Simulink vehicle modeling method based on different road surface resistance coefficients

Abstract

The invention discloses a Simulink vehicle modeling method based on different road resistance coefficients. The Simulink vehicle modeling method comprises the following steps: 1) simplifying a target vehicle model; 2) establishing a top layer model block diagram in Simulink according to the relationship between the linear speed of the trolley and the left wheel speed and the relationship between the linear speed of the trolley and the right wheel speed, wherein the output of the top layer model block diagram is the linear speed of the trolley; 3) modeling the interior of the left wheel assembly according to the relationship between the left wheel speed and the left wheel traction force and the left wheel resistance, and modeling the interior of the right wheel assembly according to the relationship between the right wheel speed and the right wheel traction force and the right wheel resistance; and the output of the top layer model is trolley displacement. The influence of different resistance coefficients on the running speed and the running distance of the vehicle is rapidly obtained through modeling and simulation, and engineers can conveniently further deeply research the influence of comprehensive factors such as traction force, resistance and vehicle speed of the vehicle on the running state of the vehicle.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle simulation modeling, and in particular to a Simulink vehicle modeling method based on different road resistance coefficients. Background Art

[0002] When a vehicle is traveling on roads with different resistance coefficients, it will experience different resistance and exhibit different motion properties. For example, when a vehicle is traveling on snowy roads, its tires are prone to slipping, but when it is traveling on concrete roads, it is not easy to slip. The resistance coefficients of snowy roads and concrete roads are different. In order to study the impact of different resistance coefficients on vehicle speed and driving distance, a Simulink vehicle modeling method based on different road resistance coefficients is proposed. Summary of the invention

[0003] In view of the above-mentioned defects or shortcomings in the prior art, it is desired to provide a Simulink vehicle modeling method based on different road resistance coefficients, which can quickly obtain the influence of different resistance coefficients on vehicle speed and distance through modeling and simulation, so as to facilitate engineers to further study the influence of comprehensive factors such as vehicle traction, resistance, and speed on the vehicle driving state.

[0004] The present invention provides a Simulink vehicle modeling method based on different road resistance coefficients, comprising:

[0005] S100: simplifying the target car model, wherein the target car is simplified to a car having only left and right wheels, and only the linear motion of the target car is considered;

[0006] S200: establishing a top-level model block diagram in Simulink according to the relationship between the linear speed of the trolley and the speeds of the left wheel and the right wheel, wherein the output of the top-level model block diagram is the linear speed of the trolley;

[0007] S300: Modeling the interior of the left wheel assembly according to the relationship between the left wheel speed, the left wheel traction and the left wheel resistance, and modeling the interior of the right wheel assembly according to the relationship between the right wheel speed, the right wheel traction and the right wheel resistance, and outputting the left wheel speed after simulation of the left wheel assembly, and outputting the right wheel speed after simulation of the right wheel assembly;

[0008] S400: Continue modeling according to the relationship between the displacement of the trolley and the linear velocity of the trolley, and construct a top-level model, wherein the output of the top-level model is the displacement of the trolley.

[0009] Preferably, the step S200 includes:

[0010] S201: Build the left wheel component and the right wheel component that are not modeled internally in Simulink;

[0011] S202: the left wheel assembly is connected to the left wheel traction assembly, the right wheel assembly is connected to the right wheel traction assembly, the left wheel traction force generated by the left wheel traction assembly is used as the input of the left wheel assembly, and the right wheel traction force generated by the right wheel traction assembly is used as the input of the right wheel assembly;

[0012] S203: Sum and evenly divide the left wheel speed output by the left wheel assembly and the right wheel speed output by the right wheel assembly to obtain the linear speed of the vehicle;

[0013] S204: Define the linear speed direction of the car as the speed in the X-axis direction, and complete the construction of the top-level model block diagram; the relationship between the linear speed of the car and the speed of the left wheel and the speed of the right wheel is shown in the following formula:

[0014]

[0015] Among them, V1 is the left wheel speed, V2 is the right wheel speed, and V3 is the linear speed of the car;

[0016] Preferably, the step S300 includes:

[0017] S301: Modeling the left wheel resistance and the right wheel resistance of the target vehicle;

