Active damping control system and method for suppressing vehicle speed oscillation

Abstract

The present invention relates to an active damping control system for suppressing vehicle speed oscillation, comprising a signal acquisition module, a vehicle drive-brake demand torque calculation module, a feedforward control module, a suppression mode judgment module, a feedback control module, an output torque coordination control module, and a motor torque control module. The present invention also relates to an active damping control method for suppressing vehicle speed oscillation, comprising the steps of: collecting accelerator pedal opening information, brake pedal opening information, wheel speed information, rotation speed information, gear information, vehicle mass information, vehicle speed information, and vehicle control mode; obtaining the vehicle drive-brake demand torque; obtaining the feedforward filtering torque; feedforward regulation control; judging and outputting the vehicle speed suppression mode; rotation speed feedback loop control, vehicle speed feedback loop control; output coordination control; motor target torque. The present invention effectively improves the vehicle speed oscillation suppression control effect and driving experience; and effectively improves oscillation in the case of drastic load changes in commercial use.

Description

Technical Field

[0001] The invention relates to the technical field of electric vehicle control, and in particular to an active damping control system and method for suppressing vehicle speed oscillation. Background Art

[0002] In vehicle engineering, unexpected longitudinal acceleration oscillations during vehicle operation often result in poor driving experience and comfort. Such oscillations are usually caused by sudden and drastic changes in driving or braking torque, wheel torque oscillations caused by clutch and powertrain actuation during gear shifting, and vehicle mode conversion.

[0003] Electric vehicles are generally easier to control than conventional powertrains due to the more precise and responsive nature of the motor torque. However, since electric vehicles do not have clutch dampers or dual-mass flywheels, rapid motor torque changes can excite more significant torsional driveline oscillations.

[0004] In the industry, existing technologies for suppressing vehicle speed oscillations mainly collect the measured speed of the motor and use it as a reference, establish a motor target speed estimation model, and perform proportional correction torque calibration based on the error between the target speed and the measured speed to achieve oscillation suppression.

[0005] In order to solve the above problems, the existing technology for suppressing vehicle speed oscillation mainly considers the measured speed of the motor system as a single reference and does not consider the influence of other factors of the vehicle. Therefore, it has the following shortcomings:

[0006] 1. Since the existing technology uses the measured motor speed as a reference, filters the current motor speed to establish the target control speed, and performs open-loop torque correction on the difference between the target speed and the motor speed, the control accuracy and effect cannot achieve optimal control;

[0007] 2. The existing technology realizes torque correction by mathematically modeling the power transmission system and calculating the target speed of the motor. However, since the dynamic mechanical characteristics between the power transmission system components are difficult to quantify and the mechanical transmission clearance cannot be estimated, it is difficult to establish an accurate model of the vehicle power transmission system to determine the target speed of the motor. Summary of the invention

[0008] In view of the above problems, the present invention provides an active damping control system and method for suppressing vehicle speed oscillations, with the aim of effectively improving the vehicle speed oscillation suppression control effect and driving experience; effectively improving oscillations in different vehicle speed ranges and driving modes, and significantly improving driving comfort in the case of drastic load changes on commercial vehicles.

[0009] To solve the above problems, the technical solution provided by the present invention is:

[0010] An active damping control system for suppressing vehicle speed oscillation comprises a signal acquisition module, a vehicle drive-brake demand torque calculation module, a feedforward control module, a suppression mode judgment module, a feedback control module, an output torque coordination control module, and a motor torque execution control module; wherein:

[0011] The vehicle driving-braking required torque calculation module is used to calculate the vehicle driving-braking required torque;

[0012] The feedforward control module is used to calculate the feedforward filter torque and perform feedforward regulation control on the vehicle driving-braking demand torque;

[0013] The suppression mode determination module is used to determine whether to activate the vehicle speed suppression mode, and to determine the specific vehicle speed suppression mode;

[0014] The feedback control module is used to execute rotation speed feedback loop control and vehicle speed feedback loop control.

[0015] Preferably, the signal acquisition module is used to collect accelerator pedal opening information, brake pedal opening information, wheel speed information, rotation speed information, gear information, and vehicle mass information; the wheel speed information is obtained through a wheel speed sensor; the rotation speed information is obtained through a rotation speed sensor;

[0016] The motor torque execution control module is used to output the motor target torque;

[0017] The output torque coordination control module is used to coordinate the outputs of the feedforward control module and the feedback control module.

[0018] Preferably, it also includes a peripheral subsystem; the peripheral subsystem includes an accelerator pedal, a brake pedal, a shift handle, a vehicle speed acquisition module, a motor system, a gearbox, and a drive axle; the vehicle speed acquisition module is used to collect vehicle speed information;

[0019] The vehicle driving-braking demand torque includes driving demand torque and braking demand torque; the vehicle speed suppression mode includes Tip-in / Tip-out control mode, creep control mode, shift control mode, and braking control mode.

