Eps slip compensation control system

Abstract

This invention discloses an EPS slip compensation control system, including a data acquisition module, a slip state recognition module, a slip torque calculation module, and an EPS motor; the data acquisition module is used to acquire the current hand force torque m. tbt Motor torque m mot Vehicle speed v veh and motor RPS speed v rps The sliding state recognition module identifies the current hand force torque m based on the obtained data. tbt Motor torque m mot Vehicle speed v veh and motor RPS speed v rps The system determines whether the drive belt is currently slipping; the slip torque calculation module calculates the motor compensation torque when the drive belt is slipping; the EPS motor compensates based on the motor compensation torque output by the slip torque calculation module. This invention enables normal steering control even when the EPS drive belt is slipping.

Description

Technical Field

[0001] This invention belongs to the field of driver assistance technology, specifically relating to an EPS slip compensation control system. Background Technology

[0002] A schematic diagram of the structure of an EPS system driven by a transmission belt in the prior art is shown below. Figure 1 As shown, the EPS power motor transmits torque to the steering rack via a drive belt. When the rack seal reduces its sealing effectiveness due to aging or damage, moisture, dust, and other impurities enter the rack through the seal. When these impurities accumulate in the housing at the end of the drive belt pulley, such as… Figure 2 As shown by the dashed circle, a large blocking torque is generated. The motor torque is output to the pulley. As the transmission belt tightens to overcome the blocking torque, the motion changes from static friction to dynamic friction. The blocking torque decreases, resulting in a reduction in the required torque. Consequently, the motor's assist torque decreases, and the transmission belt tension decreases. This causes the blocking torque to increase, forming static friction. The cyclical switching between static and dynamic friction causes unstable output from the EPS power-assisted motor, resulting in a sawing motion when using the hand, and a decrease in steering performance.

[0003] The technical problem to be solved by this invention is how to achieve normal steering control under the slipping condition of EPS drive belt. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides an EPS slip compensation control system, including a data acquisition module, a slip state recognition module, a slip torque calculation module, and an EPS motor;

[0005] The data acquisition module is used to obtain the current hand force torque m tbt Motor torque m mot Vehicle speed v veh and motor RPS speed v rps The sliding state recognition module identifies the current hand force torque m based on the obtained data. tbt Motor torque m mot Vehicle speed v veh and motor RPS speed v rps The system determines whether the current drive belt is in a slipping state; the slip torque calculation module is used to calculate the motor compensation torque when the drive belt is in a slipping state; the EPS motor compensates according to the motor compensation torque output by the slip torque calculation module.

[0006] Preferably, the motor compensation torque is a square wave, sine wave, or triangular wave with a fixed amplitude and frequency.

[0007] Preferably, at the start of compensation, the amplitude of the motor compensation torque is at a preset gradient Mot. gradient Increment to target amplitude Mot Amp .

[0008] Preferably, the amplitude is 1 Nm.

[0009] Preferably, the frequency is 20Hz.

[0010] Preferably, the preset gradient Mot gradient It is 1 Nm / s.

[0011] Preferably, the method for determining whether the current transmission belt is in a slipping state is as follows:

[0012] Step 1, calculate the effective motor torque Mot eff ;

[0013] Step 2, determine the vehicle speed v veh Is it greater than the vehicle speed threshold v? lim ;

[0014] Step 3, determine the motor RPS speed v rps Less than the limit v rpslow If the effective motor torque is less than the limit value Mot for a period of time t1, the condition continues for more than t1. mineff ;

[0015] Step 4, when the motor RPS speed v rps Greater than the limit v rpslow At that time, determine whether the effective motor torque is greater than Mot. maxeff ;

[0016] Step 5, when the motor RPS speed v rps Greater than the limit v rpslow At that time, determine the motor RPS speed v rps Does it exceed the limit value v within time t2? rpsup ;

[0017] Step 6, when the motor RPS speed v rps Greater than the limit v rpsup At that time, determine the effective motor torque Mot within time t3. eff Is the change less than Mot? gradient Determine the motor RPS speed v within time t4. rps Is it less than the limit value v? rpslow ;

[0018] Step 7, determine the motor RPS speed v rps Less than the limit v rpslow Does the time last for t5, during which the effective motor torque Mot eff Is it smaller than Mot? mineff ;

[0019] Step 8: All the above judgment conditions are met, and the motor RPS speed v rps and effective motor torque Mot eff If the directions are consistent and there is no reversal, it is determined that the current transmission belt is in a slipping state.

