Active control method, device, vehicle and storage medium of electric drive system

Abstract

The present invention provides an active control method, device, vehicle and storage medium for an electric drive system, and relates to the field of vehicle technology. The method includes: when the vehicle satisfies both active damping control conditions and active anti-skid control conditions, determining the oscillation speed and anti-skid target speed of the vehicle's electric drive system; determining the compensation torque for active damping control according to the oscillation speed; determining the intervention torque for active anti-skid control according to the actual speed, oscillation speed and anti-skid target speed of the motor of the electric drive system that have been acquired; determining the actual request torque for the motor to execute according to the acquired request torque, compensation torque and intervention torque of the motor. The present invention effectively combines active damping control and active anti-skid control to avoid the occurrence of conflicting control signals between the two active control strategies, and ensures that when active damping control and active anti-skid control are running at the same time, the two will not interfere with each other and can play their respective best effects.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to an active control method and device for an electric drive system, a vehicle and a storage medium. Background Art

[0002] For vehicles with electric drive systems, thanks to the active control strategy, accurate measurement of motor speed and acceleration as well as fast and accurate torque control are achieved, which facilitates better dynamic control of wheel and body motion, thereby improving vehicle stability, safety and driving experience. Among them, the active control strategy mainly includes active damping control and active anti-skid control. Active damping control is used to suppress the speed oscillation of the corresponding transmission system of the vehicle, and active anti-skid control is used to prevent the vehicle from skidding.

[0003] However, since both active damping control and active anti-skid control are achieved by actively adjusting the requested torque of the motor based on changes in motor speed, when active damping control and active anti-skid control are running at the same time, they are likely to interfere with each other and affect their normal operation, thereby affecting the speed oscillation suppression effect of active damping control and the effect of active anti-skid control in preventing the vehicle from skidding. Summary of the invention

[0004] The problem solved by the present invention is: how to avoid mutual interference between active damping control and active anti-skid control and give full play to their respective good effects when the two are running simultaneously.

[0005] In order to solve the above problems, the present invention provides an active control method of an electric drive system, comprising:

[0006] When the vehicle satisfies both the active damping control condition and the active anti-skid control condition, determining the oscillation speed and the anti-skid target speed of the electric drive system of the vehicle;

[0007] According to the oscillation speed, a compensation torque for active damping control is determined; according to the acquired actual speed of the motor of the electric drive system, the oscillation speed and the anti-skid target speed, a modified speed of the motor and a speed deviation between the modified speed and the anti-skid target speed are determined, and according to the speed deviation, an intervention torque for active anti-skid control is determined; wherein the modified speed is a difference between the actual speed and the oscillation speed, and the speed deviation is a difference between the modified speed and the anti-skid target speed;

[0008] An actual request torque for execution of the electric machine is determined according to the acquired request torque of the electric machine, the compensation torque, and the intervention torque.

[0009] Optionally, when the vehicle satisfies both the active damping control condition and the active anti-skid control condition, determining the oscillation speed and the anti-skid target speed of the electric drive system of the vehicle comprises:

[0010] When the actual speed satisfies the active damping control condition and the acquired actual slip rate of the vehicle satisfies the active anti-skid control condition, the oscillation speed is determined according to the actual speed, and the anti-skid target speed is determined, wherein the anti-skid target speed is the motor speed when the slip rate of the vehicle's wheels on the current road surface reaches the optimal slip rate.

[0011] Optionally, determining the oscillation speed according to the actual speed includes:

[0012] The oscillation speed is determined according to the actual speed or according to the actual speed and the acquired actual torque of the motor by using at least one of a frequency domain analysis method, a time domain analysis method and a model estimation method.

[0013] Optionally, determining the compensation torque for active damping control according to the oscillation speed includes:

[0014] The compensation torque for active damping control corresponding to the oscillation speed is determined according to the signal parameter of the oscillation speed.

[0015] Optionally, determining the anti-skid target speed includes:

[0016] Determining the optimal slip rate of the wheel on the current road surface according to the acquired adhesion coefficient of the wheel of the vehicle on the current road surface;

[0017] According to the optimal slip ratio and the acquired body speed of the vehicle, the motor speed when the slip ratio of the wheel on the current road surface reaches the optimal slip ratio is determined as the anti-skid target speed.

[0018] Optionally, determining the intervention torque for active anti-skid control according to the speed deviation comprises:

[0019] determining a rate of change of the velocity deviation;

[0020] The intervention torque is determined according to the speed deviation and a rate of change of the speed deviation.

[0021] Optionally, determining the actual requested torque for the motor to execute according to the acquired requested torque of the motor, the compensation torque and the intervention torque comprises:

[0022] The compensation torque and the intervention torque are added to the request torque to obtain the actual request torque.

[0023] In order to solve the above problems, the present invention further provides an active control device for an electric drive system, comprising:

[0024] A speed determination unit, for determining an oscillation speed and an anti-skid target speed of an electric drive system of the vehicle when the vehicle satisfies both an active damping control condition and an active anti-skid control condition;

[0025] an adjustment torque determination unit, configured to determine a compensation torque for active damping control according to the oscillation speed; and to determine a modified speed of the motor and a speed deviation between the modified speed and the anti-skid target speed according to the acquired actual speed of the motor of the electric drive system, the oscillation speed and the anti-skid target speed, and to determine an intervention torque for active anti-skid control according to the speed deviation; wherein the modified speed is a difference between the actual speed and the oscillation speed, and the speed deviation is a difference between the modified speed and the anti-skid target speed;

[0026] The actual request torque determination unit is configured to determine an actual request torque for execution of the motor according to the acquired request torque of the motor, the compensation torque and the intervention torque.

