New energy vehicle differential anti-impact control method

Abstract

This invention discloses an anti-shock control method for differentials in new energy vehicles, belonging to the field of differential control technology. The invention first calculates the speed difference, the rate of change of the speed difference, and the impact rate; then, it sequentially solves for the instantaneous impact intensity, first-order and second-order impact energy, and generates an impact trend factor; next, it enhances the impact rate by increasing the impact rate of change, and calculates the torque correction coefficient by combining the impact enhancement influence factor and the torque influence factor, performing an initial correction on the target torque; then, it uses the impact trend factor and the first-order impact energy to obtain a feedforward correction coefficient, completing a second correction of the target torque; finally, it calculates an anti-saturation compensation coefficient to compensate the integral term of the PI control model constructed based on the second-corrected target torque, forming an adaptive anti-saturation PI control model and outputting the final requested torque to the motor controller. This invention improves the control response speed through impact trend prediction and optimizes PI control by combining the half-shaft torsional energy storage state, effectively suppressing secondary impacts.

Description

Technical Field

[0001] This invention relates to the field of differential control technology, and specifically to a shock-resistant control method for differentials in new energy vehicles. Background Technology

[0002] New energy vehicles, especially electric vehicles using distributed drive or wheel-side motor drive, have powertrain structures that differ significantly from traditional internal combustion engine vehicles. In these vehicles, the differential, as a key transmission component connecting the left and right drive wheels, plays a crucial role in adjusting the speed difference between the two wheels when the vehicle is turning or driving on uneven surfaces. However, due to the fast response speed and strong instantaneous torque output capability of electric motors, under conditions such as rapid acceleration, rapid deceleration, sudden changes in road surface adhesion coefficient (such as on icy or bumpy roads), or rapid torque switching, severe dynamic torque fluctuations and sudden changes in speed difference can easily occur between the left and right half-shafts of the differential.

[0003] These drastic dynamic changes translate into mechanical impact loads, directly affecting the differential's gear pairs, housing, and half-shafts. Prolonged or high-intensity impacts not only exacerbate wear and pitting on gear teeth but can also lead to tooth breakage or half-shaft torsion, severely impacting the reliability and lifespan of the transmission system. Furthermore, the impact loads are transmitted to the vehicle body via the drivetrain, causing noticeable longitudinal impacts or jerks, reducing driving smoothness and ride comfort.

[0004] Existing control strategies for differentials mostly focus on torque distribution or limited-slip functions, such as PID control based on speed difference thresholds or simple slope limiting. When faced with transient and nonlinear shock conditions, these methods lack the ability to predict the shock trend and can only respond passively after the shock occurs. Furthermore, the PI control process does not consider the torsional energy storage state of the half-shaft, and the integral term is prone to causing torque overshoot during torsional rebound, leading to secondary shocks to the differential. Summary of the Invention

[0005] To address the aforementioned shortcomings in the existing technology, the present invention provides a shock-resistant control method for differentials in new energy vehicles, which solves the problems of insufficient shock trend prediction capability leading to response lag and failure to consider the torsional energy storage state of the half-shaft, resulting in easy generation of secondary shocks during PI control.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by this invention is: a shock resistance control method for a differential in a new energy vehicle, comprising the following steps: S1. Collect the speed of the left and right half-shafts of the differential, obtain the speed difference and the rate of change of speed difference, and calculate the impact rate; S2. Based on the speed difference and the rate of change of speed difference, calculate the instantaneous impact intensity, first-order impact energy, and second-order impact energy in sequence, and generate the impact trend factor. S3. Enhance the impact rate based on the impact change rate, and calculate the torque correction coefficient by combining the impact enhancement influence factor and the torque influence factor to correct the target torque and obtain the corrected target torque. S4. Based on the impact trend factor and the first-order impact energy, obtain the feedforward correction coefficient, and perform a second correction on the target torque to obtain the second-corrected target torque. S5. Calculate the anti-saturation compensation coefficient based on the half-shaft torsion angle, compensate the integral term of the PI control model constructed based on the secondary correction target torque, form an adaptive anti-saturation PI control model, and output the final requested torque at the next moment to the motor controller.

