A method, device and computer program product for drawing a tire rolling resistance cloud map

Abstract

The present invention relates to the technical field of computer intelligent design of tires, and in particular to a method, device and computer program product for drawing a tire rolling resistance cloud map. The present invention realizes the drawing of a tire rolling resistance cloud map. By analyzing the rolling resistance cloud map, it can be seen that the rolling resistance of the units on both sides of the tread is relatively large, and the rolling resistance of the unit at the contact part between the bead and the rim is the largest. This can provide intuitive data guidance to tire designers, and these two parts can be focused on to reduce the rolling resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of computer intelligent design of tires, and in particular to a method, device and computer program product for drawing a tire rolling resistance cloud map. Background Art

[0002] With the achievement and implementation of the consensus on "carbon neutrality" and "carbon peak" worldwide, the requirements for environmental protection are getting higher and higher. In the field of tires, reducing the rolling resistance of tires can effectively reduce fuel consumption. Even for electric vehicles, which are already very popular, reducing the rolling resistance of tires can significantly increase the range of vehicles. Therefore, following the labeling method, there is another wave of enthusiasm for reducing the rolling resistance of tires. The rolling resistance of tires mainly comes from the hysteresis loss of rubber materials, which accounts for more than 90% of the rolling resistance of tires. At present, the research on rolling resistance mainly includes experimental and simulation methods. With the development of finite element technology and computer technology, simulation methods have sufficient efficiency and accuracy and have become an effective tool for predicting tire performance. At present, the simulation prediction of rolling resistance only focuses on the contribution rate and sum of each component, which has limited guiding role in the analysis of actual tires. It is necessary to intuitively see the rolling resistance of different parts of the tire, and then to have a targeted and detailed analysis, which requires the tire rolling resistance to be displayed in the form of a cloud map. At present, the calculation of tire rolling resistance has not been integrated into the general analysis software, resulting in the inability to analyze the rolling resistance intuitively. Even if the general analysis software can be used to calculate the rolling resistance of the tire through secondary development or subroutine methods, the transmission of data on the general software platform is limited by the software type and version, which is very inconvenient for different users to call. Therefore, it is necessary to invent a method for drawing a tire rolling resistance cloud map to achieve convenient cross-platform data analysis. Summary of the invention

[0003] The purpose of the present invention is to solve the problems existing in the above-mentioned prior art, namely, the calculation of tire rolling resistance is not currently integrated into the general analysis software, resulting in the inability to intuitively analyze the rolling resistance. Even if the general analysis software can be used to calculate the rolling resistance of the tire through secondary development or subroutine methods, the transmission of data under the general software platform is limited by the software type and version, which is very inconvenient when different users call it.

[0004] Furthermore, a method for drawing a tire rolling resistance cloud map is provided to realize intuitive visual analysis of tire rolling resistance, avoiding dependence on general software and the inconvenience of data transmission between general software.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0006] A method for drawing a tire rolling resistance cloud map, the method comprising the following steps:

[0007] 1) Get the cross-section mesh information of the tire: read the mesh data of the tire finite element simulation analysis input file, obtain the node number and node coordinates, and store the node data as a Python program data dictionary Node: {node number: [node x coordinate, node y coordinate]}, where the node coordinate is a list with two elements; read the unit data, the unit is a triangular or quadrilateral mesh, and store the unit data as a Python program data dictionary Element: {unit number: [node 1, node 2, node 3, node 4 (only 4 deformed meshes have this node)]}, where the key value of the Element dictionary is a list, and the nodes in the list are arranged in a counterclockwise direction to form the corner points of the unit;

[0008] 2) Extract tire rolling resistance data: store the calculated rolling resistance data of each tire unit as a Python program data dictionary RR: {unit number: unit rolling resistance value rr}; traverse the values ​​of the rolling resistance data dictionary RR to obtain the maximum rolling resistance value of the unit rr_max and the minimum rolling resistance value of the unit rr_min;

[0009] 3) Generate unit graphics: Convert the node and unit data dictionaries obtained in the first step. First, traverse the Element dictionary, and generate the node number of each unit in the dictionary into a new PyQt5.QtCore graphic point QPointF (node ​​x coordinate, node y coordinate) according to the coordinate value in the Node dictionary. Generate a new python data dictionary Ploygon: {unit number: [QPointF (node ​​1 x coordinate, node 1 y coordinate), QPointF (node ​​2 x coordinate, node 2 y coordinate), QPointF (node ​​3 x coordinate, node 3 y coordinate), QPointF (node ​​4 x coordinate, node 4 y coordinate) (if there are 3 nodes in the unit, there is no node 4)]};

