Torque directional distribution electric drive axle configuration optimization method based on layered topological graph

Abstract

The invention discloses a torque directional distribution electric drive axle configuration optimization method based on a hierarchical topological graph. The method comprises the steps that 1, a graph model, a matrix model and an adjacent matrix of a torque directional distribution electric drive axle are defined; 2, defining constraint conditions of an adjacent matrix based on a basic design principle of the torque directional distribution electric drive axle, and constructing a digital configuration library of the torque directional distribution electric drive axle; 3, constructing a universal dynamical model of the torque directional distribution electric drive axle, wherein the universal dynamical model comprises a basic transmission unit dynamical model, a connecting shaft dynamical model, a connecting model, a power input model and a load model; and 4, evaluating the torque directional distribution electric drive axle assembly, selecting an optimal configuration based on the evaluation score, and displaying a configuration optimization result through a radar map. According to the method, the performance of the torque directional distribution electric drive axle assembly can be systematically and scientifically evaluated, and theoretical guidance is provided for efficient and scientific design and optimization of the torque directional distribution electric drive axle.

Description

Technical Field

[0001] The invention relates to the field of electric vehicle transmission system design, and in particular to a method for optimizing the configuration of an electric drive axle with torque directional distribution based on a hierarchical topology diagram. Background Art

[0002] The torque-oriented electric drive axle is a centralized electric drive system that can achieve torque-oriented distribution on electric vehicles. By applying reasonable torque-oriented distribution under different working conditions, it can effectively improve the maneuverability, stability, passability and economy of electric vehicles. It has the characteristics of high integration, high performance and high driving efficiency, and has considerable application prospects in high-end electric vehicles. Generally speaking, the torque-oriented electric drive axle consists of two drive motors and multiple sets of planetary gears and other transmission elements. The diverse connection methods between the transmission elements lead to its transmission configuration scheme having outstanding diversified characteristics. This diversified characteristic leads to huge challenges in the selection of the transmission configuration scheme of the torque-oriented electric drive axle, which requires the support of a systematic and scientific method system.

[0003] In the existing technical solutions, the evaluation and configuration optimization of electric drive axles mainly rely on performance tests at the vehicle level. This method usually evaluates the performance of the drive axle assembly from the perspective of the power and economy of the vehicle. Although the performance test at the vehicle level provides a certain reference value, it fails to go deep into the internal structure and working principle of the drive axle assembly, making it difficult to make a direct and comprehensive evaluation of the performance of the electric drive axle itself during the design stage, and thus it is difficult to provide effective theoretical guidance for the selection of the transmission configuration scheme of the electric drive axle.

[0004] As a branch of topology, graph theory provides a new perspective to solve this problem. Based on the hierarchical topological graph model in graph theory, the various connection modes of the transmission elements of the torque-oriented distribution electric drive axle can be represented as corresponding graph models, and then converted into corresponding algebraic models to achieve the "digital" modeling of its diversified transmission configuration schemes, and then quantitatively analyze the various performance indicators of the torque-oriented distribution electric drive axle. This method can not only systematically and scientifically make a direct and comprehensive evaluation of the performance of the torque-oriented distribution electric drive axle itself, but also efficiently handle the complex torque-oriented distribution electric drive axle system design process, and provide a reliable theoretical basis for its configuration optimization.

[0005] Therefore, in view of the lack of a systematic and scientific evaluation system for the torque-oriented distribution electric drive axle assembly, the present invention provides a method for optimizing the configuration of the torque-oriented distribution electric drive axle based on a hierarchical topological diagram. The method includes a method for constructing an evaluation system directly for the drive axle assembly and a method for selecting and quantifying evaluation indicators. Through this system, the performance of the torque-oriented distribution electric drive axle assembly itself can be evaluated more systematically and scientifically, providing a scientific basis for its design and optimization, thereby promoting the design optimization research and wider application of the torque-oriented distribution electric drive axle, and further promoting the development of electric vehicles towards higher integration, higher performance and higher driving efficiency. Summary of the invention

[0006] The purpose of the present invention is to provide a systematic and scientific method for optimizing the configuration of an electric drive axle with torque oriented distribution based on a hierarchical topological diagram, so as to guide the selection of the optimal configuration scheme with a scientific method during the design stage of the electric drive axle with torque oriented distribution, thereby improving its design efficiency and the rationality of the design method.

[0007] The technical solution provided by the present invention is:

[0008] The method for optimizing the configuration of an electric drive axle with torque directional distribution based on a hierarchical topology graph comprises the following steps:

[0009] Step 1: Define the graphical model, matrix model and adjacency matrix of the torque-oriented electric drive axle.

[0010] Step 2: Build a digital configuration library of the torque-oriented electric drive axle.

[0011] Step 3: Construct a general dynamic model of the electric drive axle with torque directional distribution.

[0012] Step 4: Evaluate the torque-oriented electric drive axle assembly and select the optimal configuration based on the evaluation score, and display the configuration optimization results through a radar chart.

[0013] The basic structure of the torque directional distribution electric drive axle includes: a drive motor, a TV motor, a main reducer, a TV coupling mechanism, a differential, a left half shaft, a right half shaft and a housing. For a partial torque directional distribution electric drive axle configuration, its basic structure also includes an additional coupling mechanism. The TV coupling mechanism is composed of a two-stage planetary gear, and the additional coupling mechanism is composed of a one-stage planetary gear. The planetary gear can be a single planetary gear planetary gear or a double planetary gear planetary gear. The differential can be a bevel gear differential or a double planetary gear planetary gear differential. By selecting and combining various types of planetary gears and differentials at different positions, and constructing various different connection relationships between the basic elements of these planetary gears, differentials and the TV motor, various torque directional distribution electric drive axle configurations with different characteristics can be obtained.

[0014] In step 1, the graph model is a hierarchical topological graph model. In the graph model, various components of the torque oriented distribution electric drive axle and their connection relationships are represented by different points and lines.

