanes, turns or parks while driving in a straight line, because the current road conditions or crosswinds have not changed significantly, when the controller detects that the vehicle enters the straight driving state again after changing lanes, turning or parking, it can quickly and accurately provide deviation compensation for the vehicle with the deviation compensation torque of the EPS motor before the vehicle changes lanes, turns or parks, effectively improving the response speed.

[0053] The current operating parameters of the vehicle include the steering angle of the steering wheel and the current speed of the vehicle; determining that the vehicle is in a deviation state based on the historical compensation torque and the current operating parameters of the vehicle includes:

[0054] If the historical compensation torque is not 0, it is determined that the vehicle is in a running-off state; or if the historical compensation torque is 0, the vehicle is determined to be in a running-off state when the following conditions are met at the same time within a first preset duration period: the current steering torque belongs to a first steering torque range; the steering angle of the steering wheel is less than a second threshold; the current speed of the vehicle is within a first preset speed range.

[0055] If the historical compensation torque is not 0, it is considered that the vehicle has a deviation problem and is determined to be in a deviation state. If the historical compensation torque is 0, but crosswind, high road surface on one side, unstable tire pressure or deformation of the vehicle suspension can cause the vehicle to deviate. For example, if the vehicle deviates to the left, the steering wheel is freely placed in the middle position, and the vehicle will automatically deviate to the left. At this time, the driver needs to maintain a right hand force for a long time to keep the car running in a straight line. Therefore, the current operating parameters of the vehicle can be obtained in real time to determine whether the vehicle is deviating. If the steering torque of the steering wheel is between 0.5Nm and 2Nm, and the steering angle of the steering wheel is less than 5deg, and the current speed of the vehicle is between 60km / h and 120km / h, and it lasts for 30s, it is determined that the vehicle is in a deviation state and enters the deviation compensation state. The EPS motor provides a deviation compensation torque to control the steering wheel to deflect to the right through a preset algorithm to offset the driver's correction force. If the vehicle passes through a higher road on the left side at this time, the vehicle will automatically deviate to the right. The driver needs to maintain a left hand force for a long time to keep the car moving in a straight line. The compensation torque output by the EPS motor to control the vehicle's right deviation will gradually decrease, or even increase in the opposite direction until it offsets the driver's correction force.

[0056] When the vehicle enters a straight-line driving state again after changing lanes, turning or parking, it is necessary to provide deviation compensation for the vehicle quickly and accurately. Therefore, the following conditions are met at the same time during the second preset duration period to determine that the vehicle is in a straight-line driving state:

[0057] The current steering torque belongs to the second steering torque range, the steering angle of the steering wheel is less than the third threshold, and the current speed of the vehicle is within the second preset speed range. The second steering torque range can be 0.5Nm to 2Nm, the third threshold can be 5deg, the second preset speed range can be 60km / h to 120km / h, and the second preset duration can be 3s; when all the above conditions are met and last for 3s, the controller determines that the vehicle has re-entered the straight-line driving state, and re-enters the deviation compensation mode at this time, and uses the compensation torque output by the EPS motor stored last time as the initial compensation torque of the EPS motor.

[0058] If the compensation torque of the EPS motor stored last time is the deviation compensation torque for controlling the vehicle to the right, and the current driver's hand force is to the right and the steering wheel angle is to the right, the controller uses the historical compensation torque as the initial compensation torque of the EPS motor, and calculates the final compensation torque output by the EPS motor based on the current steering torque of the steering wheel and the compensation torque currently output by the EPS motor. At the same time, the compensation torque output by the EPS motor is controlled to rise to the final compensation torque output by the EPS motor according to the preset compensation torque output slope, until the output compensation torque of the EPS motor is consistent with the final compensation torque output by the EPS motor, and then the output torque of the EPS motor is updated in real time according to the driver's hand force and direction. For example, when the vehicle deviates to the left due to tire pressure or suspension problems, when the controller enters the deviation compensation mode again from the non-deviation compensation mode, the EPS motor can quickly and accurately provide the deviation compensation torque for controlling the vehicle to the right.

[0059] If the last stored compensation torque of the EPS motor is the deviation compensation torque for controlling the vehicle to the right, and the controller determines that the current driver's hand force is to the left and the steering wheel angle is to the left, the controller will clear the historical compensation torque of the EPS motor stored last time, and provide the deviation compensation torque for controlling the vehicle to the left according to the preset algorithm. The compensation torque increases from 0 and is updated in real time with the size and direction of the driver's hand force until the driver's corrected hand force is offset. For example, the side wind causes the vehicle to deviate to the left. When the controller determines that the vehicle deviates to the left, it controls the EPS motor to provide the deviation compensation torque for controlling the vehicle to the right; if the driver turns around and enters the deviation compensation mode again, the side wind will cause the vehicle to deviate to the right at this time, and the last stored compensation torque of the EPS motor is no longer applicable to the current working condition. Therefore, the controller clears the last stored compensation torque of the EPS motor, and controls the EPS motor to provide the deviation compensation torque for controlling the vehicle to the left according to the preset algorithm, and updates in real time with the driver's hand force, to ensure that the EPS motor can quickly and accurately provide the reverse deviation compensation torque.

