阅读说明：本技术 一种车辆路面负载转矩确定方法和系统 (Method and system for determining vehicle road surface load torque ) 是由 韩立金 刘瑞 刘辉 王伟达 马越 张海涛 于 2020-04-27 设计创作，主要内容包括：本发明涉及一种车辆路面负载转矩确定方法和系统。该方法包括：获取耦合机构动力学模型；根据耦合机构动力学模型,以输入轴转速和输出轴转速为系统的状态变量,以电机A的转矩和电机B的转矩为控制变量构建系统状态空间模型；根据系统状态空间模型构建观测器模型；获取检测状态量,并根据所设定的状态量对观测器模型进行修正,得到修正后的观测器模型；获取电机A的转矩、电机B的转矩和反馈矩阵；利用修正后的观测器模型,根据电机A的转矩、电机B的转矩和反馈矩阵确定路面负载转矩。本发明所提供的车辆路面负载转矩确定方法和系统,能够简化负载转矩测量方法的复杂性,同时,能够摒弃现有技术检测负载转矩的传感器,从而降低检测成本。(The invention relates to a vehicle road load torque determination method and a vehicle road load torque determination system. The method comprises the following steps: acquiring a coupling mechanism dynamic model; according to a coupling mechanism dynamic model, a system state space model is constructed by taking the rotating speed of an input shaft and the rotating speed of an output shaft as state variables of a system and taking the torque of a motor A and the torque of a motor B as control variables; constructing an observer model according to the system state space model; acquiring a detection state quantity, and correcting the observer model according to the set state quantity to obtain a corrected observer model; acquiring the torque of a motor A, the torque of a motor B and a feedback matrix; and determining the road load torque according to the torque of the motor A, the torque of the motor B and the feedback matrix by using the corrected observer model. The method and the system for determining the vehicle road surface load torque can simplify the complexity of a load torque measuring method, and can abandon a sensor for detecting the load torque in the prior art, thereby reducing the detection cost.)

1. A method of determining a road surface load torque of a vehicle, characterized by comprising:

acquiring a coupling mechanism dynamic model;

according to the coupling mechanism dynamic model, a system state space model is constructed by taking the rotating speed of an input shaft and the rotating speed of an output shaft as state variables of the system and taking the torque of a motor A and the torque of a motor B as control variables;

constructing an observer model according to the system state space model;

acquiring a detection state quantity, and correcting the observer model according to the set state quantity to obtain a corrected observer model;

acquiring the torque of the motor A, the torque of the motor B and a feedback matrix;

and determining the road load torque according to the torque of the motor A, the torque of the motor B and the feedback matrix by using the corrected observer model.

2. A method of determining road load torque for a vehicle as claimed in claim 1, wherein said coupling mechanism dynamics model is:

wherein k is₁Representing a first characteristic line of stars, k₂Representing a second planet row characteristic parameter, k₃Representing a third planet row characteristic parameter, T_ARepresenting the torque, T, of the motor A_BRepresenting the torque, T, of the motor B_iRepresenting the torque, T, of input i_oWhich is indicative of the torque at the output,which is indicative of the angular acceleration of the input shaft,representing angular acceleration of the output shaft, b₁₁、b₁₂、b₂₁And b₂₂All represent constants.

3. A method of determining road load torque for a vehicle as claimed in claim 1, wherein said system state space model is:

wherein the content of the first and second substances,representing the derivative of the state quantity, X representing the state quantity, X comprising the coupling mechanism input shaft angular accelerationAnd output shaft angular acceleration

4. A road surface load torque determination method for a vehicle according to claim 1, wherein said modified observer model is:

wherein the content of the first and second substances,a derivative of a state quantity of the observer model after correction, z a state quantity of the observer model after correction, y a prime mover power transmission system output quantity, u an input control quantity, and u ═ T_A,T_B]，T_ARepresenting the torque, T, of the motor A_BWhich represents the torque of the motor B and,representing road load torque, L representing a feedback matrix, A₁₁、A₂₁、B₁、B₂、A₁₂And A₂₂Are all constant.

5. A method according to claim 1, wherein said determining a road load torque from said torque of said electric machine a, said torque of said electric machine B and said feedback matrix using said modified observer model specifically comprises:

determining an output quantity and an input control quantity according to the torque of the motor A and the torque of the motor B by using the system state space model;

and determining the road load torque according to the output quantity and the input control quantity by using the corrected observer model.

6. A road surface load torque determination method for a vehicle according to claim 1, wherein said detection state quantity includes a vehicle speed and a road surface load quantity.

