A control method for steering deviation correction

Abstract

This invention relates to the field of electronic steering system technology, specifically a control method for steering deviation correction, including state transitions between a compensation algorithm inactive state, a compensation algorithm active state, a compensation algorithm active state, a compensation algorithm hold state, and a fade-out state, as well as the calculation of rack compensation force for each state. This invention can cope with driving environments involving road inclines or continuous crosswinds, detect road conditions in real time and provide steering compensation, reducing the steering force required for the driver to maintain straight-line driving, lowering driver fatigue, improving driving comfort, and enhancing the driving experience.

Description

Technical Field

[0001] This invention relates to the field of electronic steering system technology, and more specifically to a control method for correcting steering deviation. Background Technology

[0002] With the development of the automotive industry, automobiles now possess comprehensive functions, generally meeting the needs of various driving environments. Driving comfort and intelligent features are increasingly becoming important factors for consumers when choosing a car. Steering, as one of the most frequent driver maneuvers, presents a significant challenge: how to improve the intelligence of the steering system—that is, how to enable real-time road condition recognition and provide corresponding software assistance based on the current road conditions, thereby reducing the driver's workload and improving comfort—has become an urgent issue to address.

[0003] Generally, roads slope towards the roadside to allow water to drain away. If a car is driving on a sloping straight road or in the presence of a persistent crosswind, the driver must constantly apply steering torque to keep the vehicle in a straight line, resulting in high driving intensity and low driving comfort.

[0004] Therefore, it is necessary to design a steering deviation correction control method that can detect road conditions in real time and adjust the auxiliary power, thereby reducing the steering force required for the driver to keep the vehicle driving in a straight line, reducing the driver's driving intensity, and improving driving comfort. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a steering deviation correction control method that can detect road conditions in real time and adjust the auxiliary power, thereby reducing the steering force required by the driver to keep the vehicle driving in a straight line, reducing the driver's driving intensity, and improving driving comfort.

[0006] To achieve the above objectives, this invention provides a steering deviation correction control method, comprising the following steps: Step 1, after the vehicle is powered on, it enters a state where the compensation algorithm is not activated and continues to Step 2; Step 2, in the state where the compensation algorithm is not activated, if the conditions of compensation function being enabled, vehicle speed signal, and hand force signal being valid are simultaneously met, then it enters a state where the compensation algorithm is activated and continues to Step 3; Step 3, in the state where the compensation algorithm is activated, if the conditions of lateral angular velocity ≤ 1 deg / s and vehicle speed between 30 km / h and 100 km / h are simultaneously met, then... If the following conditions are met: lateral angular velocity > 1 deg / s², vehicle speed < 30 km / h, vehicle speed > 100 km / h, steering wheel angle ≤ 5 deg, applied force on the steering wheel < 2 Nm, and vehicle acceleration < 1 m / s², then the compensation algorithm is activated and step 4 continues. If any of the following conditions are met: compensation function disabled, vehicle speed signal invalid, or hand force signal invalid, then the process enters a fade-out state and continues to step 6. In step 4, when the compensation algorithm is activated, if the following conditions are met: lateral angular velocity > 1 deg / s², vehicle speed < 30 km / h, vehicle speed > 100 km / h, steering wheel angle > 5 deg, applied force on the steering wheel < 2 Nm, and vehicle acceleration < 1 m / s², then the compensation algorithm is activated and step 4 continues. If any of the following conditions are met: the force applied to the steering wheel is ≥2Nm, or the vehicle acceleration is >1m / s², then the system enters the compensation algorithm holding state and continues to step 5; if any of the following conditions are met: compensation function disabled, vehicle speed signal invalid, or force signal invalid, then the system enters the fade-out state and continues to step 6; if the steering wheel angle signal or lateral angular velocity signal is invalid, then the system enters the compensation algorithm active state and continues to step 3; in step 5, while in the compensation algorithm holding state, if the following conditions are met: compensation function disabled, vehicle speed signal invalid, or force signal invalid... If any of the following conditions are met, the process enters the fade-out state and continues to step 6; if the following conditions are met simultaneously: lateral angular velocity ≤ 1 deg / s, vehicle speed between 30 km / h and 100 km / h, steering wheel angle ≤ 5 deg, hand force applied to the steering wheel < 2 Nm, and vehicle acceleration < 1 m / s², the process enters the compensation algorithm activation state and continues to step 4; if the following conditions are met: steering angle signal invalid, lateral angular velocity signal invalid, lateral angular velocity > 15 deg / s, vehicle speed > 5 km / h, and steering wheel angle > 50 deg... If any of the following conditions are met: the applied force on the steering wheel is >4 Nm and maintained for 100 ms; the vehicle speed is >5 km / h; the rack compensation force is >78 N; the applied force on the steering wheel is >0.25 Nm; and the compensation torque and the applied force are in opposite directions and maintained for 1000 ms, then the compensation algorithm is activated and step 3 continues. In step 6, during the exit state, the rack compensation force decreases according to the set slope. When the rack compensation force is 0, the compensation algorithm is deactivated and step 2 continues.