[0007] Furthermore, the formula for calculating the impact rate in S13 is: , in, For the first Impact rate at any moment For the first The rate of change of the speed difference at time t, For the first The difference in rotational speed at any given moment For the first The target torque at any given time, This is a sign function; a positive value inside the parentheses represents 1, a negative value represents -1, and a value of 0 represents 0. Used to assign time numbers, and || for absolute value operations.

[0008] Furthermore, S2 includes the following sub-steps: S21. Calculate the instantaneous impact strength based on the speed difference and the rate of change of the speed difference; S22. Based on the instantaneous impact intensity, the current first-order impact energy is obtained through first-order recursion; S23. Perform a second-order recursion on the first-order impact energy to obtain the current second-order impact energy; S24. Subtract the current first-order impact energy from the current second-order impact energy, and divide by the current second-order impact energy to obtain the impact trend factor.

[0009] Furthermore, the formula for calculating the instantaneous impact strength in S21 is: , in, For the first The instantaneous impact intensity at a given moment For the first The rate of change of the speed difference at time t, For the first The difference in rotational speed at any given moment The minimum rotational speed is represented by ||, and the absolute value is used for calculation. The formula for calculating the first-order impact energy in S22 is: , in, For the first The first-order impact energy at any given moment. For the first The first-order impact energy at any given moment. The sampling period is It is a first-order forgetting factor; The formula for calculating the second-order impact energy in S23 is: , in, For the first The second-order impact energy at that moment, For the first The second-order impact energy at that moment, It is a second-order forgetting factor. .

[0010] Furthermore, S3 includes the following sub-steps: S31. Determine whether the impact rate is less than or equal to the impact rate threshold. If yes, assign the torque correction coefficient to 1. If no, determine whether the target torque is less than or equal to the target torque threshold. If yes, assign the torque correction coefficient to 1. If no, obtain the impact change rate of the impact rate. S32. Based on the impact change rate, obtain the enhancement coefficient, enhance the impact rate, and map it as an impact enhancement influence factor; S33. Obtain the torque influence factor based on the target torque; S34. Weight the torque influence factor and the impact enhancement influence factor to obtain the comprehensive influence factor. Subtract the comprehensive influence factor from 1 to obtain the torque correction coefficient. S35. Multiply the torque correction factor by the target torque to obtain the corrected target torque.

[0011] Furthermore, the formula for calculating the enhancement factor in S32 is as follows: , in, For the first The enhancement coefficient at time step 1, where max is the maximum of the two values. For the first The rate of change of the impact at time t, Here, | represents the time number, and | is the absolute value operator. For impact adjustable proportional coefficient; The formula for calculating the impact enhancement effect factor in S32 is as follows: , in, For the first The impact of time enhances the influencing factor. For the first Impact rate at any given moment; The formula for calculating the torque influence factor in S33 is as follows: , in, For the first Torque influence factor at time, For the first The target torque at any given time.

[0012] Furthermore, S4 includes the following sub-steps: S41. Determine whether the target torque is less than or equal to the target torque threshold. If yes, assign the value of the feedforward correction coefficient to 1. If no, proceed to step S42. S42. The first-order impact energy is enhanced by using an impact trend factor to obtain the energy trend term; S43. Use an exponential function to convert the energy trend term into a feedforward correction coefficient; S44. Multiply the feedforward correction coefficient by the correction target torque to obtain the secondary correction target torque.

[0013] Furthermore, the expression for the energy trend term in S42 is: , in, For the first The energy trend term at any given moment. For the first The first-order impact energy at any given moment. To obtain the maximum of the two, For the first The impact trend factor at any moment, The time number; The formula for calculating the feedforward correction coefficient in S43 is as follows: , in, For the first Feedforward correction coefficient at time step It is a natural constant. This is the adjustable scaling factor for the energy trend term.

[0014] Furthermore, S5 includes the following sub-steps: S51. Based on the speed difference and the actual output torque of the motor, obtain the half-shaft torsion angle; S52. Calculate the anti-saturation compensation coefficient based on the half-shaft torsion angle and the preset maximum torsion angle threshold. S53. Subtract the secondary correction target torque from the actual output torque of the motor to obtain the torque error; S54. Based on the torque error, establish a PI control model; S55. The integral term in the PI control model is compensated by the anti-saturation compensation coefficient to obtain the adaptive anti-saturation PI control model. S56. The torque increment output by the adaptive anti-saturation PI control model is superimposed with the actual output torque of the motor to obtain the final requested torque at the next moment, and then output to the motor controller.