[0020] An active damping control method for suppressing vehicle speed oscillation using an active damping control system for suppressing vehicle speed oscillation comprises the following steps:

[0021] S100. Collect the accelerator pedal opening information, the brake pedal opening information, the wheel speed information, the speed information, the gear information, the vehicle mass information, the vehicle speed information, and the vehicle control mode; the vehicle control mode includes a power mode, an economic mode, and an intelligent mode;

[0022] S200. Obtaining the vehicle driving-braking required torque;

[0023] S300. Calculate the feedforward filter torque;

[0024] S400. According to the feedforward filter torque, the feedforward regulation control is performed on the vehicle driving-braking demand torque; the feedforward regulation control includes torque change rate control and positive and negative reverse zero crossing control;

[0025] S500. Determine whether to activate the vehicle speed suppression mode; then perform the following operations according to the determination result: if it is determined that the vehicle speed suppression mode is not activated, return and execute S500 again from the beginning;

[0026] If it is determined that the vehicle speed suppression mode is activated, the vehicle speed suppression mode is further determined and output; S600. Execute the speed feedback loop control and the vehicle speed feedback loop control;

[0027] S700. Execute output coordination control;

[0028] S800: Execute the motor target torque.

[0029] Preferably, in S200, the vehicle drive-brake demand torque is obtained by searching a vehicle drive-brake demand torque mapping table; the vehicle drive-brake demand torque mapping table is manually preset and includes a vehicle drive demand torque mapping table and a vehicle brake demand torque mapping table; wherein:

[0030] The vehicle driving demand torque mapping table is a two-dimensional table, in which each row represents a value of the vehicle speed information, each column represents a value of the accelerator pedal opening information, and the cell where a row and a column intersect represents the driving demand torque value corresponding to this row and this column;

[0031] The vehicle braking demand torque mapping table is a two-dimensional table, in which each row represents a value of the vehicle speed information, each column represents a value of the brake pedal opening information, and the unit where the row and column intersect represents the value of the braking demand torque corresponding to this row and this column.

[0032] Preferably, S300 specifically includes the following steps:

[0033] S310. Obtain the speed information and the gear information;

[0034] S320. Obtain the cutoff frequency by looking up the table according to the speed information and the gear information, which is specifically expressed as follows:

[0035] τ=f(N,θm)

[0036] Wherein: τ is the cut-off frequency; N is the gear information; θm is the speed information; f() is the speed-gear-cut-off frequency corresponding function, which is manually preset in the ECU;

[0037] S330. Calculate the output signal curve according to the cutoff frequency, which is specifically expressed as follows:

[0038]

[0039] Wherein: y(t) is the output signal curve; t is time; dT is the operation step; T is the time constant; u(t) is the input signal curve.

[0040] Preferably, the torque change rate control in S400 specifically includes the following steps:

[0041] S410. Obtaining demand torque interval division information; the demand torque interval division information includes a plurality of serially connected demand torque intervals, which are preset manually; each of the demand torque intervals includes a maximum torque value, a minimum torque value, an increasing change rate, and a decreasing change rate;

[0042] S420. Compare the feedforward filtered torque with each of the required torque intervals in the required torque interval division information one by one until the feedforward filtered torque falls into one of the required torque intervals;

[0043] S430. Correct the feedforward filtered torque according to the rising change rate and the falling change rate of the required torque interval into which the feedforward filtered torque falls, to obtain the processed feedforward filtered torque.

[0044] Preferably, S500 specifically includes the following steps:

[0045] S510. Determining whether to activate the vehicle speed suppression mode specifically includes the following steps:

[0046] S511. Obtain the accelerator pedal opening information, the brake pedal opening information, the gear position information, the vehicle speed information, the shift handle status information, the TSC traction intervention status information, and the ABS anti-lock braking status information;

[0047] S512. Make the following judgment based on the accelerator pedal opening information, the brake pedal opening information, the shift handle state information, the TSC traction intervention state information, and the ABS anti-lock state information:

[0048] If the TSC traction intervention state information is activated, or the ABS anti-lock braking state information is not activated, it is determined that the vehicle speed suppression mode is not activated; then S520 is executed;

[0049] If the vehicle speed information is greater than the manually preset vehicle speed activation judgment threshold, it is determined that the vehicle speed suppression mode is activated; then S520 is executed;

[0050] S520. Perform the following operations according to the judgment result of S512:

[0051] If it is determined that the vehicle speed suppression mode is not activated, the process returns to and executes S500 again from the beginning;

[0052] If it is determined that the vehicle speed suppression mode is activated, S530 is executed;

[0053] S530. Perform the following operations according to the shift handle state information, the accelerator pedal opening information, and the brake pedal opening information:

[0054] If the shift handle state information indicates that the gear shift is in progress, determining that the vehicle speed suppression mode is the gear shift control mode;

[0055] If the brake pedal opening information indicates that the vehicle is in a braking process, determining that the vehicle speed suppression mode is the braking control mode;

[0056] If the accelerator pedal opening information is greater than a manually preset vehicle speed suppression accelerator opening threshold, determining that the vehicle speed suppression mode is the Tip-in / Tip-out control mode;

[0057] otherwise, determining that the vehicle speed suppression mode is the creep control mode;

[0058] S540. Output the vehicle speed suppression mode.