[0060] In order to prevent the vehicle from being affected by the deviation compensation torque output by the EPS motor when the vehicle is changing lanes, turning, making a U-turn or parking, it is necessary to stop the EPS motor compensation torque when it is determined that the vehicle is not in a straight-line driving state. Therefore, the method of this embodiment further includes:

[0061] When the vehicle is determined to be in a non-straight driving state based on the current steering torque, the steering angle of the steering wheel and the current speed of the vehicle, the EPS motor is controlled to exit the deviation compensation mode and stop outputting the compensation torque according to the preset compensation torque output slope. At the same time, the compensation torque output by the EPS motor corresponding to the vehicle being in a non-straight driving state, that is, when the EPS motor exits the deviation compensation mode, is used as the historical compensation torque of the EPS motor. The vehicle is determined to be in a non-straight driving state if the following conditions are met within the third preset duration: if the current steering torque is greater than the fourth threshold, or the steering angle of the steering wheel is greater than the fifth threshold, or the current speed of the vehicle is less than the sixth threshold.

[0062] After entering the deviation compensation mode, if the controller determines that the vehicle enters a non-straight driving condition such as changing lanes, turning, U-turning or parking, the controller exits the deviation compensation mode and switches the deviation compensation function to the non-compensation state. At this time, the controller uses sensors to monitor the driver's hand force, the steering angle of the steering wheel and the current vehicle speed in real time to determine whether the vehicle is in a non-straight driving state. For example, when it is detected that the driver's hand force is greater than 2Nm, or the steering angle of the steering wheel is greater than 5deg, or the current vehicle speed is less than 60km / h, and any of the above conditions are met and maintained for 2s, the controller determines that the driver enters a lane change, turning, U-turning or parking condition, then the controller records and stores the size and direction of the compensation torque output by the corresponding EPS motor when the vehicle enters a non-straight driving state, and reduces the provided deviation compensation torque to 0 according to the set slope.

[0063] like Figure 5 As shown, in a second aspect of the present invention, an EPS deviation compensation control device is provided, comprising:

[0064] The processing module is configured to obtain the historical compensation torque of the EPS motor when it is determined that the vehicle is in a straight-line driving state; when it is determined that the vehicle is in a non-straight-line driving state, use the compensation torque output by the EPS motor corresponding to the non-straight-line driving state as the historical compensation torque of the EPS motor.

[0065] The control module is configured to control the EPS motor to enter the deviation compensation mode when it is determined that the vehicle is in a deviation state based on historical compensation torque and current operating parameters of the vehicle, and to control the output torque of the EPS motor based on the historical compensation torque and the current steering torque of the steering wheel; when it is determined that the vehicle is in a non-straight driving state, control the EPS motor to exit the deviation compensation mode and stop outputting the compensation torque according to a preset compensation torque output slope.

[0066] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0067] In a third aspect of the present invention, an EPS deviation compensation control system is provided, comprising:

[0068] The EPS deviation compensation control device mentioned above; and

[0069] The torque sensor is configured to collect current steering torque of the steering wheel.

[0070] In a fourth aspect of the present invention, a vehicle is provided, comprising the EPS deviation compensation control system described above.

[0071] In summary, in this embodiment, when it is determined that the vehicle is in a straight-line state without deviation, the EPS motor does not enter the deviation compensation mode, so as to ensure that the vehicle can maintain straight-line driving without moving the steering wheel; when it is determined that the vehicle is in a straight-line state, the EPS motor enters the deviation compensation mode and adjusts the compensation torque output by the EPS motor according to the current steering torque of the steering wheel. When the current steering torque of the steering wheel is less than or equal to a certain threshold, the compensation torque output by the EPS motor is maintained to ensure that the driver can still maintain straight-line driving of the vehicle without correcting the steering wheel, thereby reducing the driver's fatigue in straight-line driving conditions; when it is determined that the vehicle is not in a straight-line driving state, that is, the driver When entering non-straight driving conditions such as changing lanes, turning, U-turn, and parking, the EPS motor is controlled to exit the deviation compensation mode and stop outputting the compensation torque according to the preset compensation torque output slope, so as to eliminate the influence of the deviation compensation torque on the vehicle steering. At the same time, the output compensation torque of the EPS motor corresponding to when the EPS motor exits the deviation compensation mode is used as the historical compensation torque of the EPS motor, so that the EPS motor can quickly and accurately provide the deviation compensation torque when entering the deviation compensation mode next time, effectively improving the driver's driving experience in non-straight driving conditions, thereby ensuring that the EPS motor can quickly and accurately provide the deviation compensation torque when the driver switches between straight and non-straight conditions.

[0072] The optional embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the technical concept of the embodiments of the present invention, a variety of simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all belong to the protection scope of the embodiments of the present invention.

[0073] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not further describe various possible combinations.

[0074] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the embodiments of the present invention, they should also be regarded as the contents disclosed in the embodiments of the present invention.

