A method for generating a flexible folding body of a skateboard chassis

Abstract

A flexible folding body generation method of a skateboard chassis, comprising the following steps: defining the deformation rule of flexible material; bending the flexible material into a half-cylinder shape, and defining an array of bending angles according to the body characteristics; according to the generated simplified membrane of the optimized body, extending a closed whole membrane according to the body-chassis size ratio planned in the early design stage, defining the integration of the body and chassis as a simulation object, and optimizing the shape and structure according to the feedback of the simulation environment; integrally adjusting the integration according to the integration optimization result; developing details of the skateboard chassis according to the integration result; and integrating the flexible material body and the chassis into a complete vehicle product. The simulation environment generated by the present application is used to integrally optimize the unity of the skateboard chassis and the body, so that the body and the chassis after decoupling in the later design stage can maintain consistency in appearance after respective details are perfected and designed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of skateboard chassis, more specifically to a flexible folding body generation method for skateboard chassis. BACKGROUND

[0002] The skateboard chassis technology has good advantages, not only can save a lot of space, but also can improve the transmission efficiency, is a direction of new energy vehicle development, can develop various forms of vehicle body in cooperation with its unique upper and lower body decoupling form, such as: fiber plastic integrated injection molding vehicle body, rod piece quilt frame vehicle body, steel plate stamping forming welded vehicle body and the like.

[0003] A Chinese invention patent with application publication number CN115179871A discloses a sliding chassis system with separated upper and lower vehicle bodies, comprising an upper vehicle body and a lower vehicle body, the upper vehicle body is connected with the lower vehicle body through matching standardized interfaces. The invention solves the problems of high cost and long cycle caused by frequent matching and development of upper and lower vehicle bodies in the vehicle factory through the sliding chassis system with separated upper and lower vehicle bodies and the design method, and achieves the effect of developing and reusing the lower vehicle body and focusing on developing the diversity of the upper vehicle body.

[0004] However, due to the complex working environment of the wheels of the skateboard chassis, high-speed vibration, noise and braking, the development cycle of the vehicle body matched with the skateboard suspension is very long, and the vehicle body is detachable, so the utilization rate is not high, so the development cost cannot well cover the use value of the vehicle body. In addition, several vehicle bodies are matched with one chassis according to the use, and the vehicle body is relatively large in size, so the idle vehicle body also needs to occupy space resources, further increasing the cost.

[0005] Therefore, there is an urgent need for a flexible folding body generation method of skateboard chassis which can consider the use cost, multi-dimensional performance and quality requirements at the initial development stage, and an automatic design scheme generation method. SUMMARY

[0006] The present application provides a flexible folding body generation method for skateboard chassis, which realizes the rapid generation of the initial design scheme of the vehicle body, continuously receives the feedback of the microscopic simulation results, finds the appropriate material arrangement form which can balance the performance / reliability / repair and other aspects of the requirements and can be solidified to design the detailed scheme.

[0007] The present application adopts the following technical scheme:

[0008] A flexible folding body generation method for skateboard chassis, comprising the following steps:

[0009] Step one, define the deformation rule of flexible material;

[0010] Step 2: Based on the characteristics of the vehicle body, the flexible material is initially bent into a semi-cylindrical shape. By controlling the angles of each bending angle, a vehicle body shape that can mostly meet the intended use, i.e., a simplified vehicle body membrane, is simulated, and the simplified vehicle body membrane is optimized.

[0011] Step 3: Based on the optimized simplified body membrane generated in Step 2, a closed integral membrane is extended according to the body-chassis size ratio planned in the initial design phase. The integrated body and chassis is defined as the simulation object, and the shape and structure are optimized based on the feedback from the simulation environment.

[0012] Step 4: Adjust the integration body based on the results of the integration optimization in step 3;

[0013] Step 5: Develop the details of the skateboard chassis based on the integrated adjustment results of step 4;

[0014] Step 6: Integrate the flexible material body and skateboard chassis into a complete vehicle product.

[0015] In a preferred embodiment, the above step 1 specifically includes: 1.1 designing the force-bearing nodes of the flexible material, and dividing the flexible material into ordered triangular faces by the force-bearing nodes. These triangular faces are defined as non-bendable basic units, and each triangular face has a vertical dividing line and an oblique dividing line. The flexible material can be bent at characteristic angles along the vertical dividing line and the oblique dividing line; 1.2 by defining the overall node array, the grid lines are constrained together according to the common nodes; when the angle between each triangular face along the vertical dividing line and the oblique dividing line is <180°, the defined two-dimensional material surface achieves a curled-up effect in three-dimensional space.

