Torque compensation control method based on accelerator pedal and automobile

Abstract

The invention discloses a torque compensation control method based on an accelerator pedal. The torque compensation control method comprises the steps that a torque query value Tmap is obtained by querying a torque Map table according to the vehicle speed and the opening degree of the accelerator pedal; according to the change rate of the detected accelerator pedal and the current vehicle speed, a torque compensation value Torcomplex is obtained through calculation; and controlling the output torque of the motor based on the sum of the torque query value Tmap and the torque compensation value Torcomplex. The method has the advantages that the change rate of the accelerator pedal and the current vehicle speed are detected, the output torque of the motor is compensated, the real intention of a driver is achieved, and the driving feeling of the driver is improved.

Description

Technical Field

[0001] The invention relates to the field of torque control of electric vehicles, and in particular to a torque compensation control method based on an accelerator pedal. Background Art

[0002] With the advancement of technological change, new energy vehicles have developed rapidly in recent years, and the market penetration rate of new energy vehicles has increased day by day. New energy vehicles have entered ordinary families. New energy vehicles mainly include pure electric vehicles, hybrid vehicles, hydrogen fuel vehicles, etc. The drive motor is the main torque output, and there is a proportional relationship between the output torque value and the accelerator pedal opening.

[0003] At present, the proportional relationship between the accelerator pedal opening and the output torque of the drive motor can be roughly divided into three types: soft, linear, and hard; different types give drivers different driving experiences, but these three types cannot meet the needs of everyone.

[0004] At present, the market mostly adopts linear proportional relationship. According to the external characteristic map of the drive motor, the corresponding torque map is formulated in combination with the accelerator pedal opening, and the vehicle speed-torque map is calibrated and optimized to achieve the expected effect. When the driver is driving, the vehicle controller VCU will look up the table according to the accelerator pedal opening and vehicle speed pressed by the driver, and obtain the corresponding torque to send to the actuator drive motor. When the driver presses the accelerator pedal rapidly, this torque calculation method cannot fully express the driver's intention, that is, the output torque cannot meet the driver's demand for rapid torque output, resulting in the torque output control of the electric vehicle unable to meet the actual needs of the driver. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a torque compensation control method based on an accelerator pedal, which compensates the output torque of the motor by detecting the rate of change of the accelerator pedal and the current vehicle speed, so as to achieve the driver's true intention and improve the driver's driving experience.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is: a torque compensation control method based on an accelerator pedal, comprising:

[0007] Query the torque map table according to the vehicle speed and the accelerator pedal opening to obtain the torque query value Tmap;

[0008] The torque compensation value Tor is calculated based on the change rate of the accelerator pedal and the current vehicle speed. comps ;

[0009] Based on the torque query value Tmap and the torque compensation value Tor comps The sum of the two controls the motor to output torque.

[0010] The torque map is a vehicle speed - pedal opening - torque comparison table Map set for the pre - calibration report.

[0011] The throttle change rate is the ratio of the difference between the throttle opening at the current moment and the throttle opening at the previous moment to the time Δt:

[0012] The calculation of the throttle pedal change rate is as follows:

[0013]

[0014] Where Acc(t) is the throttle pedal opening calculated at the current moment, Acc(t - 1) is the throttle pedal opening calculated at the previous moment, and Δt is the data acquisition period.

[0015] The obtained throttle change rate signal after acquisition and calculation is subjected to first - order low - pass filtering. A moderate filtering coefficient and multiple filtering methods are used to filter the throttle pedal change rate.

[0016] The driver's intention is judged according to the throttle pedal change rate and the current vehicle speed, and the torque compensation value is calculated according to the schematic diagram.

[0017] When the throttle pedal change rate d(Acc)>m, at this time the torque compensation value Tor comps is 0, and TMap is used to control the motor torque output; where m is pre - calibrated as the upper limit value of the throttle opening change rate when stepping on the pedal normally.