[0027] To solve the above problems, the present invention further provides a vehicle, including a memory and a processor;

[0028] The memory is used to store computer programs;

[0029] The processor is used to implement the above-mentioned active control method of the electric drive system when executing the computer program.

[0030] To solve the above problems, the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is read and executed by a processor, the above-mentioned active control method of the electric drive system is implemented.

[0031] Compared with the prior art, the present invention has the following beneficial effects: when the vehicle satisfies both the active damping control condition and the active anti-skid control condition, the present invention effectively combines the two control strategies of active damping control and active anti-skid control to ensure their respective good effects and avoid mutual interference. Specifically, when the vehicle satisfies both control conditions, the oscillation speed and the anti-skid target speed of the electric drive system are first determined; then, according to the oscillation speed and the anti-skid target speed, the compensation torque for active damping control and the intervention torque for active anti-skid control are respectively determined. In this process, the actual speed is subtracted from the oscillation speed to obtain the corrected speed, the corrected speed is subtracted from the anti-skid target speed to obtain the speed deviation, and the intervention torque is determined according to the speed deviation, which not only eliminates the influence of the oscillation speed on the determination of the intervention torque, but also eliminates the influence of the oscillation speed on the active anti-skid control, ensuring that the active anti-skid control can be carried out smoothly and effectively, but also avoids the situation where the high-frequency oscillation speed causes control lag and deteriorates the effect of the active anti-skid control. Finally, by using the compensation torque and intervention torque as the adjustment signal of the request torque, the request torque is adjusted to obtain the actual request torque actually used for the motor to execute. The motor controller of the electric drive system will control the motor according to the actual request torque to ensure that active damping control and active anti-skid control are achieved at the same time. In this way, the advantages of the two active control strategies are effectively combined to avoid the conflict of control signals between the two active control strategies, ensuring that when active damping control and active anti-skid control are running at the same time, the two will not interfere with each other and can play their best effects, thereby improving the stability, handling and safety of the vehicle and improving the overall driving experience of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of a flow chart of an active control method for an electric drive system in an embodiment of the present invention;

[0033] Figure 2 A schematic diagram of a flow chart of an active control method for an electric drive system in an embodiment of the present invention;

[0034] Figure 3 It is a structural block diagram of an active control device for an electric drive system in an embodiment of the present invention;

[0035] Figure 4 It is a schematic diagram of the structure of the communication connection between the memory and the processor of the vehicle in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0037] The active control method of the electric drive system is applied to vehicles using an electric drive system (i.e., vehicles driven by an electric drive system), such as electric vehicles, hybrid vehicles, etc. Specifically, the active control method of the electric drive system is used to avoid mutual interference between the active damping control and the active anti-skid control while realizing the active damping control and the active anti-skid control of the vehicle, and to make the active damping control and the active anti-skid control play their respective good effects. Among them, the electric drive system includes a motor controller, a motor (i.e., a drive motor), etc., and the motor drives the wheels through a corresponding transmission system.

[0038] Combination Figure 1 , Figure 2 As shown, an embodiment of the present invention provides an active control method for an electric drive system, comprising the following steps:

[0039] Step 100: When the vehicle satisfies both the active damping control condition and the active anti-skid control condition, determine the oscillation speed and the anti-skid target speed of the electric drive system of the vehicle.

[0040] Specifically, when the corresponding operating parameters of the vehicle simultaneously satisfy the active damping control conditions and the active anti-skid control conditions, that is, when it is determined based on the corresponding operating parameters of the vehicle that the vehicle currently has speed oscillation and slipping, it is determined that active damping control and active anti-skid control are required for the vehicle at the same time to suppress the continued oscillation of the speed and prevent the vehicle from continuing to slip. In this regard, through step 100, when the vehicle simultaneously satisfies the active damping control conditions and the active anti-skid control conditions, the oscillation speed and the anti-skid target speed of the electric drive system are first determined to lay the foundation for the execution of the subsequent steps of the method of this embodiment, that is, to facilitate the subsequent active damping control and active anti-skid control according to the oscillation speed and the anti-skid target speed.

[0041] Step 200, determining a compensation torque for active damping control according to the oscillation speed; determining a corrected speed of the motor and a speed deviation between the corrected speed and the anti-skid target speed according to the actual speed, oscillation speed and anti-skid target speed of the motor of the electric drive system that have been acquired, and determining an intervention torque for active anti-skid control according to the speed deviation; wherein the corrected speed is the difference between the actual speed and the oscillation speed, and the speed deviation is the difference between the corrected speed and the anti-skid target speed.

[0042] Specifically, the mechanical resonance caused by the transmission gear clearance, transmission shaft system and suspension stiffness damping characteristics of the transmission system of the vehicle's electric drive system will cause the speed oscillation of the transmission system. If no corresponding measures are taken to suppress the speed oscillation, vibrations that can be felt by the driver will be generated, affecting the driving experience of the vehicle. Therefore, in step 200, according to the oscillation speed, the compensation torque for suppressing the oscillation in the active damping control is determined (or calculated) to offset the corresponding oscillation effect and maintain the stability of the motor speed and the stability of the vehicle operation.