[0015] The various types of elements include: power input and output elements, external transmission elements and internal transmission elements. The power input and output elements, as the source of power input or the destination of power output, can only establish a connection relationship with the external transmission elements, including the TV motor, the housing, the left half shaft and the housing of the differential, belonging to the first layer of the diagram model, represented by solid dots; the external transmission elements can be connected with all types of elements, including the sun gear, planetary carrier and ring gear of the TV coupling mechanism and the additional coupling mechanism, belonging to the second layer of the diagram model, represented by hollow dots; the internal transmission elements can establish a connection relationship with the external transmission elements, which mainly refers to the planetary gears of the TV coupling mechanism and the additional coupling mechanism, belonging to the third layer of the diagram model, also represented by hollow dots.

[0016] The connection relationship is defined as: coaxial rotation, represented by dotted lines; meshing transmission, represented by double arrows; rotating support, represented by thin solid lines; fixed connection, represented by thick solid lines; connection and non-connection between an element and itself, represented by no connecting lines.

[0017] In step 1, the matrix model is defined as a square matrix, each row (column) of which represents an element, and the element value represents the type of connection relationship between the elements. ij , which indicates that the element represented by the i-th row and the element represented by the j-th row are connected by the value a ij The connection relationship represented is connected. The row (column) order of the matrix model corresponds to the order of the elements in the graph model, and is arranged in the hierarchical order of the power input and output elements, the external transmission elements, and the internal transmission elements. Among them, the power input and output elements are arranged in the order of the TV motor, the housing, the left half shaft, and the housing of the differential; the external transmission elements are arranged in the order of the first-stage planetary gear of the TV coupling mechanism, the second-stage planetary gear of the TV coupling mechanism, and the additional coupling mechanism, and the elements are sorted in the order of their sun gear, planet carrier, and ring gear; the internal transmission elements are arranged in the order of the planetary gear of the first-stage planetary gear of the TV coupling mechanism, the planetary gear of the second-stage planetary gear of the TV coupling mechanism, and the planetary gear of the additional coupling mechanism.

[0018] Preferably, in the matrix model, fixed connection is represented by 1, connection between an element and itself is represented by a, meshing transmission is represented by b, rotation support is represented by c, coaxial rotation is represented by d, and no connection relationship is represented by 0.

[0019] In step 1, the adjacency matrix is ​​defined as a submatrix of the matrix model, specifically a part of the matrix model used to represent the connection relationship between various components of the torque directional distribution electric drive axle, mainly referring to the adjacency matrix M used to represent the connection relationship between the power input and output components and the external transmission components. Pi (i=1, 2, 3) and an adjacency matrix M for representing the internal connection relationship of the external transmission element Gij (ij=12,23). Among them, M Pi Specifically, it includes: an adjacency matrix M for representing the connection relationship between the first-stage planetary gear of the TV coupling mechanism and the power input and output element P1 , an adjacency matrix M for representing the connection relationship between the second-stage planetary gear of the TV coupling mechanism and the power input and output element P2 and an adjacency matrix M for representing the connection relationship between the additional coupling mechanism and the power input and output element P3 ;M Gij Specifically, it includes: an adjacency matrix M used to represent the connection relationship between the first and second stage planetary gears of the TV coupling mechanism G12 and an adjacency matrix M for representing the connection relationship between the second-stage planetary gear of the TV coupling mechanism and the additional coupling mechanism G23 .

[0020] The step 2 is specifically divided into the following steps:

[0021] Step 1: Clarify the basic design principles of the torque-oriented electric drive axle, specifically including: the three groups of identical external transmission elements of the two-stage planetary gearbox in the TV coupling mechanism need to be connected to each other, to the TV motor and the housing, to the left half-shaft and the additional coupling mechanism or the housing of the differential; the external transmission elements of the additional coupling mechanism need to be connected to the TV coupling mechanism, the left half-shaft, and the housing of the differential, respectively.

[0022] Step 2: Define the constraints of the adjacency matrix, specifically:

[0023] (1)M G12 ,M G23 There is only one element value corresponding to the fixed connection relationship and only in the diagonal position, and the remaining element values ​​correspond to the disconnected relationship;

[0024] (2)M P1 ,M P2In M G12 The values ​​of the elements in the rows and columns corresponding to the elements whose values ​​correspond to the fixed connection relationship all correspond to the disconnected relationship; P2 ,M P3 In M G23 The values ​​of the elements in the rows and columns corresponding to the elements with fixed connection values ​​all correspond to no connection values;

[0025] (3)M P1 There are only two columns with elements whose values ​​correspond to fixed connections, and these elements are in the first and third rows respectively; M P2 There is only one column with elements whose values ​​correspond to the fixed connection relationship, and these elements are in the second row; M P3 There are only two columns with elements whose values ​​correspond to fixed connections, and these elements are in the 3rd and 4th rows respectively;

[0026] (4)[M P1 ,M P2 ,M P3 ] The element values ​​that do not correspond to a fixed connection relationship all correspond to a non-connected relationship.

[0027] Step 3: Filter the adjacency matrix set based on the constraints.

[0028] Step 4: Generate a matrix model based on the adjacency matrix set and build a configuration library.

[0029] The step 3 is specifically divided into the following steps:

[0030] Step 1: Construct the dynamic model of the basic transmission unit, which specifically includes the planetary gear dynamic model and the bevel gear differential dynamic model. The dynamic model of the basic transmission unit refers to the state space equation expression that takes into account the element inertia and viscous damping, with the rotational angular velocity of the basic element of the basic transmission unit as the state variable and the input torque of the basic input element of the basic transmission unit as the input variable. The basic elements refer to the sun gear, planet carrier, ring gear and planet gear of the planetary gear mechanism. The basic input elements refer to the sun gear, planet carrier and ring gear of the planetary gear mechanism.

[0031] Step 2: Construct the dynamic model of the connecting shaft, specifically:

[0032] K c ∫(ω cl -ω cr )dt=T cn

[0033] Among them, K c is the stiffness of the connecting shaft; ω cl ,ω cr are the rotational angular velocities of the left and right end faces of the connecting shaft, T cn is the internal torque of the connecting shaft.

