Method and system for calculating collision force during inter-tooth engagement of jaw clutch

Abstract

The invention discloses a method and system for calculating impact force during tooth engagement of a jaw clutch, and belongs to the technical field of computers.The method comprises the steps that a closed geometric contour is extracted from an image during engagement of the jaw clutch; constructing a hierarchical bounding box tree according to the geometric contour; performing collision detection on the jaw clutch according to the hierarchical bounding box tree to obtain a collision detection result; according to the collision detection result, calculating the area of a collision surface by adopting a Monte Carlo algorithm; and according to physical characteristics and the collision surface area, calculating the collision force of each collision position during inter-tooth engagement. According to the embodiment of the invention, through the above steps, the collision surface can be determined, the collision force of each collision position during tooth engagement of the jaw clutch can be rapidly and accurately calculated, and the test and development efficiency of the jaw clutch is improved.

Description

Technical Field

[0001] The present application relates to the field of computer technology, and in particular to a method and system for calculating the collision force when tooth-to-tooth clutch engages. Background Art

[0002] The electronically controlled mechanical transmission (EMT) that uses a tooth clutch instead of a synchronizer is not only simpler and more compact in structure but also cheaper to develop. To achieve impact-free shifting control of EMT and reduce the time of power interruption, it is crucial to establish a calculation model for inter-tooth collision force that can accurately reflect the dynamic shifting process. However, there is very limited information on the modeling and simulation of the tooth clutch during the EMT shifting process, especially the calculation model that can fully reflect the inter-tooth collision situation. Although the collision model based on the microscopic surface or the finite element analysis method can construct a complex system model, such methods are often computationally complex and computationally burdensome, and are not suitable for the calculation of collision force in shifting control. Therefore, it is particularly important to establish a model that can adapt to complex concave-convex mixed contours and has a small amount of calculation. Such a model should be able to effectively describe the collision process between the clutch and the clutch ring, and be able to calculate the collision force generated at different collision positions.

[0003] At present, most of the inter-tooth collision calculations use a small ball collision model to calculate the inter-tooth collision force. This calculation method has two main challenges: one is that the collision surface cannot be clearly defined, and the other is that it is difficult to determine the depth of the collision. Due to the characteristics of the transmission system, the collision process cannot be simply simulated by a spherical collision surface. Summary of the invention

[0004] To solve at least one of the above problems, the main purpose of the embodiments of the present application is to propose a method and system for calculating the collision force when the teeth of a tooth clutch are engaged, aiming to accurately calculate the collision force at different contact positions during the engagement process.

[0005] To achieve the above object, one aspect of an embodiment of the present application provides a method for calculating the collision force when the teeth of a dog clutch are engaged, the method comprising:

[0006] extracting a closed geometric contour from the image of the dog clutch being engaged;

[0007] Constructing a hierarchical bounding box tree according to the geometric outline;

[0008] performing collision detection on the dog clutch according to the hierarchical bounding box tree to obtain a collision detection result;

[0009] According to the collision detection result, a Monte Carlo algorithm is used to calculate the collision surface area;

[0010] The collision force at each collision position when the teeth are engaged is calculated based on the physical characteristics and the collision surface area.

[0011] In some embodiments, extracting a closed geometric contour from the image of the dog clutch being engaged includes:

[0012] According to the geometric parameters in the image when the tooth clutch is engaged, the shapes of the teeth of the engagement sleeve and the shapes of the teeth of the meshing gear ring in the tooth clutch are extracted to obtain a closed geometric contour.

[0013] In some embodiments, constructing a hierarchical bounding box tree according to the geometric outline comprises the following steps:

[0014] Converting the geometric contour into elements consisting of line segments or circular arcs;

[0015] Generating an axis-aligned bounding box for each of the elements;

[0016] Based on the hierarchical relationship of the elements, a binary tree is used to generate a hierarchical bounding box tree according to the axis-aligned bounding box.

[0017] In some embodiments, performing collision detection on the dog clutch according to the hierarchical bounding box tree to obtain a collision detection result comprises the following steps:

[0018] Obtaining leaf nodes of the hierarchical bounding box tree where axis-aligned bounding boxes overlap;

[0019] The intersection of the geometric outlines in the leaf nodes is determined to obtain a collision detection result.

[0020] In some embodiments, determining the intersection of the geometric outlines in the leaf nodes comprises the following steps:

[0021] Calculate the projections of the geometric outline of the leaf node on the horizontal axis and the vertical axis to obtain a first projection and a second projection;

[0022] When the first projection and the second projection overlap in both the horizontal axis and the vertical axis, it is determined that the geometric contours intersect.