[0043] Moreover, when the vehicle enters a low-adhesion road surface during driving, the wheels are prone to excessive slip or skidding, which will greatly affect the stability and safety of the vehicle, and also affect the acceleration performance and deceleration braking capability of the vehicle. Therefore, in step 200, according to the actual speed, oscillation speed and anti-skid target speed of the motor of the electric drive system of the vehicle that have been acquired, the intervention torque for active anti-skid control is determined, so as to adjust the motor speed by adjusting the motor output torque, so that the actual motor speed is close to the anti-skid target speed, thereby optimizing the slip rate of the wheel, preventing the vehicle from skidding, maintaining the traction and stability of the vehicle, and improving the dynamic performance and safety of the vehicle. Among them, compared with directly using the difference between the actual speed and the anti-skid target speed to determine the intervention torque of the active anti-skid control, in the method of this embodiment, the corrected speed is obtained by subtracting the actual speed from the oscillating speed (or, the oscillating speed is filtered out from the actual speed to obtain the corrected speed), and the corrected speed is subtracted from the anti-skid target speed to obtain the speed deviation for determining the intervention torque of the active anti-skid control (or, the anti-skid target speed is filtered out from the corrected speed to obtain the speed deviation). On the one hand, the influence of the oscillating speed on the determination of the intervention torque is eliminated, that is, the influence of the oscillating speed on the active anti-skid control is eliminated, thereby ensuring that the active anti-skid control can be carried out smoothly and effectively; on the other hand, the situation in which the control lag caused by the high-frequency oscillating speed in determining the intervention torque for the active anti-skid control is avoided, thereby deteriorating the active anti-skid control effect. Among them, high-frequency oscillating speed causes control lag. For example, when processing the speed signal during active anti-skid control, if the oscillating speed is not filtered out, the high-frequency oscillating speed signal will produce corresponding phase lag and time delay after corresponding filtering processing, thereby causing the obtained control signal to have phase lag and time delay; control lag deteriorates the active anti-skid control effect. For example, when control lag occurs, it will cause the control cycle to be too large, which may lead to a rapid increase in slip rate and a sharp decrease in friction (adhesion) between the wheel and the ground, which may cause the vehicle to skid, become unstable, etc., and seriously affect driving safety.

[0044] In this way, since the oscillation speed corresponds to a relatively high frequency, after filtering out the oscillation speed, the correction speed and speed deviation both correspond to lower frequencies. According to the oscillation speed of the higher frequency, the compensation torque adjustment frequency determined is also relatively high; according to the speed deviation of the lower frequency, the intervention torque adjustment frequency determined is also relatively low. In this way, the mutual influence between the active damping control and the active anti-skid control when they are running simultaneously is weakened or avoided. Exemplarily, the main goal of the active damping control is to suppress high-frequency oscillations in the system. For example, when the oscillation frequency is in the range of 5~15Hz, the compensation torque adjustment frequency determined according to the oscillation speed can also be set in the same range, corresponding to the oscillation frequency, so as to effectively suppress high-frequency oscillations; the main goal of the active anti-skid control is to control the slippage of the wheel. The intervention torque adjustment frequency determined according to the speed deviation of the lower frequency (such as the frequency range of 1~2Hz) can also be set in the same range, corresponding to the frequency corresponding to the speed deviation, so as to effectively control the slippage of the wheel. In some embodiments, for the compensation torque and the intervention torque, the adjustment period can be taken as the inverse of the adjustment frequency, such as for the intervention torque adjustment frequency in the frequency range of 1~2Hz, the intervention torque adjustment period is 0.5~1 second.

[0045] Step 300 : Determine the actual requested torque for the motor to be executed according to the acquired requested torque, compensation torque and intervention torque of the motor.

[0046] Specifically, the compensation torque and intervention torque obtained in step 200 are used as torque adjustment signals for adjusting the currently acquired request torque for the motor, and the request torque actually used for the motor to execute (recorded as the actual request torque) or the request instruction containing the actual request torque is obtained, and the motor controller of the electric drive system can be used to control the motor to execute the actual request torque or the request instruction, thereby realizing active damping control and active anti-skid control at the same time. Among them, the current request torque for the motor is the request torque given by the vehicle controller, such as the request torque determined by the vehicle controller according to the input of the driver in the form of controlling the accelerator pedal. When the vehicle does not execute active damping control and active anti-skid control, the electric drive system controls the motor according to the request torque given by the vehicle controller, and the motor passively executes the torque instruction from the vehicle controller to obtain the actual torque corresponding to the request torque; when the vehicle simultaneously executes active damping control and active anti-skid control, the request torque given by the vehicle controller is actively adjusted to obtain the actual request torque actually used for the motor to execute, as a new request torque, and is sent to the electric drive system through the vehicle controller for execution, so as to realize active damping control and active anti-skid control. Thus, compared with using the compensation torque and intervention torque obtained in step 200 as torque adjustment signals to adjust the current actual torque of the motor to obtain a new request torque for the motor, the method of this embodiment directly uses the compensation torque and intervention torque as the torque adjustment signal of the request torque of the motor. On the one hand, it can avoid delays, errors and instability in the actual torque measurement process, which helps to improve the response speed, accuracy and stability of the control; on the other hand, the request torque is used as the input of the motor, and the actual torque is the feedback of the motor output. Adjustment is made based on the request torque, which simplifies the control logic, does not require a complex feedback adjustment mechanism, and has the advantages of being more intuitive, easy to implement and debug. In this way, the method of this embodiment is efficient, stable, and concise, and the control effect is better guaranteed.