[0034] Step 3: Define the connection relationship model, which specifically includes the connection model between the power input and output elements and the external transmission elements and the connection model between the external transmission elements.

[0035] The connection model between the power input and output elements and the external transmission element is specifically:

[0036]

[0037] in, are respectively the output torque vector and the rotational angular velocity vector of the power input and output elements; They are respectively the output torque vector and the rotational angular velocity vector of the first-stage planetary gear of the TV coupling mechanism, the second-stage planetary gear of the TV coupling mechanism and the additional coupling mechanism to the external transmission element.

[0038] The connection model for connecting the external transmission elements to each other is specifically:

[0039]

[0040] Step 4: Define the power input model and load model. The power input model specifically refers to the TV motor input model; the load model specifically includes the housing load model and the half-axle load model.

[0041] Step 5: Construct a general dynamic model of the electric drive axle assembly with torque oriented distribution, whose submodules include: the power input model, the load model, the connection relationship model, the dynamic model of the connecting shaft, and the dynamic model of the basic transmission unit. The input and output of the power input model and the dynamic model of the basic transmission unit are connected through the connecting shaft model, and the connection relationship is expressed through the connection relationship model, so that the general dynamic model of the electric drive axle assembly with torque oriented distribution can represent all configurations in the configuration library by changing the adjacency matrix.

[0042] The step 4 is specifically divided into the following steps:

[0043] The first step is to select assembly evaluation indicators, which are specifically selected based on the dynamic response characteristics of the torque directional distribution electric drive axle assembly and the rationality of its configuration.

[0044] Step 2: Calculate the assembly evaluation index of each configuration in the configuration library based on the matrix model of the torque oriented distribution electric drive axle and the general dynamics model of the torque oriented distribution electric drive axle assembly.

[0045] Preferably, the evaluation indicators mainly include: response time, peak time, overshoot, stability evaluation value, maximum differential torque and configuration process rationality evaluation value, etc.

[0046] Preferably, the response time is: the time required for the output torque of the left half shaft and the right half shaft to reach its stable value after the required torque signal is input to the TV motor and the drive motor; the peak time is: the time required for the output torque of the left half shaft and the right half shaft to reach its maximum value after the required torque signal is input to the TV motor and the drive motor; the overshoot is: the maximum deviation of the output torque of the left half shaft and the right half shaft when it exceeds the target torque value for the first time after the required torque signal is input to the TV motor and the drive motor; the stability evaluation value is: the standard deviation of the output torque of the left half shaft and the right half shaft after the required torque signal is input to the TV motor and the drive motor after reaching the stable value; the maximum differential torque is: the differential torque generated by the TV motor at the left half shaft and the right half shaft after the TV motor outputs the maximum torque; the configuration rationality evaluation value is given by combining multiple design factors, including whether there is a planetary carrier straddling the ring gear, whether the arrangement between the planetary rows is compact, and the connection distance between the planetary row output element and the left half shaft and the right half shaft.

[0047] Step 3: Normalize the overall evaluation indicators of each configuration and obtain the single indicator evaluation score and the total evaluation score.

[0048] The specific calculation formula for the evaluation score of the single evaluation index is:

[0049]

[0050] Among them, S ji is the evaluation score of the jth evaluation index of the ith configuration in the configuration library; N a is the number of evaluation indicators; N sj is the number of sub-evaluation indicators of the jth evaluation indicator; s ijk is the score of the kth sub-evaluation index of the jth evaluation index of the ith configuration in the configuration library; s jkmin ,s jkmax are respectively the minimum and maximum values ​​of the scores of the kth sub-evaluation index of the jth evaluation index of all configurations in the configuration library.

[0051] The specific calculation formula of the total evaluation score is:

[0052]

[0053] Among them, S ti is the total evaluation score of the i-th configuration in the configuration library; w jis the total evaluation weight of the jth evaluation index. Its specific value is given according to actual needs and needs to meet the following requirements:

[0054]

[0055] Step 4: Display the configuration optimization results through radar chart.

[0056] The dimensions of the radar chart correspond one-to-one to the selected assembly evaluation indicators. The coordinates under each dimension reflect the scores of the corresponding evaluation indicators of the corresponding configuration. The graphic area formed by the lines connecting the coordinate points under all dimensions reflects the total evaluation score of the corresponding configuration.

[0057] The beneficial effects of the present invention are:

[0058] (1) The torque-oriented distribution electric drive axle configuration optimization method based on the hierarchical topology provided by the present invention realizes the evaluation of the configuration from the perspective of the overall cost itself, instead of relying solely on the test verification at the vehicle level. This not only improves the pertinence and accuracy of the configuration evaluation, but also significantly shortens the evaluation cycle and speeds up the iteration speed of design optimization.

[0059] (2) The torque-oriented distribution electric drive axle configuration optimization method based on the hierarchical topology diagram provided by the present invention can systematically and completely carry out configuration design from a theoretical perspective through automated digital modeling and evaluation index calculation. It can clearly and intuitively list all possible configuration schemes, and through the application of mathematical tools, find more feasible and effective configuration schemes, providing a scientific and efficient way for the design of the torque-oriented distribution electric drive axle, and providing powerful guidance for scheme design.

[0060] (3) The torque-oriented distribution electric drive axle configuration optimization method based on the hierarchical topology provided by the present invention can intuitively reflect the performance of the drive axle assembly in various aspects through specific scores. Through the scores of various evaluation indicators, designers can quickly identify and select the configuration that meets specific performance requirements. This quantitative evaluation method can not only improve the efficiency of configuration selection, but also enhance the objectivity and accuracy of design decisions. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 It is the main flow chart of the method for optimizing the configuration of an electric drive axle with torque directional distribution based on a hierarchical topology diagram described in the present invention.

[0062] Figure 2 It is a basic structural schematic diagram of an example of the torque directional distribution electric drive axle of the present invention.