[0015] Furthermore, the formula for calculating the anti-saturation compensation coefficient in S52 is as follows: , in, For the first Constant anti-saturation compensation coefficient, For the first Half-shaft torsion angle at any moment The preset maximum torsion angle threshold, The time number; The expression for the adaptive anti-saturation PI control model in S55 is: , in, The first output of the adaptive anti-saturation PI control model Torque increment at any moment For the first Torque error at any moment This refers to the torque error in the integral term. For integration variables, This is the proportionality coefficient. is the integral coefficient.

[0016] The beneficial effects of this invention are as follows: 1. This invention constructs multi-dimensional impact characteristic quantities such as impact rate, instantaneous impact intensity, first-order impact energy, and second-order impact energy by calculating the speed difference and the rate of change of speed difference, and generates an impact trend factor. It can detect the impact development trend in advance before the impact has fully developed, which solves the problem that existing methods can only respond passively after the impact occurs, and significantly improves the impact resistance response speed of the differential.

[0017] 2. This invention enhances the first-order impact energy by using an impact trend factor, generates a feedforward correction coefficient, and performs a secondary correction on the target torque, thereby realizing active feedforward intervention based on the impact energy accumulation trend and effectively suppressing torque mutations under impact conditions.

[0018] 3. This invention uses the left half-shaft speed, right half-shaft speed and actual motor output torque to estimate the current torsion angle of the half-shaft in real time, and for the first time introduces the torsional energy storage state of the half-shaft into the differential PI control process; by calculating the anti-saturation compensation coefficient through the half-shaft torsion angle, the incremental integral term of the PI controller is dynamically attenuated. When the half-shaft torsion angle increases, the integral action is automatically weakened to prevent torque overshoot and secondary impact caused by integral saturation during torsional rebound, thereby improving the control smoothness and safety of the differential under transient impact conditions. Attached Figure Description

[0019] Figure 1 This is a flowchart of a shock resistance control method for a differential in a new energy vehicle. Detailed Implementation

[0020] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0021] like Figure 1 As shown, a shock resistance control method for a differential in a new energy vehicle includes the following steps: S1. Collect the speed of the left and right half-shafts of the differential, obtain the speed difference and the rate of change of speed difference, and calculate the impact rate; S2. Based on the speed difference and the rate of change of speed difference, calculate the instantaneous impact intensity, first-order impact energy, and second-order impact energy in sequence, and generate the impact trend factor. S3. Enhance the impact rate based on the impact change rate, and calculate the torque correction coefficient by combining the impact enhancement influence factor and the torque influence factor to correct the target torque and obtain the corrected target torque. S4. Based on the impact trend factor and the first-order impact energy, obtain the feedforward correction coefficient, and perform a second correction on the target torque to obtain the second-corrected target torque. S5. Calculate the anti-saturation compensation coefficient based on the half-shaft torsion angle, compensate the integral term of the PI control model constructed based on the secondary correction target torque, form an adaptive anti-saturation PI control model, and output the final requested torque at the next moment to the motor controller.

[0022] In this embodiment, S1 includes the following sub-steps: S11. Subtract the speed of the left half-shaft from the speed of the right half-shaft of the differential to obtain the speed difference: ,in, For the first The difference in rotational speed at any given moment For the first The rotational speed of the left half-shaft at that moment. For the first The rotational speed of the right half-shaft at any given moment; S12. Using the current speed difference, subtract the speed difference from the previous speed difference, and then divide by the sampling period to obtain the speed difference change rate: ,in, For the first The rate of change of the speed difference at time t, For the first The difference in rotational speed at any given moment For the first The difference in rotational speed at any given moment The sampling period; S13. Take the absolute value of the rate of change of speed difference, and calculate the impact rate by combining the positive and negative signs of the speed difference and the target torque: ,in, For the first Impact rate at any moment For the first The rate of change of the speed difference at time t, For the first The difference in rotational speed at any given moment For the first The target torque at any given time, This is a sign function; a positive value inside the parentheses represents 1, a negative value represents -1, and a value of 0 represents 0. Used to assign time numbers, and || for absolute value operations.

