A method and system for calculating collision force when tooth-to-tooth clutch engages

Abstract

This application discloses a method and system for calculating the collision force during engagement of a jaw clutch, belonging to the field of computer technology. The method includes: extracting a closed geometric contour from an image of the jaw clutch engaged; constructing a hierarchical bounding box tree based on the geometric contour; performing collision detection on the jaw clutch based on the hierarchical bounding box tree to obtain collision detection results; calculating the collision surface area using a Monte Carlo algorithm based on the collision detection results; and calculating the collision force at each collision position during engagement based on physical characteristics and the collision surface area. Through the above steps, the collision surface can be clearly identified, thus enabling rapid and accurate calculation of the collision force at each collision position during engagement of the jaw clutch, improving the testing and development efficiency of jaw clutches.

Description

Technical Field

[0001] This application relates to the field of computer technology, and in particular to a method and system for calculating the collision force when the teeth of a toothed clutch engage. Background Technology

[0002] Electromechanical transmissions (EMTs) that replace synchronizers with jaw clutches offer a simpler, more compact structure and lower development costs. To achieve shock-free shifting control and reduce power interruption time in EMTs, establishing a computational model that accurately reflects the inter-tooth collision force during dynamic shifting is crucial. However, modeling and simulation information regarding jaw clutches during EMT shifting is very limited, especially computational models that comprehensively reflect inter-tooth collision. While collision models based on microscopic surfaces or finite element analysis can construct complex system models, these methods are often computationally complex and computationally burdensome, making them unsuitable for calculating collision forces in shifting control. Therefore, establishing a model that can adapt to complex, mixed-convex profiles while requiring less computation is particularly important. This model should effectively describe the collision process between the engagement sleeve and the engagement gear ring and be able to calculate the collision forces generated at different collision locations.

[0003] Currently, most inter-tooth collision calculations use a small ball collision model to calculate the collision force. This method has two main challenges: first, it is impossible to define the collision surface clearly; second, it is difficult to determine the collision depth. Due to the characteristics of transmission systems, the collision process cannot be simply simulated using a spherical collision surface. Summary of the Invention

[0004] To address at least one of the aforementioned problems, the main objective of this application is to propose a method and system for calculating the collision force during engagement of a toothed clutch, aiming to achieve accurate calculation of the collision force at different contact positions during engagement.

[0005] To achieve the above objectives, one aspect of this application proposes a method for calculating the collision force during gear engagement of a jaw clutch, the method comprising:

[0006] Extract the closed geometric contour from the image of the engagement of the jaw clutch;

[0007] Construct a hierarchical bounding box tree based on the geometric contours;

[0008] Based on the hierarchical bounding box tree, collision detection is performed on the jaw clutch to obtain the collision detection result;

[0009] Based on the collision detection results, the collision surface area is calculated using the Monte Carlo algorithm;

[0010] Based on the physical properties and the area of ​​the collision surface, the collision force at each collision position during tooth engagement is calculated.

[0011] In some embodiments, extracting the closed geometric profile from the image of the engagement of the jaw clutch includes:

[0012] Based on the geometric parameters in the image of the engagement of the tooth clutch, the shapes of each tooth of the engagement sleeve and each tooth 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 based on the geometric contour includes the following steps:

[0014] The geometric contour is converted into elements composed of line segments or arcs;

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

[0016] Based on the hierarchical relationship of the elements, a hierarchical bounding box tree is generated by aligning the bounding boxes according to the axis using a binary tree.

[0017] In some embodiments, the collision detection of the jaw clutch based on the hierarchical bounding box tree to obtain the collision detection result includes the following steps:

[0018] Obtain the leaf nodes of the axis-aligned bounding boxes that overlap in the hierarchical bounding box tree;

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

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

[0021] Calculate the projections of the geometric contours of the leaf nodes onto the horizontal and vertical axes to obtain the first projection and the second projection;

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

[0023] In some embodiments, calculating the collision surface area using the Monte Carlo algorithm based on the collision detection results includes the following steps:

[0024] The collision surface is determined based on the number of intersection points between the tooth contour segments of the engagement sleeve and the tooth contour segments of the meshing gear in the collision detection results.