[0063] Figure 3 This is an example of the torque directional distribution electric drive axle diagram model described in the present invention.

[0064] Figure 4 This is an example of the torque directional distribution electric drive axle matrix model described in the present invention.

[0065] Figure 5 A sub-flow chart is constructed for the digital configuration library of the torque directional distribution electric drive axle described in the present invention.

[0066] Figure 6 A sub-flow chart is constructed for the general dynamics model of the torque directional distribution electric drive axle described in the present invention.

[0067] Figure 7 It is a system block diagram of the planetary gear dynamics model described in the present invention.

[0068] Figure 8 It is a system block diagram of the bevel gear differential dynamics model described in the present invention.

[0069] Fig. 9 It is a system block diagram of the general dynamics model of the torque directional distribution electric drive axle assembly described in the present invention.

[0070] Fig.10 This is a sub-flow chart for evaluating the torque directional distribution electric drive axle assembly according to the present invention.

[0071] Fig.11 This is a radar chart of the optimization results of the torque directional distribution electric drive axle configuration described in the present invention. DETAILED DESCRIPTION

[0072] An embodiment of the present invention is given below in conjunction with the accompanying drawings to further explain the present invention in detail so that those skilled in the art can implement it according to the description. It should be noted that changes to the embodiment do not constitute innovation to the present invention.

[0073] like Figure 1 As shown, the method for optimizing the configuration of the electric drive axle based on the torque directional distribution of the layered topology diagram specifically includes the following steps:

[0074] Step 1: Define the graphical model, matrix model and adjacency matrix of the torque-oriented electric drive axle.

[0075] Step 2: Start the sub-process of building the digital configuration library of the torque oriented distribution electric drive axle.

[0076] Step 3: Start the sub-process of building the general dynamics model of the torque-oriented electric drive axle.

[0077] Step 4: Start the torque directional distribution electric drive axle assembly evaluation sub-process.

[0078] End: Get the radar chart display of the configuration optimization results.

[0079] like Figure 2 As shown, the torque directional distribution electric drive axle described in the present invention is mainly composed of a TV motor 1, a TV coupling mechanism 2, a housing 3, an additional coupling mechanism 4, a differential 5, a main reducer 6, a drive motor 7, a left half shaft 8 and a right half shaft 9.

[0080] Among them, the TV coupling mechanism 2 is composed of a first-stage planetary gear 21 of a TV coupling mechanism and a second-stage planetary gear 22 of a TV coupling mechanism, wherein the first-stage planetary gear 21 of the TV coupling mechanism is mainly composed of a first-stage sun gear 211 of a TV coupling mechanism, a first-stage planetary carrier 212 of a TV coupling mechanism, a first-stage ring gear 213 of a TV coupling mechanism and a first-stage planetary gear 214 of a TV coupling mechanism; the second-stage planetary gear 22 of the TV coupling mechanism is mainly composed of basic elements such as a second-stage sun gear 221 of a TV coupling mechanism, a second-stage planetary carrier 222 of a TV coupling mechanism, a second-stage ring gear 223 of a TV coupling mechanism and a second-stage planetary gear 224 of a TV coupling mechanism.

[0081] The additional coupling mechanism 4 is mainly composed of an additional coupling mechanism sun gear 401 , an additional coupling mechanism planet carrier 402 , an additional coupling mechanism ring gear 403 and additional coupling mechanism planet gears 404 .

[0082] The differential 5 is mainly composed of a differential case 501 , a differential left side gear 502 , a differential right side gear 503 and a differential planetary gear 504 .

[0083] Figure 2 It is an example configuration of the torque oriented distribution driven electric drive axle described in the present invention. By changing the connection mode between the TV motor 1, the TV coupling mechanism 2, the additional coupling mechanism 4 and the differential 5, various torque oriented distribution electric drive axle configurations can be obtained.

[0084] like Figure 3 As shown, in step 1, the graph model is a hierarchical topological graph model, in which various components of the torque directional distribution electric drive axle and their connection relationships are represented by different points and lines.

[0085] The various components include power input and output components, external transmission components and internal transmission components. Among them, the power input and output components are the source of power input or the destination of power output, and can only establish a connection relationship with the external transmission components, including TV motor 1, housing 3, left half shaft 8 and differential housing 501. Figure 3 Use M, G, V in sequence L, D indicates that it belongs to the first layer of the graphical model and is represented by solid dots; the external transmission element can establish a connection relationship with the power input and output element, the other external transmission elements and the internal transmission element, including a TV coupling mechanism primary sun gear 211, a TV coupling mechanism primary planet carrier 212, a TV coupling mechanism primary ring gear 213, a TV coupling mechanism secondary sun gear 221, a TV coupling mechanism secondary planet carrier 222, a TV coupling mechanism secondary ring gear 223, an additional coupling mechanism sun gear 401, an additional coupling mechanism planet carrier 402 and an additional coupling mechanism ring gear 403, in Figure 3 In the figure, they are represented by S1, H1, R1, S2, H2, R2, S3, H3, and R3, which belong to the second layer of the diagram model and are represented by hollow dots; the inner transmission element can only establish a connection relationship with the outer transmission element, including the first-level planetary gear 214 of the TV coupling mechanism, the second-level planetary gear 224 of the TV coupling mechanism, and the planetary gear 404 of the additional coupling mechanism. Figure 3 In the figure, they are represented by P1, P2, and P3 respectively, belonging to the third layer of the graph model, and are also represented by hollow dots.

[0086] like Figure 3 As shown, in step 1, the connection relationship includes: coaxial rotation, represented by dotted lines; meshing transmission, represented by double arrows; rotation support, represented by thin solid lines; fixed connection, represented by thick solid lines. For the connection between the element and itself and the non-connection relationship, no line is connected to represent it.

[0087] like Figure 4 As shown, in step 1, the matrix model is a symmetrical square matrix, and only the upper right part thereof is defined to fully express the connection topology relationship information of the torque directional distribution electric drive axle configuration. Each row (column) of the matrix model represents an element, and each element thereof represents that the element represented by the row where the element is located is connected to the element represented by the column where the element is located through a connection method represented by the element value.