[0007] When the compensation algorithm is not activated, the rack compensation force is 0, the short-cycle rack force compensation value is 0, and the long-cycle rack force compensation value is the long-cycle rack force compensation value of the previous moment.

[0008] The long-cycle rack force compensation value is stored in an electrically erasable programmable read-only memory (EEPROM).

[0009] When the compensation algorithm is active, the short-cycle rack force compensation value decreases at a rate of 200 N / s until it becomes 0, and the long-cycle rack force compensation value is the long-cycle rack force compensation value of the previous moment. The rack compensation force = short-cycle rack force compensation value + long-cycle rack force compensation value.

[0010] When the compensation algorithm is active, the following steps are included: Step a, calculate the rack force, rack force = hand force applied to the steering wheel × constant × conversion coefficient between hand force and rack force; Step b, calculate the long-cycle rack force compensation value, long-cycle rack force compensation value = rack force × integrated influence coefficient + previous long-cycle rack force compensation value; Step c, calculate the short-cycle rack force compensation value, short-cycle rack force compensation value = rack force × short-cycle integrated influence coefficient + previous short-cycle rack force compensation value, and correct the short-cycle rack force compensation value according to the limit of the short-cycle rack force compensation value; Step d, correct the rack compensation force, when the vehicle speed signal is valid, the intermediate variable rack force compensation value = rack compensation force × correction coefficient, when the vehicle speed signal is invalid, the intermediate variable rack force compensation value = 0; Step e, calculate the final output torque, final output torque = intermediate variable rack force compensation value × conversion coefficient between rack force and steering motor force.

[0011] The constant is 0.04, the conversion coefficient between hand force and rack force is 2315, the integration influence coefficient is 0.0012, the short cycle integration influence coefficient is 0.46137, and the conversion coefficient between rack force and steering motor force is 0.00043197.

[0012] When the vehicle speed is greater than 10 km / h and less than or equal to 30 km / h, the limit for short-cycle rack force compensation is 157. When the vehicle speed is greater than 30 km / h and less than 100 km / h, the limit for short-cycle rack force compensation is 157~141, and the limit for short-cycle rack force compensation decreases proportionally with the increase of vehicle speed. When the vehicle speed is greater than or equal to 100 km / h and less than or equal to 120 km / h, the limit for short-cycle rack force compensation is 141~0, and the limit for short-cycle rack force compensation decreases proportionally with the increase of vehicle speed.

[0013] When the vehicle speed is greater than 10 km / h and less than or equal to 30 km / h, the correction factor is 0 to 1, and the correction factor increases proportionally with the increase of vehicle speed. When the vehicle speed is greater than 30 km / h and less than 100 km / h, the correction factor is 1. When the vehicle speed is greater than or equal to 100 km / h and less than or equal to 120 km / h, the correction factor is 1 to 0.5, and the correction factor decreases proportionally with the increase of vehicle speed.

[0014] When the compensation algorithm maintains its state, the short-cycle rack force compensation value, the long-cycle rack force compensation value, and the rack compensation force remain at their original values.

