Torsional vibration control method and device for hybrid electric vehicle, medium and equipment

Abstract

The invention provides a torsional vibration control method and device for a hybrid electric vehicle, a medium and equipment, and is used for establishing a target torsional vibration controller and controlling torsional vibration generated in the mode switching process of the hybrid electric vehicle. The method comprises the steps that a nonlinear clutch friction model is established and linearized, and the torque of a clutch in the sliding friction process is determined; establishing a linear time-varying model according to the power transmission route of the hybrid electric vehicle; time-varying scheduling parameters are obtained through a rotating speed sensor; based on the torque of the clutch in the sliding friction process, the linear time-varying model and the time-varying scheduling parameters, an augmentation matrix of a linear time-varying closed-loop system is established; and based on a multi-cell LPV finite time H-infinity robust gain control strategy, controlling the linear time-varying closed-loop system, and determining a target torsional vibration controller. The torsional vibration generated in the mode switching process of the hybrid electric vehicle can be effectively restrained.

Description

Technical Field

[0001] The present application relates to the technical field of torsional vibration, and in particular to a method, device, medium and equipment for controlling torsional vibration of a hybrid electric vehicle. Background Art

[0002] With the energy crisis and increasingly serious environmental problems caused by pollutant emissions, new energy vehicles have become an important direction for automobile energy conservation and emission reduction. But at the same time, the problems brought about by new energy vehicles due to their structure and new power are becoming more and more obvious.

[0003] The advantages of hybrid vehicles mainly rely on their complex electromechanical composite transmission system. Through the reasonable and coordinated distribution of torque of multiple motors and engines, free switching of various driving modes can be achieved, which reduces energy consumption to a certain extent. However, due to its complex structural characteristics, torsional vibration of the transmission system will inevitably occur during the mode switching process, affecting driving comfort, and thus puts higher requirements on the NVH performance of the whole vehicle.

[0004] The earliest method was the passive control method, which was purely mechanical, so that the low-frequency vibration frequency of the vehicle avoided the resonance range of the human body, and achieved certain improvements by adjusting the stiffness and damping of the vehicle's half-axles. However, this method requires changes to the vehicle structure and may cause vibration problems in other frequency bands. Another method is the active control method, which treats the power source as an actuator of the compensating torque to suppress vibration, and applies a "counter-excitation" to the transmission system through feedback control to suppress vibration. However, the existing feedback control method needs to be calibrated under specific working conditions and cannot meet the torsional vibration effects of the half-axles under different operating modes.

[0005] Therefore, how to suppress the torsional vibration of the hybrid vehicle power transmission system by building a model and conducting in-depth analysis is a technical problem that urgently needs to be solved in this field. Summary of the invention

[0006] In view of this, the present application provides a hybrid electric vehicle torsional vibration control method, device, medium and electronic equipment, the main purpose of which is to improve the efficiency of torsional vibration control.

[0007] According to one aspect of the present application, a method for controlling torsional vibration of a hybrid vehicle is provided, which is used to establish a target torsional vibration controller to control the torsional vibration generated by the hybrid vehicle during mode switching. The method comprises:

[0008] Establish a nonlinear clutch friction model and linearize it to determine the clutch torque during the sliding process;

[0009] According to the power transmission route of hybrid electric vehicle, a linear time-varying model is established;

[0010] Obtain time-varying dispatch parameters through speed sensors;

[0011] Based on the torque of the clutch during the slipping process, the linear time-varying model, and the time-varying scheduling parameters, an augmented matrix of the linear time-varying closed-loop system is established;

[0012] Based on the multi-cell LPV finite time H ∞ A robust gain control strategy is used to control the linear time-varying closed-loop system and determine a target torsional vibration controller.

[0013] In one implementation, the step of establishing a nonlinear clutch friction model and linearizing it to determine the torque of the clutch during the sliding friction process includes:

[0014] Establish a reset integrator nonlinear friction model and determine the corresponding relationship between the clutch friction model and the relative sliding speed;

[0015] The friction coefficient in the corresponding relationship is Taylor expanded to obtain the corresponding relationship between the linearized friction coefficient and the relative sliding speed;

[0016] Based on the corresponding relationship between the linearized friction coefficient and the relative sliding speed, the torque of the clutch during the sliding friction process is obtained.

[0017] In one implementation, establishing a linear time-varying model according to the power transmission route of the transmission system includes:

[0018] According to the power transmission route of the transmission system, determine the components and linkage relationships of multiple power sources, multiple clutches and multiple transmission mechanisms;

[0019] Analyze the working state, friction state and engagement state of each component during mode switching;

[0020] According to the working state, friction state and engagement state of each component, a transmission system dynamics equation is established to obtain a linear time-varying model.