[0059] Preferably, the speed feedback loop control in S600 specifically includes the following steps:

[0060] Sa610. Collect the wheel speed information and the rotation speed information;

[0061] Sa620. According to the wheel speed information and the rotation speed information, the rotation speed error is calculated; specifically, it is expressed as follows:

[0062]

[0063] in: is the speed error; is the motor angular acceleration, obtained by deriving the speed information θm; is the wheel rotation angular acceleration, obtained by deriving the wheel speed information; the wheel speed information is expressed by the symbol θw; i 0 is the rear axle main reduction ratio; i g is the gearbox ratio;

[0064] Sa630. Perform proportional differential control calculation according to the speed error and the vehicle speed suppression mode to obtain the first feedback control torque; specifically, it is expressed as follows:

[0065]

[0066] Where: ΔT loop1 is the first feedback control torque; K p1 is the first proportionality coefficient; K d is the differential coefficient;

[0067] The first proportional coefficient and the differential coefficient are corrected according to the vehicle speed suppression mode and the vehicle load; specifically, they are expressed as follows:

[0068] M 1 =g 1 (Mod,m)

[0069] Where: M 1 is the first parameter matrix; g 1 () is the first correction function, which is preset manually; Mod is the vehicle speed suppression mode; m is the vehicle load, which is collected by the vehicle load sensor;

[0070] The vehicle speed feedback loop control in S600 specifically includes the following steps:

[0071] Sb610. Collect the vehicle speed information;

[0072] Sb620. Obtain the target vehicle speed by filtering the random noise of the vehicle speed information through an artificially preset low-pass filter;

[0073] Sb630. Calculate the vehicle speed error; specifically, it is expressed as follows:

[0074] Δυ=υ t -υ w

[0075] Where: Δυ is the vehicle speed error; υ t is the target vehicle speed; w is the vehicle speed information;

[0076] Sb640. The second feedback control torque is calculated according to the vehicle speed error; specifically, it is expressed as follows:

[0077] ΔT loop2 =K p2 *Δυ

[0078] Where: ΔT loop2 is the second feedback control torque; K p2is the second proportionality coefficient;

[0079] The second proportional coefficient is corrected according to the vehicle speed suppression mode and the vehicle load; specifically, it is expressed as follows:

[0080] M 2 =g 2 (Mod,m)

[0081] Where: M 2 is the second parameter matrix; g 2 () is the second correction function, which is preset manually.

[0082] Preferably, the output coordination control in S700 specifically includes the following steps:

[0083] S710. Coordinate and arbitrate the first feedback control torque and the second feedback control torque to obtain a total feedback control torque; specifically, it is expressed as follows:

[0084] T fb =ΔT loop1 +ηΔT loop2

[0085] Where: T fb is the total torque of the feedback control; η is the adjustment factor, which is calibrated by engineering, and η∈[0,1];

[0086] The motor target torque in S800 is specifically expressed as follows:

[0087] T cmd =T ff +T fb

[0088] Where: T cmd is the motor target torque; T ff is the processed feedforward filtered torque obtained in S430.

[0089] Compared with the prior art, the present invention has the following advantages:

[0090] 1. The present invention has established a complete active damping control method and system for suppressing vehicle speed oscillation, and has established a vehicle drive-brake demand torque feedforward control, a dual closed-loop feedback control based on vehicle speed and motor speed, and has comprehensively considered the vehicle's driving conditions, judged the vehicle speed suppression control mode, and adjusted different algorithm parameters in different modes and vehicle load compensation, thereby effectively improving the vehicle speed oscillation suppression control effect and driving experience;

[0091] 2. Since the present invention establishes a complete active damping control method and system, quantifies the dynamic mechanical characteristics between the powertrain components, comprehensively considers the rotational speed and vehicle speed, and performs feedforward pre-adjustment and dual-loop feedback, it effectively improves the oscillation in different vehicle speed ranges and driving modes. For commercial vehicles with drastic load changes, the effect of improving driving comfort is very obvious. BRIEF DESCRIPTION OF THE DRAWINGS

[0092] Figure 1 A schematic diagram of the system structure of a specific embodiment of the present invention;

[0093] Figure 2 It is a parameter transfer schematic diagram of a specific embodiment of the present invention;

[0094] Figure 3 A schematic diagram of a method flow chart of a specific embodiment of the present invention;

[0095] Figure 4 The figure is a schematic diagram of the vehicle speed suppression mode determination flow chart of a specific embodiment of the present invention. DETAILED DESCRIPTION

[0096] The present invention is further explained below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0097] like Figure 1 As shown, an active damping control system for suppressing vehicle speed oscillation includes a signal acquisition module, a vehicle drive-brake demand torque calculation module, a feedforward control module, a suppression mode judgment module, a feedback control module, an output torque coordination control module, and a motor torque execution control module; wherein:

[0098] In this specific embodiment, the signal acquisition module is used to collect accelerator pedal opening information, brake pedal opening information, wheel speed information, rotation speed information, gear information, and vehicle mass information; the wheel speed information is obtained through a wheel speed sensor; the rotation speed information is obtained through a rotation speed sensor.