[0015] During the exit phase, if the vehicle speed signal or the hand force signal fails, the rack compensation force decreases at a rate of 200 N / s until it reaches 0; if both the vehicle speed signal and the hand force signal are valid, the rack compensation force decreases at a rate of 300 N / s until it reaches 0.

[0016] Compared with existing technologies, this invention designs a steering deviation correction control method that can cope with driving environments with road inclines or continuous crosswinds, detect road conditions in real time and provide steering compensation, reduce the steering force required for the driver to keep the vehicle driving in a straight line, reduce the driver's driving intensity, improve driving comfort, and enhance the driving experience. Implementation

[0017] The present invention will now be described in further detail.

[0018] This invention is a control method for correcting steering deviation, comprising the following steps: Step 1, after the vehicle is powered on, the compensation algorithm is not activated and Step 2 is continued.

[0019] When the compensation algorithm is not activated, the rack compensation force is 0, the short-cycle rack force compensation value is 0, and the long-cycle rack force compensation value is the long-cycle rack force compensation value from the previous moment; that is, the entire algorithm does not provide compensation. However, the long-cycle rack force compensation value is retained, storing the long-cycle rack force compensation value learned from the previous moment. The long-cycle rack force compensation value is stored in an electrically erasable programmable read-only memory (EEPROM) to ensure that it is not lost after the key power is turned off.

[0020] Step 2: When the compensation algorithm is not activated, if the conditions of compensation function being enabled, vehicle speed signal and hand force signal being valid are met simultaneously, then the compensation algorithm is activated and Step 3 is continued. At this time, it is equivalent to the function being enabled and the important input signals required by the function being valid.

[0021] When the compensation algorithm is active, the short-cycle rack force compensation value decreases at a rate of 200 N / s until it becomes 0. The long-cycle rack force compensation value is the long-cycle rack force compensation value of the previous moment. The rack compensation force = short-cycle rack force compensation value + long-cycle rack force compensation value. The rack compensation force will gradually decrease until it is equal to the long-cycle rack force compensation value.

[0022] Step 3: While the compensation algorithm is active, if the following conditions are simultaneously met: lateral angular velocity ≤ 1 deg / s, vehicle speed between 30 km / h and 100 km / h, steering wheel angle ≤ 5 deg, hand force applied to the steering wheel < 2 Nm, and vehicle acceleration < 1 m / s², then the compensation algorithm is activated and step 4 continues. These conditions are used to identify whether the vehicle is currently traveling on a sloping road or a road with continuous crosswinds, and whether the actual driving conditions are suitable for power assist compensation.

[0023] When the compensation algorithm is active, the following steps are included: Step a, calculate the rack force, where rack force = hand force applied to the steering wheel × constant × conversion coefficient between hand force and rack force; Step b, calculate the long-cycle rack force compensation value, where long-cycle rack force compensation value = rack force × integrated influence coefficient + long-cycle rack force compensation value from the previous moment; Step c, calculate the short-cycle rack force compensation value, where short-cycle rack force compensation value = rack force × short-cycle integrated influence coefficient + short-cycle rack force compensation value from the previous moment, and correct the short-cycle rack force compensation based on the limit of the short-cycle rack force compensation value. Step d: Correct the rack compensation force. When the vehicle speed signal is valid, the intermediate variable rack force compensation value = rack compensation force × correction coefficient. When the vehicle speed signal is invalid, the intermediate variable rack force compensation value = 0. The rate of change of the intermediate variable rack force compensation value is limited to 800 N / s, and the upper and lower limits are -312 N and 312 N, respectively. Step e: Calculate the final output torque. The final output torque = intermediate variable rack force compensation value × rack force and steering motor force conversion coefficient. The upper and lower limits of the final output torque are -0.12196 and 0.12196, respectively.

[0024] Among them, the constant is 0.04, the conversion coefficient between hand force and rack force is 2315, the integration influence coefficient is 0.0012, the short-cycle integration influence coefficient is 0.46137, and the conversion coefficient between rack force and steering motor force is 0.00043197. The constants or coefficients in the algorithm are related to the actual mechanical structure. Different hardware designs may cause parameter changes, requiring recalibration.