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

[0026] The Monte Carlo algorithm is used to calculate the intersection area between the coupling sleeve and the contact segment to obtain the first intersection area;

[0027] The Monte Carlo algorithm is used to calculate the intersection area between the meshing gear ring and the contact section to obtain the second intersection area;

[0028] The first intersection area and the second intersection area are combined to form the collision surface area.

[0029] In some embodiments, calculating the collision force at each collision position during tooth engagement based on physical characteristics and the collision surface area includes the following steps:

[0030] The contact force is calculated based on Young's modulus using the first and second cross areas.

[0031] Linear penetration is calculated based on the first intersection area, the second intersection area, and the contact segment length;

[0032] The linear contact stiffness is calculated based on 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] The contact penetration speed and sliding speed are calculated based on the first absolute velocity of the engagement sleeve and the second absolute velocity of the meshing gear ring at the center point between the intersection points;

[0035] The impact force is calculated based on the effective stiffness, the linear penetration, the damping coefficient, and the contact penetration velocity.

[0036] To achieve the above objective, another aspect of this application proposes a system for calculating the collision force during engagement of a jaw clutch, the system comprising:

[0037] The first module is used to extract a closed geometric profile from the image of the engagement of the jaw clutch;

[0038] The second module is used to construct a hierarchical bounding box tree based on the geometric contour;

[0039] The third module is used to perform collision detection on the jaw clutch based on the hierarchical bounding box tree, and obtain the collision detection result;

[0040] The fourth module is used to calculate the collision surface area using the Monte Carlo algorithm based on the collision detection results;

[0041] The fifth module is used to calculate the collision force at each collision position when the teeth are engaged, based on the physical characteristics and the area of ​​the collision surface.

[0042] To achieve the above objectives, another aspect of this application provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the method described above.

[0043] To achieve the above objectives, another aspect of the embodiments of this application proposes a computer-readable storage medium storing a computer program that, when executed by a processor, implements the methods described above.

[0044] The embodiments of this application include at least the following beneficial effects: This application provides a method and system for calculating the collision force when the teeth of a jaw clutch engage. This method extracts a closed geometric contour from an image of the jaw clutch engaging; constructs a hierarchical bounding box tree based on the geometric contour; performs collision detection on the jaw clutch based on the hierarchical bounding box tree to obtain collision detection results; calculates the collision surface area using a Monte Carlo algorithm based on the collision detection results; and calculates the collision force at each collision position when the teeth engage based on physical characteristics and the collision surface area. This overall process clearly defines the collision surface and allows for rapid and accurate calculation of the collision force at each collision position, which is beneficial for improving the testing and development efficiency of jaw clutches. Attached Figure Description

[0045] The accompanying drawings are used to provide a further understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0046] Figure 1 This is a flowchart of a method for calculating the collision force when the teeth of a toothed clutch engage, provided in an embodiment of this application.

[0047] Figure 2 This is a schematic diagram of the hierarchical bounding box tree provided in the embodiments of this application;

[0048] Figure 3 This is a schematic diagram of the geometric distribution provided in the embodiments of this application;

[0049] Figure 4 This is a schematic diagram of the hierarchical bounding box tree of the geometry provided in the embodiments of this application;

[0050] Figure 5 This is a schematic diagram of bounding box overlap provided in an embodiment of this application;

[0051] Figure 6 This is a schematic diagram showing that only the surrounding box overlaps between the teeth, as provided in an embodiment of this application;

[0052] Figure 7This is a schematic diagram of inter-tooth collision provided in an embodiment of this application;

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

[0054] Figure 9 This is a schematic diagram illustrating the calculation of the first and second cross areas provided in an embodiment of this application;

[0055] Figure 10 This is a schematic diagram of the electromechanical transmission structure system based on a dog clutch without synchronizer provided in the embodiments of this application;

[0056] Figure 11 This is a schematic diagram of a module of a system for calculating the collision force between the teeth of a toothed clutch, provided in an embodiment of this application.

[0057] Figure 12 This is a schematic diagram of the hardware structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[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 with reference to 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 merely examples of devices and methods consistent with some aspects of the embodiments of the present application as detailed in the appended claims.