[0088] The order of rows (columns) of the matrix model is: TV motor 1, housing 3, left half shaft 8, differential housing 501, TV coupling mechanism primary sun gear 211, TV coupling mechanism primary planet carrier 212, TV coupling mechanism primary ring gear 213, TV coupling mechanism secondary sun gear 221, TV coupling mechanism secondary planet carrier 222, TV coupling mechanism secondary ring gear 223, additional coupling mechanism sun gear 401, additional coupling mechanism planet carrier 402, additional coupling mechanism ring gear 403, TV coupling mechanism primary planet gear 214, TV coupling mechanism secondary planet gear 224 and additional coupling mechanism planet gear 404, and the corresponding symbol order is: M, G, V L,D,S1,H1,R1,S2,H2,R2,S3,H3,R3,P1,P2,P3.

[0089] The corresponding relationship between the element value and the connection relationship of the matrix model is: 1 represents a fixed connection; a represents the connection between the element and itself; b represents meshing transmission; c represents a rotating support; d represents coaxial rotation; and 0 represents no connection relationship.

[0090] like Figure 4 As shown, in step 1, the adjacency matrix is ​​a submatrix of the matrix model, and is a key part of the connection topology relationship of the torque directional distribution electric drive axle configuration, which specifically includes: the adjacency matrix M representing the connection relationship between the first-stage planetary gear 21 of the TV coupling mechanism and the power input and output element P1 , the adjacency matrix M representing the connection relationship between the second-stage planetary gear 22 of the TV coupling mechanism and the power input and output elements P2 , an adjacency matrix M representing the connection relationship between the additional coupling mechanism 4 and the power input and output element P3 , the adjacency matrix M representing the connection relationship between the first-stage planetary gear train 21 of the TV coupling mechanism and the second-stage planetary gear train 22 of the TV coupling mechanism G12 , representing the adjacency matrix M of the connection relationship between the second-stage planetary gear 22 of the TV coupling mechanism and the additional coupling mechanism 4 G23 .

[0091] like Figure 5 As shown, in step 2, the sub-process of constructing the digital configuration library of the torque directional distribution electric drive axle of the present invention is as follows:

[0092] Step 1: Clarify the basic design principles of the torque directional distribution electric drive axle. In this embodiment, the specific principles are:

[0093] (1) The primary sun gear 211 of the TV coupling mechanism and the secondary sun gear 221 of the TV coupling mechanism, the primary planet carrier 212 of the TV coupling mechanism and the secondary planet carrier 222 of the TV coupling mechanism, and the primary ring gear 213 of the TV coupling mechanism and the secondary ring gear 223 of the TV coupling mechanism need to be connected to each other, connected to the TV motor 1 and the housing 3, and connected to the left half shaft 8 and the additional coupling mechanism 4 respectively;

[0094] (2) The additional coupling mechanism sun gear 401 , the additional coupling mechanism planet carrier 402 and the additional coupling mechanism ring gear 403 need to be connected to the TV coupling mechanism 2 , the left half shaft 8 and the differential case 501 respectively.

[0095] Step 2: Define the constraints of the adjacency matrix. In this embodiment, they are specifically:

[0096] (1)MG12 ,M G23 There is only one element value of 1 and it is only in the diagonal position, and the rest of the elements are 0;

[0097] (2)M P1 ,M P2 In M G12 The values ​​of the rows and columns corresponding to the elements with a value of 1 are both 0; P2 ,M P3 In M G23 The element values ​​of the rows and columns corresponding to the elements with value 1 are both 0;

[0098] (3)M P1 There are only two columns with elements with value 1, and the elements with value 1 are in the 1st and 3rd rows respectively; M P2 There is only one column with an element whose value is 1, and the element whose value is 1 is in the second row; M P3 There are only two columns with elements with value 1, and the elements with value 1 are in two different rows;

[0099] (4)[M P1 ,M P2 ,M P3 ]The values ​​of all elements that are not 1 are 0.

[0100] Step 3: Filter the adjacency matrix set based on the constraints.

[0101] Step 4: Generate a matrix model based on the adjacency matrix set and build a configuration library.

[0102] like Figure 6 As shown, in step 3, the sub-process of constructing the general dynamics model of the torque directional distribution electric drive axle of the present invention is as follows:

[0103] Step 1: Construct the dynamic model of the basic transmission unit, including the planetary gear dynamic model and the bevel gear differential dynamic model.

[0104] The system block diagram of the planetary row dynamics model is as follows: Figure 7 As shown, its expression is:

[0105]

[0106] in, ω sp ,ω hp ,ω rp ,ω pp are the rotational angular velocities of the sun gear, planet carrier, ring gear and planet gear of the planetary gear train; T sp ,T hp ,T rpare the input torques of the sun gear, planet carrier and ring gear of the planetary gear set; M Ap ,M Bp is the coefficient matrix, which are M Ap0 ,M Bp0 The last four lines of M Ap0 ,M Bp0 are intermediate variables, and their calculation formulas are:

[0107]

[0108] Among them, B PG ,M PG is the structural characteristic matrix of the planetary gear; N T is the transformation matrix. PG ,M PG ,N T The expressions are:

[0109]

[0110]

[0111] Among them, N p is the number of planetary gear sets in the planetary gear train; R sp ,R pp are the pitch circle radii of the sun gear and planet gear of the planetary gear row respectively; J sp ,J hp ,J rp ,J pp are the rotational inertia of the sun gear, planet carrier, ring gear and planet gear of the planetary gear row; ξ p is the viscous damping coefficient of the planetary gear.