[0023] This invention obtains the speed difference by subtracting the speed of the left half-shaft from the speed of the right half-shaft, reflecting the degree of motion difference between the output shafts at both ends of the differential. By calculating the rate of change of the speed difference, this invention captures the speed change rate of the speed difference per unit time, effectively distinguishing between steady-state steering conditions and transient impact conditions—the speed difference changes gradually during steady-state steering, while the rate of change of the speed difference increases significantly during impacts, thus enabling rapid detection of impact events. This invention constructs an impact rate index, fusing the amplitude of the rate of change of the speed difference with the direction information of the speed difference and the target torque: the absolute value of the rate of change of the speed difference characterizes the severity of the impact, while the sign function reflects the coupling direction between the impact and the driving intention—when the direction of the speed difference is consistent with the direction of the requested torque, the impact rate is positive, indicating that the drive exacerbates the expansion of the speed difference; when the two directions are opposite, the impact rate is negative, indicating that the drive is suppressing the speed difference.

[0024] The target torque is the torque applied by the driver or the upper-level controller.

[0025] In this embodiment, S2 includes the following sub-steps: S21. Calculate the instantaneous impact strength based on the speed difference and the rate of change of the speed difference; S22. Based on the instantaneous impact intensity, the current first-order impact energy is obtained through first-order recursion; S23. Perform a second-order recursion on the first-order impact energy to obtain the current second-order impact energy; S24. Subtract the current first-order impact energy from the current second-order impact energy, and divide by the current second-order impact energy to obtain the impact trend factor.

[0026] The formula for calculating instantaneous impact strength in S21 is: , in, For the first The instantaneous impact intensity at a given moment For the first The rate of change of the speed difference at time t, For the first The difference in rotational speed at any given moment Minimum speed (minimum speed is used to avoid...) =0, for (Unable to respond), | | is the absolute value operation.

[0027] This invention It reflects the instantaneous impact acceleration between the meshing surfaces of the differential gears and is the source of the impact force; The relative friction velocity at the time of impact is the source of the impact velocity, and the product of the two quantifies the severity of the impact.

[0028] The formula for calculating the first-order impact energy in S22 is: , in, For the first The first-order impact energy at any given moment. For the first The first-order impact energy at any given moment. The sampling period is It is a first-order forgetting factor.

[0029] The formula for calculating the second-order impact energy in S23 is: , in, For the first The second-order impact energy at that moment, For the first The second-order impact energy at that moment, It is a second-order forgetting factor. .

[0030] This invention obtains the first-order impact energy by performing a first-order recursive filter on the instantaneous impact intensity, and utilizes a first-order forgetting factor. By exponentially smoothing the historical impact energy, the cumulative memory effect of the impact energy is preserved, enabling the control system to perceive the duration of the impact, while avoiding drastic fluctuations in indicators caused by instantaneous noise interference, thus achieving stable quantification of impact intensity. Based on this, a second-order impact energy is obtained by performing a second-order recursive filter on the first-order impact energy, and a setting is established. This gives the second-order filter a stronger smoothing hysteresis characteristic. Thus, the first-order impact energy reflects the immediate cumulative level of the impact, while the second-order impact energy reflects the long-term background level of the impact. The two form an impact characterization system with different time scales. When the impact suddenly intensifies, the first-order energy rises rapidly while the second-order energy rises slowly due to the hysteresis characteristic, and the difference between the two is naturally amplified.

[0031] The formula for calculating the impact trend factor in S24 is: , in, For the first The impact trend factor at any moment, For the first The first-order impact energy at any given moment. For the first The second-order impact energy at that moment, It is a very small constant.

[0032] First-order impact energy Second-order impact energy reflects the immediate cumulative level of the impact. Due to the use of a larger forgetting factor It exhibits stronger smoothing and hysteresis characteristics, reflecting the long-term background level of the shock; when the shock is in a steady state, and near, Approaching zero; when the shock suddenly intensifies, Rapidly climbing Because of the slow increase in lagging characteristics, the difference between the two widens rapidly. This significantly increases the likelihood of anticipating a worsening trend in the impact.