[0023] In some embodiments, the calculating the collision surface area using a Monte Carlo algorithm according to the collision detection result comprises the following steps:

[0024] Determining the collision surface according to the number of intersection points between the tooth contour segment of the coupling sleeve and the tooth contour segment of the meshing gear ring in the collision detection result;

[0025] The contour segment between the intersection points is regarded as the contact segment, and the length of the contact segment is obtained;

[0026] Using a Monte Carlo algorithm to calculate the intersection area between the engagement sleeve and the contact section to obtain a first intersection area;

[0027] Calculating the intersection area between the meshing gear ring and the contact segment using a Monte Carlo algorithm to obtain a second intersection area;

[0028] The first intersection area and the second intersection area are combined into a collision surface area.

[0029] In some embodiments, the step of calculating the collision force at each collision position when the teeth are engaged based on the physical characteristics and the collision surface area includes the following steps:

[0030] Calculating a contact force based on the Young's modulus according to the first intersection area and the second intersection area;

[0031] Calculating linear penetration according to the first intersection area, the second intersection area and the contact segment length;

[0032] Calculating a linear contact stiffness according to the contact force and the linear penetration;

[0033] The effective stiffness is calculated based on the linear contact stiffness and the maximum solid stiffness;

[0034] Calculate the contact penetration speed and the sliding speed according to the first absolute speed of the engagement sleeve and the second absolute speed of the meshing gear ring at the center point between the intersection points;

[0035] The collision force is calculated according to the effective stiffness, the linear penetration, the damping coefficient, and the contact penetration speed.

[0036] To achieve the above purpose, another aspect of the embodiment of the present application provides a system for calculating the collision force when the teeth of a dog clutch are engaged, the system comprising:

[0037] A first module is used to extract a closed geometric contour from the image when the dog clutch is engaged;

[0038] The second module is used to construct a hierarchical bounding box tree according to the geometric outline;

[0039] A third module is used to perform collision detection on the dog clutch according to the hierarchical bounding box tree to obtain a collision detection result;

[0040] The fourth module is used to calculate the collision surface area by using the Monte Carlo algorithm according to the collision detection result;

[0041] The fifth module is used to calculate the collision force at each collision position when the gears engage according to the physical characteristics and the collision surface area.

[0042] To achieve the above-mentioned purpose, another aspect of an embodiment of the present application provides an electronic device, the electronic device comprising a memory and a processor, the memory storing a computer program, and the processor implementing the above-mentioned method when executing the computer program.

[0043] To achieve the above objective, another aspect of an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method described above is implemented.

[0044] The embodiments of the present application include at least the following beneficial effects: the present application provides a method and system for calculating the collision force when the tooth-to-tooth clutch is engaged, and the scheme extracts a closed geometric contour from the image when the tooth-to-tooth clutch is engaged; constructs a hierarchical bounding box tree based on the geometric contour; performs collision detection on the tooth-to-tooth clutch based on the hierarchical bounding box tree to obtain a collision detection result; calculates the collision surface area based on the collision detection result using a Monte Carlo algorithm; and calculates the collision force at each collision position when the tooth-to-tooth clutch is engaged based on the physical characteristics and the collision surface area. The overall steps can clarify the collision surface and can quickly and accurately calculate the collision force at each collision position, which is beneficial to improving the testing and development efficiency of the tooth-to-tooth clutch. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings are used to provide further understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0046] Figure 1 is a flow chart of a method for calculating the collision force when the tooth-to-tooth clutch is engaged, provided in an embodiment of the present application;

[0047] Figure 2 is a schematic diagram of a hierarchical bounding box tree provided in an embodiment of the present application;

[0048] Figure 3 It is a schematic diagram of geometric body distribution provided in the embodiment of the present application;

[0049] Figure 4 is a schematic diagram of a hierarchical bounding box tree of a geometric body provided in an embodiment of the present application;

[0050] Figure 5 is a schematic diagram of overlapping bounding boxes provided in an embodiment of the present application;

[0051] Figure 6 is a schematic diagram of only the bounding boxes overlapping between teeth provided by an embodiment of the present application;

[0052] Figure 7is a schematic diagram of a collision between teeth provided in an embodiment of the present application;

[0053] Figure 8 is a schematic diagram of a collision surface provided in an embodiment of the present application;

[0054] Fig. 9 is a schematic diagram of calculating the first intersection area and the second intersection area provided in an embodiment of the present application;

[0055] Fig.10 is a schematic diagram of a tooth-type synchronizer-free electronically controlled mechanical transmission structure system provided in an embodiment of the present application;

[0056] Fig.11 It is a module schematic diagram of a system for calculating the collision force when the tooth-to-tooth clutch is engaged, provided in an embodiment of the present application;

[0057] Fig.12 It is a schematic diagram of the hardware structure of the electronic device provided in the embodiment of the present application. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the embodiments of the present application. They are only examples of devices and methods consistent with some aspects of the embodiments of the present application as detailed in the attached claims.