[0047] In this way, when the vehicle satisfies both the active damping control condition and the active anti-skid control condition, the method of this embodiment ensures the good effects of each of them and avoids mutual interference by effectively combining the two control strategies of active damping control and active anti-skid control. Specifically, when the vehicle satisfies both control conditions, the oscillation speed and the anti-skid target speed of the electric drive system are first determined; then, according to the oscillation speed and the anti-skid target speed, the compensation torque for active damping control and the intervention torque for active anti-skid control are determined respectively. In this process, the actual speed is subtracted from the oscillation speed to obtain the corrected speed, the corrected speed is subtracted from the anti-skid target speed to obtain the speed deviation, and the intervention torque is determined according to the speed deviation, which not only eliminates the influence of the oscillation speed on the determination of the intervention torque, but also eliminates the influence of the oscillation speed on the active anti-skid control, ensuring that the active anti-skid control can be carried out smoothly and effectively, but also avoids the situation where the high-frequency oscillation speed causes control lag and deteriorates the effect of the active anti-skid control. Finally, by using the compensation torque and intervention torque as the adjustment signal of the request torque, the request torque is adjusted to obtain the actual request torque actually used for the motor to execute. The motor controller of the electric drive system will control the motor according to the actual request torque to ensure that active damping control and active anti-skid control are achieved at the same time. In this way, the advantages of the two active control strategies are effectively combined to avoid the conflict of control signals between the two active control strategies, ensuring that when active damping control and active anti-skid control are running at the same time, the two will not interfere with each other and can play their best effects, thereby improving the stability, handling and safety of the vehicle and improving the overall driving experience of the vehicle.

[0048] Optionally, for electric vehicles driven only by electric drive systems, active control methods of electric drive systems may be used to avoid mutual interference between active damping control and active anti-skid control while realizing the simultaneous operation of active damping control and active anti-skid control of the vehicle, and to make active damping control and active anti-skid control play their respective good effects. For vehicles that use electric drive systems and other drive systems at the same time, when only the electric drive system is used to drive the vehicle, such as when a hybrid vehicle is operating in a pure electric mode, a series mode, an extended range mode, or other modes that only require the electric drive system to drive the vehicle, the vehicle may use active control methods of electric drive systems to avoid mutual interference between active damping control and active anti-skid control while realizing the simultaneous operation of active damping control and active anti-skid control of the vehicle, and to make active damping control and active anti-skid control play their respective good effects. For vehicles that use both electric drive systems and other drive systems, when the electric drive system and other drive systems drive the vehicle simultaneously, such as a hybrid vehicle operating in parallel mode, the vehicle is driven by both the motor and the engine. In this regard, if the engine and the motor drive different drive shafts respectively, the vehicle can use an active control method for the electric drive system to achieve active damping control and active anti-skid control of the electric drive system part, and can be combined with the corresponding damping control and anti-skid control for the engine part to achieve active damping control and active anti-skid control of the vehicle as a whole.

[0049] Optionally, step 100 includes:

[0050] When the actual speed meets the active damping control conditions and the actual slip rate of the vehicle that has been acquired meets the active anti-skid control conditions, the oscillation speed is determined according to the actual speed, and the anti-skid target speed is determined, wherein the anti-skid target speed is the motor speed when the slip rate of the vehicle's wheels on the current road surface reaches the optimal slip rate.

[0051] Exemplarily, when the vehicle has corresponding speed oscillation, the vehicle meets the active damping control condition. For example, the active damping control condition includes the existence of oscillating speed in the actual speed (that is, when the actual speed signal shows periodic fluctuations or oscillations). In this way, it can be judged whether the vehicle meets the active damping control condition based on the actual speed of the motor that has been acquired. When the vehicle has slippage and the slippage reaches a certain degree, the vehicle meets the active anti-skid control condition. For example, the active anti-skid control condition includes that the current slip rate of the vehicle (recorded as the actual slip rate) is greater than or equal to a preset threshold. In this way, it can be judged whether the vehicle meets the active anti-skid control condition based on the actual slip rate of the vehicle that has been acquired.

[0052] When the actual speed of the motor meets the active damping control conditions and the actual slip rate of the vehicle meets the active anti-skid control conditions, the oscillation speed is determined according to the actual speed, and the motor speed corresponding to the optimal slip rate of the vehicle's wheels on the current road surface is determined as the anti-skid target speed. In this way, active damping control and active anti-skid control can be performed according to the oscillation speed and the anti-skid target speed.

[0053] Optionally, the method further comprises:

[0054] The actual slip ratio of the vehicle is determined according to the actual rotation speed and the acquired vehicle body speed.

[0055] Specifically, the current slip rate of the vehicle (recorded as the actual slip rate) is determined based on the acquired actual rotation speed and the current vehicle body speed. The slip rate represents the wheel rotation speed (i.e., wheel linear speed). The vehicle speed (i.e. body speed) The difference between them is specifically expressed as: slip rate = ( - ) / . It can be obtained by multiplying the wheel angular velocity by the wheel radius; the wheel angular velocity can be obtained by a wheel speed sensor, or by multiplying the actual speed of the motor by the transmission ratio i of the transmission system connecting the motor output shaft and the wheel. It can be obtained by a positioning system (such as Beidou, GPS, etc.), or calculated based on the wheel speed, the acceleration of the vehicle body (which can be monitored by a monitoring mechanism such as an acceleration sensor), the steering wheel angle and the slope of the road surface where the wheel is currently located.

[0056] Optionally, determining the oscillation speed according to the actual speed includes:

[0057] The oscillation speed is determined according to the actual speed or according to the actual speed and the acquired actual torque of the motor by using at least one of a frequency domain analysis method, a time domain analysis method and a model estimation method.

[0058] In this embodiment, the oscillation speed of the electric drive system is determined based on the actual speed, and at least one of a frequency domain analysis method, a time domain analysis method and a model estimation method can be used.