[0059] Although functional modules are divided in the system diagram and a 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 aforementioned figures 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 may be used herein to describe various concepts, but unless otherwise stated, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the words “if,” “when,” or “in response to a determination” as used herein may be interpreted as “when…” or “when…” or “in response to a determination.”

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

[0062] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

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

[0064] In related technologies, most inter-tooth collision calculations use a small ball collision model to calculate the collision force between teeth. This method has two drawbacks: firstly, it cannot clearly define the collision surface, and secondly, it is difficult to determine the collision depth. Due to the characteristics of transmission systems, the collision process cannot be simply simulated using a spherical collision surface.

[0065] In view of this, this application provides a method and system for calculating the collision force between teeth of a tooth clutch during engagement. The scheme is based on a hierarchical bounding box collision detection algorithm to characterize the collision situation between teeth, then uses the Monte Carlo method to calculate the collision surface, and finally combines physical characteristics to calculate the collision force between teeth, thereby realizing the calculation of the collision force at different contact positions between teeth during engagement.

[0066] This application provides a method for calculating the collision force when the teeth of a jaw clutch engage, relating to the field of computer technology. This method can be applied to a terminal, a server, or software running on either a terminal or a server. In some embodiments, the terminal can be a smartphone, tablet, laptop, desktop computer, smart speaker, smartwatch, or in-vehicle terminal, but is not limited to these. The server can be configured as an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, 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 implementing the method for calculating the collision force when the teeth of a jaw clutch engage, but is not limited to the above forms.

[0067] This application can be used in a wide variety of general-purpose or special-purpose computer system environments or configurations. Examples include: 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, and distributed computing environments including any of the above systems or devices. This 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. This application can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0068] Figure 1 This is an optional flowchart of a method for calculating the collision force between the teeth of a jaw clutch provided in an embodiment of this application. Figure 1 The method may include, but is not limited to, steps S100 to S500.

[0069] Step S100: Extract the closed geometric contour from the image of the engagement of the jaw clutch.

[0070] Step S200: Construct a hierarchical bounding box tree based on the geometric contour.

[0071] Step S300: Based on the hierarchical bounding box tree, perform collision detection on the jaw clutch to obtain the collision detection result.

[0072] Step S400: Based on the collision detection results, calculate the collision surface area using the Monte Carlo algorithm.

[0073] Step S500: Based on the physical characteristics and the area of ​​the collision surface, calculate the collision force at each collision position when the teeth are engaged.

[0074] Steps S100 to S500, as illustrated in this embodiment, involve extracting a closed geometric contour from the image of the dog clutch during engagement; constructing a hierarchical bounding box tree based on the geometric contour; performing collision detection on the dog clutch based on the hierarchical bounding box tree to obtain collision detection results; calculating the collision surface area using a Monte Carlo algorithm based on the collision detection results; and calculating the collision force at each collision position during engagement based on physical characteristics and the collision surface area. This comprehensive process clearly defines the collision surface and collision depth, enabling rapid and accurate calculation of the collision force at each collision position during engagement of the dog clutch, thus improving the testing and development efficiency of dog clutches.

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

[0076] Step S110: Based on the geometric parameters in the image of the engagement of the toothed clutch, extract the shape of each tooth of the engagement sleeve and the shape of each tooth of the meshing gear ring in the toothed clutch to obtain 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: Convert the geometric contour into elements composed of line segments or arcs;

[0079] Step S230: Generate 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 by aligning the bounding boxes according to the axis 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: Obtain the leaf nodes of the axis-aligned bounding boxes that overlap in the hierarchical bounding box tree;

[0083] Step S320: Determine the intersection of the geometric contours in the leaf nodes to obtain the collision detection result.

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

[0085] Step S321: Calculate the projection of the geometric contour of the leaf node onto the horizontal and vertical axes to obtain the first projection and the second projection.

[0086] Step S322: When the first projection and the second projection overlap on both the horizontal and vertical axes, 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: Determine the collision surface based on the number of intersection points between the tooth contour segment of the engagement sleeve and the tooth contour segment of the meshing gear in the collision detection results.