[0018] When the throttle pedal change rate d(Acc)>n and d(Acc)<m, the vehicle speed is judged:

[0019] When the vehicle speed is greater than the vehicle speed threshold V1, at this time the torque compensation value Tor comps is 0, and TMap is used to control the motor torque output;

[0020] When the vehicle speed V>vehicle speed threshold V2 and V<vehicle speed threshold V1, at this time the torque compensation value Tor comps =C factor1 *Tor current ;

[0021] When the vehicle speed V is less than the vehicle speed threshold V2, at this time the torque compensation value is Tor comps =C factor2 *Tor current ;

[0022] Where the vehicle speed thresholds V1 and V2 are pre - calibrated and set; Tor current is the current required torque; C factor1 、C factor2 are torque compensation coefficients.

[0023] When the change rate d(Acc) of the accelerator pedal is less than n, it is determined that the change rate of the accelerator pedal opening is small at this time, and the torque compensation value Tor comps is 0, and TMap is used to control the motor torque output;

[0024] An electric vehicle controls the output torque of the motor by using the torque compensation control method described above.

[0025] The advantages of the present invention are as follows: By detecting the change rate of the accelerator pedal and the current vehicle speed, the output torque of the motor is compensated to achieve the true intention of the driver and improve the driving experience of the driver. The present invention considers introducing the parameter of the change rate of the accelerator pedal. Through the change rate of the accelerator pedal, the eagerness of the driver to accelerate is judged, the driving intention of the driver can be accurately judged, the torque request can be quickly responded to, and the driving experience of the driver can be improved. Brief Description of the Drawings

[0026] The following briefly describes the content expressed in each drawing of the present invention specification and the marks in the drawings:

[0027] Figure 1 It is a flowchart of the compensation control method of the present invention. Detailed Embodiment

[0028] The following further details the specific embodiments of the present invention by describing the optimal embodiments with reference to the drawings.

[0029] The torque algorithm of ordinary vehicles looks up a table according to the vehicle speed and the accelerator pedal opening to calculate the required torque of the vehicle; the present invention considers introducing the parameter of the change rate of the accelerator pedal. Through the change rate of the accelerator pedal, the eagerness of the driver to accelerate is judged, the driving intention of the driver can be accurately judged, the torque request can be quickly responded to, and the driving experience of the driver can be improved. The scheme includes:

[0030] A torque compensation control method based on the accelerator pedal includes the following steps:

[0031] S1. Query the torque Map table according to the vehicle speed and the accelerator pedal opening to obtain the torque query value Tmap;

[0032] S2. Calculate the torque compensation value Tor according to the detected change rate of the accelerator pedal and the current vehicle speed comps ;

[0033] S3. Control the motor to output torque based on the sum of the torque query value Tmap and the torque compensation value Tor comps and.

[0034] Where the torque map is a vehicle speed - pedal opening - torque comparison table Map set by pre - calibration report.

[0035] The throttle change rate is the ratio of the difference between the throttle opening at the current moment and the throttle opening at the previous moment to the time Δt:

[0036] The calculation of the throttle pedal change rate is as follows:

[0037]

[0038] Where Acc(t) is the throttle pedal opening calculated at the current moment, Acc(t - 1) is the throttle pedal opening calculated at the previous moment, and Δt is the data acquisition period.

[0039] To reduce interference, the throttle change rate signal obtained by acquisition and calculation is subjected to first-order low-pass filtering, and a moderate filtering coefficient and multiple filtering methods are used for the throttle pedal change rate after filtering.

[0040] The driver's intention is judged according to the throttle pedal change rate and the current vehicle speed, and the torque compensation value is calculated according to the driving intention, so that the torque output can reflect the driver's intention as much as possible, where:

[0041] When the throttle pedal change rate d(Acc) > m, the torque compensation value Tor comps is 0, and TMap is used to control the motor torque output; where m is pre-calibrated as the upper limit value of the pedal opening change rate when stepping on the pedal normally.