[0016] In a preferred embodiment, the strategy for optimizing the simplified membrane of the vehicle body in the above step 2 is as follows: (1) By changing the length of the vertical dividing line and the oblique dividing line, the shape of the unit triangles that constitute the overall membrane structure is changed to further increase the deformability of the flexible material vehicle body; (2) By selecting the diagonal direction of the rectangular unit separated by each vertical dividing line, the guiding and transmission path of the force energy of the flexible vehicle body skeleton is controlled; (3) By arranging and combining the oblique fold lines of each rectangular unit in the ring force environment, the division method that can disperse the force to each node in the environment the fastest is selected and fixed, and it is used as the basis for further optimizing the overall structure of "body + chassis"; (4) By changing the folding angle, the vehicle body shape that is most suitable for the ring simulation environment is simulated. The vehicle body shape is characterized and evaluated using the following formula:

[0017]

[0018] n: simulation calculation beat number; K: number of nodes; Δmove kn :Each beat records the state change from 0 to K nodes.

[0019] In a preferred embodiment, the specific process of the above step three is as follows: 3.1 The original diagonal selection information of the integrated body is removed, and all are changed to a double diagonal structure, and a rectangular unit is divided into four triangular units for shape adaptability adjustment; 3.2 A force balance algorithm is used to define that each triangular face of the integrated body has equal force balance; 3.3. An in-circulation flow field environment is established to simulate the movement of a skateboard chassis vehicle; 3.4. By preventing the separation of the vortex airflow attached to the tail of the integrated body, the tearing of the flexible material body due to shape reasons is reduced.

[0020] The specific process of step 3.4 is as follows: 3.4.1 Record the air pressure, density, velocity, and streamline information generated by the simulated particles during the aerodynamic simulation; 3.4.2 Track and detect the air pressure at the rear of the vehicle in the simulation, and adjust the size of the three sides and the angles between the triangular elements at the rear of the vehicle to guide the airflow to quickly fill the cavity formed when the integrated structure passes through the simulated culvert air by adjusting the size of the three sides of the triangular elements at the rear of the vehicle. 3.4.3 Record the aerodynamic streamline parameters during the simulation to detect turbulent losses and search for high-energy-consuming stripping gas vortices. 3.4.4 Capture the high-loss streamlines and identify the triangular elements along their paths using a distance algorithm. Then, adjust the three sides and angles of the triangular elements to transform the shape of the integrated structure and improve the aerodynamic characteristics. 3.4.5 Repeat steps 3.4.1-3.4.4, gradually optimizing the aerodynamic characteristics of the integrated structure at each calculation cycle. 3.4.6 Average and reassign the size, position, and angles of the triangular elements symmetrical about the longitudinal axis of the vehicle to ensure bilateral symmetry of the overall optimized form-finding structure.

[0021] In a preferred embodiment, the specific process of the above step four is as follows: 4.1 According to the vehicle body feature triangular array, the array belonging to the vehicle body is removed from the overall triangular array to form a detachable flexible vehicle body entity; 4.2 The angle division of the vehicle body is restored. For the original bending of the broken line caused by the triangle refinement, the three points of the starting end, the middle end and the rear end of the broken line after being bent at a certain angle are defined as a rigid body, and the flexible material is converted into a rational Bezier curve according to the feature points; 4.3 The formed curve is used as the skeleton of the flexible vehicle body; 4.4 According to the topological size of the skeleton node, the size and geometric shape of the flexible material body material attached thereto are generated; 4.5 The geometric material is cut according to the purpose and designed with windows, doors and air-conditioning vents to make it suitable for different purposes.

[0022] It can be seen from the above description of the present invention that, compared with the prior art, the present invention has the following advantages:

[0023] 1. The present invention utilizes a virtually generated simulation environment to perform integrated form-finding optimization on the unified entity formed by the skateboard chassis and body, so that the body and chassis, after being decoupled in the later stages of the design, can maintain consistency in appearance even after their respective details are refined and the design is expanded.

[0024] 2. The present invention uses flexible body material as the body of the skateboard chassis. Due to its foldable storage feature, it saves storage space for idle body. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the flexible material of the present invention being divided into ordered triangular faces by stress nodes.