[0025] When the vehicle speed is greater than 10 km / h and less than or equal to 30 km / h, the limit for short-cycle rack force compensation is 157. When the vehicle speed is greater than 30 km / h and less than 100 km / h, the limit for short-cycle rack force compensation is 157~141, and the limit for short-cycle rack force compensation decreases proportionally with the increase of vehicle speed. When the vehicle speed is greater than or equal to 100 km / h and less than or equal to 120 km / h, the limit for short-cycle rack force compensation is 141~0, and the limit for short-cycle rack force compensation decreases proportionally with the increase of vehicle speed.

[0026] When the vehicle speed is greater than 10 km / h and less than or equal to 30 km / h, the correction factor is 0 to 1, and the correction factor increases proportionally with the increase of vehicle speed. When the vehicle speed is greater than 30 km / h and less than 100 km / h, the correction factor is 1. When the vehicle speed is greater than or equal to 100 km / h and less than or equal to 120 km / h, the correction factor is 1 to 0.5, and the correction factor decreases proportionally with the increase of vehicle speed.

[0027] If any of the following conditions are met: compensation function off, vehicle speed signal failure, or hand force signal failure, then the process enters the fade-out state and continues to step 6.

[0028] During the exit phase, if the vehicle speed signal or the hand force signal fails, the rack compensation force decreases at a rate of 200 N / s until it reaches 0; if both the vehicle speed signal and the hand force signal are valid, the rack compensation force decreases at a rate of 300 N / s until it reaches 0.

[0029] Step 4: When the compensation algorithm is active, if any of the following conditions are met: lateral angular velocity > 1 deg / s, vehicle speed < 30 km / h, vehicle speed > 100 km / h, steering wheel angle > 5 deg, hand force applied to the steering wheel ≥ 2 Nm, or vehicle acceleration > 1 m / s², then the compensation algorithm is held and Step 5 continues.

[0030] When the compensation algorithm maintains its state, the short-cycle rack force compensation value, the long-cycle rack force compensation value, and the rack compensation force remain at their original values.

[0031] If any of the following conditions are met: compensation function off, vehicle speed signal invalid, or hand force signal invalid, the system enters the fade-out state and continues to step 6; if the steering wheel angle signal or lateral angular velocity signal is invalid, the system enters the compensation algorithm active state and continues to step 3.

[0032] Step 5: While the compensation algorithm is in the active state, if any one of the following conditions is met: compensation function off, vehicle speed signal invalid, or hand force signal invalid, then the process enters the fade-out state and continues to Step 6. If the following conditions are met simultaneously: lateral angular velocity ≤ 1 deg / s, vehicle speed between 30 km / h and 100 km / h, steering wheel angle ≤ 5 deg, hand force applied to the steering wheel < 2 Nm, and vehicle acceleration < 1 m / s², then the process enters the active state of the compensation algorithm and continues to Step 4. If any one of the following conditions is met: steering angle signal invalid, lateral angular velocity signal invalid, lateral angular velocity > 15 deg / s and vehicle speed > 5 km / h and steering wheel angle > 50 deg and hand force applied to the steering wheel > 4 Nm and maintained for 100 ms, or vehicle speed > 5 km / h and rack compensation force > 78 N and hand force applied to the steering wheel > 0.25 Nm and compensation torque and hand force are in opposite directions and maintained for 1000 ms, then the process enters the active state of the compensation algorithm and continues to Step 3.

[0033] Step 6: In the gradual exit state, the rack compensation force decreases according to the set slope. When the rack compensation force is 0, the compensation algorithm is inactive and Step 2 continues.

[0034] When entering roads without lane markings, or in vehicles without lane keeping assist (i.e., without cameras), or with lane keeping assist but the function is manually disabled, or with lane keeping assist but the function is malfunctioning (e.g., a camera malfunction), the present invention can be configured to enable straight driving even on sloping roads or in continuous crosswinds when the steering wheel angle is 0 degrees.