[0020] Preferably, in step 1, the effective motor torque Mot eff The calculation method is as follows: Mot eff =m tbt *R tbt2mot *E tbt2mot +m mot Among them, R tbt2mot E represents the gear ratio from the steering wheel to the motor. tbt2mot This refers to the transmission efficiency from the steering wheel to the motor output shaft.

[0021] Compared with the prior art, the present invention can effectively solve the problem that the drive pulley at the motor end slips due to foreign matter mixed in the EPS pulley end housing, causing changes in belt tension and resulting in stick-slip phenomenon in the torque output of the EPS motor, which makes it difficult for the driver to control the driving direction. Attached Figure Description

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0023] Figure 1 This is a schematic diagram of an EPS system driven by a transmission belt.

[0024] Figure 2 This is a schematic diagram of the EPS sliding compensation control system structure in Example 1;

[0025] Figure 3 This is a schematic diagram of the torque and speed conditions in the method for determining whether the current transmission belt is in a slipping state in Example 1. Detailed Implementation

[0026] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can fully understand other advantages and technical effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific embodiments, and the details in this specification can also be applied based on different viewpoints, with various modifications or changes made without departing from the overall design concept of the invention. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. The following exemplary embodiments of the present invention can be implemented in many different forms and should not be construed as being limited to the specific embodiments set forth herein. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the technical solutions of these exemplary embodiments to those skilled in the art.

[0027] Example 1

[0028] like Figure 2 As shown, this embodiment provides an EPS slip compensation control system, including a data acquisition module, a slip state recognition module, a slip torque calculation module, and an EPS motor.

[0029] The data acquisition module includes a vehicle speed sensor, a motor RPS sensor, a steering wheel force sensor, and a motor torque sensor.

[0030] The data acquisition module obtains data from various sensors, such as the current hand force torque m. tbt Motor torque m mot Vehicle speed v veh Motor RPS speed v rps .

[0031] The slippage state recognition module determines whether the current transmission belt is in a slippage state based on the obtained sensor data, and sets the slippage state flag bit: 0 indicates that no slippage has occurred; 1 indicates that the transmission belt has slipped.

[0032] Specifically, such as Figure 3 As shown, the method for determining whether the transmission belt is currently in a slipping state is as follows:

[0033] Step 1, calculate the effective motor torque Mot eff ;

[0034] The effective motor torque is calculated as follows: Mot eff =m tbt *R tbt2mot *E tbt2mot +m mot Among them, R tbt2mot E represents the gear ratio from the steering wheel to the motor. tbt2mot The transmission efficiency from the steering wheel to the motor output shaft;

[0035] Step 2, determine the vehicle speed v veh Is it greater than the vehicle speed threshold v? lim (e.g., 7km / h);

[0036] Step 3, determine the motor RPS speed v rps Less than the limit v rpslow (e.g., 10° / s), lasting for more than time t1 (e.g., 100ms), during which the minimum effective motor torque is less than the limit Mot. mineff (e.g., 0.05 Nm);

[0037] Step 4, when the motor RPS speed v rps Greater than the limit v rpslowAt that time, determine whether the effective motor torque is greater than Mot. maxeff (e.g., 1.8 Nm);

[0038] Step 5, when the motor RPS speed v rps Greater than the limit v rpslow At that time, determine the motor RPS speed v rps Does it exceed the limit value v within time t2 (50ms)? rpsup (e.g., 100° / s);

[0039] Step 6, when the motor RPS speed v rps Greater than the limit v rpsup At that time, determine the effective motor torque Mot within the time interval t3 (90ms). eff Is the change less than Mot? gradient (e.g., 0.7 Nm), determine the motor RPS speed v within time t4 (300 ms). rps Is it less than the limit value v? rpslow (e.g., 10° / s);

[0040] Step 7, determine the motor RPS speed v rps Less than the limit v rpslow Does the time (e.g., 10° / s) last for t5 (80ms), during which the effective motor torque Mot eff Is it smaller than Mot? mineff ;

[0041] Step 8: All the above judgment conditions are met, and the motor RPS speed v rps and effective motor torque Mot eff If the directions are consistent and there is no reversal, it is determined that the current transmission belt is in a slipping state.