[0026] Figure 2 This is a schematic diagram of the state of the triangular surfaces of the flexible material of the present invention after being folded along the dividing line.

[0027] Figure 3 It is a schematic diagram of the flexible material of the present invention being bent into a semi-cylinder shape.

[0028] Figure 4 This is a schematic diagram of a closed overall membrane extending from the simplified membrane of the vehicle body of the present invention.

[0029] Figure 5 Schematic diagram of the collapse of the flexible folding body of the present invention. DETAILED DESCRIPTION

[0030] The following describes specific embodiments of the present invention with reference to the accompanying drawings. Numerous details are provided below to provide a comprehensive understanding of the present invention, but those skilled in the art will appreciate that the present invention can be practiced without these details. Well-known components, methods, and processes are not described in detail below.

[0031] This embodiment provides a method for generating a flexible folding body of a skateboard chassis, comprising the following steps:

[0032] Step 1: Define the deformation rules of the flexible material.

[0033] 1.1 As Figure 1 , No. 1-101 is the stress node of the flexible material of the design target. The flexible material is divided into ordered triangular faces by these nodes. These triangular faces are defined as non-bendable basic units. The edge of each triangular face has a vertical dividing line and an oblique dividing line. The material can be bent to a specific angle along the vertical dividing line and the oblique dividing line. Figure 1 The bendable lines are all straight lines, so the definition method is: starting node number - ending node number.

[0034] 1.2 By defining an overall node array, the grid lines are constrained together based on common nodes, such as Figure 2, the vertical split line and the oblique split line are connected together through the 95th node. By defining the angle of folding along the split line, when the angle between each triangular surface along the split line is <180°, the defined two-dimensional material surface will achieve the effect of curling up in three-dimensional space. In reality, the body of the flexible material defined in this way can also greatly reduce the storage space in the curled state.

[0035] Step two, define the folding angle array according to the designed body characteristics.

[0036] Referring to Figure 3 According to the body characteristics, the flexible material is preliminarily folded into a half-cylinder shape, and by controlling the angle of each folding angle, most of the body shapes that can meet the use purpose can be simulated. In order to adapt to the stress condition of the body film, the following strategies can be taken:

[0037] 2.1 By changing the length of the vertical split line and the oblique split line, the shape of the unit triangle constituting the overall film structure can be changed, further increasing the deformability of the flexible material body;

[0038] 2.2 By selecting the diagonal direction of each vertical split line, the stress energy guiding and transmission path of the flexible body skeleton can be controlled. As shown in Figure 1 The solid line is the vertical split line, and the dashed line is the oblique split line. The oblique split line is obtained by choosing two oblique lines in a box.

[0039] 2.3 By default, the vehicle design is initially analyzed to be left-right symmetrical, so the longitudinal center of the body is taken as the reference to mirror the left and right split solutions;

[0040] 2.4 Define the stress and fixed nodes to prepare for the stress structure optimization of the flexible body;

[0041] 2.5 By optimizing the arrangement and combination of the oblique folding lines of each rectangular unit in the ring stress environment, the division mode that disperses stress to each node in the environment the fastest is selected and fixed, which is used as the basis for further optimizing the overall structure of "body + chassis";

[0042] 2.6 By changing the folding angle, the most suitable body shape for the ring simulation environment is simulated, and the evaluation formula is as follows:

[0043]

[0044] n: simulation calculation beats; K: node number; Δmove kn : Record the state change of each beat from 0 to K nodes.

[0045] Consider the extreme case, when the given angle is too small, the entire simulation film can not be maintained under the existing stress environment, the structure collapses, so that the node is irregular displacement, and in the simulation environment can not stop disorderly movement; therefore, the smaller the Optimization_Degree, the better the optimization degree.

