Anti-slip and anti-hopping control method for electric vehicle and electronic device

Abstract

The application discloses a method for anti-slip and anti-hopping control of an electric vehicle, comprising the following steps: step one, a motor controller MCU acquires N speed differences of a current period and past N periods; step two, after the N speed differences are given weight values according to preset weights, abnormal data is removed; step three, a speed difference Spderr is recalculated according to the result of step two; step four, the motor controller MCU receives a torque T1 issued by a vehicle controller VCU; step five, after the speed difference Spderr is compared with a first preset speed threshold SPD1, and after the issued torque T1 is compared with a maximum motor torque Tmax according to a comparison result, an output motor torque instruction Tcmd is obtained, when wheels slip or hop, the method can effectively reduce the motor torque output, can effectively reduce the mutation of the slipping and hopping motor speed, and can avoid the motor controller phase current overcurrent fault caused by the motor speed mutation.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of new energy vehicles, in particular to a skid and lift-off prevention control method for an electric vehicle and an electronic device. BACKGROUND

[0002] Traditional vehicles usually use internal combustion engines as power, but internal combustion engines accelerate the consumption of limited human energy and also cause serious environmental problems. Therefore, new energy vehicles with zero emissions, low heat radiation, low noise and environmental optimization have been valued and welcomed by people. Traditional fuel vehicles have ESP modules to prevent wheel skidding or sharp changes, while electric vehicles usually do not have skid or lift-off prevention systems. When the electric vehicle accelerates over the deceleration belt, bumpy road or low adhesion road, the wheels may lift off or skid, causing the motor speed to change sharply and causing the motor controller phase current to overcurrent. Not only the driving safety cannot be guaranteed, but also the vehicle health is not good, so the problem needs to be solved. SUMMARY

[0003] The application provides a skid and lift-off prevention control method for an electric vehicle and an electronic device, which does not increase the cost of other hardware. When the wheels skid or lift off, the motor torque output can be effectively reduced, thereby effectively reducing the sudden change of the skid and lift-off motor speed, and avoiding the motor controller phase current overcurrent fault caused by the sudden change of the motor speed.

[0004] The technical solution adopted by the application to solve the technical problem is to provide a skid and lift-off prevention control method for an electric vehicle, comprising the following steps,

[0005] Step 1: The motor controller MCU obtains the N speed differences of the current period and the past N periods;

[0006] Step 2: After assigning weight values to the N speed differences according to the preset weights, the abnormal data is removed;

[0007] Step 3: The speed difference Spderr is recalculated according to the result of step 2;

[0008] Step 4: The motor controller MCU receives the torque T1 issued by the vehicle controller VCU;

[0009] Step 5: After comparing and judging the speed difference Spderr with the first preset speed threshold SPD1, the issued torque T1 is compared and judged with the maximum motor torque Tmax according to the comparison and judgment result, and the output motor torque instruction Tcmd is obtained.

[0010] As preferred, in step one, the motor controller MCU obtains N speed differences of the current period and the past N periods, including that the motor controller MCU obtains 6 speed differences S1, S2, S3, S4, S5 and S6 of the current period and the past 6 periods, extracts 6 groups of data for collation and analysis, and obtains the output motor torque command Tcmd as a reference more real and reasonable.

[0011] As preferred, in step two, the N speed differences are given weight values according to preset weights, and abnormal data is removed, including,

[0012] The 6 speed differences S1, S2, S3, S4, S5 and S6 are given weight values according to the length of time from the current period to obtain 6 weight speed differences.

[0013] The 6 weight speed differences are removed according to the length of time from the current period.

[0014] As preferred, the 6 weight speed differences are removed according to the length of time from the current period, including that the difference value of adjacent weight speed differences in the 6 weight speed differences is calculated, and the one far from the current period of the two speed differences corresponding to the largest difference value is removed.

[0015] As preferred, in step three, the speed difference Spderr is recalculated according to the result of step two, including that the remaining speed differences are given weights according to the result of step two to obtain the speed difference Spderr.