[0089] Step S420: Take the contour segment between the intersection points as the contact segment and obtain the length of the contact segment;

[0090] Step S430: The Monte Carlo algorithm is used to calculate the intersection area between the coupling sleeve and the contact segment to obtain the first intersection area;

[0091] Step S440: The Monte Carlo algorithm is used to calculate the cross area between the meshing gear ring and the contact section to obtain the second cross area;

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

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

[0094] Step S510: Calculate the contact force based on Young's modulus according to the first cross area and the second cross area;

[0095] Step S520: Calculate linear penetration based on the first intersection area, the second intersection area, and the contact segment length;

[0096] Step S530: Calculate the linear contact stiffness based on the contact force and the linear penetration.

[0097] Step S540: Calculate the effective stiffness based on the linear contact stiffness and the maximum solid stiffness;

[0098] Step S550: Based on the first absolute velocity of the engagement sleeve and the second absolute velocity of the meshing gear ring at the center point between the intersection points, the contact penetration speed and the sliding speed are calculated.

[0099] Step S560: The collision force is calculated based on the effective stiffness, the linear penetration, the damping coefficient, and the contact penetration velocity.

[0100] The following is a detailed introduction and explanation of the solution of this application embodiment, using specific application examples of gear engagement scenarios with a toothed clutch:

[0101] This application provides a method for calculating the collision force between the teeth of a toothed clutch during engagement. This method can be applied to determine the collision force calculation at different contact positions between the teeth during engagement. Specifically, it may include the following stages:

[0102] (1) Pre-processing stage. When the tooth clutch is about to engage, the calculation of the inter-tooth collision force of the present application embodiment is initiated, and the pre-processing stage is entered.

[0103] Before acquiring data, it is generally necessary to model the jaw clutch. First, the geometry and key parameters of the teeth, as well as the relative positions and angles between each tooth, are determined based on defined geometric parameters. Then, based on the extracted key parameters, smooth boundaries of the meshing teeth are constructed using curve fitting techniques (such as B-splines or Bezier curves). The boundary data of each meshing tooth are stitched together to form a complete geometric contour, ensuring that the boundaries form a closed loop within the engagement area. By comparing the actual scan data and the fitted contour, an error correction algorithm (least squares method) is used to adjust the accuracy of the closed contour, thereby establishing a 3D model of the jaw clutch. Based on the 3D model of the jaw clutch, the geometric contour of the jaw clutch is projected onto a 2D plane to obtain planar data. This planar data is then stored as a point set coordinate vector format (such as DXF or SVG) to obtain a closed geometric contour, which is convenient for subsequent simulation and modeling.

[0104] Furthermore, the preprocessing stage transforms the closed geometric contour into elements composed of discontinuous line segments or arcs, and then generates axis-aligned bounding boxes for these elements. Each axis-aligned bounding box encloses an element that forms the tooth; these elements are two-dimensional. An axis-aligned bounding box (AABB) is a rectangular bounding box whose sides are aligned with axes (e.g., the x-axis and y-axis). The x-axis refers to the horizontal axis of the coordinate system, and the y-axis refers to the vertical 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 for that level and the geometric primitive information of the target component. For example... Figure 2 As shown, the outermost bounding box refers to Figure 2The highest level bounding box. Bounding box information is used in the collision detection stage to determine whether there is a collision (or intersection), while the geometric primitive information of the target part is used for the segmentation of the next level primitive, and the hierarchical bounding box tree is generally not reconstructed in the collision detection stage.

[0106] It's important to note that the line segments enclosed by rectangles are the constituent elements of the tooth, and this is a two-dimensional concept. The tooth is divided into elements composed of line segments, with each discontinuous segment generating a bounding box. The primitive information refers to the shape of the tooth, which is then divided into different line segments, each enclosed by a rectangle.

[0107] (2) Collision Detection Stage. After preprocessing, the collision detection stage begins. The collision detection stage determines whether a collision has occurred between the two teeth by detecting whether the contour segments of the upper teeth on the left and right gear rings of the toothed clutch intersect. One side of the left and right gear rings is the engagement sleeve gear ring, and the other side is the meshing gear ring.

[0108] Specifically, collision detection of the jaw clutch is performed based on the hierarchical bounding box tree, including the following steps: obtaining the leaf nodes of the axis-aligned bounding boxes that overlap in the hierarchical bounding box tree; determining the intersection of the geometric contours in the leaf nodes to obtain the collision detection result.