[0033] In this embodiment, the first-order forgetting factor Take 0.9, the second-order forgetting factor. By setting a constraint of 0.98, the first-order impact energy reflects the immediate cumulative level of the impact, while the second-order impact energy reflects the long-term background level of the impact, thus forming differentiated time response scales. and The values ​​can be adjusted according to specific circumstances and are not limited to the specific values ​​indicated in this embodiment.

[0034] In this embodiment, S3 includes the following sub-steps: S31. Determine whether the impact rate is less than or equal to the impact rate threshold. If yes, assign the torque correction coefficient to 1. If no, determine whether the target torque is less than or equal to the target torque threshold. If yes, assign the torque correction coefficient to 1. If no, obtain the impact change rate of the impact rate and execute S32~S34. S32. Based on the impact change rate, obtain the enhancement coefficient, enhance the impact rate, and map it as an impact enhancement influence factor; S33. Obtain the torque influence factor based on the target torque; S34. Weight the torque influence factor and the impact enhancement influence factor to obtain the comprehensive influence factor. Subtract the comprehensive influence factor from 1 to obtain the torque correction coefficient. S35. Multiply the torque correction factor by the target torque to obtain the corrected target torque.

[0035] In this embodiment, the formula for calculating the impact change rate in S31 is: , in, For the first The rate of change of the impact at time t, For the first Impact rate at any moment For the first Impact rate at any given moment.

[0036] The formula for calculating the enhancement factor in S32 is: ,in, For the first The enhancement coefficient at time step 1, where max is the maximum of the two values. For the first The rate of change of the impact at time t, Here, | represents the time number, and | is the absolute value operator. This is the adjustable proportionality coefficient for impact. The formula for calculating the impact enhancement influence factor in S32 is: ,in, For the first The impact of time enhances the influencing factor. For the first Impact rate at any given moment.

[0037] This invention calculates the impact change rate Capture the development trend of the impact and construct an enhancement coefficient. This enhancement factor only occurs when the impact intensifies. It is activated in time and automatically reset to zero during impact decay, realizing one-way targeted enhancement in the direction of impact deterioration; the enhanced impact rate is mapped to the impact enhancement influence factor, enabling the control system to amplify the impact risk weight and intervene in torque correction in the early stage of impact aggravation, and automatically withdraw from enhancement during the impact decay stage to restore normal response, realizing adaptive intervention throughout the entire impact process.

[0038] The formula for calculating the torque influence factor in S33 is as follows: , in, For the first Torque influence factor at time, For the first The target torque at any given time.

[0039] The formula for calculating the torque correction factor in S34 is: , , in, For the first Torque correction factor at time 10:00 For the first The comprehensive influencing factors of time, To increase the weight of impact factors, The weights of the torque influence factor, .

[0040] In this embodiment, Taking 0.7, the impact risk should dominate, and the torque influence factor... As an auxiliary correction, we take 0.3.

[0041] This invention achieves precise differentiation between stable and impact conditions through dual condition judgment of impact rate threshold and target torque threshold. Under slight impact or low torque conditions, the torque correction coefficient is directly maintained at 1 to ensure smooth power output and responsiveness; torque correction is only activated under combined high impact and high torque conditions to avoid unnecessary power limitation.

[0042] The impact rate threshold is set according to the vehicle ride comfort requirements, and the target torque threshold is set according to the transmission system's tolerance. Both the impact rate threshold and the target torque threshold are positive numbers.

[0043] In this embodiment, S4 includes the following sub-steps: S41. Determine whether the target torque is less than or equal to the target torque threshold. If yes, assign the value of the feedforward correction coefficient to 1. If no, proceed to step S42. S42. The first-order impact energy is enhanced by using an impact trend factor to obtain the energy trend term; S43. Use an exponential function to convert the energy trend term into a feedforward correction coefficient; S44. Multiply the feedforward correction coefficient by the correction target torque to obtain the secondary correction target torque.

[0044] The expression for the energy trend term in S42 is: , in, For the first The energy trend term at any given moment. For the first The first-order impact energy at any given moment. To obtain the maximum of the two, For the first The impact trend factor at any moment, The time number; The formula for calculating the feedforward correction coefficient in S43 is as follows: , in, For the first Feedforward correction coefficient at time step It is a natural constant. This is the adjustable scaling factor for the energy trend term.