[0059] Although the functional modules are divided in the system schematic diagram and the logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the system or the order in the flowchart. The terms "first / S100", "second / S200", etc. in the specification, claims and the above drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0060] It is understood that the terms "first", "second", etc. used in this application can be used to describe various concepts in this article, but unless otherwise specified, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another concept. For example, without departing from the scope of the embodiment of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the words "if" and "if" as used herein can be interpreted as "at the time of" or "when" or "in response to determination".

[0061] The terms "at least one", "multiple", "each", "any", etc. used in this application, at least one includes one, two or more, multiple includes two or more, each refers to each of the corresponding multiple, and any refers to any one of the multiple.

[0062] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0063] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0064] In the related art, most of the inter-tooth collision calculations use a small ball collision model to calculate the inter-tooth collision force. This method cannot clearly define the collision surface and it is difficult to determine the collision depth. Due to the characteristics of the transmission system, the collision process cannot be simply simulated by a spherical collision surface.

[0065] In view of this, a method and system for calculating the collision force between the teeth of a tooth clutch when engaged are provided in an embodiment of the present application. The scheme characterizes the inter-tooth collision situation based on a hierarchical bounding box collision detection algorithm, and then calculates the collision surface using the Monte Carlo method. Finally, the inter-tooth collision force is calculated in combination with the physical characteristics, thereby realizing the calculation of the collision force at different contact positions between the teeth during the engagement process.

[0066] A method for calculating the collision force when the tooth-type clutch is engaged provided in an embodiment of the present application relates to the field of computer technology. A method for calculating the collision force when the tooth-type clutch is engaged provided in an embodiment of the present application can be applied to a terminal, can also be applied to a server, and can also be software running in a terminal or a server. In some embodiments, the terminal can be a smart phone, a tablet computer, a laptop computer, a desktop computer, a smart speaker, a smart watch, and a car terminal, etc., but is not limited to this; the server side can be configured as an independent physical server, or it can be configured as a server cluster or a distributed system composed of multiple physical servers, and can also be configured as a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms. The server can also be a node server in a blockchain network; the software can be an application that implements a method for calculating the collision force when the tooth-type clutch is engaged, etc., but is not limited to the above forms.

[0067] The present application can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, etc. The present application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The present application can also be practiced in distributed computing environments, in which tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media including storage devices.

[0068] Figure 1 is an optional flow chart of a method for calculating the collision force when the tooth-to-tooth clutch is engaged provided in an embodiment of the present application. Figure 1 The method may include but is not limited to steps S100 to S500.

[0069] Step S100, extracting a closed geometric contour from the image of the dog clutch being engaged.

[0070] Step S200: constructing a hierarchical bounding box tree according to the geometric outline.

[0071] Step S300: performing collision detection on the dog clutch according to the hierarchical bounding box tree to obtain a collision detection result.

[0072] Step S400: Calculate the collision surface area using a Monte Carlo algorithm according to the collision detection result.

[0073] Step S500: Calculate the collision force at each collision position when the gears are engaged according to the physical characteristics and the collision surface area.

[0074] Steps S100 to S500 shown in the embodiment of the present application are as follows: extracting a closed geometric contour from the image when the tooth clutch is engaged; constructing a hierarchical bounding box tree based on the geometric contour; performing collision detection on the tooth clutch based on the hierarchical bounding box tree to obtain a collision detection result; calculating the collision surface area based on the collision detection result using a Monte Carlo algorithm; and calculating the collision force at each collision position when the tooth-to-tooth engagement is performed based on the physical characteristics and the collision surface area. The overall steps can clarify the collision surface and the collision depth, and then quickly and accurately calculate the collision force at each collision position when the tooth clutch is engaged, which is beneficial to improving the testing and development efficiency of the tooth clutch.

[0075] In some embodiments, step S100 may include, but is not limited to, step S110:

[0076] Step S110, extracting the shapes of the teeth of the engagement sleeve and the teeth of the meshing gear ring in the dog clutch according to the geometric parameters in the image when the dog clutch is engaged, and obtaining a closed geometric contour.