[0046] Step three, based on the optimized body film generated in the last step, the closed whole film is extended according to the size ratio of the body-chassis planned in the early design, and the integration of the body and chassis is defined as the simulation object, and the shape and structure are optimized according to the feedback of the simulation environment. Specifically as follows:

[0047] 3.1 Based on the optimized body film generated in the last step, the closed whole film is extended according to the size ratio of the body-chassis planned in the early design, and the integration of the body and chassis is defined as the simulation object, and the shape and structure are optimized according to the feedback of the simulation environment. Specifically as follows:

[0048] 3.2 Remove the original diagonal line selection information of the integration body, and change it to double diagonal line structure; divide a rectangular element into four triangular elements for shape adaptability adjustment, Figure 4 As can be seen, the system numbers each triangular patch in the model body; using the force balance algorithm, the force balance of each triangular patch of the integration body is defined as equal, so that the constraint internal environment of the balanced force of the internal pressure of the cavity can be constructed with very small calculation cost, which is convenient for subsequent integration body aerodynamic optimization, such as Figure 5 If the internal pressure is negative, the flexible folding body will collapse.

[0049] 3.3, establish the in-circulating flow field environment of the simulation skateboard chassis vehicle motion;

[0050] 3.4, prevent the separation of vortex air flow attached to the tail of the integration body, reduce the tearing of the flexible material body caused by the shape, the specific steps are as follows:

[0051] 3.4.1 Record the air pressure, density, velocity and streamline information generated by the calculation simulation particles in the aerodynamic simulation;

[0052] 3.4.2 For the negative pressure of the rear vacuum, track and detect the air pressure of the tail part in the simulation, adjust the size of the three edges of the triangular element and the folding angle between the triangular elements to guide the air flow to quickly fill the cavity formed when the integration body passes through the simulation culvert, Figure 4 As can be seen in the figure, the rear part of the roof is adjusted downward to guide the downflow;

[0053] 3.4.3 For the turbulence loss, record the aerodynamic streamline parameters in the simulation, search for large energy consumption stripping gas vortex, which generally appears in the area where the wind speed changes sharply and the vector is disorderly.

[0054] 3.4.4 By capturing the large loss streamline, the triangular unit of the streamline passing path is identified according to the distance algorithm, and then the whole shape is transformed and integrated by adjusting the three edges and the angle of the broken line, which does not require the left and right angle to be symmetrical;

[0055] 3.4.5 Repeat steps 3.4.1-3.4.4, and gradually optimize the aerodynamic characteristics of the integrated body according to each calculation beat;

[0056] 3.4.6 Geometry balance, average reassignment of the size, position and mutual angle of the triangular unit according to the symmetry of the vehicle longitudinal axis, so that the structure is symmetrical after the whole optimization;

[0057] Step four, according to the results of the integration optimization, the integrated body is integrated adjusted.

[0058] 4.1, according to the characteristics of the triangular array defined in step two, the array belonging to the body is separated from the whole triangular array to form a detachable flexible body entity;

[0059] 4.2, restore the fold angle division, for the original fold line bending phenomenon caused by triangular refinement, since the characteristics recorded in step three are found, the three points of the start, middle and end of the fold line after bending at a certain angle are defined as rigid body, and the flexible material is converted according to the characteristic points Rational Bezier curve, since the body is set to be symmetrical, only half of the characteristic points need to be defined;

[0060] 4.3, the formed curve is used as the skeleton of the flexible body;

[0061] 4.4, according to the topological size of the skeleton node, the size and geometric shape of the flexible body material attached to it are generated;

[0062] 4.5, according to the use, the geometric material is cut and designed to open windows, doors and air conditioning ports, so as to adapt to different uses. Like a piece of flexible material, it can adapt to different window design.

[0063] Step five, according to the integration finding result, the details of the skateboard chassis are developed.

[0064] Step six, integrate the flexible material body and the skateboard chassis to become a complete vehicle product.

[0065] The above is only a specific embodiment of the present application, but the design concept of the present application is not limited to this. Any non-essential modification of the present application using this concept shall be regarded as an infringement of the protection scope of the present application.