[0099] The motor torque execution control module is used to output the motor target torque.

[0100] The output torque coordination control module is used to coordinate the outputs of the feedforward control module and the feedback control module.

[0101] The vehicle drive-brake demand torque calculation module is used to calculate the vehicle drive-brake demand torque in different modes;

[0102] The feedforward control module is used to calculate the feedforward filter torque and perform feedforward regulation and control on the vehicle's driving-braking demand torque.

[0103] It should be noted that the purpose of feedforward regulation and control of the vehicle driving-braking demand torque is to reduce the system disturbance error.

[0104] The inhibition mode determination module is used to determine whether to activate the vehicle speed inhibition mode and determine the specific vehicle speed inhibition mode;

[0105] The feedback control module is used to execute speed feedback loop control and vehicle speed feedback loop control.

[0106] like Figure 2 As shown, it should be noted that the purpose of executing the rotation speed feedback loop control and the vehicle speed feedback loop control is to realize the calculation of the suppression compensation torque of the rotation speed error and the vehicle speed error.

[0107] It should be further explained that feedforward regulation is for pre-adjustment torque, and feedback control is for compensation torque; this requires the above-mentioned output torque coordination control module to coordinate output.

[0108] In this specific embodiment, it also includes a peripheral subsystem; the peripheral subsystem includes an accelerator pedal, a brake pedal, a shift handle, a vehicle speed acquisition module, a motor system, a gearbox, and a drive axle; the vehicle speed acquisition module is used to collect vehicle speed information.

[0109] The vehicle driving-braking demand torque includes driving demand torque and braking demand torque; the vehicle speed suppression mode includes Tip-in / Tip-out control mode, creep control mode, shift control mode, and braking control mode.

[0110] like Figure 3 As shown, an active damping control method for suppressing vehicle speed oscillation using an active damping control system for suppressing vehicle speed oscillation comprises the following steps:

[0111] S100. Collect accelerator pedal opening information, brake pedal opening information, wheel speed information, rotation speed information, gear information, vehicle mass information, vehicle speed information, and vehicle control mode; the vehicle control mode includes power mode, economy mode, and intelligent mode.

[0112] S200. Obtain the vehicle driving-braking required torque.

[0113] In this specific embodiment, the vehicle drive-brake demand torque is obtained by searching the vehicle drive-brake demand torque mapping table in S200; the vehicle drive-brake demand torque mapping table is manually preset and includes a vehicle drive demand torque mapping table and a vehicle brake demand torque mapping table; wherein:

[0114] The vehicle driving demand torque mapping table is a two-dimensional table, in which each row represents a value of vehicle speed information, each column represents a value of accelerator pedal opening information, and the unit where the row and column intersect represents the driving demand torque value corresponding to this row and this column.

[0115] The vehicle braking demand torque mapping table is a two-dimensional table, in which each row represents a value of vehicle speed information, each column represents a value of brake pedal opening information, and the unit where the row and column intersect represents the value of the braking demand torque corresponding to this row and this column.

[0116] As shown in Table 1, a vehicle driving demand torque mapping table is given as an example.

[0117] It should be noted that Table 1 is presented in this specific embodiment as an example of implementing the method of the present invention, and the numerical values ​​therein do not constitute an impact on the determination of the scope of the claims; on the other hand, in practical applications, the data in the table should be appropriately adjusted according to actual working conditions, environment and other factors.

[0118] Table 1. Example of vehicle drive demand torque mapping table

[0119]

[0120] S300. Calculate and obtain the feedforward filter torque.

[0121] It should be noted that the feedforward control module in the present invention receives the vehicle driving-braking required torque and performs feedforward adjustment through a low-pass filtering method.

[0122] It should be further explained that there are many technologies for implementing low-pass filtering. In this specific embodiment, a first-order RC filter is used for feedforward adjustment; this is because the low-pass filter can effectively improve the longitudinal acceleration oscillation of the vehicle, but it will also cause torque transmission delay. Therefore, the time constant of the low-pass filter should be selected in an appropriate range, taking into account both avoiding oscillation and real-time response.

[0123] In this specific embodiment, S300 specifically includes the following steps:

[0124] S310. Obtain speed information and gear information.

[0125] S320. Obtain the cutoff frequency by looking up the table according to the speed information and the gear information, which is specifically expressed as follows:

[0126] τ=f(N,θm) (1)

[0127] Among them: τ is the cut-off frequency; N is the gear information; θm is the speed information; f() is the speed-gear-cut-off frequency correspondence function, which is manually preset in the ECU.