[0059] Exemplarily, for the frequency domain analysis method, the actual speed signal can be converted from the time domain to the frequency domain through tools such as Fourier transform, and the high-frequency components can be identified therefrom, and these high-frequency components are the oscillating speed parts. Specifically, the actual speed signal is Fourier transformed to obtain a frequency domain signal; the spectrum of the frequency domain signal is analyzed to identify the frequency and amplitude corresponding to the high-frequency components; the identified high-frequency components are restored to the time domain to obtain the oscillating speed. Among them, power spectral density analysis can be used to calculate the power spectral density of the motor speed signal, and analyze whether there is a specific oscillation frequency in the spectrum to identify periodic or non-periodic oscillations.

[0060] For the time domain analysis method, the actual speed signal can be directly processed in the time domain through tools such as filters to remove low-frequency components and retain only the corresponding high-frequency components. Specifically, a suitable filter is selected; the actual speed signal is processed through the filter to remove low-frequency components, and the filtered signal is the oscillation speed. Among them, the filter can use a notch filter or a bandpass filter to extract signal components in a specific frequency range. Exemplarily, the input and output of the notch filter are expressed as follows:

[0061] ,

[0062] ,

[0063] in: x ( n ) represents the input value at the current sampling moment; x ( n -1) represents the input value at the last sampling moment; x ( n -2) represents the input value of the last two sampling moments; y ( n ) represents the output value at the current sampling moment; y ( n -1) indicates the output value at the last sampling moment; y ( n -2) represents the output value of the last two sampling moments; T Represents the calling cycle of the designed filter; T Indicates the period value corresponding to the center frequency of the signal to be filtered out by the notch filter; g Represents the gain coefficient, and its value determines the degree of attenuation of the filter on the signal to be filtered out.

[0064] For the model estimation method, a dynamic model between the actual speed and the actual torque is established, and the oscillation component is determined through model analysis. Specifically, a dynamic model of the motor is established, which includes the relationship between the speed and the torque; the actual speed and the actual torque are used as inputs, and the corresponding response (which includes the transient behavior of the motor, such as oscillation, stable state, transition process, etc.) is estimated through the model; the high-frequency oscillation component is extracted from the model output (i.e., the response) to obtain the oscillation speed. For example, a speed estimation model based on an algorithm such as Kalman filtering is used, and the actual speed and actual torque of the motor are used as inputs of the speed estimation model, and the model output obtains a smoothed reference speed; the actual speed is compared with the reference speed, and the deviation between the two is obtained as the oscillation speed, thereby effectively separating the high-frequency oscillation component in the actual speed of the motor. In some embodiments, the deviation between the actual speed and the reference speed needs to be filtered accordingly to obtain the oscillation speed.

[0065] In the method of this embodiment, in addition to using one of the frequency domain analysis method, the time domain analysis method and the model estimation method to determine the oscillation speed, multiple frequency domain analysis methods, time domain analysis methods and model estimation methods can also be used to analyze the actual speed signal from different angles, comprehensively judge the oscillation components, and verify each other, so as to improve the accuracy and reliability of oscillation speed identification and reduce the influence of errors and noise on the identification results. Among them, when the oscillation speed is determined based on the actual speed and the above method is used, the actual torque of the motor (which can be used to provide additional information about the motor's operating status and dynamic characteristics) can also be combined, and the relationship between the motor speed and torque can be comprehensively considered to analyze the dynamic behavior of the motor to further improve the estimation accuracy of the oscillation speed.

[0066] Optionally, determining the compensation torque for active damping control according to the oscillation speed includes:

[0067] According to the signal parameter of the oscillation speed, a compensation torque for active damping control corresponding to the oscillation speed is determined.

[0068] The oscillating speed is the oscillating component of the motor at a specific frequency, which is usually caused by the mechanical resonance or other dynamic effects of the electric drive system. Active damping control reduces or eliminates the oscillation phenomenon of the motor by identifying and compensating for these oscillating components; the calculation of the compensation torque is based on the amplitude and phase of the oscillating speed, ensuring that the phase of the compensation torque is opposite to the oscillation, thereby suppressing the oscillation. Exemplarily, the amplitude and phase of the oscillating speed are first determined, such as using a frequency domain analysis method (such as Fourier transform) or a time domain analysis method (such as time domain signal analysis) based on the actual speed signal to extract the amplitude and phase information of the oscillating speed; then, the damping torque (i.e., the compensation torque) is calculated, such as using a predetermined damping coefficient based on the amplitude, phase and frequency of the oscillating speed to calculate the corresponding compensation torque, which should be opposite to the phase of the oscillating speed to suppress the oscillation, and the frequency of the compensation torque should be the same as the frequency of the oscillating speed to ensure the accuracy and effectiveness of the compensation effect; finally, the obtained compensation torque is superimposed on the requested torque of the motor to adjust the output torque of the motor to achieve active damping control. Alternatively, the current operating condition of the vehicle is first obtained based on the current state data of the vehicle (including the actual speed of the motor, the actual torque of the motor, the gear position of the vehicle, the current vehicle speed, torque request information, etc.); then, the gain coefficient of the active damping control is determined based on the current operating condition of the vehicle; finally, the compensation torque is determined based on the gain coefficient and the oscillation speed, for example, the compensation torque is obtained by multiplying the speed fluctuation amount (i.e., the oscillation speed) by a coefficient, and the coefficient is the gain coefficient (for different working conditions, the selected gain coefficient is different, therefore, it is necessary to determine the corresponding gain coefficient according to the working condition; the gain coefficient obtained through the working condition can generally be calibrated according to the actual vehicle).