[0042] When the throttle pedal change rate d(Acc) > n and d(Acc) < m, the vehicle speed is judged:

[0043] When the vehicle speed is greater than the vehicle speed threshold V1, the torque compensation value Tor comps is 0, and TMap is used to control the motor torque output;

[0044] When the vehicle speed V > the vehicle speed threshold V2 and V < the vehicle speed threshold V1, the torque compensation value Tor comps = C factor1 * Tor current ;

[0045] When the vehicle speed V is less than the vehicle speed threshold V2, the torque compensation value at this time is Tor comps = C factor2 * Tor current ;

[0046] Where the vehicle speed thresholds V1 and V2 are pre-calibrated and set; Tor current is the current required torque; C factor1 、C factor2is the torque compensation coefficient. m is the upper limit value. If it is greater than this value, it indicates that the change rate is in an abnormal state, and at this time, there is no need to increase the torque compensation value. V1 is a relatively large speed threshold. If the vehicle speed is greater than this value, it means that the vehicle speed is relatively high, and no compensation is performed for driving safety; at other vehicle speeds, compensation is performed according to requirements.

[0047] When the change rate of the accelerator pedal d(Acc) < n, it is determined that the change rate of the accelerator pedal opening is small at this time, and the torque compensation value Tor comps is 0, and TMap is used to control the motor torque output. n is the lower limit value of the change rate of the pedal opening under normal driving requirements. If it is lower than this value, it means that the change rate is not large, and at this time, there is no need to increase the torque compensation value.

[0048] In this embodiment, an electric vehicle is further provided. This electric vehicle uses the torque compensation control method in the above embodiment to control the output torque of the motor.

[0049] The present invention proposes a driving torque compensation method based on the accelerator pedal, which specifically includes the following steps:

[0050] 1. Calculation of the change rate of the accelerator pedal:

[0051] The accelerator change rate is the ratio of the difference between the accelerator opening at the current moment and the accelerator opening at the previous moment to Δt. The calculation of the accelerator pedal change rate is as follows:

[0052]

[0053] where Acc(t) is the accelerator pedal opening calculated at the current moment, Acc(t - 1) is the accelerator pedal opening calculated at the previous moment, and Δt is the data acquisition period.

[0054] 2. Smoothness of the change rate of the accelerator pedal

[0055] To obtain a smooth accelerator change rate curve, the initially calculated accelerator change rate signal is subjected to first-order low-pass filtering. The present invention uses a moderate filtering coefficient and multiple filtering methods for filtering to ensure that the curve is not distorted and is smooth.

[0056] Let

[0057] y(t) = ax(t) + (1 - a)y(t - 1)

[0058] The curve is subjected to three-time low-pass filtering to obtain:

[0059] y(t) = a 2 x(t) + 2a(1 - a)y(t - 1) + (1 - a) 2 y(t - 2)

[0060] Where: a is the filtering coefficient;

[0061] y(t) is the change rate of the accelerator pedal at the current moment;

[0062] y(t - 1) is the change rate of the accelerator pedal at the previous moment;

[0063] The change rate of the accelerator pedal after filtering is used for subsequent torque compensation calibration.

[0064] 3. Torque Compensation

[0065] Judge the driver's intention based on the change rate of the accelerator pedal and the current vehicle speed, and perform torque compensation. The specific steps are as follows:

[0066] (1) When the change rate of the accelerator pedal d(Acc) > m, since the value of m is too large and it is only possible to reach under stress conditions, no torque compensation is performed in this case, and Tor comps is 0.

[0067] (2) When the change rate of the accelerator pedal d(Acc) > n and d(Acc) < m, judge the vehicle speed:

[0068] When the vehicle speed is greater than the vehicle speed threshold V1, the torque compensation value Tor comps is 0, and TMap is used to control the motor torque output;

[0069] When the vehicle speed V > the vehicle speed threshold V2 and V < the vehicle speed threshold V1, the torque compensation value Tor comps = C factor1 * Tor current ;

[0070] When the vehicle speed V is less than the vehicle speed threshold V2, the torque compensation value at this time is Tor comps = C factor2 * Tor current ;

[0071] Different speed intervals adopt different torque compensation coefficients C factor1 、C factor2 .