Claims

1. An EPS deviation compensation control method, applied to an EPS system, wherein the EPS system includes an EPS motor, and the EPS motor is used to provide a compensation torque to a steering wheel to control the rotation of the steering wheel, characterized in that: The method comprises: When it is determined that the vehicle is in a straight-line driving state, obtaining a historical compensation torque of the EPS motor; When it is determined that the vehicle is in a deviation state according to the historical compensation torque and the current operating parameters of the vehicle, the compensation torque output by the EPS motor is controlled according to the historical compensation torque and the current steering torque of the steering wheel; Controlling the compensation torque output by the EPS motor according to the historical compensation torque and the current steering torque of the steering wheel includes: When it is determined based on the current steering torque that the steering wheel rotation direction is consistent with the steering wheel rotation direction corresponding to the historical compensation torque, the historical compensation torque is used as the initial compensation torque of the EPS motor, and the compensation torque output by the EPS motor is adjusted based on the current steering torque until the current steering torque is not greater than a first threshold value, and the compensation torque output by the EPS motor corresponding to the current steering torque being not greater than the first threshold value is maintained; When the steering wheel rotation direction determined based on the current steering torque is opposite to the steering wheel rotation direction corresponding to the historical compensation torque, the historical compensation torque is cleared, and the compensation torque output by the EPS motor is controlled based on the current steering torque until the current steering torque is no greater than a first threshold, and the compensation torque output by the EPS motor corresponding to the current steering torque being no greater than the first threshold is maintained.

2. The EPS deviation compensation control method according to claim 1, characterized in that: The historical compensation torque is used as the initial compensation torque of the EPS motor, comprising: The compensation torque output by the EPS motor is controlled according to a preset compensation torque output slope until the compensation torque output by the EPS motor reaches the historical compensation torque.

3. The EPS deviation compensation control method according to claim 1, characterized in that: The current operating parameters of the vehicle include the steering angle of the steering wheel and the current speed of the vehicle; Determining that the vehicle is in a deviation state according to the historical compensation torque and the current operating parameters of the vehicle includes: If the historical compensation torque is not 0, it is determined that the vehicle is in a deviation state; or If the historical compensation torque is 0, it is determined that the vehicle is in a deviation state when the following conditions are met simultaneously within the first preset duration period: The current steering torque belongs to a first steering torque range; The steering angle of the steering wheel is less than a second threshold; The current vehicle speed of the vehicle is within a first preset speed range.

4. The EPS deviation compensation control method according to claim 3, characterized in that: If the following conditions are met simultaneously during the second preset duration, it is determined that the vehicle is in a straight-line driving state: The current steering torque belongs to a second steering torque range, the steering angle of the steering wheel is less than a third threshold, and the current vehicle speed of the vehicle is within a second preset speed range.

5. The EPS deviation compensation control method according to claim 3, characterized in that: The method further comprises: When it is determined that the vehicle is in a non-straight driving state based on the current steering torque, the steering angle of the steering wheel and the current speed of the vehicle, the EPS motor is controlled to stop outputting the compensation torque, and the compensation torque output by the EPS motor when it is determined that the vehicle is in a non-straight driving state is used as the historical compensation torque of the EPS motor.

6. The EPS deviation compensation control method according to claim 5, characterized in that: If the following conditions are met during the third preset duration, it is determined that the vehicle is in a non-straight-line driving state: If the current steering torque is greater than the fourth threshold, or the steering angle of the steering wheel is greater than the fifth threshold, or the current vehicle speed is less than the sixth threshold.

7. An EPS deviation compensation control device, characterized in that: include: a processing module configured to obtain a historical compensation torque of the EPS motor when it is determined that the vehicle is in a straight-line driving state; a control module configured to control the torque output by the EPS motor according to the historical compensation torque and the current steering torque of the steering wheel when it is determined that the vehicle is in a deviation state according to the historical compensation torque and the current operating parameters of the vehicle; Controlling the compensation torque output by the EPS motor according to the historical compensation torque and the current steering torque of the steering wheel includes: When it is determined based on the current steering torque that the steering wheel rotation direction is consistent with the steering wheel rotation direction corresponding to the historical compensation torque, the historical compensation torque is used as the initial compensation torque of the EPS motor, and the compensation torque output by the EPS motor is adjusted based on the current steering torque until the current steering torque is not greater than a first threshold value, and the compensation torque output by the EPS motor corresponding to the current steering torque being not greater than the first threshold value is maintained; When the steering wheel rotation direction determined based on the current steering torque is opposite to the steering wheel rotation direction corresponding to the historical compensation torque, the historical compensation torque is cleared, and the compensation torque output by the EPS motor is controlled based on the current steering torque until the current steering torque is no greater than a first threshold, and the compensation torque output by the EPS motor corresponding to the current steering torque being no greater than the first threshold is maintained.

8. An EPS deviation compensation control system, characterized in that: include: The EPS deviation compensation control device as claimed in claim 7; as well as The torque sensor is configured to collect current steering torque of the steering wheel.

9. A car, characterized in that: Including the EPS deviation compensation control system as described in claim 8.

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