7. A vehicle road surface load torque determination system, comprising:

the coupling mechanism dynamic model acquisition module is used for acquiring a coupling mechanism dynamic model;

the system state space model building module is used for building a system state space model by taking the rotating speed of an input shaft and the rotating speed of an output shaft as state variables of a system and taking the torque of the motor A and the torque of the motor B as control variables according to the coupling mechanism dynamic model;

the observer model building module is used for building an observer model according to the system state space model;

the observer model correction module is used for acquiring the detected state quantity and correcting the observer model according to the set state quantity to obtain a corrected observer model;

the road load torque determining module is used for acquiring a module for acquiring the torque of the motor A, the torque of the motor B and a feedback matrix;

and determining the road load torque according to the torque of the motor A, the torque of the motor B and the feedback matrix by using the corrected observer model.

8. The system of claim 7, wherein the road load torque determination module specifically includes:

an input output quantity determining unit, which is used for determining an output quantity and an input control quantity according to the torque of the motor A and the torque of the motor B by using the system state space model;

and a road load torque determination unit for determining a road load torque from the output quantity and the input control quantity by using the corrected observer model.

Technical Field

The invention relates to the field of vehicle road surface load torque determination, in particular to a vehicle road surface load torque determination method and a vehicle road surface load torque determination system.

Background

In order to cope with global resource shortage and climate warming, the automobile industry such as Europe, America and the like in China has successively completed the standard regulation formulation of fuel consumption of passenger cars of 2020 and even longer in each year, and the fuel consumption of the passenger cars and the corresponding CO₂Emissions place more stringent requirements. The fuel consumption standard of the passenger vehicle is like DaomClise sword which is highly suspended at the top of the automobile enterprise, and the fuel consumption standard of the passenger vehicle forces the automobile enterprise to increase the investment in the field of new energy automobiles.

A hybrid vehicle refers to a vehicle having two or more power sources and a power conversion device. The hybrid electric vehicle can adjust the working point of the engine to enable the engine to operate in a high-efficiency area, can reduce energy loss of the engine by controlling idling start-stop or sliding start-stop of the engine and the like, and can recycle energy by recovering braking energy. The hybrid electric vehicle has the characteristics of energy conservation and emission reduction, and draws wide attention.

In the process of solving the control variables, information of ground loads is needed, and different ground loads correspond to different control variable results. The existing vehicle sensor has complex torque measuring method and higher cost.

Disclosure of Invention

The invention aims to provide a vehicle road surface load torque determination method and a vehicle road surface load torque determination system, which can reduce the load torque detection cost and simplify the complexity of a load torque measurement method.

In order to achieve the purpose, the invention provides the following scheme:

a vehicle road surface load torque determination method, comprising:

acquiring a coupling mechanism dynamic model;

according to the coupling mechanism dynamic model, a system state space model is constructed by taking the rotating speed of an input shaft and the rotating speed of an output shaft as state variables of the system and taking the torque of a motor A and the torque of a motor B as control variables;

constructing an observer model according to the system state space model;

acquiring a detection state quantity, and correcting the observer model according to the set state quantity to obtain a corrected observer model;

acquiring the torque of the motor A, the torque of the motor B and a feedback matrix;

and determining the road load torque according to the torque of the motor A, the torque of the motor B and the feedback matrix by using the corrected observer model.

Optionally, the coupling mechanism dynamic model is:

wherein k is₁Representing a first characteristic line of stars, k₂Representing a second planet row characteristic parameter, k₃Representing a third planet row characteristic parameter, T_ARepresenting the torque, T, of the motor A_BRepresenting the torque, T, of the motor B_iRepresenting the torque, T, of input i_oWhich is indicative of the torque at the output,

which is indicative of the angular acceleration of the input shaft,

representing angular acceleration of the output shaft, b₁₁、b₁₂、b₂₁And b₂₂All represent constants.

Optionally, the system state space model is:

wherein the content of the first and second substances,

representing the derivative of the state quantity, X representing the state quantity, X comprising the coupling mechanism input shaft angular accelerationAnd output shaft angular accelerationY represents the output quantity, Y comprises the speed omega of the input shaft of the coupling mechanism_iAnd the output shaft rotating speed omega of the coupling mechanism_oU represents a control quantity, and includes a torque U of the motor A₁And the torque u of the motor B₂And B is interference amount, A is a system matrix B is a control matrix, C is an output matrix, and A, B and C are constant matrixes.

Optionally, the modified observer model is:

wherein the content of the first and second substances,a derivative of a state quantity of the observer model after correction, z a state quantity of the observer model after correction, y a prime mover power transmission system output quantity, u an input control quantity, and u ═ T_A,T_B]，T_ARepresenting the torque, T, of the motor A_BWhich represents the torque of the motor B and,representing road load torque, L representing a feedback matrix, A₁₁、A₂₁、B₁、B₂、A₁₂And A₂₂Are all constant.

Optionally, the determining the road load torque according to the torque of the motor a, the torque of the motor B and the feedback matrix by using the corrected observer model specifically includes:

determining an output quantity and an input control quantity according to the torque of the motor A and the torque of the motor B by using the system state space model;

and determining the road load torque according to the output quantity and the input control quantity by using the corrected observer model.