[0042] The slip torque calculation module is used to calculate the motor compensation torque when the drive belt is in a slipping state. The motor compensation torque is a square wave, sine wave, or triangular wave with a fixed amplitude and frequency.

[0043] Amplitude is Mot Amp (e.g., 1Nm), frequency F fre (20Hz), and the amplitude at the start of compensation is at a preset gradient of Mot. gradient (e.g., 1 Nm / s) Incremented to the target amplitude Mot Amp This is to prevent sudden compensation from interfering with driving.

[0044] The EPS motor is compensated based on the motor compensation torque output by the sliding torque calculation module.

[0045] The present invention has been described in detail above through specific embodiments and examples, but these are not intended to limit the invention. Many modifications and improvements can be made by those skilled in the art without departing from the principles of the invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. An EPS sliding compensation control system, characterized in that, Includes a data acquisition module, a sliding state recognition module, a sliding torque calculation module, and an EPS motor; The data acquisition module is used to obtain the current hand force torque m tbt Motor torque m mot Vehicle speed v veh and motor RPS speed v rps The sliding state recognition module identifies the current hand force torque m based on the obtained data. tbt Motor torque m mot Vehicle speed v veh and motor RPS speed v rps Determine whether the current drive belt is in a slipping state; The sliding torque calculation module is used to calculate the motor compensation torque when the drive belt is in a slipping state; The EPS motor is compensated based on the motor compensation torque output by the sliding torque calculation module.

2. The EPS sliding compensation control system according to claim 1, characterized in that, The motor compensation torque is a square wave, sine wave, or triangle wave with a fixed amplitude and frequency.

3. The EPS sliding compensation control system according to claim 2, characterized in that, At the start of compensation, the amplitude of the motor compensation torque is at a preset gradient Mot. gradient Increment to target amplitude Mot Amp .

4. The EPS sliding compensation control system according to claim 2, characterized in that, The amplitude is 1 Nm.

5. The EPS sliding compensation control system according to claim 2, characterized in that, The frequency is 20Hz.

6. The EPS sliding compensation control system according to claim 3, characterized in that, The preset gradient Mot gradient It is 1 Nm / s.

7. The EPS sliding compensation control system according to claim 1, characterized in that, The method for determining whether the transmission belt is currently in a slipping state is as follows: Step 1, calculate the effective motor torque Mot eff ; Step 2, determine the vehicle speed v veh Is it greater than the vehicle speed threshold v? lim ; Step 3, determine the motor RPS speed v rps Less than the limit v rpslow If the effective motor torque is less than the limit value Mot for a period of time t1, the condition continues for more than t1. mineff ; Step 4, when the motor RPS speed v rps Greater than the limit v rpslow At that time, determine whether the effective motor torque is greater than Mot. maxeff ; Step 5, when the motor RPS speed v rps Greater than the limit v rpslow At that time, determine the motor RPS speed v rps Does it exceed the limit value v within time t2? rpsup ; Step 6, when the motor RPS speed v rps Greater than the limit v rpsup At that time, determine the effective motor torque Mot within time t3. eff Is the change less than Mot? gradient Determine the motor RPS speed v within time t4. rps Is it less than the limit value v? rpslow ; Step 7, determine the motor RPS speed v rps Less than the limit v rpslow Does the time last for t5, during which the effective motor torque Mot eff Is it smaller than Mot? mineff ; Step 8: All the above judgment conditions are met, and the motor RPS speed v rps and effective motor torque Mot eff If the directions are consistent and there is no reversal, it is determined that the current transmission belt is in a slipping state.

8. The EPS sliding compensation control system according to claim 7, characterized in that, In step 1, the effective motor torque Mot eff The calculation method is as follows: Mot eff =m tbt *R tbt2mot *E tbt2mot +m mot Among them, R tbt2mot E represents the gear ratio from the steering wheel to the motor. tbt2mot This refers to the transmission efficiency from the steering wheel to the motor output shaft.

Images