[0045] In S44, the feedforward correction factor is multiplied by the target torque: ,in, For the first The target torque for secondary correction at time t, For the first Feedforward correction coefficient at time step For the first The target torque is corrected at any given time.

[0046] S41 determines the target torque threshold and maintains the feedforward correction coefficient at 1 under low torque conditions, avoiding excessive intervention in light load conditions and ensuring smooth power delivery during low-speed, low-torque driving. Secondly, S42 constructs an energy trend term: first-order impact energy. It reflects the cumulative intensity of the impact and serves as the basis for the energy trend term; The enhancement is activated only when the impact trend factor is positive (i.e., the impact is in the intensification stage), so that the energy trend term is amplified when the impact worsens and returns to the base value when the impact subsides. This achieves unidirectional enhancement in the direction of impact intensification and avoids over-correction during the natural attenuation process of the impact. S43 uses an exponential function to map the energy trend term to a feedforward correction coefficient. The exponential decay form makes the correction coefficient close to 1 (almost no correction) when the energy trend term is small, and decays rapidly when the energy trend term increases, exhibiting a nonlinear correction characteristic of "no intervention for small impacts and strong suppression for large impacts".

[0047] S3 is a first-level transient correction based on the impact rate. and its rate of change Calculate the torque correction factor It has a fast response speed and is used to quickly weaken the target torque and suppress the peak impact in the early stage of the impact; S4 correction is the second-level continuous correction, based on the first-order impact energy. and shock trend factors Calculate the feedforward correction coefficient The response is relatively delayed, but the correction strength increases exponentially with energy accumulation. It is used to deeply limit torque and prevent differential overload when the impact continues.

[0048] In this embodiment, S5 includes the following sub-steps: S51. Based on the speed difference and the actual output torque of the motor, obtain the half-shaft torsion angle; S52. Calculate the anti-saturation compensation coefficient based on the half-shaft torsion angle and the preset maximum torsion angle threshold. S53. Subtract the secondary correction target torque from the actual output torque of the motor to obtain the torque error; S54. Based on the torque error, establish a PI control model; S55. The integral term in the PI control model is compensated by the anti-saturation compensation coefficient to obtain the adaptive anti-saturation PI control model. S56. The torque increment output by the adaptive anti-saturation PI control model is superimposed with the actual output torque of the motor to obtain the final requested torque at the next moment, and then output to the motor controller.

[0049] The formula for obtaining the torsion angle of the half-shaft in S51 is: , in, For the first Half-shaft torsion angle at any moment For the first Half-shaft torsion angle at any moment The sampling period is For the first The difference in rotational speed at any given moment For the first The actual output torque of the motor at any given time. It is the equivalent torsional stiffness coefficient of the half-shaft.

[0050] The formula for calculating the anti-saturation compensation coefficient in S52 is as follows: , in, For the first Constant anti-saturation compensation coefficient, For the first Half-shaft torsion angle at any moment The preset maximum torsion angle threshold, The time number; The expression for the adaptive anti-saturation PI control model in S55 is: , in, The first output of the adaptive anti-saturation PI control model Torque increment at any moment For the first Torque error at any moment This refers to the torque error in the integral term. For integration variables, This is the proportionality coefficient. is the integral coefficient.

[0051] Limit the final requested torque. ,in, This is the minimum torque of the motor. This is the maximum torque of the motor. This is the final requested torque for the next moment.

[0052] This invention solves the torque overshoot and secondary impact problems caused by integral saturation in traditional PI control under differential shock conditions by constructing an adaptive anti-saturation PI control model based on the half-shaft torsion angle. By integrating the differential terms of the speed difference and the actual output torque of the motor to estimate the current torsion angle of the half-shaft, the torsion angle observation can dynamically reflect the influence of torque changes on the torsional deformation of the half-shaft; and an anti-saturation compensation coefficient is constructed. When the torsion angle is small, the compensation coefficient is close to 1, and the integral action accumulates normally to ensure control accuracy. When the torsion angle is close to... The compensation coefficient decays rapidly to 0, achieving stronger nonlinear protection with more severe torsion; by directly applying the compensation coefficient to the increment of the integral term, it represents pre-emptive attenuation rather than traditional post-emptive limiting, resulting in a smoother integral curve. When the impact causes increased torsion of the half-shaft... The automatic reduction slows down the integral accumulation rate, preventing excessive accumulation of the integral term during the torsional energy storage state of the half-shaft. This mechanism fundamentally avoids torque overshoot shock caused by integral saturation during half-shaft torsional rebound, achieving smooth control and differential hardware protection under shock conditions.