[0021] In one implementation, the step of obtaining the time-varying scheduling parameter through the rotation speed sensor includes:

[0022] The speed difference signal at both ends of the clutch measured by the speed sensor is used to obtain the time-varying scheduling parameters.

[0023] In one implementation, the augmented matrix of the linear time-varying closed-loop system is established based on the torque of the clutch during the sliding process, the linear time-varying model, and the time-varying scheduling parameter, including:

[0024] An augmented matrix of a linear time-varying closed-loop system is established with the tracking errors of the wheel speed and the torsion angle, wherein the augmented state is introduced with the expected wheel speed and the expected torsion angle, and the torque expression of the current clutch in the linear time-varying model is calculated according to the torque of the clutch during the slipping process, and the augmented matrix of the linear time-varying closed-loop system is constructed in combination with the time-varying scheduling parameters.

[0025] In one implementation, the multi-cell LPV finite time H ∞ A robust gain control strategy is used to control the linear time-varying closed-loop system and determine a target torsional vibration controller, including:

[0026] With the goal of minimizing the tracking error of wheel speed and torsion angle, a multi-cell LPV finite time H ∞ A robust gain feedback strategy is used to control the linear parameter time-varying closed-loop system and determine the target torsional vibration controller.

[0027] In one implementation, the tracking error of the wheel speed and the torsion angle is minimized based on the multi-cell LPV finite time H ∞ A robust gain feedback strategy is used to control the linear parameter time-varying closed-loop system and determine the target torsional vibration controller, including:

[0028] Determine the multi-cell LPV finite time H ∞ The robust gain feedback strategy is: under the action of input u, the wheel speed and torsion angle track the expected value;

[0029] Use polytopes to describe linear parameter time-varying closed-loop systems;

[0030] Design a finite time H for each vertex of the polyhedron ∞ Robust controller, so that the controller satisfies H under the condition of finite time ∞ performance;

[0031] The polytope vertex gains are solved and the continuous global LPV finite time H is obtained through weighted fitting. ∞ A robust controller is used as the target torsional vibration controller.

[0032] In one implementation, the method further includes:

[0033] The output of the target torsional vibration controller is connected to the motor actuator and the clutch actuator as input, and acts on the vehicle transmission system through the motor actuator and the clutch actuator to suppress the torsional vibration of the transmission system.

[0034] According to one aspect of the present application, a hybrid vehicle torsional vibration control device is provided, which is used to establish a target torsional vibration controller to control the torsional vibration generated by the hybrid vehicle during mode switching. The device includes:

[0035] A nonlinear clutch friction model building unit is used to build a nonlinear clutch friction model and linearize it to determine the torque of the clutch during the sliding process;

[0036] A linear time-varying model building unit is used to build a linear time-varying model according to the power transmission route of the hybrid vehicle;

[0037] A time-varying dispatch parameter determination unit, used for obtaining the time-varying dispatch parameter through a rotation speed sensor;

[0038] An augmented matrix establishing unit, used to establish an augmented matrix of a linear time-varying closed-loop system based on the torque of the clutch during the slipping process, the linear time-varying model, and the time-varying scheduling parameters;

[0039] Controller design unit for multi-cell LPV finite-time H ∞ A robust gain control strategy is used to control the linear time-varying closed-loop system and determine a target torsional vibration controller.

[0040] According to one aspect of the present application, a storage medium is provided, in which a computer program is stored, wherein the computer program is configured to execute the above method when running.

[0041] According to one aspect of the present application, an electronic device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor is configured to run the computer program to execute the above method.

[0042] By means of the above technical solution, the present application provides a method, device, medium and equipment for controlling torsional vibration of a hybrid vehicle. The present application establishes an augmented matrix of a linear time-varying closed-loop system by establishing a nonlinear clutch friction model and linearizing it, and a linear time-varying model, and integrates time-varying scheduling parameters, and based on a multi-cell LPV finite time H ∞ Robust gain control strategy is used to control the time-varying closed-loop system and determine the target torsional vibration controller. It can be seen that the present application scheme fully considers the effect of factors such as nonlinear friction on torsional vibration in mode switching, proposes a modeling method for a linearized clutch friction model, and establishes a linear time-varying model for hybrid vehicle mode switching. Compared with the transmission system torsional vibration model of traditional vehicles, it can more accurately represent the low-frequency torsional vibration characteristics of the transmission system, improve torsional vibration modeling and torsional vibration suppression, and effectively improve the effect of torsional vibration suppression; in addition, the present application proposes a multi-cell LPV (linear variable parameter) finite time H ∞Robust variable gain control active control strategy, which utilizes the fast response characteristics of the motor to achieve good control effects. It can be applied to the torsional vibration problems of the transmission system caused by different clutch states. It can also ensure the dynamic performance of the vehicle while achieving the torsional vibration of the transmission system, and can optimize the NVH (noise, vibration and harshness) performance of the whole vehicle in terms of engineering and technical issues.