[0016] As preferred, in step five, after comparing and judging the speed difference Spderr with the first preset speed threshold SPD1, the torque T1 is compared and judged with the maximum motor torque Tmax according to the comparison and judgment result to obtain the output motor torque command Tcmd, including,

[0017] The motor controller MCU judges whether Spderr is greater than or equal to the first preset speed threshold SPD1, if yes, the maximum motor torque Tmax decreases according to the first preset slope K1, and then judges whether the maximum motor torque Tmax is less than the minimum limit torque Tmin.

[0018] If Spderr is less than the first preset speed threshold SPD1, it is judged whether Spderr is less than or equal to the second preset speed threshold SPD2; if yes, the maximum motor torque Tmax increases according to the second preset slope K2, and then it is judged whether Tmax is greater than or equal to the motor mechanical external characteristic.

[0019] If Spderr is greater than the second preset speed threshold SPD2, it is directly judged whether the maximum motor torque Tmax is less than the minimum limit torque Tmin.

[0020] If the Tmax is greater than or equal to the mechanical external characteristic of the motor, the Tmax is equal to the mechanical external characteristic of the motor, and then it is determined whether the maximum torque Tmax of the motor is less than the minimum limited torque Tmin; if not, it is directly determined whether the maximum torque Tmax of the motor is less than the minimum limited torque Tmin.

[0021] After the comparison and determination according to the comparison result, the output motor torque instruction Tcmd is obtained by comparing and determining the issued torque T1 and the maximum torque Tmax of the motor.

[0022] SPD1 is a first preset speed threshold value, used for determining whether to enable the method; SPD2 is a second preset speed threshold value, used for determining whether to exit the method; K1 is a first preset slope, used for the descending slope of the maximum torque Tmax of the motor; K2 is a second preset slope, used for the ascending slope of the maximum torque Tmax of the motor; Tmin is a minimum limited torque, used for the minimum torque limit value of the method.

[0023] As a preferred, it is determined whether the maximum torque Tmax of the motor is less than the minimum limited torque Tmin, including, it is determined whether Tmax is less than Tmin; if Tmax is less than Tmin, Tmax is equal to Tmin, and if not, it is continuously determined whether T1 is greater than Tmax.

[0024] As a preferred, it is continuously determined whether T1 is greater than Tmax, including, it is continuously determined whether T1 is greater than Tmax, if yes, the motor torque instruction Tcmd is equal to Tmax, and if not, Tcmd is equal to T1, and the output motor torque instruction Tcmd is obtained.

[0025] An electronic device includes a memory and a processor, the memory is used for storing one or more computer instructions, wherein the one or more computer instructions are executed by the processor to implement the anti-slip and anti-flying control method for an electric vehicle as described in any one of the above.

[0026] The substantial effect of the present application is:

[0027] (1) The anti-slip and anti-flying control method for an electric vehicle compares and determines the issued torque T1 and the maximum torque Tmax of the motor according to the comparison result after comparing and determining the speed difference Spderr and the first preset speed threshold value SPD1, and obtains the output motor torque instruction Tcmd, without increasing other hardware costs. When the wheels slip or fly, the motor torque output can be effectively reduced, so as to effectively reduce the sudden change of the slip and flying motor speed, and thus the motor controller phase current overcurrent fault caused by the sudden change of the motor speed can be avoided.

[0028] (2) The anti-slip and anti-hopping control method for electric vehicles of the present application obtains 6 weighted speed differences by assigning weight values to 6 speed differences S1, S2, S3, S4, S5 and S6 according to the length of time from the current period, calculates the difference value of adjacent weighted speed differences in the 6 weighted speed differences, and eliminates one of the two speed differences corresponding to the largest difference value that is far away from the current period, thereby reasonably eliminating suspicious data and achieving higher accuracy.

[0029] (3) The anti-slip and anti-hopping control method for electric vehicles of the present application reassigns weights to the remaining speed differences after eliminating suspicious data to obtain a speed difference Spderr, thereby achieving higher accuracy.