[0128] It should be noted that, in this specific embodiment, considering the gear position N of the gearbox and the motor speed (measured value) θm, the time constant of the low-pass filter, that is, the cutoff frequency τ, is set as a function of N and θm, that is, the time constant τ = f(N, θm) to adjust the optimal state of the response, and at the same time set a suitable cutoff frequency τ.

[0129] It should be further explained that the vehicle driving-braking demand torque is smoothed to avoid unexpected sudden spikes.

[0130] In order to further demonstrate the application process of the present invention, this specific embodiment also provides a specific example of a speed-gear-cutoff frequency corresponding function f() as follows.

[0131] It should be noted that f() given below is given in this specific embodiment as an example of implementing the method of the present invention, and the numerical value therein does not constitute an impact on the determination of the scope of the claims; on the other hand, in practical applications, the data in the formula should be appropriately adjusted according to actual working conditions, environment and other factors.

[0132] It should be further explained that this example is based on a vehicle with a low-speed motor and a 4-speed AMT. The speed-gear-cutoff frequency corresponding function f() selected by τ is expressed as follows:

[0133]

[0134] S330. Calculate the output signal curve according to the cutoff frequency, which is specifically expressed as follows:

[0135]

[0136] Among them: y(t) is the output signal curve; t is time; dT is the operation step, which is preset manually; T is the time constant; u(t) is the input signal curve.

[0137] In this specific embodiment, dT=0.01s.

[0138] It should be noted that T is the time constant, which is the reciprocal of the cut-off frequency τ; and in engineering practice, the low-pass filtering effect is changed by adjusting T.

[0139] S400. Perform feedforward regulation control on the vehicle drive-braking demand torque according to the feedforward filter torque; the feedforward regulation control includes torque change rate control and positive and negative reverse zero-crossing control.

[0140] In this specific embodiment, the torque change rate control in S400 specifically includes the following steps:

[0141] S410. Obtain demand torque interval division information; the demand torque interval division information includes multiple serially connected demand torque intervals, which are preset manually; each demand torque interval includes a maximum torque value, a minimum torque value, an increasing change rate, and a decreasing change rate.

[0142] S420. Compare the feedforward filtered torque with each required torque interval in the required torque interval division information one by one until the feedforward filtered torque falls into one of the required torque intervals.

[0143] S430. Correct the feedforward filtered torque according to the rising change rate and falling change rate of the demand torque interval into which the feedforward filtered torque falls, to obtain a processed feedforward filtered torque.

[0144] In order to further demonstrate the application process of the present invention, this specific embodiment also provides a required torque interval division information and a selection process of the rising change rate and the falling change rate.

[0145] It should be noted that the examples given below are presented as examples of implementing the method of the present invention, and the numerical values ​​therein do not constitute an impact on the determination of the scope of the claims; on the other hand, in practical applications, the data involved should be appropriately adjusted according to actual working conditions, environment and other factors.

[0146] The required torque interval division information is divided into 3 required torque intervals:

[0147] The first required torque range: [-1000Nm, -200Nm].

[0148] The second required torque range: (-200Nm, 200Nm].

[0149] The third required torque range: (200Nm, 1000Nm].

[0150] If the feedforward filtered torque falls into the first required torque interval, the first rising rate is r_Rate 1 =500Nm / s, the first drop rate is f_Rate 1 =-500Nm / s.

[0151] If the feedforward filtered torque falls into the second required torque range, the second rising rate is r_Rate 2 =100Nm / s, the second decreasing rate is f_Rate 2 =-100Nm / s.

[0152] If the feedforward filtered torque falls into the third required torque interval, the third rising rate is r_Rate 3=400Nm / s, the third descent rate is f_Rate 3 =-400Nm / s.

[0153] It should be noted again that different setting values ​​of the rising rate of change and the falling rate of change can be selected according to calibration under different working conditions.

[0154] S500. Determine whether to activate the vehicle speed suppression mode; then perform the following operations according to the determination result:

[0155] If it is determined that the vehicle speed suppression mode is not activated, the process returns to and executes S500 again from the beginning.

[0156] If it is determined that the vehicle speed suppression mode is activated, the vehicle speed suppression mode is further determined and output.

[0157] like Figure 4 As shown, in this specific embodiment, S500 specifically includes the following steps:

[0158] S510. Determine whether to activate the vehicle speed suppression mode, specifically including the following steps:

[0159] S511. Obtain accelerator pedal opening information, brake pedal opening information, gear position information, vehicle speed information, shift handle status information, TSC traction intervention status information, and ABS anti-lock braking status information.

[0160] S512. Make the following judgment based on the accelerator pedal opening information, brake pedal opening information, shift handle status information, TSC traction intervention status information, and ABS anti-lock braking status information:

[0161] If the TSC traction intervention state information is activated, or the ABS anti-lock braking state information is not activated, it is determined that the vehicle speed suppression mode is not activated; then S520 is executed.

[0162] If the vehicle speed information is greater than the manually preset vehicle speed activation judgment threshold, it is determined that the vehicle speed suppression mode is activated; then S520 is executed.