[0035] The steering deviation correction control method of this invention has a self-learning function. Even if the mechanical structure of the vehicle's steering system wears and ages, the method can still function without human intervention for recalibration, ensuring the reliability of this function throughout the entire life cycle of the steering system. It can even solve the problem of vehicle pulling to one side due to uneven tire pressure on both sides of the vehicle to a certain extent. Example

[0036] When a vehicle is traveling on a slope or in a crosswind, the driver applies a certain amount of force to the steering wheel to maintain a straight course; in this example, the force is 1 Nm. Under suitable conditions, the steering system controller can learn and compensate for the force using the aforementioned method and apply it to the driving process.

[0037] First, the compensation function is activated, and both the vehicle speed signal and the hand force signal are valid, entering the compensation algorithm activation state. At this time, the long-cycle rack force compensation value plays a major role, while the short-cycle rack force compensation value has no effect. If this is the first time the function has been activated, and the previous long-cycle rack force compensation value was 0, and the previous short-cycle rack force compensation value was 0, and if the lateral angular velocity is 0.5 degrees / s, the vehicle speed is 50 km / h, the steering wheel angle is 3 degrees, the hand force applied to the steering wheel is 1 Nm, and the vehicle acceleration is 0.5 m / s², then the compensation algorithm is activated, and the calculations are as follows:

[0038] Rack force = Hand force applied to the steering wheel × Constant × Conversion coefficient between hand force and rack force = 1 × 0.04 × 2315 = 92.60 N. Long-cycle rack force compensation value = Rack force × Integrated influence coefficient + Long-cycle rack force compensation value at the previous moment = 92.60 × 0.0012 + 0 = 0.11 N. Short-cycle rack force compensation value = Rack force × Short-cycle integrated influence coefficient + Short-cycle rack force compensation value at the previous moment = 92.60 × 0.46137 + 0 = 42.72 N. The long-cycle rack force compensation value and the short-cycle rack force compensation value will continue to integrate under the condition that the conditions are met.

[0039] Since the short-cycle rack force compensation value is less than the limit of the short-cycle rack force compensation value, no correction is performed.

[0040] Rack compensation force = short-cycle rack force compensation value + long-cycle rack force compensation value = 0.11 + 42.72 = 42.83 N.

[0041] Since the vehicle speed is 50 km / h and the correction factor is 1, the intermediate variable rack force compensation value = rack compensation force × correction factor = 42.83 × 1 = 42.83 N. The rate of change of the intermediate variable rack force compensation value is limited to 800 N / s, with upper and lower limits of -312 N and 312 N, respectively.

[0042] Final output torque = intermediate variable rack force compensation value × rack force and steering motor force conversion coefficient = 42.83 × 0.00043197 = 0.01850128 Nm. The upper and lower limits of the final output torque are -0.12196 and 0.12196, respectively. Example

[0043] When a vehicle is traveling on a sloping road or in a crosswind, the driver applies a certain amount of force to the steering wheel to maintain a straight course. In this example, the force is 0.5 Nm, and this example is taken after Example 1. Under certain conditions, the steering system controller can learn the compensation force using the aforementioned method and apply it to the current driving process.

[0044] First, the compensation function is activated, and both the vehicle speed signal and the hand force signal are valid, entering the compensation algorithm activation state. At this time, the long-cycle rack force compensation value plays a major role, while the short-cycle rack force compensation value has no effect. Because this is not the first time the function has been activated, and the long-cycle rack force compensation value is stored in an electrically erasable programmable read-only memory (EEPROM), the previous long-cycle rack force compensation value was 0.11N, and the previous short-cycle rack force compensation value was 0N. If the lateral angular velocity is 0.5deg / s, the vehicle speed is 50km / h, the steering wheel angle is 3deg, the hand force applied to the steering wheel is 0.5Nm, and the vehicle acceleration is 0.5m / s², the compensation algorithm is now activated, and the calculations are as follows:

[0045] Rack force = Hand force applied to the steering wheel × Constant × Conversion coefficient between hand force and rack force = 0.5 × 0.04 × 2315 = 46.30 N. Long-cycle rack force compensation value = Rack force × Integrated influence coefficient + Long-cycle rack force compensation value at the previous moment = 46.30 × 0.0012 + 0.11 = 0.17 N. Short-cycle rack force compensation value = Rack force × Short-cycle integrated influence coefficient + Short-cycle rack force compensation value at the previous moment = 46.30 × 0.46137 + 0 = 21.36 N. The long-cycle rack force compensation value and the short-cycle rack force compensation value will continue to integrate under the condition that the conditions are met.