[0043] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0045] Figure 1 A flow chart of a hybrid vehicle torsional vibration control method provided by an embodiment of the present application is shown;

[0046] Figure 2 A schematic diagram of a power transmission route of a hybrid vehicle transmission system provided by an embodiment of the present application is shown;

[0047] Figure 3 An example flow chart of a hybrid vehicle torsional vibration control method provided by an embodiment of the present application is shown;

[0048] Figure 4 A schematic diagram of a polyhedron of a linear time-varying closed-loop system provided in an embodiment of the present application is shown;

[0049] Figure 5 A schematic diagram of an application scenario of a hybrid vehicle torsional vibration control method provided by an embodiment of the present application is shown;

[0050] Figure 6 A schematic structural diagram of a hybrid vehicle torsional vibration control device provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0051] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only embodiments of a part of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0052] During the research process, the inventors of the embodiments of the present application discovered that the existing torsional vibration control schemes ignored the effects of factors such as nonlinear friction of different clutches, and were unable to accurately characterize the self-excited torsional vibration coupling behavior of the power-split hybrid vehicle mode switching process. The dynamic model has strong nonlinearity and time-varying properties, and has certain limitations. Various studies have been conducted on the torsional vibration control of hybrid powertrain systems. However, in order to facilitate the robust analysis and synthesis of controllers, the torsional vibration control of hybrid vehicles is mostly based on simplified linear models, which cannot guarantee the global stability of mode switching and has a certain degree of conservatism.

[0053] Therefore, the present application provides a method for controlling torsional vibration of a hybrid vehicle, aiming to improve the following aspects:

[0054] 1. A modeling method for the linearized clutch friction model is proposed, and a linear time-varying model for hybrid vehicle mode switching is established. Compared with the transmission system torsional vibration model of traditional vehicles, it can more accurately represent the low-frequency torsional vibration characteristics of the transmission system, and improve the efficiency and feasibility of torsional vibration modeling and torsional vibration suppression analysis;

[0055] 2. Based on the linear time-varying model established above, a polyhedral LPV (linear parameter varying) finite time H ∞ Robust variable gain control active control strategy, which utilizes the fast response characteristics of the motor to achieve good control effects. It can be applied to the torsional vibration problems of the transmission system caused by different clutch states. It can also ensure the dynamic performance of the vehicle while achieving the torsional vibration of the transmission system, and can optimize the NVH performance of the whole vehicle in terms of engineering and technical issues.

[0056] See also Figure 1 , is a schematic diagram of a hybrid vehicle torsional vibration control method provided in an embodiment of the present application. The hybrid vehicle torsional vibration control method is used to establish a target torsional vibration controller to control the torsional vibration generated by the hybrid vehicle during the mode switching process.

[0057] S101: Establish a nonlinear clutch friction model and linearize it to determine the torque of the clutch during the sliding friction process.

[0058] In order to consider the effect of nonlinear friction on torsional vibration during mode switching, a nonlinear clutch friction model is established in the embodiment of the present application. Since the clutch friction characteristics play a certain damping role in the vehicle transmission system, a reset integrator nonlinear friction model can be established. Specifically, a reset integrator nonlinear friction model can be established to determine the corresponding relationship between the clutch friction model and the relative sliding speed; the friction coefficient in the corresponding relationship is Taylor-inverted to obtain the corresponding relationship between the linearized friction coefficient and the relative sliding speed; based on the corresponding relationship between the linearized friction coefficient and the relative sliding speed, the torque of the clutch during the sliding process is obtained. The specific calculation method can be found in the description below.

[0059] S102: Establish a linear time-varying model according to the power transmission route of the hybrid vehicle.

[0060] The power system of a hybrid vehicle generally includes multiple power sources (such as motors and engines), clutches, transmission mechanisms (such as planetary gear transmission mechanisms) and other components. In the power system, the power transmission route involves the working state of each component (whether it is working), the friction state (whether it is in a sliding state) and the engagement state between components during the mode switching process, which is the key to establishing a linear time-varying model.