[0163] S520. Perform the following operations according to the judgment result of S512:

[0164] If it is determined that the vehicle speed suppression mode is not activated, the process returns to and executes S500 again from the beginning.

[0165] If it is determined that the vehicle speed suppression mode is activated, S530 is executed.

[0166] S530. Perform the following operations according to the shift handle status information, the accelerator pedal opening information, and the brake pedal opening information:

[0167] If the shift lever state information indicates that the vehicle is in the shifting process, it is determined that the vehicle speed suppression mode is the shifting control mode.

[0168] If the brake pedal opening information indicates that the vehicle is in the braking process, it is determined that the vehicle speed suppression mode is the braking control mode.

[0169] If the accelerator pedal opening information is greater than the manually preset vehicle speed suppression accelerator opening threshold, it is determined that the vehicle speed suppression mode is the Tip-in / Tip-out control mode.

[0170] Otherwise, it is determined that the vehicle speed suppression mode is the creep control mode.

[0171] S540. Output vehicle speed suppression mode.

[0172] S600. Execute speed feedback loop control and vehicle speed feedback loop control.

[0173] In this specific embodiment, the speed feedback loop control in S600 specifically includes the following steps:

[0174] Sa610. Collect wheel speed information and rotation speed information.

[0175] Sa620. According to the wheel speed information and the rotation speed information, the rotation speed error is calculated; specifically, it is expressed as follows:

[0176]

[0177] in: is the speed error; is the motor angular acceleration, obtained by differentiating the speed information θm; is the wheel rotation angular acceleration, which is obtained by differentiating the wheel speed information; the wheel speed information is expressed by the symbol θw; i 0 is the rear axle main reduction ratio; i g is the gearbox ratio;

[0178] It should be noted that, as mentioned above, this example is based on a vehicle configuration with a low-speed motor and a 4-speed AMT;

[0179] In this specific embodiment, the rear axle main reduction ratio i 0 =5.6; Transmission ratio i in 3rd gear g =1.89

[0180] Sa630. Perform proportional differential control calculation according to the speed error and vehicle speed suppression mode to obtain the first feedback control torque; specifically, it is expressed as follows:

[0181]

[0182] Where: ΔT loop1is the first feedback control torque; K p1 is the first proportionality coefficient; K d is the differential coefficient.

[0183] The first proportional coefficient and the differential coefficient are corrected according to the vehicle speed suppression mode and the vehicle load; specifically, they are expressed as follows:

[0184] M 1 =g 1 (Mod,m)(6)

[0185] Where: M 1 is the first parameter matrix; g 1 () is the first correction function, which is preset manually; Mod is the vehicle speed suppression mode; m is the vehicle load, which is collected by the vehicle load sensor.

[0186] The vehicle speed feedback loop control in S600 specifically includes the following steps:

[0187] Sb610. Collect vehicle speed information.

[0188] Sb620. Obtain the target vehicle speed by filtering the random noise of the vehicle speed information through an artificially preset low-pass filter.

[0189] Sb630. Calculate the vehicle speed error; specifically, it is expressed as follows:

[0190] Δυ=υ t -υ w (7)

[0191] Where: Δυ is the vehicle speed error; υ t is the target vehicle speed; w It is the vehicle speed information.

[0192] Sb640. The second feedback control torque is calculated based on the vehicle speed error; specifically, it is expressed as follows:

[0193] ΔT loop2 =K p2 *Δυ (8)

[0194] Where: ΔT loop2 is the second feedback control torque; K p2 is the second proportionality coefficient.

[0195] It should be noted that in order to simplify the parameter optimization work brought about by the dual closed-loop feedback control, the closed loop is generally designed as a pure proportional one in engineering applications.

[0196] The second proportional coefficient is corrected according to the vehicle speed suppression mode and the vehicle load; specifically, it is expressed as follows:

[0197] M2 =g 2 (Mod,m)(9)

[0198] Where: M 2 is the second parameter matrix; g 2 () is the second correction function, which is preset manually.

[0199] S700. Execute output coordination control.

[0200] In this specific embodiment, the output coordination control in S700 specifically includes the following steps:

[0201] S710. Coordinate and arbitrate the first feedback control torque and the second feedback control torque to obtain the total feedback control torque; specifically, it is expressed as follows:

[0202] T fb =ΔT loop1 +ηΔT loop2 (10)

[0203] Where: T fb is the total torque for feedback control; η is the adjustment factor, which is calibrated through engineering and η∈[0,1] to improve the stability of the control system.

[0204] The motor target torque in S800 is specifically expressed as follows:

[0205] T cmd =T ff +T fb (11)

[0206] Where: T cmd is the motor target torque; T ff is the processed feedforward filtered torque obtained in S430.

[0207] S800: Execute motor target torque.

[0208] It should be noted that T cmd This is the final result of controlling the motor by this method. The motor controller MCU receives the T cmd After receiving the torque request, the control target value is executed in response.

[0209] It should be noted that the above-mentioned feedback control method adopts the classic PID control in engineering, which is not limited to the technical method shown in this specific embodiment, and other technical solutions can also be adopted, such as MPC (model predictive control) and other control methods can also achieve the same invention effect.