[0072] (3) When the change rate of the accelerator pedal d(Acc) < n, since the change rate of the accelerator pedal is not large, it is determined that the driver's acceleration intention is not obvious, and no torque compensation is performed, and Tor comps is 0.

[0073] Where: C factor1 、C factor2 are torque compensation coefficients; V is the vehicle speed; V1, V2 are vehicle speed thresholds; Tor current is the current required torque; m, n are the change rates of the accelerator pedal.

[0074] The key concept of the present invention is to introduce the accelerator pedal opening rate to judge the driver's driving intention, and perform torque compensation on the basis of the original torque, thereby improving the driver's driving experience.

[0075] Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, they are all within the protection scope of the present invention.

Claims

1. A torque compensation control method based on an accelerator pedal, characterized in that: including Query the torque Map table according to the vehicle speed and throttle pedal opening to obtain the torque query value Tmap; The torque compensation value Tor is calculated based on the change rate of the accelerator pedal and the current vehicle speed. comps ; Based on the torque query value Tmap and the torque compensation value Tor comps The sum of the two controls the motor to output torque.

2. The torque compensation control method based on the accelerator pedal according to claim 1, characterized in that: The torque map is a vehicle speed - pedal opening - torque comparison table Map set for pre - calibration report.

3. The torque compensation control method based on the accelerator pedal according to claim 1, characterized in that: The throttle change rate is the ratio of the difference between the throttle opening at the current moment and the throttle opening at the previous moment to the time Δt: The calculation of the throttle pedal change rate is as follows: where Acc(t) is the throttle pedal opening calculated at the current moment, Acc(t - 1) is the throttle pedal opening calculated at the previous moment, and Δt is the data acquisition period.

4. A torque compensation control method based on an accelerator pedal as claimed in any one of claims 1 to 3, characterized in that: Perform first - order low - pass filtering on the collected and calculated throttle change rate signal, and use a moderate filtering coefficient and multiple filtering methods to filter the throttle pedal change rate.

5. A torque compensation control method based on an accelerator pedal as claimed in any one of claims 1 to 3, characterized in that: Judge the driver's intention according to the throttle pedal change rate and the current vehicle speed, and calculate the torque compensation value according to the home schematic diagram.

6. The torque compensation control method based on the accelerator pedal according to claim 5, characterized in that: When the accelerator pedal change rate d(Acc)>m, the torque compensation value Tor comps is 0, and TMap is used to control the motor torque output; where m is pre-calibrated to the upper limit of the pedal opening rate when the pedal is normally stepped on.

7. The torque compensation control method based on the accelerator pedal according to claim 6, characterized in that: When the throttle pedal change rate d(Acc)>n and d(Acc)<m, judge the vehicle speed: When the vehicle speed is greater than the vehicle speed threshold V1, the torque compensation value Tor comps When it is 0, TMap is used to control the motor torque output; When the vehicle speed V> the vehicle speed threshold V2 and V< the vehicle speed threshold V1, the torque compensation value Tor comps =C factor1 *Tor current ; When the vehicle speed V is less than the vehicle speed threshold V2, the torque compensation value is Tor comps =C factor2 *Tor current ; The speed thresholds V1 and V2 are pre-calibrated settings; Tor current is the current required torque; C factor1 , C factor2 is the torque compensation coefficient.

8. The torque compensation control method based on the accelerator pedal according to claim 6, characterized in that: When the change rate of the accelerator pedal d(Acc) < n, it is determined that the change rate of the accelerator pedal opening is small at this time, and the torque compensation value Tor comps is 0, and TMap is used to control the motor torque output.

9. An electric vehicle, characterized in that: The electric vehicle controls the output torque of the motor by using the torque compensation control method described in any one of claims 1 - 8.

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