[0061] like Figure 2 The example shows that the hybrid vehicle structure has three power sources, namely motor MG1, motor MG2 and engine, equipped with four clutches and two planetary gear transmission mechanisms. During the switching process from pure electric drive mode to hybrid drive mode, the power transmission route is that motors MG1 and MG2 work at the same time, and motor MG1 drags the engine to start, clutches CR1 and CR3 slide at the same time, and clutch CR3 is in an engaged state, and clutch CR4 is in a completely disengaged state.

[0062] In one implementation, the specific process of establishing a linear time-varying model according to the power transmission route of the transmission system may include: determining the components and linkage relationships of multiple power sources, multiple clutches, and multiple transmission mechanisms according to the power transmission route of the transmission system; analyzing the working state, friction state, and engagement state of each component during the mode switching process; establishing the transmission system dynamics equation according to the working state, friction state, and engagement state of each component to obtain a linear time-varying model. Specific examples and formulas can be found in the following description.

[0063] S103: Obtain time-varying scheduling parameters through a speed sensor.

[0064] Specifically, the speed difference signal at both ends of the clutch measured by the speed sensor can be used to obtain the time-varying scheduling parameters.

[0065] S104: Based on the torque of the clutch during the slipping process, the linear time-varying model, and the time-varying scheduling parameters, an augmented matrix of the linear time-varying closed-loop system is established.

[0066] In one implementation, the tracking error of wheel speed and torsion angle can be used to establish an augmented matrix of a linear time-varying closed-loop system, wherein the augmented state is introduced with the expected wheel speed and the expected torsion angle, and the torque expression of the current clutch in the linear time-varying model is calculated according to the torque of the clutch during the slipping process, and the augmented matrix of the linear time-varying closed-loop system is constructed in combination with the time-varying scheduling parameters. Specific formulas and examples are described below. The linear time-varying closed-loop system can be understood as a virtual model, which is the control object of the target torsional vibration controller.

[0067] S105: Based on multi-cell LPV finite time H ∞ Robust gain control strategy is used to control the linear time-varying closed-loop system and determine the target torsional vibration controller.

[0068] Specifically, the goal is to minimize the tracking error of wheel speed and torsion angle, based on the multi-cell LPV finite time H ∞ The robust gain feedback strategy controls the linear parameter time-varying closed-loop system and determines the target torsional vibration controller. For example, first, determine the multi-cell LPV finite time H ∞ The robust gain feedback strategy is: under the action of input u, the wheel speed and torsion angle track the expected value; then, the linear parameter time-varying closed-loop system is described by a polyhedron; then, a finite time H is designed for each vertex of the polyhedron. ∞ Robust controller, so that the controller satisfies H under the condition of finite time ∞ Performance; Finally, the polytope vertex gain is solved, and the continuous global LPV finite time H is obtained through weighted fitting. ∞ A robust controller is used as the target torsional vibration controller. See the example description below for details.

[0069] The following is an exemplary description of a hybrid vehicle torsional vibration control method provided in an embodiment of the present application. Figure 3 As shown, this example specifically includes the following steps 1 to 6.

[0070] Step 1: Establish a nonlinear clutch friction model and linearize it.

[0071] The clutch friction characteristics play a certain damping role for the vehicle transmission system. A reset integrator nonlinear friction model is established. The relationship between the clutch friction model and the relative sliding speed is:

[0072]

[0073] In the formula, ω rel Represents the relative sliding velocity, μ d Coulomb dynamic friction coefficient, μ s represents the static friction coefficient, and a represents the stribeck constant.

[0074] By setting the friction coefficient in Perform Taylor expansion at , ignoring the high-order terms, and obtain the relationship between the linearized friction coefficient and the relative sliding velocity:

[0075]

[0076] The torque of the clutch during the sliding process can be expressed as:

[0077]

[0078] Where n represents the number of friction pairs, R represents the effective radius, and F represents the clutch pressure.

[0079] Step 2: Establish a linear time-varying torsional vibration model through the power transmission route of the transmission system.