[0210] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are clearly stated in each claim. On the contrary, as reflected in the appended claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0211] The disclosed embodiments are described above to enable any person skilled in the art to implement or use the present invention. Various modifications of these embodiments are obvious to those skilled in the art, and the general principles defined herein may also be applied to other embodiments without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure is not limited to the embodiments given herein, but is consistent with the broadest scope of the principles and novel features disclosed in this application.

[0212] The above description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including," is explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

[0213] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An active damping control method for suppressing vehicle speed oscillation, characterized in that: An active damping control system for suppressing vehicle speed oscillation is utilized; the active damping control system for suppressing vehicle speed oscillation comprises a signal acquisition module, a vehicle drive-brake demand torque calculation module, a feedforward control module, a suppression mode judgment module, a feedback control module, an output torque coordination control module, and a motor torque execution control module; wherein: The vehicle driving-braking required torque calculation module is used to calculate the vehicle driving-braking required torque; The feedforward control module is used to calculate the feedforward filter torque and perform feedforward regulation control on the vehicle driving-braking demand torque; The suppression mode determination module is used to determine whether to activate the vehicle speed suppression mode, and to determine the specific vehicle speed suppression mode; The feedback control module is used to perform speed feedback loop control and vehicle speed feedback loop control; The signal acquisition module is used to collect accelerator pedal opening information, brake pedal opening information, wheel speed information, rotation speed information, gear information, and vehicle mass information; the wheel speed information is obtained through a wheel speed sensor; the rotation speed information is obtained through a rotation speed sensor; The motor torque execution control module is used to output the motor target torque; The output torque coordination control module is used to coordinate the outputs of the feedforward control module and the feedback control module; The active damping control system for suppressing vehicle speed oscillation further comprises a peripheral subsystem; the peripheral subsystem comprises an accelerator pedal, a brake pedal, a shift handle, a vehicle speed acquisition module, a motor system, a gearbox, and a drive axle; the vehicle speed acquisition module is used to collect vehicle speed information; The vehicle driving-braking demand torque includes driving demand torque and braking demand torque; the vehicle speed suppression mode includes Tip-in / Tip-out control mode, creep control mode, shift control mode, and braking control mode; The active damping control method for suppressing vehicle speed oscillation comprises the following steps: S100. Collect the accelerator pedal opening information, the brake pedal opening information, the wheel speed information, the speed information, the gear information, the vehicle mass information, the vehicle speed information, and the vehicle control mode; the vehicle control mode includes a power mode, an economic mode, and an intelligent mode; S200. Obtaining the vehicle driving-braking required torque; S300. Calculate the feedforward filter torque; S400. According to the feedforward filter torque, the feedforward regulation control is performed on the vehicle driving-braking demand torque; the feedforward regulation control includes torque change rate control and positive and negative reverse zero crossing control; S500. Determine whether to activate the vehicle speed suppression mode; then perform the following operations according to the determination result If it is determined that the vehicle speed suppression mode is not activated, the process returns to and executes S500 again from the beginning; If it is determined that the vehicle speed suppression mode is activated, further determining and outputting the vehicle speed suppression mode; S600. Execute the speed feedback loop control and the vehicle speed feedback loop control; S700. Execute output coordination control; S800. Execute the motor target torque; In S200, the vehicle drive-brake demand torque is obtained by searching the vehicle drive-brake demand torque mapping table; the vehicle drive-brake demand torque mapping table is manually preset and includes a vehicle drive demand torque mapping table and a vehicle brake demand torque mapping table; wherein: The vehicle driving demand torque mapping table is a two-dimensional table, in which each row represents a value of the vehicle speed information, each column represents a value of the accelerator pedal opening information, and the cell where a row and a column intersect represents the driving demand torque value corresponding to this row and this column; The vehicle braking demand torque mapping table is a two-dimensional table, in which each row represents a value of the vehicle speed information, each column represents a value of the brake pedal opening information, and the unit where a row and a column intersect represents the value of the braking demand torque corresponding to this row and this column; S300 specifically includes the following steps: S310. Obtain the speed information and the gear information; S320. Obtain the cutoff frequency by looking up the table according to the speed information and the gear information, which is specifically expressed as follows: τ=f(N,θm) Wherein: τ is the cut-off frequency; N is the gear information; θm is the speed information; f() is the speed-gear-cut-off frequency corresponding function, which is manually preset in the ECU; S330. Calculate the output signal curve according to the cutoff frequency, which is specifically expressed as follows: Wherein: y(t) is the output signal curve; t is time; dT is the operation step; T is the time constant; u(t) is the input signal curve.