[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 the root node Root, as shown below. Figure 3 As shown, and generated as Figure 4 The hierarchy of bounding box trees is shown. When performing collision detection, leaf nodes are sequentially obtained from the hierarchy of bounding box trees to obtain the contour segment T to be detected and its bounding box, and steps 1 to 3 are performed as follows:

[0110] 1. If the bounding box of T intersects with the bounding box of Root, then 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 downwards.

[0111] 2. If the bounding box of T intersects with the bounding box of G3, then it is necessary to further check whether T and G3 intersect to determine whether T has collided with G3; otherwise, there is no need to continue the detection with G3.

[0112] 3. Collision detection between X and N1 is similar to the collision detection method between X and Root. Furthermore, the principle for detecting geometric contour intersections is that each side of the rectangle corresponding to the AABB bounding box is parallel to a certain coordinate axis. Therefore, a collision can be determined by detecting whether the projections of the objects to be detected on the coordinate axis overlap.

[0113] Specifically, the collision detection results of the AABB bounding boxes can be obtained as follows: For ease of description, let's take bounding box G and bounding box H as examples, such as... Figure 5 As shown, project bounding boxes G and H onto the X and Y axes respectively. The coordinates of the maximum point of bounding box G along the Y axis are Y. Amax The minimum point coordinates are Y Amin The coordinates of the minimum point in the X-axis direction are Y. Amin The maximum point coordinate is X Amax Similarly, for the bounding box H, we can obtain Y. Bmax Y Bmin Y Bmin and X Bmax .exist Figure 5 In the figure, the line segments IJ and OP on the coordinate axes are the overlapping parts of the projections of G and H. Therefore, the two bounding boxes intersect only when both coordinate axes overlap. Based on this, the intersection of bounding boxes can be expressed by the following formula (1):

[0114]

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

[0116] In the inter-tooth interaction scenario of this application embodiment, when bounding boxes intersect, it is determined whether the contour segments within the bounding boxes intersect. If they intersect, a collision occurs between the teeth. Specifically, as shown... 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, points A and E are located on opposite sides of de, or one point is on de and the other point is on one side. Points d and e are located on opposite sides of AE, or one point is on AE and the other point is on one side, satisfying formula (2). Formula (2) is the formula for the collision detection result of the tooth:

[0117]

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

[0119] When bounding box intersections are detected, the intersection points between the bounding boxes are determined, and the calculation of intersection points between elements begins. If two objects collide, the number of intersection points will necessarily be even. Collision between the engaging sleeve and the meshing gear ring can be determined by checking if their contour segments intersect. When a collision occurs, the intersection points between the tooth contours of the engaging sleeve and the meshing gear ring need to be detected to determine the collision surface. Specifically, when a collision occurs, the teeth of the engaging sleeve and the teeth on the meshing gear ring's contour will produce two intersection points. The collision surface is then the perpendicular plane to the line containing the two intersection points, such as... Figure 8As shown.

[0120] The collision surface may include the intersection area of ​​the engaging sleeve and the contact section (first intersection area) and the intersection area of ​​the meshing gear ring and the contact section (second intersection area), wherein the contact section refers to the geometric contour portion that comes into contact during the collision.

[0121] In the oxy coordinate system, the first intersection area a1 and the second intersection area a2 can be approximately calculated using the Monte Carlo method. For example... Figure 9 As shown, T is an N×M two-dimensional array where all elements are 1, and its length and width are denoted as X. L and y w Extending the intersection line P1P2 to the boundary of the map, the map is divided into two parts. Taking the teeth of the engagement sleeve and engagement gear ring in the map, as well as the two parts separated by the extension line P1P2 and the entire map, will yield the set of pixels representing the teeth of SL and DG and the two parts. Therefore, the intersection of S1, S2, and S3 is the set of pixels corresponding to the intersection area of ​​the engagement sleeve and the contact segment, and the intersection of S2, S3, and S4 is the set of pixels corresponding to the intersection area a2 of the meshing gear ring and the contact segment. Therefore, a1 and a2 can be calculated using formula (3):

[0122]

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

[0124] By detecting collisions and determining the collision surfaces, the collision force can be 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, and the calculation formula is as follows (4):