[0077] In some embodiments, step S200 includes but is not limited to the following steps S210 to S230:

[0078] Step S210, converting the geometric outline into elements composed of line segments or arcs;

[0079] Step S230, generating an axis-aligned bounding box for each of the elements;

[0080] Step S240: Based on the hierarchical relationship of the elements, a hierarchical bounding box tree is generated according to the axis-aligned bounding box using a binary tree.

[0081] In some embodiments, step S300 includes but is not limited to the following steps S310 to S320:

[0082] Step S310, obtaining leaf nodes with overlapping axis-aligned bounding boxes in the hierarchical bounding box tree;

[0083] Step S320, determining the intersection of the geometric outlines in the leaf nodes to obtain a collision detection result.

[0084] In some embodiments, step S320 includes but is not limited to the following steps S321-S322:

[0085] Step S321, calculating the projections of the geometric outline of the leaf node on the horizontal axis and the vertical axis to obtain a first projection and a second projection;

[0086] Step S322: When the first projection and the second projection overlap in both the horizontal axis and the vertical axis, it is determined that the geometric contours intersect.

[0087] In some embodiments, step S400 includes but is not limited to the following steps S410 to S450:

[0088] Step S410, determining a collision surface according to the number of intersection points between the sleeve tooth contour segment and the meshing gear ring tooth contour segment in the collision detection result;

[0089] Step S420, taking the contour segment between the intersection points as the contact segment, and obtaining the length of the contact segment;

[0090] Step S430, using a Monte Carlo algorithm to calculate the intersection area between the engagement sleeve and the contact segment to obtain a first intersection area;

[0091] Step S440, using a Monte Carlo algorithm to calculate the intersection area between the meshing gear ring and the contact segment to obtain a second intersection area;

[0092] Step S450: combining the first intersection area and the second intersection area into a collision surface area.

[0093] In some embodiments, step S500 includes but is not limited to the following steps S510 to S560:

[0094] Step S510, calculating contact force based on the first intersection area and the second intersection area and Young's modulus;

[0095] Step S520, calculating linear penetration according to the first intersection area, the second intersection area and the contact segment length;

[0096] Step S530, calculating a linear contact stiffness according to the contact force and the linear penetration;

[0097] Step S540, calculating the effective stiffness according to the linear contact stiffness and the maximum solid stiffness;

[0098] Step S550, calculating the contact penetration speed and the sliding speed according to the first absolute speed of the center point between the intersection points at the engagement sleeve and the second absolute speed of the meshing gear ring;

[0099] Step S560: Calculate the collision force according to the effective stiffness, the linear penetration, the damping coefficient, and the contact penetration speed.

[0100] Below, in conjunction with a specific application example of a tooth clutch inter-tooth engagement scenario, the solution of the embodiment of the present application is described in detail and explained:

[0101] In an embodiment of the present application, a method for calculating the collision force when the teeth of a dog clutch are engaged is provided. The method can be applied to calculate the collision force at different contact positions between the teeth during the engagement process. Specifically, the method can include the following stages:

[0102] (1) Preprocessing stage: When the dog clutch is to be engaged, the calculation of the inter-tooth collision force of the embodiment of the present application is started, and the preprocessing stage is entered.

[0103] Before acquiring data, it is generally necessary to model the tooth clutch. First, the geometric shape and key parameters of the teeth, as well as the relative positions and angles between the teeth are determined according to the defined geometric parameters. Then, based on the extracted key parameters, the smooth boundary of the meshing teeth is constructed through curve fitting technology (such as B-spline or Bezier curve), and the boundary data of each meshing tooth is spliced ​​into a complete geometric contour, and it is ensured that the boundary is closed in the engagement area. By comparing the actual scan data and the fitted contour, the error correction algorithm (least squares method) is used to adjust the accuracy of the closed contour, and then the three-dimensional model of the tooth clutch is established. According to the three-dimensional model of the tooth clutch, the geometric contour of the tooth clutch is projected onto a two-dimensional plane to obtain plane data, and the plane data is stored as a point set coordinate vector format (such as DXF or SVG) to obtain a closed geometric contour for subsequent simulation and modeling.

[0104] Furthermore, the preprocessing stage converts the closed geometric contour into elements composed of discontinuous line segments or arcs, and then generates axis-aligned bounding boxes for these elements. The elements enclosed by each axis-aligned bounding box are the components of the tooth, which are two-dimensional. The axis-aligned bounding box (AABB bounding box) is a rectangular bounding box, the full name of which is axis-alignedbounding box. It is a rectangle, and its sides are aligned with the axis (such as the x-axis and the y-axis). The x-axis refers to the horizontal axis of the coordinate axis, and the y-axis refers to the vertical axis of the coordinate axis.