[0030] (4) The anti-slip and anti-hopping control method for electric vehicles of the present application combines real vehicle calibration to calculate the motor torque command Tcmd, thereby being more in line with reality and calculating data that is more applicable. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is the method step flow chart of Embodiment Two of the anti-slip and anti-hopping control method for electric vehicles and electronic equipment of the present application. DETAILED DESCRIPTION

[0032] The technical solutions of the present application will be further specifically described below through specific embodiments.

[0033] Embodiment One

[0034] One embodiment of the anti-slip and anti-hopping control method for electric vehicles of the present application includes the following steps in the present embodiment,

[0035] Step One: The motor controller MCU obtains 6 speed differences 5km / h, 6km / h, 8km / h, 12km / h, 9km / h and 13km / h of the current period and the past 6 periods;

[0036] Step two, 6 speed differences 5km / h, 6km / h, 8km / h, 12km / h, 9km / h and 13km / h are given weight values according to the time of distance from the current period, the weight value is the smallest, the weight value is the largest, 5km / h, 6km / h, 8km / h, 12km / h, 9km / h and 13km / h are given weight values of 0.4, 0.3, 0.1, 0.1, 0.05 and 0.05, and 6 weight speed differences are 2km / h, 1.8km / h, 0.8km / h, 1.2km / h, 0.45km / h and 0.65km / h; The difference between the adjacent weight speed difference in the six weight speed difference is calculated, and five difference values 0.2km / h, 1km / h, 0.4km / h, 0.75km / h and 0.2km / h are obtained, and the farthest one of the two speed differences corresponding to the largest difference value 1km / h is removed, that is, 8km / h corresponding to 0.8km / h in 1.8km / h and 0.8km / h is removed;

[0037] Step three, according to the result of step two, the speed difference Spderr is recalculated, including: the remaining speed difference 5km / h, 6km / h, 12km / h, 9km / h and 13km / h are given weight values to obtain the speed difference Spderr, the weight values are given again, the weight value is the smallest, the weight value is the largest, 5km / h, 6km / h, 12km / h, 9km / h and 13km / h are given weight values of 0.5, 0.2, 0.1, 0.1 and 0.1, and the speed difference Spderr is 7.1km / h;

[0038] Step four, the motor controller MCU receives the torque T1 issued by the vehicle controller VCU;

[0039] Step five, step five, after comparing and judging the speed difference Spderr with the first preset speed threshold SPD1, the issued torque T1 is compared and judged with the maximum motor torque Tmax according to the comparison and judgment result, and the output motor torque command Tcmd is obtained, including,

[0040] The motor controller MCU judges whether Spderr is greater than or equal to the first preset speed threshold SPD1, if yes, the maximum motor torque Tmax decreases according to the first preset slope K1, and then judges whether the maximum motor torque Tmax is less than the minimum limit torque Tmin;

[0041] If Spderr is less than the first preset speed threshold SPD1, then judge whether Spderr is less than or equal to the second preset speed threshold SPD2; if yes, the maximum motor torque Tmax rises according to the second preset slope K2, and then judges whether Tmax is greater than or equal to the motor mechanical external characteristic;

[0042] If Spderr is greater than the second preset speed threshold SPD2, directly determine whether the maximum torque Tmax of the motor is less than the minimum limit torque Tmin;

[0043] If Tmax is greater than or equal to the mechanical external characteristic of the motor, Tmax is equal to the mechanical external characteristic of the motor, and then determine whether the maximum torque Tmax of the motor is less than the minimum limit torque Tmin; if not, directly determine whether the maximum torque Tmax of the motor is less than the minimum limit torque Tmin;

[0044] Determine whether Tmax is less than Tmin; if Tmax is less than Tmin, Tmax is equal to Tmin, and if not, continue to determine whether T1 is greater than Tmax.

[0045] Continue to determine whether T1 is greater than Tmax; if yes, the motor torque command Tcmd is equal to Tmax, and if not, Tcmd is equal to T1, and the output motor torque command Tcmd is obtained.