[0126] F0=E1a1+E2a2 (4)

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

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

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

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

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

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

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

[0134]

[0135] In the formula, 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: to avoid unrealistic high-frequency dynamic characteristics, the linear contact stiffness is compared with the maximum solid stiffness K. max Calculate the effective stiffness K by connecting them in series e As shown in formula (8):

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

[0138] Furthermore, the collision force F is calculated. con Represented as formula (9):

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

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

[0141] In some embodiments, after calculating the collision force, the frictional force during the collision can also be calculated. The expression for calculating the frictional force is shown in equation (10):

[0142] f con =F con (10)

[0143] Where μ represents the coefficient of friction.

[0144] In this embodiment, during the entire calculation cycle of inter-tooth collision force, the system first enters a preprocessing stage. After preprocessing, it enters a collision detection stage to determine whether the teeth intersect and calculate the intersection point. The collision surface is then determined based on the intersection point. Subsequently, the collision force at the time of inter-tooth contact is calculated based on physical characteristics, thus completing the calculation of the collision force.

[0145] In some embodiments, the collision force calculation method can be used as follows: Figure 10 The illustrated electromechanical transmission system based on a dog clutch without a synchronizer includes a motor, a dog clutch, a transmission system, and a control system. The dog clutch in the transmission consists of a gear ring and an engagement sleeve. The gear ring and engagement sleeve have the same number of teeth and the same tooth profile. When shifting gears, the engagement sleeve is pushed axially by the actuator and moves towards the gear ring. A collision occurs when the teeth of the engagement sleeve contact the teeth of the gear ring. At this point, a collision detection system is activated to detect the collision, calculate the intersection point after a collision occurs, determine the collision surface, calculate the collision stiffness, and finally calculate the collision force using physical properties.

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

[0147] 1. The principle of this application is simple, using a hierarchical bounding box to characterize inter-tooth collisions. The Monte Carlo method is used to calculate the collision surface, and finally, the inter-tooth collision force is calculated through physical properties to construct a collision model. This solves the problem of not being able to determine the collision surface and collision depth when using a small ball collision model to calculate inter-tooth collision forces, effectively improving the accuracy and speed of inter-tooth collision force calculation.

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

[0149] Please see Figure 11 This application also provides a system for calculating the collision force when the teeth of a jaw clutch engage, which can realize the above-mentioned method for calculating the collision force when the teeth of a jaw clutch engage. The system includes:

[0150] The first module 101 is used to extract a closed geometric profile from the image of the dog clutch when it is engaged;

[0151] The second module 102 is used to construct a hierarchical bounding box tree based on the geometric contour;

[0152] The third module 103 is used to perform collision detection on the jaw clutch according to the hierarchical bounding box tree and obtain the collision detection result;

[0153] The fourth module 104 is used to calculate the collision surface area using the Monte Carlo algorithm based on the collision detection results.

[0154] The fifth module 105 is used to calculate the collision force at each collision position when the teeth are engaged, based on the physical characteristics and the area of ​​the collision surface.

[0155] It is understood that the content of the above method embodiments is applicable to this system embodiment. The specific functions implemented in this system embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0156] This application also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the method described above for calculating the collision force when the teeth of a jaw clutch engage. This electronic device can be any smart terminal, including tablet computers, in-vehicle computers, etc.

[0157] It is understood that the content of the above method embodiments is applicable to this device embodiment. The specific functions implemented by this device embodiment 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] Please see Figure 12 , Figure 12 The hardware structure of an electronic device according to another embodiment is illustrated. The electronic device includes:

[0159] The processor 201 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, 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 this application.

[0160] The memory 202 can be implemented as a read-only memory (ROM), static storage device, dynamic storage device, or random access memory (RAM). The memory 202 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 202 and is called and executed by the processor 201 to execute a method for calculating the collision force when the teeth of a jaw clutch engage, according to an embodiment of this application.

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

[0162] The communication interface 204 is used to enable communication and interaction between this device and other devices. Communication can be achieved through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0163] Bus 205 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, memory 202, input / output interface 203 and communication interface 204 are connected to each other within the device via bus 205.

[0165] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for calculating the collision force when the teeth of a toothed clutch engage.