[0112] The system block diagram of the bevel gear differential dynamics model is as follows: Figure 8 As shown, its expression is:

[0113]

[0114] in, ω hd ,ω sl ,ω sr ,ω pd are the rotational angular velocities of the bevel gear differential housing, the left half-shaft gear, the right half-shaft gear and the planetary gear; M Ad ,M Bd is the coefficient matrix, which are M Ad0 ,M Bd0 The last four lines of M Ad0 ,M Bd0 are intermediate variables, and their calculation formulas are:

[0115]

[0116] Among them, B DF ,M DF is the structural characteristic matrix of the bevel gear differential, and its expressions are:

[0117]

[0118]

[0119] Among them, N d is the number of planetary gear sets of the bevel gear differential; R sd ,R pd are the pitch circle radii of the half-axle gears and planetary gears of the bevel gear differential; J sd ,J hd ,J pd are the rotational inertia of the half-axle gears, housing and planetary gears of the bevel gear differential; ξ d is the viscous damping coefficient of the bevel gear differential.

[0120] Step 2: Construct the dynamic model of the component connection axis. The specific expression is:

[0121] K c ∫(ω cl -ω cr )dt=T cn

[0122] Among them, K c is the stiffness of the connecting shaft; ω cl ,ω cr are the rotational angular velocities of the left and right end faces of the connecting shaft, T cn is the internal torque of the connecting shaft.

[0123] Step 3: Define the connection relationship model, which specifically includes the connection model between the power input and output elements and the external transmission elements and the connection model between the external transmission elements.

[0124] The specific expression of the connection model between the power input and output elements and the external transmission element is:

[0125]

[0126] in, are respectively the output torque vector and the rotational angular velocity vector of the power input and output elements; are the input torque vector and the rotation angular velocity vector of the external transmission element; T M ,T G ,T VL ,T D,ω M ,ω G , ω D are the output torque and rotational angular velocity of the TV motor 1, the housing 3, the left half shaft 8 and the differential housing 501 to the external transmission element; T s1 ,T h1 ,T r1 ,ω s1 ,ω h1 ,ω r1 are the input torque and rotational angular velocity of the primary sun gear 211 of the TV coupling mechanism, the primary planet carrier 212 of the TV coupling mechanism and the primary ring gear 213 of the TV coupling mechanism respectively; T s2 ,T h2 ,T r2 ,ω s2 ,ω h2 ,ω r2 are the input torque and rotational angular velocity of the secondary sun gear 221 of the TV coupling mechanism, the secondary planetary carrier 222 of the TV coupling mechanism, and the secondary ring gear 223 of the TV coupling mechanism respectively; T s3 ,T h3 ,T r3 ,ω s3 ,ω h3 ,ω r3 They are the input torque and rotational angular velocity of the additional coupling mechanism sun gear 401 , the additional coupling mechanism planet carrier 402 and the additional coupling mechanism ring gear 403 .

[0127] The specific expression of the connection model of the external transmission elements connected to each other is:

[0128]

[0129] Step 4: Define the power input model and load model, including the TV motor input model, housing load model and half-axle load model.

[0130] The specific expression of the TV motor input model is:

[0131]

[0132] Among them, T M (s) is the Laplace transform result of the TV motor output torque function; T dm (s) is the expected input torque function of the TV motor T dm The Laplace transform result of ; s is a complex variable; ξ M is the dynamic characteristic parameter of TV motor.

[0133] The specific expression of the shell load model is:

[0134] T G =-K G ∫ω G dt

[0135] Among them, K G is the stiffness of the shell; ω G is the rotational angular velocity of the connection end between the housing and the external transmission element.

[0136] The specific expression of the half-axle load model is:

[0137] T Vi =-ξ V ω Vi ,i=L,R

[0138] Among them, T VR is the output torque of the right half shaft 9 to the external transmission element; ω VL ,ω VR are the rotational angular velocities of the left semi-axis 8 and the right semi-axis 9 respectively; ξ V is the viscous load damping coefficient of the half-shaft.

[0139] Step 5: Construct a general dynamic model of the electric drive axle assembly with torque directional distribution.

[0140] like Fig. 9 As shown, the submodules of the general dynamic model of the torque directional distribution electric drive axle assembly include: the power input model, specifically the TV motor input model; the load model, specifically including the housing load model, the left half-shaft load model and the right half-shaft load model; the connecting shaft model; the basic transmission unit dynamic model, specifically including the first-stage planetary gear dynamic model of the TV coupling mechanism, the second-stage planetary gear dynamic model of the TV coupling mechanism, the additional coupling mechanism dynamic model and the differential dynamic model; the connection relationship model.

[0141] Among them, the left half-shaft load model and the right half-shaft load model are constructed based on the half-shaft load model; the first-stage planetary gear dynamics model of the TV coupling mechanism, the second-stage planetary gear dynamics model of the TV coupling mechanism and the additional coupling mechanism dynamics model are constructed based on the planetary gear dynamics model; the differential dynamics model is constructed based on the bevel gear differential dynamics model.

[0142] like Fig. 9As shown, in the general dynamics model of the electric drive axle assembly with torque oriented distribution, the input quantity and the output quantity of the power input model and the basic transmission unit dynamics model are connected through the dynamics model of the connecting shaft, and the transformation of their connection relationship is achieved through the connection relationship model, so that the general dynamics model of the electric drive axle assembly with torque oriented distribution can represent all configurations in the configuration library by changing the adjacency matrix.

[0143] like Fig.10 As shown, the torque directional distribution electric drive axle assembly evaluation sub-process of the present invention is as follows:

[0144] Step 1: Select assembly evaluation indicators. In this embodiment, they specifically include: response time, peak time, overshoot, stability evaluation value, maximum differential torque and configuration rationality evaluation value.