[0105] In some embodiments, a binary tree is used to construct a hierarchical bounding box tree. When constructing the hierarchical bounding box tree, the root node stores the outermost bounding box, and then the tree is divided layer by layer. The leaf nodes of each level store the bounding box information of this level and the geometric primitive information of the target component. Figure 2 As shown, the outermost bounding box refers to Figure 2The bounding box information is used in the collision detection phase to determine whether there is a collision (or intersection), while the geometric primitive information of the target component is used for the next level of primitive segmentation, and the hierarchical bounding box tree is generally not reconstructed in the collision detection phase.

[0106] It should be noted that the line segments enclosed by the rectangle are the components of the tooth, which is two-dimensional. The tooth is divided into elements composed of line segments, and each discontinuous line segment generates a bounding box. The primitive information refers to the shape of the tooth, and then the tooth is divided into different line segments, and each line segment is surrounded by a rectangle.

[0107] (2) Collision detection stage. After the preprocessing is completed, the collision detection stage is entered to determine whether there is a collision between the two teeth by detecting whether the contour segments of the teeth on the left and right gear rings of the tooth clutch intersect. Among them, the left and right gear rings are the engagement ring and the meshing ring.

[0108] Specifically, collision detection is performed on the tooth clutch according to the hierarchical bounding box tree, including the following steps: obtaining leaf nodes with overlapping axis-aligned bounding boxes in the hierarchical bounding box tree; determining the intersection of geometric contours in the leaf nodes to obtain collision detection results.

[0109] For example, when there are three contour segments G1, G2 and G3, G1 and G2 form a node N1, and then N1 and G3 form a root node Root, such as Figure 3 As shown, and generated Figure 4 When performing collision detection, obtain the leaf nodes from the hierarchical bounding box tree in turn, obtain the contour segment T to be detected and its bounding box, and perform the following steps 1 to 3:

[0110] 1. If the bounding box of T intersects with the bounding box of Root, it is necessary to recursively check whether the bounding box of T intersects with the two child nodes of Root; otherwise, there is no need to continue checking downward.

[0111] 2. If the bounding box of T intersects with the bounding box of G3, it is necessary to further detect whether T and G3 intersect to determine whether T collides with G3; otherwise, there is no need to continue detecting with G3.

[0112] 3. The collision detection between X and N1 is similar to the collision detection between X and Root. Furthermore, the principle of the detection of geometric contour intersection is that each side of the rectangle corresponding to the AABB bounding box is parallel to a certain coordinate axis, so it is possible to determine whether a collision occurs by detecting whether the projections of the objects to be detected on the coordinate axis overlap.

[0113] Specifically, the collision detection result of the AABB bounding box can be obtained in the following way: For the convenience of description, take the bounding box G and the bounding box H as an example, Figure 5 As shown, the projections of bounding box G and bounding box H on the X-axis and Y-axis directions are made respectively. The maximum point coordinate of bounding box G on the Y-axis direction is Y Amax , the minimum point coordinate is Y Amin , the minimum point coordinate in the X-axis direction is Y Amin , the maximum point coordinate is X Amax , the bounding box H is the same, corresponding to Y Bmax , Y Bmin , Y Bmin and X Bmax .exist Figure 5 In the figure, the IJ and OP segments on the coordinate axes are the overlapping parts of the projections of G and H. Therefore, only when both coordinate axes overlap, it means that the two bounding boxes intersect. Based on this, the intersection of bounding boxes can be expressed by the following formula (1):

[0114]

[0115] In the formula, C re Indicates the detection result of the bounding box intersection.

[0116] In the tooth-to-tooth interaction scenario of the embodiment of the present application, when the bounding boxes intersect, it is determined whether the contour segments in the bounding boxes intersect. If they intersect, a collision occurs between the teeth. Specifically, Figure 6 and Figure 7 As shown, if line segment AE intersects line segment de, then AE and de must pass through each other, that is, point A and point E are located on both sides of de, or one of them is on de and the other is on one side; and point d and point e are located on both sides of AE, or one of them is on AE and the other is on one side, satisfying formula (2). Formula (2) is the tooth collision detection result formula:

[0117]

[0118] (3) Determine the collision surface and calculate the collision surface area.