[0046] Wherein, SPD1 is the first preset speed threshold, which needs to be calibrated by real vehicle, and is used to determine whether to enable the method; SPD2 is the second preset speed threshold, which needs to be calibrated by real vehicle, and is used to determine whether to exit the method; K1 is the first preset slope, which needs to be calibrated by real vehicle, and is used for the descending slope of the maximum torque Tmax of the motor; K2 is the second preset slope, which needs to be calibrated by real vehicle, and is used for the ascending slope of the maximum torque Tmax of the motor; Tmin is the minimum limit torque, which needs to be calibrated by real vehicle, and is used for the minimum torque limit value of the method.

[0047] Embodiment two

[0048] As shown in Figure 1 In this embodiment, the application is used for an embodiment of the anti-slip and anti-empty control method of the electric vehicle, and the speed difference Spderr is the speed difference of the current period and the last period. The specific calculation steps of the output motor torque command Tcmd are as follows:

[0049] Step S01: the motor controller MCU receives the torque T1 issued by the vehicle controller VCU;

[0050] Step S02: the motor controller MCU calculates the speed difference Spderr of the current period and the last period;

[0051] Step S03: determine whether Spderr is greater than the first preset speed threshold SPD1; if yes, execute S05 and then execute S09; if not, execute S04;

[0052] Step S04: Determine whether Spderr is less than or equal to the second preset speed threshold SPD2. If yes, execute S06 and then S07. If no, execute S09 directly.

[0053] Step S05: The maximum torque Tmax of the motor decreases according to the first preset slope K1;

[0054] Step S06: The maximum torque Tmax of the motor increases according to the second preset slope K2;

[0055] Step S07: Determine whether the maximum torque Tmax of the motor is greater than or equal to the mechanical external characteristic of the motor. If yes, execute S08 and then S09. If no, execute S09 directly.

[0056] Step S08: The maximum torque Tmax of the motor is equal to the mechanical external characteristic of the motor;

[0057] Step S09: Determine whether the maximum torque Tmax of the motor is less than the minimum limiting torque Tmin. If yes, proceed to S10; otherwise, proceed to S11.

[0058] Step S10: The maximum torque Tmax of the motor is equal to the minimum limiting torque Tmin;

[0059] Step S11: Determine whether the torque T1 sent by the VCU is greater than the maximum torque Tmax of the motor. If yes, proceed to S12; otherwise, proceed to S13.

[0060] Step S12: The motor torque command Tcmd is equal to the torque T1 issued by the VCU;

[0061] Step S13: The motor torque command Tcmd is equal to the motor maximum torque Tmax.

[0062] Among them, SPD1 is the first preset speed threshold, which needs to be calibrated on a real vehicle and is used to determine whether to enable this method; SPD2 is the second preset speed threshold, which needs to be calibrated on a real vehicle and is used to determine whether to exit this method; K1 is the first preset slope, which needs to be calibrated on a real vehicle and is used to determine the decreasing slope of the maximum motor torque Tmax; K2 is the second preset slope, which needs to be calibrated on a real vehicle and is used to determine the increasing slope of the maximum motor torque Tmax; Tmin is the minimum limit torque, which needs to be calibrated on a real vehicle and is used to determine the minimum torque limit value of this method.

[0063] Example 3

[0064] An electronic device includes a memory and a processor, the memory being used to store one or more computer instructions, wherein the one or more computer instructions are executed by the processor to implement the anti-skid and anti-aircraft control method for an electric vehicle as described in any one of the preceding descriptions.

[0065] The above-described embodiments are merely preferred ones of the present application, and are not intended to limit the present application in any form. Other variants and modifications can be made without departing from the technical solutions recited in the claims.