[0145] Step 2: Calculate the assembly evaluation index of each configuration in the configuration library. In this embodiment, the response time includes two sub-indicators: the drive motor response time and the TV motor response time. The calculation methods are respectively to calculate the time required for the output torque of the left half shaft 8 and the right half shaft 9 to reach the target torque after the required torque signal is input to the drive motor 7 and the TV motor 1; the peak time includes two sub-indicators: the peak time of the driving condition and the peak time of the differential condition. The calculation methods are respectively to calculate the time required for the left half shaft 8 and the right half shaft 9 to reach the peak torque after the required torque signal is input to the drive motor 7 and the TV motor 1; the overshoot includes the overshoot of the driving condition and the overshoot of the differential condition. The calculation methods are respectively to calculate the maximum deviation of the output torque of the left half shaft 8 and the right half shaft 9 when it exceeds the target torque value for the first time after the required torque signal is input to the drive motor 7 and the TV motor 1; the calculation method of the stability evaluation value is to calculate the standard deviation of the output torque of the left half shaft 8 and the right half shaft 9 in the relatively stable stage after the required torque signal is input to the TV motor 1 and the drive motor 7. The maximum differential torque is calculated by inputting the maximum torque signal to the TV motor 1 and then calculating the difference in output torque between the left half shaft 8 and the right half shaft 9. The calculation method of the configuration rationality evaluation value is given in a targeted manner according to the feasibility and structural rationality of each configuration in the actual manufacturing process, and the factors considered specifically include whether there is a planet carrier straddling the ring gear, whether the arrangement between each planet row is compact, and the connection distance between the external transmission element and the left half shaft and the right half shaft.

[0146] Step 3: Normalize the overall evaluation indicators of each configuration and obtain the single indicator evaluation score and the total evaluation score.

[0147] The specific calculation formula for the evaluation score of the single evaluation indicator is:

[0148]

[0149] Among them, S ji is the evaluation score of the jth evaluation index of the ith configuration in the configuration library, and when j=1-6, the corresponding evaluation indexes are response time, peak time, overshoot, stability, maximum differential torque and configuration rationality evaluation value respectively; N sj is the number of sub-evaluation indicators of the jth evaluation indicator; s ijk is the score of the kth sub-evaluation index of the jth evaluation index of the ith configuration in the configuration library; s jkmin ,s jkmax are respectively the minimum and maximum values ​​of the scores of the kth sub-evaluation index of the jth evaluation index of all configurations in the configuration library.

[0150] The specific calculation formula of the total evaluation score is:

[0151]

[0152] Among them, S ti is the total evaluation score of the i-th configuration in the configuration library; w j is the total evaluation weight of the jth evaluation index. Its specific value is given according to actual needs and needs to meet the following requirements:

[0153]

[0154] Step 4: Display the configuration optimization results through radar chart.

[0155] like Fig.11 As shown, the radar chart includes six dimensions, namely, the response time, the peak time, the overshoot, the stability, the maximum differential torque and the configuration rationality. The coordinates under each dimension reflect the score of the corresponding evaluation index of the corresponding configuration, and the graphic area formed by the connecting lines of the coordinate points under all dimensions reflects the total evaluation score of the corresponding configuration.

[0156] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A method for optimizing the configuration of an electric drive axle with torque directional distribution based on a hierarchical topology diagram, comprising the following steps: Step 1: Define the graphical model, matrix model and adjacency matrix of the torque-oriented electric drive axle; Step 2: Construct a digital configuration library of the torque directional distribution electric drive axle; Step 3: Construct a general dynamics model of the electric drive axle with torque directional distribution; Step 4: Evaluate the torque-oriented electric drive axle assembly and select the optimal configuration based on the evaluation score, and display the configuration optimization result through a radar chart; The basic structure of the torque directional distribution electric drive axle includes: Drive motor, TV motor, main reducer, TV coupling mechanism, differential, left half shaft, right half shaft and housing; for partial torque directional distribution electric drive axle configuration, its basic structure also includes an additional coupling mechanism; the TV coupling mechanism is composed of a two-stage planetary row, and the additional coupling mechanism is composed of a one-stage planetary row; the planetary row can be a single planetary gear planetary row or a double planetary gear planetary row; the differential can be a bevel gear differential, a cylindrical gear differential, or a double planetary gear single planetary gear differential with a characteristic constant of 2, and the characteristic constant is defined as the ratio of the number of teeth of the ring gear to the number of teeth of the sun gear in the planetary gear mechanism; by selecting and combining various types of planetary gears and differentials at different positions, and constructing various different connection relationships between the basic elements of these planetary gears, differentials and the TV motor, various torque directional distribution electric drive axle configurations with different characteristics can be obtained.

2. The method for optimizing electric drive axle configuration based on a layered topology diagram for torque directional distribution according to claim 1, characterized in that: In step 1, the graph model is a hierarchical topological graph model, and various components of the torque directional distribution electric drive axle and their connection relationships are represented by different points and lines; the matrix model is defined as a square matrix, each row (column) of which represents an element, and its element value represents the type of connection relationship between the elements; The various types of components include power input and output components, external transmission components and internal transmission components; the power input and output components can only establish a connection relationship with the external transmission components, including the TV motor, the housing, the left half shaft and the housing of the differential, and belong to the first layer of the graphic model; the external transmission components can establish a connection relationship with all types of components, including the sun gear, planetary carrier and ring gear of the TV coupling mechanism and the additional coupling mechanism, and belong to the second layer of the graphic model; the internal transmission components can establish a connection relationship with the external transmission components, mainly referring to the planetary gear of the TV coupling mechanism and the additional coupling mechanism, and belong to the third layer of the graphic model.

3. The method for optimizing the configuration of an electric drive axle with torque directional distribution based on a hierarchical topology diagram according to claim 2, characterized in that: The adjacency matrix is ​​defined as a submatrix of the matrix model, specifically the part of the matrix model used to represent the connection relationship between various components of the torque-oriented electric drive axle, mainly referring to the adjacency matrix used to represent the connection relationship between the power input and output components and the external transmission components and the adjacency matrix used to represent the internal connection relationship of the external transmission components.

4. The method for optimizing electric drive axle configuration based on a layered topology diagram for torque directional distribution according to claim 1, characterized in that: The step 2 is specifically divided into the following steps: Step 1: Clarify the basic design principles of torque-oriented electric drive axles; Step 2: Define the constraints of the adjacency matrix; Step 3: Screen the adjacency matrix set based on the constraint conditions; Step 4: Generate a matrix model based on the adjacency matrix set and build a configuration library.