[0010] 4) Create a color bar example: Use the colorbar function in the pyqtgraph module to generate a color bar example, and use the setLevels method to set the initial value range of the color bar: the minimum value is rr_min in step 2), and the maximum value is rr_max. The color level of the color bar is set to the CMRmap_r format of the matplotlib type through the colormap.get method of the pyqtgraph module;

[0011] 5) Add the unit to the display interface, traverse the Polygon dictionary obtained in step 3) and the RR dictionary obtained in step 2), add the unit to the PlotWidget display in the pyqtgraph module through the additem method, and assign the unit a fill color through the QBrush method. The color value is determined by mapToByte(rr);

[0012] 6) Set the scroll resistance color to be adjustable: Use the colorbar.levels method to obtain the maximum value new_max and the minimum value new_min of the color bar at this time, return the maximum and minimum values ​​obtained at this time to step 5), and calculate the color value using the following formula:

[0013] new_value= (rr - new_min) / (new_max - new_min),

[0014] Then use mapToByte(new_value) to determine the new color value, and the color of the rolling resistance can be updated in real time.

[0015] Furthermore, the present invention also discloses a computer device, including a memory, a processor and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method described in any one of the above technical solutions.

[0016] Furthermore, the present invention also discloses a computer-readable storage medium on which a computer program or instruction is stored. When the computer program or instruction is executed by a processor, the steps of the method described in any one of the above technical solutions are implemented.

[0017] Any one of the above technical solutions is a computer program product, comprising a computer program or instructions, which implement the steps of the method described in any one of the above technical solutions when executed by a processor.

[0018] The present invention adopts the above-mentioned technical solution, and realizes the drawing of the tire rolling resistance cloud map through the above technology. By analyzing the rolling resistance cloud map, it can be known that the rolling resistance of the units on both sides of the tread is relatively large, and the rolling resistance of the unit at the contact part between the bead and the rim is the largest. This can provide intuitive data guidance to tire designers, and these two parts can be focused on to reduce the rolling resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Store node data in tire mesh data file;

[0020] Figure 2 Stores the cell data in the tire mesh data file;

[0021] Figure 3 Node dictionary data generated after reading the data;

[0022] Figure 4 Element dictionary data generated after reading data;

[0023] Figure 5 The format of the file storing the rolling resistance data of each unit of the tire;

[0024] Figure 6 Read the RR dictionary data generated by the tire rolling resistance data;

[0025] Figure 7 Generated cell legend Polygon dictionary data;

[0026] Figure 8 The generated color bar;

[0027] Fig. 9 Tire rolling resistance cloud diagram drawn according to different rolling resistance values;

[0028] Fig.10 Adjust the color bar level to display the tire rolling resistance contour. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below in conjunction with the accompanying drawings: This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method is given, but the protection scope of the present invention is not limited to the following embodiments.

[0030] Take the Abaqus calculation file of 21550R15 tire as an example:

[0031] (1) Use Python program to read Abaqus input file .inp (where node information is as follows Figure 1 , unit information such as Figure 2 As shown in the figure), get some values ​​of the node Node dictionary (such as Figure 3 ), the length of the node Node dictionary is 2127, that is, there are 2127 nodes. The partial values ​​of the obtained unit dictionary Element are as follows Figure 4 As shown, the length of the Element dictionary is 1448, that is, there are 1448 units.

[0032] (2) The unit rolling resistance is stored in a .txt file. The Python program is used to read the file containing the unit number and unit rolling resistance value (e.g. Figure 5 As shown), get some values ​​of the rolling resistance dictionary RR as follows Figure 6As shown. By traversing the RR dictionary, we can find that the rolling resistance of unit 1267 is the largest, which is 0.2616, that is, rr_max=0.2616, and the minimum rolling resistance of the unit is 0, so rr_min=0.

[0033] (3) Generate unit graphics. Convert the node and unit data dictionaries obtained in the first step. First, traverse the Element dictionary and generate the node number of each unit in the dictionary into a new PyQt5.QtCore graphic point QPointF (node ​​x coordinate, node y coordinate) according to the coordinate value in the Node dictionary. Generate a new Python data dictionary Ploygon, such as Figure 7 shown.

[0034] (4) Create a color bar example. Use the colorbar function in the pyqtgraph module to generate a color bar example CalorBarItem. Use the setLevels method to set the initial value range of the color bar: the minimum value is rr_min=0 in step (2), and the maximum value is rr_max=0.2616. The color bar color level is set to the CMRmap_r format of the matplotlib type through the colormap.get method of the pyqtgraph module. The generated color bar is as follows: Figure 8 shown.