[0119] When the bounding boxes are detected to intersect, the intersection points between the bounding boxes are determined, and the intersection calculation between the elements is started. If two objects collide, the number of intersection points must be an even number. The collision between the coupling sleeve and the meshing gear ring can be determined by determining whether the contour segments of the coupling sleeve and the meshing gear ring intersect. When a collision occurs, the intersection points between the tooth contours of the coupling sleeve and the meshing gear ring need to be detected to determine the collision surface. Specifically, when a collision occurs, the teeth of the coupling sleeve and the teeth on the meshing gear ring contour generate two intersection points, and the collision surface is the vertical plane of the straight line where the two intersection points are located, such as Figure 8shown.

[0120] The collision surface may include an intersection area (first intersection area) between the coupling sleeve and the contact segment and an intersection area (second intersection area) between the meshing gear ring and the contact segment, wherein the contact segment refers to a geometric contour portion that is in contact during collision.

[0121] In the oxy coordinate system, the first cross area a1 and the second cross area a2 can be approximately calculated by the Monte Carlo method. Fig. 9 As shown, T is an N×M two-dimensional array with all elements set to 1, and its length and width are denoted by X and L and w . Extend the intersection line P1P2 to the boundary of the map, and the map is divided into two parts. Take the teeth of the coupling sleeve and the meshing gear ring in the map, as well as the two parts separated by the extension line of P1P2 and the entire map, and you will get the teeth representing SL and DG and the pixel point sets of these two parts. Therefore, the intersection of S1, S2, and S3 is the pixel set corresponding to the intersection area of ​​the coupling sleeve and the contact segment, and the intersection of S2, S3, and S4 is the pixel set corresponding to the intersection area a2 of the meshing gear ring and the contact segment. Therefore, a1 and a2 can be calculated by formula (3):

[0122]

[0123] (4) Calculate the collision force at each collision position.

[0124] Through collision detection and determination of collision surface, the collision force can be further calculated. Before that, the collision stiffness needs to be determined.

[0125] First, the contact force F0 is derived from the deformation area and the Young's modulus of the material. The calculation formula is as follows (4):

[0126] F0=E1a1+E2a2 (4)

[0127] Here, E1 represents the Young's modulus of deformation 1 (joint sleeve), and E2 represents the Young's modulus of deformation 2 (meshing ring gear).

[0128] Furthermore, the linear penetration (p) is calculated based on the deformation area and the contact segment length, and the calculation formula is as follows (5):

[0129] p=2(E1a1+E2a2) / ((E1+E2)L) (5)

[0130] Where L is the length of the contact segment P1P2. Through formula (5), the calculated linear penetration can represent the collision depth, which is helpful for simulating the collision process.

[0131] Furthermore, the linear contact stiffness is calculated: Linear contact stiffness Kc It is related to linear penetration and contact force and is expressed by formula (6).

[0132] K c =F0 / p (6)

[0133] Furthermore, the contact penetration speed V c and sliding speed V s It is obtained by the projection of the relative velocity of M on the vectors n and v, as Figure 8 As shown, it can be expressed by formula (7):

[0134]

[0135] Where V1(Q) represents the absolute velocity of point Q at deformation 1, and V2(Q) represents the absolute velocity of point Q at deformation 2.

[0136] Furthermore, the effective stiffness is calculated: In order to avoid unrealistic high-frequency dynamic characteristics, the linear contact stiffness is combined with the maximum solid stiffness K max Calculate the effective stiffness K in series e , as shown in formula (8):

[0137] K e =(K c -1 +K max -1 ) -1 (8)

[0138] Further, the collision force F is calculated. con It is expressed as formula (9):

[0139] F con =K e pH c V c (1-e -pldp ) (9)

[0140] In the formula, H c represents the damping coefficient, and dp represents the full damping penetration limit.

[0141] In some embodiments, after calculating the collision force, the friction force during the collision can also be calculated. The calculation expression of the friction force is shown in formula (10):

[0142] f con =F con (10)

[0143] Here, μ represents the friction coefficient.

[0144] In the embodiment of the present application, during the entire cycle of calculating the inter-tooth collision force, the system first enters the pre-processing stage, and after the pre-processing, enters the collision detection stage to determine whether the teeth intersect and calculate the intersection point, and determine the collision surface according to the intersection point. Then, the collision force when the teeth contact is calculated according to the physical characteristics, and the calculation of the collision force is completed.

[0145] In some embodiments, the collision force calculation method can be used for Fig.10 The structure system of the electronically controlled mechanical transmission based on the tooth-type synchronizer-free transmission shown in the figure includes a motor, a tooth-type clutch, a speed change system and a control system. The tooth-type clutch in the transmission is composed of a ring gear and a coupling sleeve, and the ring gear and the coupling sleeve have the same number of teeth and the same tooth shape. When shifting gears, the coupling sleeve is moved toward the ring gear by the axial thrust of the actuator, and a collision occurs when the teeth of the coupling sleeve contact the teeth of the ring gear. At this time, the collision detection system starts to perform collision detection, and after determining that a collision occurs, the intersection is calculated, and then the collision surface is determined, the collision stiffness is calculated, and finally the collision force is calculated through physical properties.