[0046] Since the short-cycle rack force compensation value is less than the limit of the short-cycle rack force compensation value, no correction is performed.

[0047] Rack compensation force = short-cycle rack force compensation value + long-cycle rack force compensation value = 0.17 + 21.36 = 21.53 N.

[0048] Since the vehicle speed is 50 km / h and the correction factor is 1, the intermediate variable rack force compensation value = rack compensation force × correction factor = 21.53 × 1 = 21.53 N. The rate of change of the intermediate variable rack force compensation value is limited to 800 N / s, with upper and lower limits of -312 N and 312 N, respectively.

[0049] Final output torque = intermediate variable rack force compensation value × rack force and steering motor force conversion coefficient = 21.53 × 0.00043197 = 0.00930031 Nm. The upper and lower limits of the final output torque are -0.12196 and 0.12196, respectively.

Claims

1. A control method of a deviation correction of a steering, characterized by: The method comprises the following steps: step 1, after the whole vehicle is powered on, entering a compensation algorithm inactivation state and continuing step 2; step 2, in the compensation algorithm inactivation state, if the compensation function is started, the vehicle speed signal and the hand force signal are valid, then entering a compensation algorithm activation intermediate state and continuing step 3; step 3, in the compensation algorithm activation intermediate state, if the lateral angular velocity is less than or equal to 1 deg / s, the vehicle speed is between 30 km / h and 100 km / h, the steering wheel steering angle is less than or equal to 5 deg, the hand force applied to the steering wheel is less than 2 Nm, and the vehicle acceleration is less than 1 m / s², then entering a compensation algorithm activation state and continuing step 4; if any one of the compensation function is closed, the vehicle speed signal is invalid, and the hand force signal is invalid, then entering a gradual out state and continuing step 6; step 4, in the compensation algorithm activation state, if any one of the lateral angular velocity is greater than 1 deg / s, the vehicle speed is less than 30 km / h, the vehicle speed is greater than 100 km / h, the steering wheel steering angle is greater than 5 deg, the hand force applied to the steering wheel is greater than or equal to 2 Nm, and the vehicle acceleration is greater than 1 m / s², then entering a compensation algorithm maintaining state and continuing step 5; if any one of the compensation function is closed, the vehicle speed signal is invalid, and the hand force signal is invalid, then entering the gradual out state and continuing step 6; if the steering wheel angle signal is invalid or the lateral angular velocity signal is invalid, then entering the compensation algorithm activation intermediate state and continuing step 3; step 5, in the compensation algorithm maintaining state, if any one of the compensation function is closed, the vehicle speed signal is invalid, and the hand force signal is invalid, then entering the gradual out state and continuing step 6; if the lateral angular velocity is less than or equal to 1 deg / s, the vehicle speed is between 30 km / h and 100 km / h, the steering wheel steering angle is less than or equal to 5 deg, the hand force applied to the steering wheel is less than 2 Nm, and the vehicle acceleration is less than 1 m / s², then entering the compensation algorithm activation state and continuing step 4; if any one of the steering angle signal is invalid, the lateral angular velocity signal is invalid, the lateral angular velocity is greater than 15 deg / s and the vehicle speed is greater than 5 km / h and the steering wheel steering angle is greater than 50 deg and the hand force applied to the steering wheel is greater than 4 Nm and is maintained for 100 ms, the vehicle speed is greater than 5 km / h and the rack compensation force is greater than 78 N and the hand force applied to the steering wheel is greater than 0.25 Nm and the compensation torque and the hand force are opposite and are maintained for 1000 ms, then entering the compensation algorithm activation intermediate state and continuing step 3; Step 6, in the gradual out state, the rack compensation force decreases according to a set slope, and when the rack compensation force is 0, entering the compensation algorithm inactivation state and continuing step 2.