[0080] like Figure 2 As shown, the hybrid vehicle structure has three power sources, namely motor MG1, motor MG2 and engine, equipped with four clutches and two planetary gear transmission mechanisms. During the switching process from pure electric drive mode to hybrid drive mode, the power transmission route is that motors MG1 and MG2 work at the same time, and motor MG1 drags the engine to start, clutches CR1 and CR3 slide at the same time, and clutch CR3 is in an engaged state, and clutch CR4 is in a completely disengaged state. According to the power transmission route during the mode switching process, the transmission system dynamics equation is established as:

[0081]

[0082] Where W e , W R1 , W S1 , W C1 , W R2 , W S2 , W C2 , W W Respectively represent the engine, ring gear 1, sun gear 1, planet carrier 1, ring gear 2, sun gear 2, planet carrier 2 and wheel speed, θ e ,θ R1 ,θ C2 ,θ WRespectively represent the engine, ring gear 1, planetary carrier 2, wheel torsion angle, I E ,I R1 ,I S1 ,I S2 ,I h Respectively represent the engine, ring gear 1, motor 1, motor 2, and output shaft moment of inertia, T mg1 , T mg2 , T e , T CR1 , T CR2 , T2, T C2 Respectively represent the torques of motor 1, motor 2, engine, clutch CR1, clutch CR2, sun gear 1, and ring gear 2, T V , T roll , T air , T grad They represent load torque, rolling resistance torque, air resistance torque and slope resistance torque respectively, k1 and k2 represent the stiffness of engine shaft and output shaft, c1 and c2 represent the stiffness of engine shaft and output shaft, K1 and K2 represent the front and rear planetary beat characteristic parameters, m represents the vehicle body mass, and R represents the wheel radius.

[0083] Step 3: Obtain time-varying scheduling parameters through the speed sensor.

[0084] The speed difference signal at both ends of the clutch CR1 and CR2 measured by the speed sensor is used to obtain the time-varying scheduling parameters ρ1 and ρ2, where ρ1 and ρ2 are the speed difference W1 of the clutch CR1 and the speed difference W2 of the clutch CR2, and ρ1∈[W 1min W 1max ],ρ2∈[W 2min W 2max ].

[0085] Step 4: Taking the wheel speed and the power source speed as the tracking error minimization target, establish the augmented matrix of the linear time-varying closed-loop system.

[0086] The torsional vibration level of the transmission system is reflected by the good tracking performance of the wheel speed and the torsion angle, so the model augmented matrix is ​​established based on the tracking errors of the wheel speed and the torsion angle.

[0087] Introducing a new augmented state:

[0088]

[0089] Where W W_ref ,θ _ref They represent the expected wheel speed and the expected torsion angle respectively, and e1 and e2 represent the speed and angle tracking errors respectively.

[0090] According to the linearized friction coefficient and into the clutch friction torque equation (3), the torque expression of clutch CR1 and CR2 is obtained, and the time-varying augmented matrix of the system linear parameters is constructed:

[0091]

[0092] Where A, B, and D are the state matrix, input matrix, and disturbance matrix of the transmission system, respectively. x is the state quantity, u is the input quantity, and w is the disturbance input.

[0093] x=[We W S1 W R1 W S2 W C2 W W θ e -θ R1 θ C2 / i-θ W e1 e2] T

[0094] u=[T mg1 T mg2 F CR1 F CR2 ] T

[0095] w=[Te T V ] T

[0096] Step 5: Design a polyhedral LPV finite time H ∞ Robust feedback controller to suppress torsional vibration.

[0097] Aiming at minimizing the tracking error of wheel speed and torsion angle, a multi-cell LPV finite time H ∞ Robust feedback controller to achieve torsional vibration suppression for the transmission system.

[0098] Polytopic LPV finite time H ∞ The control objective of the robust controller is to make the wheel speed and torsion angle track the expected value under the action of input u and meet the control requirements under external disturbances. The augmented model of the controlled object-linear time-varying closed-loop system can be described as:

[0099]

[0100] Where y is the measurable output and z is the controlled output.

[0101] like Figure 4 As shown, the linear time-varying closed-loop system described by the equation can be described by a polyhedron:

[0102]

[0103] in: represents each vertex of the polyhedron. These vertices are represented by the upper and lower boundaries of the time-varying parameters ρ1 and ρ2 as follows:

[0104]

[0105] The coordinates α of a point in the polyhedron Θ i It can be described as:

[0106]

[0107] in,

[0108] Design finite time H for each of the four vertices of the polyhedron ∞ The robust controller u=Kx requires the controller to satisfy H under the condition of finite time. ∞ performance:

[0109]

[0110] Where S0, S T is a given symmetric matrix, and λ represents the interference suppression level.

[0111] Limited time H ∞ The robust controller can be obtained by solving the following inequalities to obtain the symmetric matrix function X(t) and the matrix function L(t).