[0146] In summary, the embodiments of the present application have at least the following beneficial effects:

[0147] 1. The principle of this application is simple. It characterizes the inter-tooth collision by constructing a hierarchical bounding box. The Monte Carlo method is used to calculate the collision surface. Finally, the inter-tooth collision force is calculated by physical properties to construct a collision model. This solves the problem of being unable to determine the collision surface and the collision depth when using the ball collision model to calculate the inter-tooth collision force, and effectively improves the accuracy and speed of the inter-tooth collision force calculation.

[0148] 2. It can be used for simulation and control of power systems with tooth clutches as transmission elements. It has universality and versatility, simple structure, clear logic, and is easy to implement, meeting multiple application scenarios such as test development and engineering practice.

[0149] See also Fig.11 The embodiment of the present application further provides a system for calculating the collision force when the teeth of a dog clutch are engaged, which can implement the above-mentioned method for calculating the collision force when the teeth of a dog clutch are engaged, and the system includes:

[0150] A first module 101 is used to extract a closed geometric contour from the image when the dog clutch is engaged;

[0151] The second module 102 is used to construct a hierarchical bounding box tree according to the geometric outline;

[0152] A third module 103 is used to perform collision detection on the dog clutch according to the hierarchical bounding box tree to obtain a collision detection result;

[0153] The fourth module 104 is used to calculate the collision surface area using a Monte Carlo algorithm according to the collision detection result;

[0154] The fifth module 105 is used to calculate the collision force at each collision position when the gears are engaged according to the physical characteristics and the collision surface area.

[0155] It can be understood that the contents of the above method embodiments are all applicable to the present system embodiments, the functions specifically implemented by the present system embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0156] The embodiment of the present application also provides an electronic device, the electronic device includes a memory and a processor, the memory stores a computer program, and the processor implements the above-mentioned method for calculating the collision force when the tooth clutch is engaged when executing the computer program. The electronic device can be any intelligent terminal including a tablet computer, a car computer, etc.

[0157] It can be understood that the contents of the above method embodiments are all applicable to the present device embodiments, the functions specifically implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0158] See also Fig.12 , Fig.12 The hardware structure of an electronic device of another embodiment is illustrated, and the electronic device includes:

[0159] The processor 201 may be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of the present application;

[0160] The memory 202 can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device or a random access memory (RAM). The memory 202 can store an operating system and other application programs. When the technical solution provided in the embodiment of this specification is implemented by software or firmware, the relevant program code is stored in the memory 202, and the processor 201 calls and executes a method for calculating the collision force when the tooth clutch is engaged in the embodiment of this application;

[0161] Input / output interface 203, used to implement information input and output;

[0162] The communication interface 204 is used to realize the communication interaction between the device and other devices. The communication can be realized through a wired manner (such as USB, network cable, etc.) or a wireless manner (such as mobile network, WIFI, Bluetooth, etc.);

[0163] Bus 205 , which transmits information between various components of the device (e.g., processor 201 , memory 202 , input / output interface 203 , and communication interface 204 );

[0164] The processor 201 , the memory 202 , the input / output interface 203 and the communication interface 204 are connected to each other in communication within the device via the bus 205 .

[0165] An embodiment of the present application further provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the above-mentioned method for calculating the collision force when the teeth of a dog clutch are engaged.

[0166] It can be understood that the contents of the above method embodiments are all applicable to the present storage medium embodiments, the functions specifically implemented by the present storage medium embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0167] The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely disposed relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0168] The embodiments described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Those skilled in the art will appreciate that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0169] Those skilled in the art will appreciate that the technical solutions shown in the figures do not constitute a limitation on the embodiments of the present application, and may include more or fewer steps than shown in the figures, or a combination of certain steps, or different steps.

[0170] The system embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment.

[0171] Those skilled in the art will appreciate that all or some of the steps in the methods disclosed above, and the functional modules / units in the systems and devices may be implemented as software, firmware, hardware, or a suitable combination thereof.

[0172] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0173] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0174] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the system embodiments described above are only schematic. For example, the division of the above units is only a logical function division. There may be other division methods in actual implementation, such as 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 an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0175] The units described above 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.

[0176] 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.