[0069] Optionally, determining the anti-skid target speed includes:

[0070] According to the obtained adhesion coefficient of the vehicle's wheels on the current road surface, the optimal slip rate of the wheels on the current road surface is determined.

[0071] Specifically, based on the acquired adhesion coefficient of the vehicle's wheels on the current road surface, the optimal slip rate of the wheels on the current road surface is first determined, and then the motor speed when the slip rate of the wheels on the current road surface reaches the optimal slip rate is determined as the anti-skid target speed, wherein the optimal slip rate refers to the slip rate when the vehicle can obtain the best braking performance or maximize the traction between the wheels and the road surface, and the optimal slip rate of the vehicle on different road surfaces is different.

[0072] The determination of the optimal slip rate of the wheel on the current road surface can be determined based on the obtained adhesion coefficient of the vehicle's wheel on the current road surface. For example, the adhesion coefficient of the wheel on the current road surface is first determined, which can be obtained by the ratio of the vehicle's current longitudinal driving force to the vertical load force, wherein the vehicle's current vertical load force refers to the vertical force acting on the vehicle's wheels, which can also be called wheel force, which is determined by the vehicle's own weight and other wheel parameters; the vehicle's current longitudinal driving force refers to the force acting in the longitudinal direction of the vehicle, used to push the vehicle forward or restrain the vehicle from retreating; the vehicle's current longitudinal driving force and vertical load force can be calculated based on the actual torque of the motor, the speed and acceleration of the motor or the vehicle body, the wheel speed, the wheel end braking torque, the slope of the road surface where the wheel is currently located, etc. Afterwards, the optimal slip rate of the wheel on the current road surface can be determined based on the adhesion coefficient of the wheel on the current road surface. For example, by conducting experiments on the optimal slip rate and adhesion coefficient of the vehicle under different road conditions, empirical data on road conditions, adhesion coefficient and actual optimal slip rate can be obtained for training the corresponding empirical model; the adhesion coefficient of the wheel on the current road surface is used as the input of the empirical model, and the corresponding optimal slip rate is output. In some embodiments, the optimal slip rate and adhesion coefficient are also related to the wheel and tire parameters. The wheel and tire parameters and the optimal slip rate and adhesion coefficient of the vehicle under different road conditions of the corresponding wheel and tire can be used as training data of the empirical model; after the trained empirical model is obtained, the wheel and tire parameters, road conditions and the adhesion coefficient of the wheel on the current road surface can be used as the input of the empirical model, and the corresponding optimal slip rate is output.

[0073] The optimal slip rate of the wheel on the current road surface can also be determined by pre-storing corresponding information including the optimal slip rate and adhesion coefficient of the corresponding wheel tire on a variety of standard road surfaces (such as dry asphalt road surfaces, wet asphalt road surfaces, etc.), obtaining the current road surface information, and comparing the obtained current road surface information with the pre-stored information to find a standard road surface that matches or is similar to the current road surface conditions, and obtaining the optimal slip rate and adhesion coefficient of the wheel on the standard road surface that is the same as or similar to the current road surface as the optimal slip rate and adhesion coefficient of the wheel on the current road surface. Alternatively, by comparing the obtained adhesion coefficient of the wheel on the current road surface with the adhesion coefficient in the pre-stored information, the similarity between each standard road surface and the current road surface is determined based on the adhesion coefficient, so as to find a standard road surface that matches or is similar to the current road surface conditions, and obtain the optimal slip rate of the wheel on the standard road surface that is the same as or similar to the current road surface.

[0074] According to the optimal slip ratio and the acquired vehicle body speed, the motor speed when the slip ratio of the wheel on the current road surface reaches the optimal slip ratio is determined as the anti-skid target speed.

[0075] Specifically, after obtaining the optimal slip rate of the wheel on the current road surface, the optimal slip rate λ and the vehicle body speed can be used to calculate the optimal slip rate of the wheel. Determine the target wheel speed corresponding to the anti-skid target speed , there exists λ=( - ) / , that is, the target wheel speed = / (1-λ), so the anti-skid target speed can be obtained according to the wheel radius and the transmission ratio of the transmission system between the wheel and the motor.

[0076] Optionally, determining the intervention torque for active anti-skid control according to the speed deviation comprises:

[0077] Determine the rate of change of the speed deviation.

[0078] Specifically, the rate of change of the speed deviation is the rate at which the speed deviation changes over time. By determining the rate of change of the vehicle's current speed deviation, that is, determining the ratio of the difference between the speed deviation at the current moment and the speed deviation at the previous moment to the time interval between the current moment and the previous moment (the appropriate time interval can be selected as required), the changing trend and rate of the speed deviation can be understood and used to determine the intervention torque.

[0079] The intervention torque is determined based on the speed deviation and the rate of change of the speed deviation.