5. The method for optimizing electric drive axle configuration based on a layered topology diagram for torque directional distribution according to claim 4, characterized in that: The basic design principles of the torque-oriented distribution electric drive axle include: the three groups of identical external transmission elements of the two-stage planetary gears in the TV coupling mechanism need to be connected to each other, to the TV motor and the housing, and to the left half-shaft and the additional coupling mechanism or the housing of the differential; the external transmission element of the additional coupling mechanism needs to be connected to the TV coupling mechanism, the left half-shaft, and the housing of the differential, respectively.

6. The method for optimizing electric drive axle configuration based on a layered topology diagram for torque directional distribution according to claim 4, characterized in that: The constraints of the adjacency matrix include: (1)M G12 ,M G23 There is only one element value corresponding to the fixed connection relationship and only in the diagonal position, and the remaining element values ​​correspond to the disconnected relationship; (2)M P1 ,M P2 In M G12 The values ​​of the elements in the rows and columns corresponding to the elements with fixed connection values ​​all correspond to no connection values; (3)M P2 ,M P3 In M G23 The values ​​of the elements in the rows and columns corresponding to the elements whose values ​​correspond to the fixed connection relationship all correspond to the disconnected relationship; P1 There are only two columns with elements whose values ​​correspond to fixed connections, and these elements are in the first and third rows respectively; (4)M P2 There is only one column with elements whose values ​​correspond to the fixed connection relationship, and these elements are in the second row; M P3 There are only two columns with elements whose values ​​correspond to fixed connections, and these elements are in the 3rd and 4th rows respectively; [M P1 ,M P2 ,M P3 ] The element values ​​that do not correspond to the fixed connection relationship all correspond to the unconnected relationship; Among them, M P1 ,M P2 ,M P3 are adjacency matrices representing the connection relationship between the power input and output elements and the first-stage planetary gear of the TV coupling mechanism, the second-stage planetary gear of the TV coupling mechanism, and the additional coupling mechanism; M G12 ,M G23 They are adjacency matrices representing the mutual connection relationship between the two-stage planetary gear trains of the TV coupling mechanism and the connection relationship between the second-stage planetary gear train of the TV coupling mechanism and the additional coupling mechanism.

7. The method for optimizing electric drive axle configuration based on a layered topology diagram for torque directional distribution according to claim 1, characterized in that: The step 3 comprises the following steps: Step 1: Construct the dynamic model of the basic transmission unit; Step 2: Construct the dynamic model of the connecting shaft; Step 3: Define the connection relationship model; Step 4: Define the power input model and load model; Step 5: Construct a general dynamics model of the electric drive axle assembly with torque directional distribution; The submodules of the torque directional distribution electric drive axle assembly general dynamics model include: the power input model, the load model, the connection relationship model, the dynamics model of the connecting shaft and the dynamics model of the basic transmission unit; The input quantity and output quantity of the power input model and the dynamic model of the basic transmission unit are connected through the connecting shaft model, and the connection relationship is expressed by the connection relationship model, so that the general dynamic model of the torque-oriented distribution electric drive axle assembly can represent all configurations in the configuration library by changing the adjacency matrix.

8. The method for optimizing electric drive axle configuration based on a layered topology diagram for torque directional distribution according to claim 7, characterized in that: The connection relationship model includes a connection model between the power input and output elements and the external transmission element and a connection model in which the external transmission elements are connected to each other; The connection model between the power input and output elements and the external transmission element is specifically: The connection model for connecting the external transmission elements to each other is specifically: in, are the output torque vector and rotation angular velocity vector of the power input and output elements respectively, They are respectively the output torque vector and the rotation angular velocity vector of the first-stage planetary gear of the TV coupling mechanism, the second-stage planetary gear of the TV coupling mechanism and the additional coupling mechanism to the external transmission element.

9. The method for optimizing electric drive axle configuration based on a layered topology diagram for torque directional distribution according to claim 1, characterized in that: The step 4 is specifically divided into the following steps: Step 1: Selecting assembly evaluation indicators, specifically based on the dynamic response characteristics of the torque directional distribution electric drive axle assembly and the rationality of its configuration, etc.; the rationality of the configuration specifically includes whether there is a planet carrier straddling the ring gear, whether the arrangement between the planetary gears is compact, and the connection distance between the planetary gear output element and the left half shaft and the right half shaft, etc.; Step 2: Calculate the assembly evaluation index of each configuration in the configuration library based on the matrix model of the torque oriented distribution electric drive axle and the general dynamics model of the torque oriented distribution electric drive axle assembly; Step 3: Normalize the overall evaluation index of each configuration and obtain the single index evaluation score and the total evaluation score; Step 4: Display the configuration optimization results through radar chart; The dimensions of the radar chart correspond one-to-one to the selected assembly evaluation indicators. The coordinates under each dimension reflect the scores of the corresponding evaluation indicators of the corresponding configuration. The graphic area formed by the lines connecting the coordinate points under all dimensions reflects the total evaluation score of the corresponding configuration.

10. The method for optimizing electric drive axle configuration based on layered topology diagram with torque directional distribution according to claim 9, characterized in that: The specific calculation formula for the evaluation score of the single evaluation index is: Among them, S ji is the evaluation score of the jth evaluation index of the i-th configuration in the configuration library; N a is the number of evaluation indicators; N sj is the number of sub-evaluation indicators of the jth evaluation indicator; s ijk is the score of the kth sub-evaluation index of the jth evaluation index of the ith configuration in the configuration library; s jkmin ,s jkmax are the minimum and maximum values ​​of the kth sub-evaluation index of the jth evaluation index of all configurations in the configuration library; The specific calculation formula of the total evaluation score is: Among them, S ti is the total evaluation score of the i-th configuration in the configuration library; w j is the total evaluation weight of the jth evaluation index. Its specific value is given according to actual needs and needs to meet the following requirements:

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