[0177] 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, 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 multiple instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, referred to as ROM), random access memory (Random Access Memory, referred to as RAM), disk or optical disk and other media that can store programs.

[0178] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but the scope of the rights of the present invention is not limited thereto. Any modification, equivalent substitution and improvement made by a person skilled in the art without departing from the scope and essence of the present invention should be within the scope of the rights of the present invention.

Claims

1. A method for calculating the collision force when the teeth of a dog clutch are engaged, characterized in that: The following steps are involved: extracting a closed geometric contour from the image of the dog clutch being engaged; Constructing a hierarchical bounding box tree according to the geometric outline; performing collision detection on the dog clutch according to the hierarchical bounding box tree to obtain a collision detection result; According to the collision detection result, a Monte Carlo algorithm is used to calculate the collision surface area; The collision force at each collision position when the teeth are engaged is calculated based on the physical characteristics and the collision surface area.

2. The method according to claim 1, characterized in that The step of extracting a closed geometric contour from the image when the dog clutch is engaged comprises: According to the geometric parameters in the image when the tooth clutch is engaged, the shapes of the teeth of the engagement sleeve and the shapes of the teeth of the meshing gear ring in the tooth clutch are extracted to obtain a closed geometric contour.

3. The method according to claim 1, characterized in that The step of constructing a hierarchical bounding box tree according to the geometric outline comprises the following steps: Converting the geometric contour into elements consisting of line segments or circular arcs; Generating an axis-aligned bounding box for each of the elements; Based on the hierarchical relationship of the elements, a binary tree is used to generate a hierarchical bounding box tree according to the axis-aligned bounding box.

4. The method according to claim 1, characterized in that: The step of performing collision detection on the dog clutch according to the hierarchical bounding box tree to obtain a collision detection result comprises the following steps: Obtaining leaf nodes of the hierarchical bounding box tree where axis-aligned bounding boxes overlap; The intersection of the geometric outlines in the leaf nodes is determined to obtain a collision detection result.

5. The method according to claim 4, characterized in that Determining the intersection of the geometric outlines in the leaf nodes comprises the following steps: Calculate the projections of the geometric outline of the leaf node on the horizontal axis and the vertical axis to obtain a first projection and a second projection; When the first projection and the second projection overlap in both the horizontal axis and the vertical axis, it is determined that the geometric contours intersect.

6. The method according to claim 1, characterized in that The method of calculating the collision surface area using a Monte Carlo algorithm according to the collision detection result comprises the following steps: Determining the collision surface according to the number of intersection points between the tooth contour segment of the coupling sleeve and the tooth contour segment of the meshing gear ring in the collision detection result; The contour segment between the intersection points is regarded as the contact segment, and the length of the contact segment is obtained; Using a Monte Carlo algorithm to calculate the intersection area between the engagement sleeve and the contact section to obtain a first intersection area; Calculating the intersection area between the meshing gear ring and the contact segment using a Monte Carlo algorithm to obtain a second intersection area; The first intersection area and the second intersection area are combined into a collision surface area.

7. The method according to claim 6, characterized in that The method of calculating the collision force at each collision position when the gears are engaged based on the physical characteristics and the collision surface area comprises the following steps: Calculating a contact force based on the Young's modulus according to the first intersection area and the second intersection area; Calculating linear penetration according to the first intersection area, the second intersection area and the contact segment length; Calculating a linear contact stiffness according to the contact force and the linear penetration; The effective stiffness is calculated based on the linear contact stiffness and the maximum solid stiffness; Calculate the contact penetration speed and the sliding speed according to the first absolute speed of the engagement sleeve and the second absolute speed of the meshing gear ring at the center point between the intersection points; The collision force is calculated according to the effective stiffness, the linear penetration, the damping coefficient, and the contact penetration speed.

8. A system for calculating the collision force when the teeth of a dog clutch are engaged, characterized in that: include: A first module is used to extract a closed geometric contour from the image when the dog clutch is engaged; The second module is used to construct a hierarchical bounding box tree according to the geometric outline; A third module is used to perform collision detection on the dog clutch according to the hierarchical bounding box tree to obtain a collision detection result; The fourth module is used to calculate the collision surface area by using the Monte Carlo algorithm according to the collision detection result; The fifth module is used to calculate the collision force at each collision position when the gears engage according to the physical characteristics and the collision surface area.

9. An electronic device, characterized in that: including a processor and a memory; The memory is used to store programs; The processor executes the program to implement the method according to any one of claims 1 to 7.

10. A computer storage medium storing a program executable by a processor, characterized in that: The program executable by the processor is used to implement the method according to any one of claims 1 to 7 when executed by the processor.

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