2. A control method of a deviation correction of a steering according to claim 1, characterized in that: In the compensation algorithm inactivation state, the rack compensation force is 0, the short-period rack force compensation value is 0, and the long-period rack force compensation value is the long-period rack force compensation value at the last moment.

3. A control method of a deviation correction of a steering according to claim 2, characterized in that: The long-period rack force compensation value is stored in an electrically erasable programmable read-only memory (EEPROM).

4. The control method of claim 1, wherein: In the state of compensation algorithm activation, the short-period rack force compensation value is reduced at a speed of 200 N / s until it is 0, the long-period rack force compensation value is the long-period rack force compensation value of the last time, and the rack compensation force = the short-period rack force compensation value + the long-period rack force compensation value.

5. The control method of claim 1, wherein: In the state of compensation algorithm activation, the following steps are included: step a, calculating the rack force, the rack force = the hand force applied on the steering wheel * a constant * a conversion coefficient of the hand force and the rack force; step b, calculating the long-period rack force compensation value, the long-period rack force compensation value = the rack force * an integration influence coefficient + the long-period rack force compensation value of the last time; step c, calculating the short-period rack force compensation value, the short-period rack force compensation value = the rack force * a short-period integration influence coefficient + the short-period rack force compensation value of the last time, and the short-period rack force compensation value is corrected according to the limit value of the short-period rack force compensation value; step d, calculating the rack compensation force, the rack compensation force = the short-period rack force compensation value + the long-period rack force compensation value; step e, correcting the rack compensation force, when the vehicle speed signal is valid, an intermediate variable rack force compensation value = the rack compensation force * a correction coefficient, and when the vehicle speed signal is invalid, the intermediate variable rack force compensation value = 0; and step f, calculating the final output torque, the final output torque = the intermediate variable rack force compensation value * a conversion coefficient of the rack force and the steering motor force. The constant is 0.04, the conversion coefficient of the hand force and the rack force is 2315, the integration influence coefficient is 0.0012, the short-period integration influence coefficient is 0.46137, and the conversion coefficient of the rack force and the steering motor force is 0.00043197. When the vehicle speed is greater than 10 km / h and less than or equal to 30 km / h, the limit value of the short-period rack force compensation value is 157, when the vehicle speed is greater than 30 km / h and less than 100 km / h, the limit value of the short-period rack force compensation value is 157-141, and the limit value of the short-period rack force compensation value decreases at a constant rate as the vehicle speed increases, when the vehicle speed is greater than or equal to 100 km / h and less than or equal to 120 km / h, the limit value of the short-period rack force compensation value is 141-0, and the limit value of the short-period rack force compensation value decreases at a constant rate as the vehicle speed increases.

6. A control method of a deviation correction of a steering according to claim 5, characterized in that: When the vehicle speed is greater than 10 km / h and less than or equal to 30 km / h, the correction coefficient is 0-1, and the correction coefficient increases at a constant rate as the vehicle speed increases, when the vehicle speed is greater than 30 km / h and less than 100 km / h, the correction coefficient is 1, when the vehicle speed is greater than or equal to 100 km / h and less than or equal to 120 km / h, the correction coefficient is 1-0.5, and the correction coefficient decreases at a constant rate as the vehicle speed increases.

7. The control method of claim 5, wherein: In the state of compensation algorithm maintenance, the short-period rack force compensation value, the long-period rack force compensation value, and the rack compensation force maintain the original values.

8. The control method of claim 5, wherein: In the gradual exit state, if the vehicle speed signal is invalid or the hand force signal is invalid, the rack compensation force is reduced at a speed of 200 N / s until it is 0; if the vehicle speed signal is valid and the hand force signal is valid, the rack compensation force is reduced at a speed of 300 N / s until it is 0.

9. The control method of claim 1, wherein: ​ 10. The control method of claim 1, wherein: ​