[0112]

[0113] X(0)>Y2 -1 (14)

[0114] X(T) T -1 (15)

[0115] Among them, Y1∈{S w ,γ 2 I}; Y2∈{R,γ 2 S0}

[0116] Then under the finite time condition H ∞ The control problem can be solved as follows:

[0117] L(t)=K(t)X(t) (16)

[0118] ​The LMI toolbox is used to solve matrix inequalities (12)-(15) and the four polytope vertex gains K1, K2, K3, and K4 are solved. By selecting appropriate weighting functions, the polytope vertex controller is fitted to obtain the continuous global LPV finite time H ∞ Robust Controller:

[0119] K=α1K1+α2K2+α3K3+α4K4 (17)

[0120] like Figure 5 As shown in the figure, according to the difference between the expected value of the speed angle and the actual value of the speed angle signal and the linearized clutch friction coefficient, the augmented model of the linear time-varying closed-loop system is obtained. ∞ The robust controller is designed by considering the uncertainty and boundedness of the friction coefficients in the clutches CR1 and CR2 to obtain the range of the four vertices of the augmented model, and solving the controller gain based on the four vertices. Finally, the controller gain is linearly weighted to obtain the global controller gain, and the control input T is obtained by combining the controller output. mg1 , T mg2 、F CR1 、F CR2 , through the motor and clutch actuator, it acts on the vehicle transmission system to achieve the purpose of suppressing the torsional vibration of the transmission system.

[0121] In summary, the embodiment of the present application provides a method for controlling torsional vibration of a hybrid vehicle, by establishing a nonlinear clutch friction model and linearizing it, as well as a linear time-varying model, and integrating time-varying scheduling parameters, establishing an augmented matrix of a linear time-varying closed-loop system, and based on a polyhedral LPV finite time H ∞ Robust gain control strategy is used to control the time-varying closed-loop system and determine the target torsional vibration controller. It can be seen that the present application scheme fully considers the effect of factors such as nonlinear friction on torsional vibration in mode switching, proposes a modeling method for a linearized clutch friction model, and establishes a linear time-varying model for mode switching of a hybrid vehicle. Compared with the torsional vibration model of the transmission system of a traditional vehicle, it can more accurately represent the low-frequency torsional vibration characteristics of the transmission system, improve torsional vibration modeling and torsional vibration suppression, and effectively improve the effect of torsional vibration suppression; in addition, the present application proposes a multi-cell LPV finite time H ∞ Robust variable gain control active control strategy, which utilizes the fast response characteristics of the motor to achieve good control effects. It can be applied to the torsional vibration problems of the transmission system caused by different clutch states. It can also ensure the dynamic performance of the vehicle while achieving the torsional vibration of the transmission system, and can optimize the NVH performance of the whole vehicle in terms of engineering and technical issues.

[0122] Corresponding to the above method, the embodiment of the present application also provides a hybrid electric vehicle torsional vibration control device for establishing a target torsional vibration controller to control the torsional vibration generated by the hybrid electric vehicle during the mode switching process, see Figure 6 , the device comprises:

[0123] A nonlinear clutch friction model building unit 601 is used to build a nonlinear clutch friction model and linearize it to determine the torque of the clutch during the sliding friction process;

[0124] A linear time-varying model building unit 602 builds a linear time-varying model according to a power transmission route of the hybrid vehicle;

[0125] A time-varying scheduling parameter determination unit 603, configured to obtain a time-varying scheduling parameter through a speed sensor;

[0126] An augmented matrix establishing unit 604, configured to establish an augmented matrix of a linear time-varying closed-loop system based on the torque of the clutch during the slipping process, the linear time-varying model, and the time-varying scheduling parameters;

[0127] The controller design unit 605 is used to design a controller based on a multi-cell LPV finite time H ∞ A robust gain control strategy is used to control the linear time-varying closed-loop system and determine a target torsional vibration controller.

[0128] In one implementation, the nonlinear clutch friction model building unit 601 is specifically used for:

[0129] Establish a reset integrator nonlinear friction model and determine the corresponding relationship between the clutch friction model and the relative sliding speed;

[0130] The friction coefficient in the corresponding relationship is Taylor expanded to obtain the corresponding relationship between the linearized friction coefficient and the relative sliding speed;

[0131] Based on the corresponding relationship between the linearized friction coefficient and the relative sliding speed, the torque of the clutch during the sliding friction process is obtained.

[0132] In one implementation, the linear time-varying model building unit 602 is specifically used for:

[0133] According to the power transmission route of the transmission system, determine the components and linkage relationships of multiple power sources, multiple clutches and multiple transmission mechanisms;

[0134] Analyze the working state, friction state and engagement state of each component during mode switching;

[0135] According to the working state, friction state and engagement state of each component, a transmission system dynamics equation is established to obtain a linear time-varying model.

[0136] In one implementation, the time-varying scheduling parameter determining unit 603 is specifically configured to:

[0137] The speed difference signal at both ends of the clutch measured by the speed sensor is used to obtain the time-varying scheduling parameters.