[0080] For example, the intervention torque of the active anti-slip control is aimed at eliminating and controlling the correction speed. Target speed with anti-skid The difference e between them (i.e. speed deviation e= - ), so that the actual slip rate between the wheel tire and the current road surface is close to its optimal slip rate, so as to fully utilize the adhesion between the tire and the road surface, thereby ensuring the stability and safety of the vehicle while obtaining the vehicle's dynamic performance. Based on the speed deviation e and the rate of change of e, the torque amount (intervention torque) that needs to be adjusted is calculated, and a nonlinear PID control algorithm can be used, as shown in the following formula:

[0081] ,

[0082] in, represents the intervention torque at the Nth moment; represents the speed deviation at the Nth moment, represents the corrected speed at the Nth moment, represents the anti-skid target speed at the Nth moment, = - ; represents the corrected speed at the N-1th moment, represents the anti-skid target speed at the N-1th moment, - Indicates the speed deviation at the N-1th moment; , , Respectively represent the PID coefficients at the Nth moment; Represents unit time. In this way, by adopting a nonlinear PID control algorithm, its proportion P, integral I and differential coefficient D are all nonlinear functions of the error (i.e., speed deviation) e, that is, different e, take different PID coefficients, and by adjusting the change rate of the proportion, integral and differential coefficients, the calculated output of the intervention torque can be affected. When the error is large, a larger gain is used to speed up the adjustment speed; when the error is small, a smaller gain is used to avoid over-adjustment. Through these adjustments, the e transition process is regulated to achieve the purpose of adjusting the output intervention torque, and the intervention torque can adapt to the nonlinear characteristics and external interference of the electric drive system, and can eliminate the speed deviation relatively quickly.

[0083] Optionally, determining the actual requested torque for the motor to execute according to the acquired requested torque, compensation torque and intervention torque of the motor includes:

[0084] The compensation torque and the intervention torque are added to the request torque to obtain the actual request torque.

[0085] Specifically, the compensation torque and the intervention torque are superimposed on the request torque to adjust the request torque, thereby obtaining the actual request torque that is actually used for the motor to implement active damping control and active anti-skid. The motor controller of the electric drive system controls the motor to implement the actual request torque, thereby implementing active damping control and active anti-skid control at the same time.

[0086] Optionally, the compensation torque and the intervention torque are superimposed on the request torque to obtain the actual request torque, which includes:

[0087] When the compensation torque and the intervention torque are superimposed on the request torque, the superimposed torque is obtained;

[0088] When the superimposed torque is greater than or equal to the minimum limit torque of the motor and less than the maximum limit torque of the motor, the superimposed torque is used as the actual requested torque; when the superimposed torque is less than the minimum limit torque of the motor, the minimum limit torque is used as the actual requested torque; when the superimposed torque is greater than the maximum limit torque, the maximum limit torque is used as the actual requested torque.

[0089] Specifically, to ensure that the actual requested torque does not exceed the working range of the motor, after the compensation torque and the intervention torque are superimposed on the requested torque to obtain the superimposed torque, if the superimposed torque is greater than or equal to the minimum limiting torque of the motor (that is, the minimum torque value that the motor can generate. When the required torque is lower than this value, the motor cannot work effectively, which may cause performance degradation or failure), and is less than the maximum limiting torque of the motor (the maximum torque value that the motor can generate. When the required torque exceeds this value, the motor may be overloaded, causing overheating, mechanical damage or safety problems), the superimposed torque is used as the actual requested torque; if the superimposed torque is less than the minimum limiting torque of the motor, the minimum limiting torque is used as the actual requested torque; if the superimposed torque is greater than the maximum limiting torque, the maximum limiting torque is used as the actual requested torque.

[0090] Combination Figure 3 As shown, another embodiment of the present invention provides an active control device for an electric drive system, comprising:

[0091] A speed determination unit, for determining an oscillation speed and an anti-skid target speed of an electric drive system of the vehicle when the vehicle satisfies both an active damping control condition and an active anti-skid control condition;

[0092] a regulating torque determination unit, for determining a compensation torque for active damping control according to an oscillating speed; and for determining a corrected speed of the motor and a speed deviation between the corrected speed and the anti-skid target speed according to an actual speed, an oscillating speed and an anti-skid target speed of the motor of the electric drive system that have been acquired, and determining an intervention torque for active anti-skid control according to the speed deviation; wherein the corrected speed is a difference between the actual speed and the oscillating speed, and the speed deviation is a difference between the corrected speed and the anti-skid target speed;

[0093] The actual request torque determination unit is used to determine the actual request torque for the motor to execute according to the acquired request torque, compensation torque and intervention torque of the motor.

[0094] The electric drive system active control device of this embodiment is used to implement the above-mentioned electric drive system active control method. Its advantages over the prior art are the same as the advantages of the above-mentioned electric drive system active control method over the prior art, which will not be repeated here.

[0095] Combination Figure 4 As shown, another embodiment of the present invention provides a vehicle, including a memory 401 and a processor 402;

[0096] Memory 401, used for storing computer programs;

[0097] The processor 402 is used to implement the above-mentioned active control method of the electric drive system when executing the computer program.

[0098] In other words, a vehicle includes a memory 401 and a processor 402 coupled to the memory 401; the memory 401 is configured to store a computer program; and the processor 402 is configured to perform the following operations when executing the computer program:

[0099] When the vehicle satisfies both the active damping control condition and the active anti-skid control condition, determining the oscillation speed and the anti-skid target speed of the electric drive system of the vehicle;

[0100] According to the oscillation speed, a compensation torque for active damping control is determined; according to the actual speed, oscillation speed and anti-skid target speed of the motor of the electric drive system that have been obtained, a correction speed of the motor and a speed deviation between the correction speed and the anti-skid target speed are determined, and according to the speed deviation, an intervention torque for active anti-skid control is determined; wherein the correction speed is the difference between the actual speed and the oscillation speed, and the speed deviation is the difference between the correction speed and the anti-skid target speed;

[0101] According to the acquired request torque, compensation torque and intervention torque of the electric machine, an actual request torque for execution of the electric machine is determined.

[0102] The vehicle of this embodiment can be used to implement the above-mentioned active control method of the electric drive system. Its advantages over the prior art are the same as the advantages of the above-mentioned active control method of the electric drive system over the prior art, which will not be repeated here.