[0053] This invention constructs multi-dimensional impact characteristic quantities such as impact rate, instantaneous impact intensity, first-order impact energy, and second-order impact energy by calculating the speed difference and the rate of change of speed difference, and generates an impact trend factor. It can detect the impact development trend in advance before the impact is fully developed, which solves the problem that existing methods can only respond passively after the impact occurs, and significantly improves the impact resistance response speed of the differential.

[0054] This invention enhances the first-order impact energy by using an impact trend factor, generates a feedforward correction coefficient, and performs a secondary correction on the target torque, thereby realizing active feedforward intervention based on the cumulative trend of impact energy and effectively suppressing torque mutations under impact conditions.

[0055] This invention uses the left half-shaft speed, right half-shaft speed and actual motor output torque to estimate the current torsion angle of the half-shaft in real time, and for the first time introduces the torsional energy storage state of the half-shaft into the differential PI control process; by calculating the anti-saturation compensation coefficient through the half-shaft torsion angle, the incremental integral term of the PI controller is dynamically attenuated. When the half-shaft torsion angle increases, the integral action is automatically weakened to prevent torque overshoot and secondary impact caused by integral saturation during torsional rebound, thereby improving the control smoothness and safety of the differential under transient impact conditions.

[0056] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A shock resistance control method for a differential in a new energy vehicle, characterized in that, Includes the following steps: S1. Collect the speed of the left and right half-shafts of the differential, obtain the speed difference and the rate of change of speed difference, and calculate the impact rate; S2. Based on the speed difference and the rate of change of speed difference, calculate the instantaneous impact intensity, first-order impact energy, and second-order impact energy in sequence, and generate the impact trend factor. S3. Enhance the impact rate based on the impact change rate, and calculate the torque correction coefficient by combining the impact enhancement influence factor and the torque influence factor to correct the target torque and obtain the corrected target torque. S4. Based on the impact trend factor and the first-order impact energy, obtain the feedforward correction coefficient, and perform a second correction on the target torque to obtain the second-corrected target torque. S5. Calculate the anti-saturation compensation coefficient based on the half-shaft torsion angle, compensate the integral term of the PI control model constructed based on the secondary correction target torque, form an adaptive anti-saturation PI control model, and output the final requested torque at the next moment to the motor controller.

2. The shock resistance control method for differentials in new energy vehicles according to claim 1, characterized in that, The formula for calculating the impact rate in S13 is: ， in, For the first Impact rate at any moment For the first The rate of change of the speed difference at time t, For the first The difference in rotational speed at any given moment For the first The target torque at any given time, This is a sign function; a positive value inside the parentheses represents 1, a negative value represents -1, and a value of 0 represents 0. Used to assign time numbers, and || for absolute value operations.

3. The shock resistance control method for differentials in new energy vehicles according to claim 1, characterized in that, S2 includes the following steps: S21. Calculate the instantaneous impact strength based on the speed difference and the rate of change of the speed difference; S22. Based on the instantaneous impact intensity, the current first-order impact energy is obtained through first-order recursion; S23. Perform a second-order recursion on the first-order impact energy to obtain the current second-order impact energy; S24. Subtract the current first-order impact energy from the current second-order impact energy, and divide by the current second-order impact energy to obtain the impact trend factor.

4. The shock resistance control method for differentials in new energy vehicles according to claim 3, characterized in that, The formula for calculating instantaneous impact strength in S21 is: ， in, For the first The instantaneous impact intensity at a given moment For the first The rate of change of the speed difference at time t, For the first The difference in rotational speed at any given moment The minimum rotational speed is represented by ||, and the absolute value is used for calculation. The formula for calculating the first-order impact energy in S22 is: ， in, For the first The first-order impact energy at any given moment. For the first The first-order impact energy at any given moment. The sampling period is It is a first-order forgetting factor; The formula for calculating the second-order impact energy in S23 is: ， in, For the first The second-order impact energy at that moment, For the first The second-order impact energy at that moment, It is a second-order forgetting factor. .