[0138] In one implementation, the augmented matrix establishing unit 604 is specifically used for:

[0139] An augmented matrix of a linear time-varying closed-loop system is established with the tracking errors of the wheel speed and the torsion angle, wherein the augmented state is introduced with the expected wheel speed and the expected torsion angle, and the torque expression of the current clutch in the linear time-varying model is calculated according to the torque of the clutch during the slipping process, and the augmented matrix of the linear time-varying closed-loop system is constructed in combination with the time-varying scheduling parameters.

[0140] In one implementation, the controller design unit 605 is specifically configured to:

[0141] With the goal of minimizing the tracking error of wheel speed and torsion angle, a multi-cell LPV finite time H ∞ A robust gain feedback strategy is used to control the linear parameter time-varying closed-loop system and determine the target torsional vibration controller.

[0142] In one implementation, the controller design unit 605 is specifically configured to:

[0143] Determine the multi-cell LPV finite time H ∞ The robust gain feedback strategy is: under the action of input u, the wheel speed and torsion angle track the expected value;

[0144] Use polytopes to describe linear parameter time-varying closed-loop systems;

[0145] Design a finite time H for each vertex of the polyhedron ∞ Robust controller, so that the controller satisfies H under the condition of finite time ∞ performance;

[0146] The polytope vertex gains are solved and the continuous global LPV finite time H is obtained through weighted fitting. ∞ A robust controller is used as the target torsional vibration controller.

[0147] In one implementation, the controller design unit 605 is further configured to:

[0148] The output of the target torsional vibration controller is connected to the motor actuator and the clutch actuator as input, and acts on the vehicle transmission system through the motor actuator and the clutch actuator to suppress the torsional vibration of the transmission system.

[0149] An embodiment of the present application further provides a storage medium, in which a computer program is stored, wherein the computer program is configured to execute the steps of any of the above method embodiments when running.

[0150] Optionally, in this embodiment, the storage medium may be configured to store a computer program for performing the following steps:

[0151] Establish a nonlinear clutch friction model and linearize it to determine the clutch torque during the sliding process;

[0152] According to the power transmission route of hybrid electric vehicle, a linear time-varying model is established;

[0153] Obtain time-varying dispatch parameters through speed sensors;

[0154] Based on the torque of the clutch during the slipping process, the linear time-varying model, and the time-varying scheduling parameters, an augmented matrix of the linear time-varying closed-loop system is established;

[0155] Based on the multi-cell LPV finite time H ∞ A robust gain control strategy is used to control the linear time-varying closed-loop system and determine a target torsional vibration controller.

[0156] Optionally, in this embodiment, the above-mentioned storage medium may include but is not limited to: a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and other media that can store computer programs.

[0157] An embodiment of the present application further provides an electronic device, including a memory and a processor, wherein a computer program is stored in the memory, and the processor is configured to run the computer program to execute the steps in any one of the above method embodiments.

[0158] Optionally, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor, and the input / output device is connected to the processor.

[0159] Optionally, in this embodiment, the processor may be configured to perform the following steps through a computer program:

[0160] Establish a nonlinear clutch friction model and linearize it to determine the clutch torque during the sliding process;

[0161] According to the power transmission route of hybrid electric vehicle, a linear time-varying model is established;

[0162] Obtain time-varying dispatch parameters through speed sensors;

[0163] Based on the torque of the clutch during the slipping process, the linear time-varying model, and the time-varying scheduling parameters, an augmented matrix of the linear time-varying closed-loop system is established;

[0164] Based on the multi-cell LPV finite time H ∞ A robust gain control strategy is used to control the linear time-varying closed-loop system and determine a target torsional vibration controller.

[0165] Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments and optional implementation modes, and this embodiment will not be described in detail here.

[0166] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0167] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0168] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0169] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0170] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0171] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk and other media that can store program codes.

[0172] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for controlling torsional vibration of a hybrid electric vehicle, characterized in that: The method is used to establish a target torsional vibration controller to control the torsional vibration generated by the hybrid vehicle during the mode switching process, and includes: Establish a nonlinear clutch friction model and linearize it to determine the clutch torque during the sliding process; According to the power transmission route of hybrid electric vehicle, a linear time-varying model is established; Obtain time-varying dispatch parameters through speed sensors; Based on the torque of the clutch during the slipping process, the linear time-varying model, and the time-varying scheduling parameters, an augmented matrix of the linear time-varying closed-loop system is established; Based on the multi-cell LPV finite time H ∞ A robust gain control strategy is used to control the linear time-varying closed-loop system and determine a target torsional vibration controller.