Claims

1. A method for preventing skidding and airborne movement in electric vehicles, characterized in that, Includes the following steps, Step 1: The motor controller MCU obtains the N speed differences between the current period and the previous N cycles; Step 2: Assign weight values ​​to the N speed differences according to preset weights and then remove abnormal data; Step 3: Recalculate the speed difference Spderr based on the results of Step 2, including: taking a weighted average of the speed differences obtained in Step 2 to recalculate the speed difference Spderr. Step 4: The motor controller MCU receives the torque T1 sent by the vehicle controller VCU; Step 5: After comparing the speed difference Spderr with the first preset speed threshold SPD1, and then comparing the issued torque T1 with the maximum motor torque Tmax based on the comparison result, the output motor torque command Tcmd is obtained, including: The motor controller MCU determines whether Spderr is greater than or equal to the first preset speed threshold SPD1. If so, the maximum motor torque Tmax decreases according to the first preset slope K1. Then, it determines whether the maximum motor torque Tmax is less than the minimum limit torque Tmin. If Spderr is less than the first preset speed threshold SPD1, then determine whether Spderr is less than or equal to the second preset speed threshold SPD2; if so, the maximum torque Tmax of the motor increases according to the second preset slope K2, and then determine whether Tmax is greater than or equal to the mechanical external characteristics of the motor. If Spderr is greater than the second preset speed threshold SPD2, directly determine whether the maximum motor torque Tmax is less than the minimum limit torque Tmin. If Tmax is greater than or equal to the motor's mechanical external characteristic, then Tmax is equal to the motor's mechanical external characteristic. Then, determine whether the motor's maximum torque Tmax is less than the minimum limiting torque Tmin. If not, directly determine whether the motor's maximum torque Tmax is less than the minimum limiting torque Tmin. Based on the comparison and judgment results, the issued torque T1 is compared and judged with the maximum torque Tmax of the motor to obtain the output motor torque command Tcmd; Wherein, SPD1 is the first preset speed threshold, used to determine whether to enable this method; SPD2 is the second preset speed threshold, used to determine whether to exit this method; K1 is the first preset slope, used to determine the downward slope of the maximum motor torque Tmax; K2 is the second preset slope, used to determine the upward slope of the maximum motor torque Tmax; Tmin is the minimum limit torque, used to determine the minimum torque limit value of this method. The process of determining whether the maximum torque Tmax of the motor is less than the minimum limiting torque Tmin includes: determining whether Tmax is less than Tmin; if Tmax is less than Tmin, then Tmax equals Tmin; if not, then continue to determine whether T1 is greater than Tmax. The next step is to determine whether T1 is greater than Tmax. If T1 is greater than Tmax, the motor torque command Tcmd is equal to Tmax. If T1 is not greater than Tmax, the motor torque command Tcmd is equal to Tmax. The output motor torque command Tcmd is then obtained.

2. The anti-skid and anti-levitation control method for electric vehicles according to claim 1, characterized in that, Step one: The motor controller MCU obtains N speed differences between the current period and the previous N cycles. This includes the motor controller MC acquiring six speed differences S1, S2, S3, S4, S5, and S6 between the current period and the previous six cycles.

3. The anti-skid and anti-levitation control method for electric vehicles according to claim 2, characterized in that, Step two: After assigning weight values ​​to the N speed differences according to preset weights, remove outlier data, including... The six speed differences S1, S2, S3, S4, S5 and S6 are assigned weights based on the time elapsed since the current cycle, resulting in six weighted speed differences. The six weighted speed differences are then used to remove outlier data based on the time elapsed since the current period.

4. The anti-skid and anti-levitation control method for electric vehicles according to claim 3, characterized in that, The six weighted velocity differences are then used to remove outlier data based on their time elapsed since the current period. This includes calculating the difference between adjacent weighted velocity differences among the six weighted velocity differences and removing the velocity difference that is further from the current period from the two velocity differences corresponding to the largest difference.

5. The anti-skid and anti-levitation control method for electric vehicles according to claim 4, characterized in that, Step 3: Recalculate the velocity difference Spderr based on the results of Step 2, including re-weighting the remaining velocity difference to obtain the velocity difference Spderr based on the results of Step 2.

6. An electronic device, characterized in that, The device includes a memory and a processor, wherein the memory is used to store one or more computer instructions, wherein the one or more computer instructions are executed by the processor to implement the anti-skid and anti-aircraft control method for electric vehicles as described in any one of claims 1 to 5.

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