[0035] (5) Add the unit graphics to the display interface, traverse the Polygon dictionary obtained in step (3) and the RR dictionary obtained in step (2), add the unit to the PlotWidget in the pyqtgraph module through the additem method, and assign a fill color to the unit through the QBrush method. The color value is determined by mapToByte(rr). Different units have different rr values, and different colors are generated according to the rr value, such as Fig. 9 shown.

[0036] (6) Set the scroll resistance color to be adjustable. Use the colorbar.levels method to obtain the maximum value new_max and the minimum value new_min of the color bar at this time. For example, if the color bar level is dragged downward, the maximum value of the color becomes 0.16 and the minimum value becomes -0.1, that is, new_max=0.16, new_min=-0.1. Return the new_max and new_min obtained at this time to step (5), and calculate the color value using the following formula:

[0037] new_value = (rr – 0.16) / (0.16- (-0.1)), and then use mapToByte (new_value) to determine the new color value of each unit, and re-assign the color to the unit. At this time, the color of the rolling resistance can be updated in real time, such as Fig.10 shown.

[0038] The above technology is used to draw the tire rolling resistance cloud map. By analyzing the rolling resistance cloud map, it can be seen that the rolling resistance of the units on both sides of the tread is relatively large, and the rolling resistance of the unit at the contact point between the bead and the rim is the largest. This can provide intuitive data guidance for tire designers, and they can focus on these two areas to reduce rolling resistance.

[0039] The above are only preferred specific embodiments of the present invention, which are all different implementations based on the overall concept of the present invention, and the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for drawing a tire rolling resistance cloud map, characterized in that: The method comprises the following steps: 1) Get the cross-section mesh information of the tire: read the mesh data of the tire finite element simulation analysis input file, obtain the node number and node coordinates, and store the node data as a Python program data dictionary Node: {node number: [node x coordinate, node y coordinate]}, where the node coordinate is a list with two elements; read the unit data, the unit is a triangular or quadrilateral mesh, and store the unit data as a Python program data dictionary Element: {unit number: [node 1, node 2, node 3, node 4]}, only the quadrilateral mesh has node 4, and the triangular mesh does not have node 4, where the key value of the Element dictionary is a list, and the nodes in the list are arranged in a counterclockwise direction to form the corner points of the unit; 2) Extract tire rolling resistance data: store the calculated rolling resistance data of each tire unit as a Python program data dictionary RR: {unit number: unit rolling resistance value rr}; traverse the values ​​of the rolling resistance data dictionary RR to obtain the maximum rolling resistance value of the unit rr_max and the minimum rolling resistance value of the unit rr_min; 3) Generate unit graphics: Convert the node and unit data dictionaries obtained in the first step. First, traverse the Element dictionary, and generate the node number of each unit in the dictionary into a new PyQt5.QtCore graphic point QPointF (node ​​x coordinate, node y coordinate) according to the coordinate value in the Node dictionary. Generate a new python data dictionary Ploygon: {unit number: [QPointF (node ​​1 x coordinate, node 1 y coordinate), QPointF (node ​​2 x coordinate, node 2 y coordinate), QPointF (node ​​3 x coordinate, node 3 y coordinate), QPointF (node ​​4 x coordinate, node 4 y coordinate)]}, if there are 3 nodes in the unit, there is no node 4; 4) Create a color bar example: Use the colorbar function in the pyqtgraph module to generate a color bar example, and use the setLevels method to set the initial value range of the color bar: the minimum value is rr_min in step 2), and the maximum value is rr_max. The color level of the color bar is set to the CMRmap_r format of the matplotlib type through the colormap.get method of the pyqtgraph module; 5) Add the unit to the display interface, traverse the Polygon dictionary obtained in step 3) and the RR dictionary obtained in step 2), add the unit to the PlotWidget display in the pyqtgraph module through the additem method, and assign the unit a fill color through the QBrush method. The color value is determined by mapToByte(rr); 6) Set the scroll resistance color to be adjustable: Use the colorbar.levels method to obtain the maximum value new_max and the minimum value new_min of the color bar at this time, return the maximum and minimum values ​​obtained at this time to step 5), and calculate the color value using the following formula: new_value= (rr - new_min) / (new_max - new_min), Then use mapToByte(new_value) to determine the new color value, and the color of the rolling resistance can be updated in real time.

2. A computer device comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the method of claim 1.

3. A computer-readable storage medium having a computer program or instruction stored thereon, characterized in that: When the computer program or instruction is executed by a processor, the steps of the method according to claim 1 are implemented.

4. A computer program product comprising a computer program or instructions, characterized in that When the computer program or instruction is executed by a processor, the steps of the method according to claim 1 are implemented.

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