2. The method according to claim 1, characterized in that The method of establishing a nonlinear clutch friction model and linearizing it to determine the torque of the clutch during the sliding friction process includes: Establish a reset integrator nonlinear friction model and determine the corresponding relationship between the clutch friction model and the relative sliding speed; The friction coefficient in the corresponding relationship is Taylor expanded to obtain the corresponding relationship between the linearized friction coefficient and the relative sliding speed; Based on the corresponding relationship between the linearized friction coefficient and the relative sliding speed, the torque of the clutch during the sliding friction process is obtained.

3. The method according to claim 1, characterized in that The step of establishing a linear time-varying model according to the power transmission route of the transmission system includes: According to the power transmission route of the transmission system, determine the components and linkage relationships of multiple power sources, multiple clutches and multiple transmission mechanisms; Analyze the working state, friction state and engagement state of each component during mode switching; According to the working state, friction state and engagement state of each component, a transmission system dynamics equation is established to obtain a linear time-varying model.

4. The method according to claim 1, characterized in that: The obtaining of the time-varying scheduling parameters through the rotation speed sensor includes: The speed difference signal at both ends of the clutch measured by the speed sensor is used to obtain the time-varying scheduling parameters.

5. The method according to claim 1, characterized in that The method of establishing an augmented matrix of a linear time-varying closed-loop system based on the torque of the clutch during the sliding process, the linear time-varying model, and the time-varying scheduling parameters includes: An augmented matrix of a linear time-varying closed-loop system is established with the tracking errors of the wheel speed and the torsion angle, wherein the augmented state is introduced with the expected wheel speed and the expected torsion angle, and the torque expression of the current clutch in the linear time-varying model is calculated according to the torque of the clutch during the slipping process, and the augmented matrix of the linear time-varying closed-loop system is constructed in combination with the time-varying scheduling parameters.

6. The method according to claim 1, characterized in that The multi-cell LPV finite time H ∞ A robust gain control strategy is used to control the linear time-varying closed-loop system and determine a target torsional vibration controller, including: With the goal of minimizing the tracking error of wheel speed and torsion angle, a multi-cell LPV finite time H ∞ A robust gain feedback strategy is used to control the linear parameter time-varying closed-loop system and determine the target torsional vibration controller.

7. The method according to claim 6, characterized in that The goal is to minimize the tracking error of wheel speed and torsion angle, based on the multi-cell LPV finite time H ∞ A robust gain feedback strategy is used to control the linear parameter time-varying closed-loop system and determine the target torsional vibration controller, including: Determine the multi-cell LPV finite time H ∞ The robust gain feedback strategy is: under the action of input u, the wheel speed and torsion angle track the expected value; Use polytopes to describe linear parameter time-varying closed-loop systems; Design a finite time H for each vertex of the polyhedron ∞ Robust controller, so that the controller satisfies H under the condition of finite time ∞ performance; The polytope vertex gains are solved and the continuous global LPV finite time H is obtained through weighted fitting. ∞ A robust controller is used as the target torsional vibration controller.

8. The method according to any one of claims 1 to 7, characterized in that: The method further comprises: The output of the target torsional vibration controller is connected to the motor actuator and the clutch actuator as input, and acts on the vehicle transmission system through the motor actuator and the clutch actuator to suppress the torsional vibration of the transmission system.

9. A torsional vibration control device for a hybrid vehicle, characterized in that: The device is used to establish a target torsional vibration controller to control the torsional vibration generated by the hybrid vehicle during the mode switching process, and the device includes: A nonlinear clutch friction model building unit is used to build a nonlinear clutch friction model and linearize it to determine the torque of the clutch during the sliding process; A linear time-varying model building unit is used to build a linear time-varying model according to the power transmission route of the hybrid vehicle; A time-varying dispatch parameter determination unit, used for obtaining the time-varying dispatch parameter through a rotation speed sensor; An augmented matrix establishing unit, used to establish an augmented matrix of a linear time-varying closed-loop system based on the torque of the clutch during the slipping process, the linear time-varying model, and the time-varying scheduling parameters; Controller design unit for multi-cell LPV finite-time H ∞ A robust gain control strategy is used to control the linear time-varying closed-loop system and determine a target torsional vibration controller.

10. A storage medium, characterized in that: The storage medium stores a computer program, wherein the computer program is configured to execute the method according to any one of claims 1 to 9 when executed.

11. An electronic device comprising a memory and a processor, characterized in that: A computer program is stored in the memory, and the processor is configured to run the computer program to perform the method according to any one of claims 1 to 9.

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