Optionally, the detection state quantity includes a vehicle speed and a road surface load quantity.

A vehicle road surface load torque determination system comprising:

the coupling mechanism dynamic model acquisition module is used for acquiring a coupling mechanism dynamic model;

the system state space model building module is used for building a system state space model by taking the rotating speed of an input shaft and the rotating speed of an output shaft as state variables of a system and taking the torque of the motor A and the torque of the motor B as control variables according to the coupling mechanism dynamic model;

the observer model building module is used for building an observer model according to the system state space model;

the observer model correction module is used for acquiring the detected state quantity and correcting the observer model according to the set state quantity to obtain a corrected observer model;

the road load torque determining module is used for acquiring a module for acquiring the torque of the motor A, the torque of the motor B and a feedback matrix;

and determining the road load torque according to the torque of the motor A, the torque of the motor B and the feedback matrix by using the corrected observer model.

Optionally, the road load torque determination module specifically includes:

an input output quantity determining unit, which is used for determining an output quantity and an input control quantity according to the torque of the motor A and the torque of the motor B by using the system state space model;

and a road load torque determination unit for determining a road load torque from the output quantity and the input control quantity by using the corrected observer model.

According to the specific embodiment provided by the invention, the invention discloses the following technical effects:

according to the method and the system for determining the vehicle road surface load torque, provided by the invention, the road surface load torque can be accurately determined according to the torque of the motor A, the torque of the motor B and the feedback matrix by constructing a system state space model and an observer model, so that the complexity of a load torque measuring method can be simplified. Meanwhile, a sensor for detecting the load torque in the prior art can be abandoned, so that the detection cost is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is a flow chart of a method for determining a road load torque of a vehicle provided by an embodiment of the present invention;

fig. 2 is a block diagram of a road surface load observation model (road surface load observer) according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a vehicle road load torque determination system according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention aims to provide a vehicle road surface load torque determination method and a vehicle road surface load torque determination system, which can reduce the load torque detection cost and simplify the complexity of a load torque measurement method.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

Fig. 1 is a flowchart of a method for determining a road load torque of a vehicle according to an embodiment of the present invention, and as shown in fig. 1, the method for determining the road load torque of the vehicle includes:

s1, acquiring a coupling mechanism dynamic model;

s2, constructing a system state space model by taking the rotating speed of an input shaft and the rotating speed of an output shaft as state variables of a system and taking the torque of a motor A and the torque of a motor B as control variables according to the coupling mechanism dynamic model;

s3, constructing an observer model according to the system state space model;

s4, acquiring the detected state quantity, and correcting the observer model according to the set state quantity to obtain a corrected observer model;

s5, acquiring the torque of the motor A, the torque of the motor B and a feedback matrix;

and S6, determining road surface load torque according to the torque of the motor A, the torque of the motor B and the feedback matrix by using the corrected observer model.

As another specific embodiment provided by the invention, the method establishes the state observer based on the state space equation of the power system to estimate the load torque, thereby improving the practicability of the engine starting control strategy. The specific implementation mode is as follows:

(1) and according to a coupling mechanism dynamic model, selecting the rotating speed of an input shaft and the rotating speed of an output shaft as state variables of the system, and the torques of a motor A and a motor B as control variables of the system, and establishing a system state space expression.

(2) Adding the state x on the basis of the state space expression obtained in the step (1)₁＝T_fAnd establishing a new system state space expression.

(3) For the state variable x₁Introducing v and w, constructing a state space expression of the v and w, constructing a dimension reduction observer aiming at an unmeasured subsystem, and obtaining a dynamic equation of an observation error of the dimension reduction observer as

(4) And (4) because the derivative of the output variable y exists in the introduced variable w, reducing the sensitivity of the system to noise by introducing a new state variable z, and substituting the new state variable z into the observer equation obtained in the step (3) to obtain a new observer equation insensitive to noise.

(5): setting the input control quantity u to [ T ]_A,T_B]And substituting the output quantity y into the original system state space model formula (3).

(6) According to the observer equation (12) established in the step (4), the y obtained in the step (5) and the controlled variable u, the feedback matrix L are substituted into the formula (12) to calculate the state variable x₁Is estimated value of

Wherein the reduced order load state observer is designed

The coupling mechanism dynamic model is as follows:

in the formula, wherein k₁Representing a first characteristic line of stars, k₂Representing a second planet row characteristic parameter, k₃Representing a third planet row characteristic parameter, T_ARepresenting the torque, T, of the motor A_BRepresenting the torque, T, of the motor B_iRepresenting the torque, T, of input i_oWhich is indicative of the torque at the output,which is indicative of the angular acceleration of the input shaft,representing angular acceleration of the output shaft, b₁₁、b₁₂、b₂₁And b₂₂All represent constants.