2. The active damping control method for suppressing vehicle speed oscillation according to claim 1, characterized in that: The torque change rate control in S400 specifically includes the following steps: S410. Obtaining demand torque interval division information; the demand torque interval division information includes a plurality of serially connected demand torque intervals, which are preset manually; each of the demand torque intervals includes a maximum torque value, a minimum torque value, an increasing change rate, and a decreasing change rate; S420. Compare the feedforward filtered torque with each of the required torque intervals in the required torque interval division information one by one until the feedforward filtered torque falls into one of the required torque intervals; S430. Correct the feedforward filtered torque according to the rising change rate and the falling change rate of the required torque interval into which the feedforward filtered torque falls, to obtain the processed feedforward filtered torque.

3. The active damping control method for suppressing vehicle speed oscillation according to claim 2, characterized in that: S500 specifically includes the following steps: S510. Determining whether to activate the vehicle speed suppression mode specifically includes the following steps: S511. Obtain the accelerator pedal opening information, the brake pedal opening information, the gear position information, the vehicle speed information, the shift handle status information, the TSC traction intervention status information, and the ABS anti-lock braking status information; S512. Make the following judgment based on the accelerator pedal opening information, the brake pedal opening information, the shift handle state information, the TSC traction intervention state information, and the ABS anti-lock state information: If the TSC traction intervention state information is activated, or the ABS anti-lock braking state information is not activated, it is determined that the vehicle speed suppression mode is not activated; then S520 is executed; If the vehicle speed information is greater than the manually preset vehicle speed activation judgment threshold, it is determined that the vehicle speed suppression mode is activated; then S520 is executed; S520. Perform the following operations according to the judgment result of S512: If it is determined that the vehicle speed suppression mode is not activated, the process returns to and executes S500 again from the beginning; If it is determined that the vehicle speed suppression mode is activated, S530 is executed; S530. Perform the following operations according to the shift handle state information, the accelerator pedal opening information, and the brake pedal opening information: If the shift handle state information indicates that the gear shift is in progress, determining that the vehicle speed suppression mode is the gear shift control mode; If the brake pedal opening information indicates that the vehicle is in a braking process, determining that the vehicle speed suppression mode is the braking control mode; If the accelerator pedal opening information is greater than a manually preset vehicle speed suppression accelerator opening threshold, determining that the vehicle speed suppression mode is the Tip-in / Tip-out control mode; otherwise, determining that the vehicle speed suppression mode is the creep control mode; S540. Output the vehicle speed suppression mode.

4. The active damping control method for suppressing vehicle speed oscillation according to claim 3, characterized in that: The speed feedback loop control in S600 specifically includes the following steps: Sa610. Collect the wheel speed information and the rotation speed information; Sa620. According to the wheel speed information and the rotation speed information, the rotation speed error is calculated; specifically, it is expressed as follows: in: is the speed error; is the motor angular acceleration, obtained by deriving the speed information θm; is the wheel rotation angular acceleration, obtained by deriving the wheel speed information; the wheel speed information is expressed by the symbol θw; i0 is the rear axle main reduction ratio; i g is the gearbox ratio; Sa630. Perform proportional differential control calculation according to the speed error and the vehicle speed suppression mode to obtain the first feedback control torque; specifically, it is expressed as follows: Where: ΔT loop1 is the first feedback control torque; K p1 is the first proportionality coefficient; K d is the differential coefficient; The first proportional coefficient and the differential coefficient are corrected according to the vehicle speed suppression mode and the vehicle load; specifically, they are expressed as follows: M1=g1(Mod,m) Wherein: M1 is the first parameter matrix; g1() is the first correction function, which is preset manually; Mod is the vehicle speed suppression mode; m is the vehicle load, which is collected by the vehicle load sensor; The vehicle speed feedback loop control in S600 specifically includes the following steps: Sb610. Collect the vehicle speed information; Sb620. Obtain the target vehicle speed by filtering the random noise of the vehicle speed information through an artificially preset low-pass filter; Sb630. Calculate the vehicle speed error; specifically, it is expressed as follows: δυ=υ t -u w Where: Δυ is the vehicle speed error; υ t is the target vehicle speed; w is the vehicle speed information; Sb640. The second feedback control torque is calculated according to the vehicle speed error; specifically, it is expressed as follows: ΔT loop2 =K p2 *Two Where: ΔT loop2 is the second feedback control torque; K p2 is the second proportionality coefficient; The second proportional coefficient is corrected according to the vehicle speed suppression mode and the vehicle load; specifically, it is expressed as follows: M2=g2(Mod,m) Wherein: M2 is the second parameter matrix; g2() is the second correction function, which is preset manually.

5. The active damping control method for suppressing vehicle speed oscillation according to claim 4, characterized in that: The output coordination control in S700 specifically includes the following steps: S710. Coordinate and arbitrate the first feedback control torque and the second feedback control torque to obtain a total feedback control torque; specifically, it is expressed as follows: T fb =ΔT loop1 +ηΔT loop2 Where: T fb is the total torque of the feedback control; η is the adjustment factor, which is calibrated by engineering, and η∈[0,1]; The motor target torque in S800 is specifically expressed as follows: T cmd =T ff +T fb Where: T cmd is the motor target torque; T ff is the processed feedforward filtered torque obtained in S430.

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