[0166] It can be understood that the contents of the above method embodiments are all applicable to the present storage medium embodiment, the functions specifically implemented by the present storage medium embodiment 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] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0168] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

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

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

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

[0172] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0173] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0174] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the system embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interfaces, apparatuses, or units, and may be electrical, mechanical, or other forms.

[0175] The units described above as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0176] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0177] If the integrated unit is implemented as 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 this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0178] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A method for calculating the collision force during gear engagement of a jaw clutch, characterized in that, Includes the following steps: Extract the closed geometric contour from the image of the engagement of the jaw clutch; Construct a hierarchical bounding box tree based on the geometric contours; Based on the hierarchical bounding box tree, collision detection is performed on the jaw clutch to obtain the collision detection result; Based on the collision detection results, the collision surface area is calculated using the Monte Carlo algorithm; Based on the physical properties and the area of ​​the collision surface, the collision force at each collision position during tooth engagement is calculated. The step of calculating the collision surface area using the Monte Carlo algorithm based on the collision detection results includes the following steps: The collision surface is determined based on the number of intersection points between the tooth contour segments of the engagement sleeve and the tooth contour segments of the meshing gear in the collision detection results. The contour segment between the intersection points is taken as the contact segment, and the length of the contact segment is obtained; The Monte Carlo algorithm is used to calculate the intersection area between the coupling sleeve and the contact segment to obtain the first intersection area; The Monte Carlo algorithm is used to calculate the intersection area between the meshing gear ring and the contact section to obtain the second intersection area; The first intersection area and the second intersection area are combined to form the collision surface area; The calculation of the collision force at each collision position during tooth engagement, based on physical characteristics and the collision surface area, includes the following steps: The contact force is calculated based on Young's modulus using the first and second cross areas. Linear penetration is calculated based on the first intersection area, the second intersection area, and the contact segment length; The linear contact stiffness is calculated based on the contact force and the linear penetration. The effective stiffness is calculated based on the linear contact stiffness and the maximum solid stiffness. The contact penetration speed and sliding speed are calculated based on the first absolute velocity of the engagement sleeve and the second absolute velocity of the meshing gear ring at the center point between the intersection points; The impact force is calculated based on the effective stiffness, the linear penetration, the damping coefficient, and the contact penetration velocity.

2. The method according to claim 1, characterized in that, Extracting the closed geometric contour from the image of the engagement of the jaw clutch includes: Based on the geometric parameters in the image of the engagement of the tooth clutch, the shapes of each tooth of the engagement sleeve and each tooth 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 process of constructing a hierarchical bounding box tree based on the geometric contour includes the following steps: The geometric contour is converted into elements composed of line segments or arcs; Generate an axis-aligned bounding box for each of the elements; Based on the hierarchical relationship of the elements, a hierarchical bounding box tree is generated by aligning the bounding boxes according to the axis using a binary tree.

4. The method according to claim 1, characterized in that, The step of performing collision detection on the jaw clutch based on the hierarchical bounding box tree to obtain the collision detection result includes the following steps: Obtain the leaf nodes of the axis-aligned bounding boxes that overlap in the hierarchical bounding box tree; The intersection of geometric contours in the leaf nodes is determined to obtain the collision detection result.

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

6. A system for implementing the method of calculating the collision force during engagement of a jaw clutch as described in any one of claims 1-5, characterized in that, include: The first module is used to extract a closed geometric profile from the image of the engagement of the jaw clutch; The second module is used to construct a hierarchical bounding box tree based on the geometric contour; The third module is used to perform collision detection on the jaw clutch based on the hierarchical bounding box tree, and obtain the collision detection result; The fourth module is used to calculate the collision surface area using the Monte Carlo algorithm based on the collision detection results; The fifth module is used to calculate the collision force at each collision position when the teeth are engaged, based on the physical characteristics and the area of ​​the collision surface.

7. An electronic device, characterized in that, Including the processor and memory; The memory is used to store programs; The processor executes the program to implement the method as described in any one of claims 1 to 5.

8. A computer storage medium storing a processor-executable program, characterized in that, The processor-executable program, when executed by the processor, is used to implement the method as described in any one of claims 1 to 5.

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