Selecting the rotating speed omega of the input shaft according to the dynamic model obtained by the formula (1)_iAnd the rotational speed omega of the output shaft_oThe torque T of motor A being a state variable of the system_AAnd torque T of motor B_BAs control of the systemThe system variables, namely:

the state space expression of the coupling mechanism at this stage is:

in the formula (I), the compound is shown in the specification,

representing the derivative of the state quantity, X representing the state quantity, X comprising the coupling mechanism input shaft angular acceleration

And output shaft angular accelerationY represents the output, including the input shaft speed ω of the coupling mechanism_iAnd the output shaft rotating speed omega of the coupling mechanism_oAnd U represents a control quantity including a torque U of the motor A₁And the torque u of the motor B₂And B is interference amount, A is a system matrix B is a control matrix, C is an output matrix, and A, B and C are constant matrixes.

The rank of the matrix [ BAB ] is 2, so the system can be completely controlled; since the rank of the matrix [ CCA ] T is 2, the system is fully intuitive.

The load torque is considered to be a constant value during one sampling period.

The state space expression of the system is rewritten as follows according to equation (3):

in the formula (I), the compound is shown in the specification,

from equation (4), the input shaft speed and the output shaft speed (state variable x)₂) Can be directly measured by the output variable y, and also requires the load on the road surface (state variable x)₁) And designing a dimension reduction observer. The state space expression for the non-measurable subsystem is:

order to

Then there is

And designing an observer aiming at the subsystem (7), namely the dimension reduction observer of the original system. Introducing a feedback matrix L, and according to an observer theory, an observer equation of the subsystem (7) is as follows:

in the formula, the feedback matrix L takes the value of L ═ L₁l₂]Wherein l is₁And l₂Are all design parameters.

The dynamic equation of the observer observation error obtained according to the equations (7) and (8) is:

in the formula: t is_fIn order to load the road surface,is an estimated road load value.

Thus, the solution to the observation error is:

in the formula, c₀Is constant, the stable condition of the system is

At this time, the observation error of the load torque gradually approaches 0 in an exponential manner with time t, and the approach rate thereof is correlated with the pole arrangement position.

The presence of a derivative of the output variable y in the variable w introduced in equation (6) increases the sensitivity of the system to noise, and therefore defines a new state variable z:

it can be substituted by the formula (8):

wherein the content of the first and second substances,

a derivative of a state quantity of the observer model after correction, z a state quantity of the observer model after correction, y a prime mover power transmission system output quantity, u an input control quantity, and u ═ T_A,T_B]，T_ARepresenting the torque, T, of the motor A_BWhich represents the torque of the motor B and,

representing road load torque, L representing a feedback matrix, A₁₁、A₂₁、B₁、B₂、A₁₂And A₂₂Are all constant.

The state variable x can be obtained by the formula (12)₁Is estimated value ofIt is used.

Figure 2 shows theThe observer model takes the output variable and the control variable of the state space expression of the prime power transmission system as input, and obtains the road load T through the introduced state variable z_fThe observed value of (1).

In addition, corresponding to the above vehicle road surface load torque determination method, the present invention also provides a vehicle road surface load torque determination system, as shown in fig. 3, the system comprising: the system comprises a coupling mechanism dynamic model acquisition module 1, a system state space model construction module 2, an observer model construction module 3, an observer model correction module 4, an acquisition module 5 and a road surface load torque determination module 6.

The coupling mechanism dynamic model obtaining module 1 is used for obtaining a coupling mechanism dynamic model; the system state space model building module 2 is used for building a system state space model by taking the rotating speed of an input shaft and the rotating speed of an output shaft as state variables of a system and taking the torque of the motor A and the torque of the motor B as control variables according to the coupling mechanism dynamic model; the observer model building module 3 is used for building an observer model according to the system state space model; the observer model correction module 4 is used for acquiring a detected state quantity and correcting the observer model according to the set state quantity to obtain a corrected observer model; the acquisition module 5 is used for acquiring the torque of the motor A, the torque of the motor B and a feedback matrix; and the road load torque determination module 6 is used for determining the road load torque according to the torque of the motor A, the torque of the motor B and the feedback matrix by using the corrected observer model.

The road surface load torque determination module 6 specifically includes: an input-output amount determination unit and a road surface load torque determination unit.

An input output quantity determining unit, which is used for determining an output quantity and an input control quantity according to the torque of the motor A and the torque of the motor B by using the system state space model; and the road load torque determining unit is used for determining the road load torque according to the output quantity and the input control quantity by using the corrected observer model.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. For the system disclosed by the embodiment, the description is relatively simple because the system corresponds to the method disclosed by the embodiment, and the relevant points can be referred to the method part for description.

The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.