5. The shock resistance control method for differentials in new energy vehicles according to claim 1, characterized in that, S3 includes the following steps: S31. Determine whether the impact rate is less than or equal to the impact rate threshold. If yes, assign the torque correction coefficient to 1. If no, determine whether the target torque is less than or equal to the target torque threshold. If yes, assign the torque correction coefficient to 1. If no, obtain the impact change rate of the impact rate. S32. Based on the impact change rate, obtain the enhancement coefficient, enhance the impact rate, and map it as an impact enhancement influence factor; S33. Obtain the torque influence factor based on the target torque; S34. Weight the torque influence factor and the impact enhancement influence factor to obtain the comprehensive influence factor. Subtract the comprehensive influence factor from 1 to obtain the torque correction coefficient. S35. Multiply the torque correction factor by the target torque to obtain the corrected target torque.

6. The shock resistance control method for differentials in new energy vehicles according to claim 5, characterized in that, The formula for calculating the enhancement factor in S32 is: ， in, For the first The enhancement coefficient at time step 1, where max is the maximum of the two values. For the first The rate of change of the impact at time t, Here, | represents the time number, and | is the absolute value operator. For impact adjustable proportional coefficient; The formula for calculating the impact enhancement effect factor in S32 is as follows: ， in, For the first The impact of time enhances the influencing factor. For the first Impact rate at any given moment; The formula for calculating the torque influence factor in S33 is as follows: ， in, For the first Torque influence factor at time, For the first The target torque at any given time.

7. The shock resistance control method for differentials in new energy vehicles according to claim 1, characterized in that, S4 includes the following steps: S41. Determine whether the target torque is less than or equal to the target torque threshold. If yes, assign the value of the feedforward correction coefficient to 1. If no, proceed to step S42. S42. The first-order impact energy is enhanced by using an impact trend factor to obtain the energy trend term; S43. Use an exponential function to convert the energy trend term into a feedforward correction coefficient; S44. Multiply the feedforward correction coefficient by the correction target torque to obtain the secondary correction target torque.

8. The shock resistance control method for differentials in new energy vehicles according to claim 7, characterized in that, The expression for the energy trend term in S42 is: ， in, For the first The energy trend term at any given moment. For the first The first-order impact energy at any given moment. To obtain the maximum of the two, For the first The impact trend factor at any moment, The time number; The formula for calculating the feedforward correction coefficient in S43 is as follows: ， in, For the first Feedforward correction coefficient at time step It is a natural constant. This is the adjustable scaling factor for the energy trend term.

9. The shock resistance control method for differentials in new energy vehicles according to claim 1, characterized in that, S5 includes the following steps: S51. Based on the speed difference and the actual output torque of the motor, obtain the half-shaft torsion angle; S52. Calculate the anti-saturation compensation coefficient based on the half-shaft torsion angle and the preset maximum torsion angle threshold. S53. Subtract the secondary correction target torque from the actual output torque of the motor to obtain the torque error; S54. Based on the torque error, establish a PI control model; S55. The integral term in the PI control model is compensated by the anti-saturation compensation coefficient to obtain the adaptive anti-saturation PI control model. S56. The torque increment output by the adaptive anti-saturation PI control model is superimposed with the actual output torque of the motor to obtain the final requested torque at the next moment, and then output to the motor controller.

10. The shock resistance control method for differentials in new energy vehicles according to claim 9, characterized in that, The formula for calculating the anti-saturation compensation coefficient in S52 is as follows: ， in, For the first Constant anti-saturation compensation coefficient, For the first Half-shaft torsion angle at any moment The preset maximum torsion angle threshold, The time number; The expression for the adaptive anti-saturation PI control model in S55 is: ， in, The first output of the adaptive anti-saturation PI control model Torque increment at any moment For the first Torque error at any moment This refers to the torque error in the integral term. For integration variables, This is the proportionality coefficient. is the integral coefficient.

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