[0103] Another embodiment of the present invention provides a computer-readable storage medium, which stores a computer program. When the computer program is read and executed by a processor, the above-mentioned active control method of the electric drive system is implemented.

[0104] In other words, a non-volatile computer-readable storage medium stores a computer program, which, when executed by a processor, causes the processor to perform the following operations:

[0105] When the vehicle satisfies both the active damping control condition and the active anti-skid control condition, determining the oscillation speed and the anti-skid target speed of the electric drive system of the vehicle;

[0106] According to the oscillation speed, a compensation torque for active damping control is determined; according to the actual speed, oscillation speed and anti-skid target speed of the motor of the electric drive system that have been obtained, a correction speed of the motor and a speed deviation between the correction speed and the anti-skid target speed are determined, and according to the speed deviation, an intervention torque for active anti-skid control is determined; wherein the correction speed is the difference between the actual speed and the oscillation speed, and the speed deviation is the difference between the correction speed and the anti-skid target speed;

[0107] According to the acquired request torque, compensation torque and intervention torque of the electric machine, an actual request torque for execution of the electric machine is determined.

[0108] The technical solution of the embodiment of the present invention, in essence or in other words, the part that contributes to the prior art, or the whole or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) or a processor to execute all or part of the steps of the method of the embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

[0109] The computer-readable storage medium of this embodiment can be used to implement the above-mentioned active control method of the electric drive system. Its advantages over the prior art are the same as the advantages of the above-mentioned active control method of the electric drive system over the prior art, and will not be repeated here.

[0110] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. An active control method for an electric drive system, characterized in that: include: When the vehicle satisfies both the active damping control condition and the active anti-skid control condition, determining the oscillation speed and the anti-skid target speed of the electric drive system of the vehicle; According to the oscillation speed, a compensation torque for active damping control is determined; according to the acquired actual speed of the motor of the electric drive system, the oscillation speed and the anti-skid target speed, a modified speed of the motor and a speed deviation between the modified speed and the anti-skid target speed are determined, and according to the speed deviation, an intervention torque for active anti-skid control is determined; wherein the modified speed is a difference between the actual speed and the oscillation speed, and the speed deviation is a difference between the modified speed and the anti-skid target speed; An actual request torque for execution of the electric machine is determined according to the acquired request torque of the electric machine, the compensation torque, and the intervention torque.

2. The active control method of the electric drive system according to claim 1, characterized in that: When the vehicle satisfies both the active damping control condition and the active anti-skid control condition, determining the oscillation speed and the anti-skid target speed of the electric drive system of the vehicle comprises: When the actual speed satisfies the active damping control condition and the acquired actual slip rate of the vehicle satisfies the active anti-skid control condition, the oscillation speed is determined according to the actual speed, and the anti-skid target speed is determined, wherein the anti-skid target speed is the motor speed when the slip rate of the vehicle's wheels on the current road surface reaches the optimal slip rate.

3. The active control method of the electric drive system according to claim 2, characterized in that: Determining the oscillation speed according to the actual speed comprises: The oscillation speed is determined according to the actual speed or according to the actual speed and the acquired actual torque of the motor by using at least one of a frequency domain analysis method, a time domain analysis method and a model estimation method.

4. The active control method of the electric drive system according to claim 1, characterized in that: Determining the compensation torque for active damping control according to the oscillation speed includes: The compensation torque for active damping control corresponding to the oscillation speed is determined according to the signal parameter of the oscillation speed.

5. The active control method of the electric drive system according to claim 2, characterized in that: Determining the anti-skid target speed includes: Determining the optimal slip rate of the wheel on the current road surface according to the acquired adhesion coefficient of the wheel of the vehicle on the current road surface; According to the optimal slip ratio and the acquired body speed of the vehicle, the motor speed when the slip ratio of the wheel on the current road surface reaches the optimal slip ratio is determined as the anti-skid target speed.

6. The active control method of the electric drive system according to claim 1, characterized in that: Determining the intervention torque for active anti-skid control according to the speed deviation comprises: determining a rate of change of the velocity deviation; The intervention torque is determined according to the speed deviation and a rate of change of the speed deviation.

7. The active control method of an electric drive system according to any one of claims 1 to 6, characterized in that: The determining the actual requested torque for the motor to be executed according to the acquired requested torque of the motor, the compensation torque and the intervention torque comprises: The compensation torque and the intervention torque are added to the request torque to obtain the actual request torque.

8. An active control device for an electric drive system, characterized in that: include: A speed determination unit, for determining an oscillation speed and an anti-skid target speed of an electric drive system of the vehicle when the vehicle satisfies both an active damping control condition and an active anti-skid control condition; an adjustment torque determination unit, for determining a compensation torque for active damping control according to the oscillation speed; and for determining, according to the acquired actual speed of the motor of the electric drive system, the oscillation speed and the anti-skid target speed, a modified speed of the motor and a speed deviation between the modified speed and the anti-skid target speed, and determining, according to the speed deviation, an intervention torque for active anti-skid control; wherein the modified speed is a difference between the actual speed and the oscillation speed, and the speed deviation is a difference between the modified speed and the anti-skid target speed; The actual request torque determination unit is configured to determine an actual request torque for execution of the motor according to the acquired request torque of the motor, the compensation torque and the intervention torque.

9. A vehicle, characterized in that: including memory and processor; The memory is used to store computer programs; The processor is used to implement the active control method of the electric drive system according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is read and executed by a processor, the method for actively controlling an electric drive system according to any one of claims 1 to 7 is implemented.

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