Claims

1. A method for generating a flexible folding body of a skateboard chassis, characterized in that: The following steps are involved: Step 1: Define the deformation rules of the flexible material; specifically, the following steps are performed: 1.1 Design the stress nodes of the flexible material, and use the stress nodes to divide the flexible material into ordered triangular faces. These triangular faces are defined as non-bendable basic units. Each triangular face has a vertical dividing line and an oblique dividing line, and the flexible material can bend along the vertical dividing line and the oblique dividing line to achieve characteristic angles; 1.2 By defining an overall node array, the grid lines are constrained together according to the common nodes; when the angle between the triangular faces along the vertical dividing line and the oblique dividing line is less than 180 degrees, the defined two-dimensional material surface achieves a curled-up effect in three-dimensional space; Step 2: According to the characteristics of the vehicle body, the flexible material is initially bent into a semi-cylindrical shape. By controlling the angles of each bending angle, the vehicle body shape that can meet most of the usage purposes, namely the simplified vehicle body membrane, is simulated, and the simplified vehicle body membrane is optimized; the optimization strategy is as follows: (1) By changing the length of the vertical dividing line and the oblique dividing line, the shape of the unit triangles that constitute the overall membrane structure is changed to further increase the deformability of the flexible material vehicle body; (2) By selecting the diagonal direction of the rectangular unit separated by each vertical dividing line, the guiding and transmission path of the force energy of the flexible vehicle body skeleton is controlled; (3) By arranging and combining the oblique folding lines of each rectangular unit in the ring force environment, the division method that can disperse the force to each node in the environment is selected and fixed, and it is used as the basis for further optimizing the overall structure of "body + chassis"; (4) By changing the folding angle, the vehicle body shape that is most suitable for the ring simulation environment is simulated; Step 3: Based on the optimized simplified body membrane generated in Step 2, a closed integral membrane is extended according to the body-chassis size ratio planned in the initial design phase. The integrated body and chassis are defined as the simulation object, and the shape and structure are optimized based on the feedback from the simulation environment. The specific process is as follows: 3.1 The original diagonal selection information of the integrated body is removed, and all are replaced with a double diagonal structure. A rectangular unit is divided into four triangular units for shape adaptability adjustment; 3.2 Using a force balance algorithm, each triangular face of the integrated body is defined to have equal force balance; 3.

3. An in-circulation flow field environment is established to simulate the motion of a skateboard chassis vehicle; 3.

4. By preventing the separation of the vortex airflow attached to the tail of the integrated body, the tearing of the flexible material body due to shape reasons is reduced; Step 4: According to the results of the integrated optimization in step 3, the integrated body is adjusted in an integrated manner. The specific process is as follows: 4.1 According to the characteristic triangular array of the vehicle body, the array belonging to the vehicle body is removed from the overall triangular array to form a detachable flexible vehicle body entity; 4.2 The angle division of the vehicle body is restored. For the original bending of the broken line caused by the triangle refinement, the three points of the starting end, the middle end, and the rear end of the broken line after being bent at a certain angle are defined as a rigid body. The flexible material is converted into a rationalized Bezier curve according to the characteristic points; 4.3 The formed curve is used as the skeleton of the flexible vehicle body; 4.4 According to the topological size of the skeleton node, the size and geometric shape of the flexible material body material attached to it are generated; 4.5 According to the purpose, the geometric material is cut and designed with windows, doors, and air-conditioning vents to make it suitable for different purposes; Step 5: Develop the details of the skateboard chassis based on the integrated adjustment results of step 4; Step 6: Integrate the flexible material body and skateboard chassis into a complete vehicle product.

2. The method for producing a flexible folding body of a skateboard chassis according to claim 1, wherein: The body shape in the strategy (4) adopts the following characterization evaluation formula: Optimization_Degree= n: simulation calculation beat number; K: number of nodes; :Each beat records the state change from 0 to K nodes.

3. The method for producing a flexible folding body of a skateboard chassis according to claim 1, wherein: The specific process of step 3.4 is as follows: 3.4.1 Record the air pressure, density, velocity, and streamline information generated by the simulated particles during aerodynamic simulation; 3.4.2 To address the rear vacuum negative pressure, the air pressure at the rear of the vehicle was tracked and monitored during simulation. By adjusting the size of the three sides of the triangular units at the rear of the vehicle and the angles between the triangular units, the airflow was directed to quickly fill the void created when the integrated body passed through the simulated culvert air. 3.4.3 In view of turbulent losses, record the aerodynamic streamline parameters in the simulation and search for high-energy-consuming stripping gas vortices; 3.4.4 By capturing the high-loss streamlines, identify the triangular elements along the streamline path according to the distance algorithm, and then transform the shape of the integrated body by adjusting its three sides and the angle of the fold line to improve the aerodynamic characteristics; 3.4.5 Repeat steps 3.4.1-3.4.4, and gradually optimize the aerodynamic characteristics of the integrated body according to each calculation cycle; 3.4.6 Average and re-assign the size, position, and mutual fold angles of the triangular elements symmetrical about the longitudinal axis of the vehicle to make the structure symmetrical after overall optimization.

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