[0018] S302: The left wheel traction force is used as the input of the left wheel component, and the interior of the left wheel component is modeled according to the relationship between the left wheel speed, the left wheel traction force and the left wheel resistance; the right wheel traction force is used as the input of the right wheel component, and the interior of the right wheel component is modeled according to the relationship between the right wheel speed, the right wheel traction force and the right wheel resistance; the output of the left wheel component is the left wheel speed, and the output of the right wheel component is the right wheel speed;

[0019] The relationship between the left wheel speed, the left wheel traction and the left wheel resistance is shown in the following formula:

[0020]

[0021] The relationship between the right wheel speed, the right wheel traction and the right wheel resistance is shown in the following formula:

[0022]

[0023] Among them, F1 is the traction of the left wheel, F2 is the traction of the right wheel, f1 is the resistance of the left wheel, f2 is the resistance of the right wheel, V1 is the speed of the left wheel, V2 is the speed of the right wheel, and m is the mass of the target car;

[0024] The mass of the target car borne by the left and right wheels is m / 2. The difference between the left wheel traction and the left wheel resistance divided by the mass borne by the left wheel is the left wheel acceleration, and the left wheel acceleration is integrated over the running time to get the left wheel speed; the difference between the right wheel traction and the right wheel resistance divided by the mass borne by the right wheel is the right wheel acceleration, and the right wheel acceleration is integrated over the running time to get the right wheel speed.

[0025] Preferably, modeling the left wheel resistance and the right wheel resistance of the target vehicle includes:

[0026] Define the relationship between the left wheel resistance, resistance coefficient and left wheel speed of the target car, and define the relationship between the right wheel resistance, resistance coefficient and right wheel speed of the target car;

[0027] The relationship between the left wheel resistance, the drag coefficient and the left wheel speed is shown in the following formula:

[0028] f1=K*V1

[0029] The relationship between the right wheel resistance, the drag coefficient and the right wheel speed is shown in the following formula:

[0030] f2=K*V2

[0031] Among them, f1 is the left wheel resistance, f2 is the right wheel resistance, K is the resistance coefficient, V1 is the left wheel speed, and V2 is the right wheel speed.

[0032] Preferably, the step S400 includes:

[0033] The linear velocity of the car is integrated with respect to the running time to construct a top-level model, wherein the output of the top-level model is the displacement of the car;

[0034] The relationship between the displacement of the trolley and the linear velocity of the trolley is shown in the following formula:

[0035] X=∫V3dt

[0036] Among them, V3 is the linear velocity of the car, and X is the displacement of the car.

[0037] Preferably, it also includes:

[0038] A scope module is placed at the end of the left wheel assembly and the right wheel assembly, and the resistance coefficient, mass and wheel radius of the target vehicle are defined in the workspace. A step module is used to simulate the external force provided to the left wheel traction assembly and the right wheel traction assembly. After the simulation of the left wheel assembly, a curve graph of the left wheel speed and the running time is output and displayed through the scope module. After the simulation of the right wheel assembly, a curve graph of the right wheel speed and the running time is output and displayed through the scope module.

[0039] Preferably, it also includes:

[0040] A scope module is placed at the end of the top-level model, and the resistance coefficient, mass and wheel radius of the target car are defined in the workspace. The step module is used to simulate the external force provided to the left wheel traction component and the right wheel traction component. After the top-level model is simulated, the scope module is used to output and display the curve graph of the car's linear speed and displacement versus the running time.

[0041] Compared with the prior art, the beneficial effects of the present invention are:

[0042] The present invention simplifies the vehicle into a target car with only a left wheel and a right wheel, and only considers the straight-line running of the target car, thereby improving the simplicity of subsequent modeling; firstly, a top-level model block diagram is built based on Simulink, and then the interior of the left wheel component and the right wheel component in the top-level model block diagram are modeled, so that the top-level model block diagram outputs the linear speed of the car, and the linear speed of the car output by the top-level model block diagram is integrated with the running time to obtain the displacement of the car, thereby completing the overall construction of the top-level model; after the top-level model is built, scope modules are placed at the rear ends of the left wheel component, the right wheel component and the top-level model, and then different resistance coefficients are defined in the workspace, and the corresponding scope module will pop up a curve graph, through which the simulation results can be intuitively observed; and the left wheel component and the right wheel component can be simulated separately, and the left wheel component simulation After simulation, the scope module is used to output and display the curve graph of the left wheel speed and running time. After simulation of the right wheel component, the scope module is used to output and display the curve graph of the right wheel speed and running time. The curve graph allows you to conveniently and intuitively observe the influence of different resistance coefficients on the running speed of a single wheel. The top-level model can be simulated as a whole. After simulation of the top-level model, the scope module is used to output and display the curve graph of the car's linear speed and displacement and running time. The curve graph allows you to intuitively observe the influence of different resistance coefficients on the car's linear speed and displacement. Based on Simulink modeling, you can intuitively observe the influence of different resistance coefficients on the vehicle's running speed and driving distance, which provides a reference for subsequent in-depth research on the influence of comprehensive factors such as vehicle traction, resistance, and speed on the vehicle's driving state.

[0043] It should be understood that the contents described in the summary of the invention are not intended to limit the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0045] Figure 1 is a flow chart of the modeling method of the present invention;

[0046] Figure 2 It is a schematic diagram of the top-level model block diagram;

[0047] Figure 3 is a schematic diagram of a left wheel assembly;

[0048] Figure 4 is a schematic diagram of the top-level model;

[0049] Figure 5 This is a simulation result of the left wheel assembly;

[0050] Figure 6 The simulation results of the top model when the drag coefficient is 0.2;

[0051] Figure 7 The simulation results of the top model when the drag coefficient is 0.6. DETAILED DESCRIPTION

[0052] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It should also be noted that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0053] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0054] Please refer to Figure 1 to Figure 7 The embodiment of the present invention provides a Simulink vehicle modeling method based on different road resistance coefficients, using MATLAB functions to define model parameters and completing the model building in Simulink; the modeling method includes:

[0055] Step S100: simplifying the target car model, the target car is simplified to a car with only left and right wheels, and only the linear motion of the target car is considered;

[0056] Specifically, the vehicle motion properties include linear motion and rotational motion. The present invention only considers the linear operation of the target car. The simplified target car has only two wheels, the left wheel and the right wheel, and only considers the influence of traction and friction on the wheels of the target car, without considering other factors, which is convenient for subsequent modeling and simulation.

[0057] Step S200: Figure 2 and Figure 3 As shown, a top-level model block diagram is established in Simulink according to the relationship between the linear speed of the car and the speeds of the left wheel and the right wheel. The output of the top-level model block diagram is the linear speed of the car.

[0058] Specifically, in Simulink, a top-level model block diagram is constructed by using the functional modules in Simulink. Before the top-level model block diagram is constructed, the components included in the top-level model block diagram and the input-output relationship between the components are first determined; the top-level model block diagram includes a left wheel component and a right wheel component. The traction provided by the engine acts on the left and right wheels of the target car. The left wheel traction force is input through the left wheel traction force component (Left force component), and the right wheel traction force is input through the right wheel traction force component (Right force component). The left wheel traction force and the right wheel traction force act on the left wheel and the right wheel respectively to generate the left wheel speed and the right wheel speed. The left wheel speed is the output Speed ​​of the left wheel component (Left Wheel component), and the right wheel speed is the output Speed ​​of the right wheel component (Right Wheel component). The left wheel speed and the right wheel speed are taken as inputs for summing, and the sum is divided by 2 to output the linear speed of the target car.

[0059] After the input-output relationship is determined, the top-level model block diagram is constructed. The construction steps are as follows:

[0060] S201: Build the left wheel component (Right Wheel component) and the right wheel component (Right Wheel component) that are not modeled internally in Simulink;

[0061] S202: the left wheel component is connected to the left wheel traction component, the right wheel component is connected to the right wheel traction component, the left wheel traction force generated by the left wheel traction component is used as the input of the left wheel component, and the right wheel traction force generated by the right wheel traction component is used as the input of the right wheel component; specifically, the Left force component is connected to the left wheel component as the input end of the unmodeled left wheel component, and the Right force component is connected to the right wheel component as the input end of the unmodeled right wheel component;

[0062] S203: The left wheel speed output by the left wheel assembly and the right wheel speed output by the right wheel assembly are summed and evenly divided to obtain the linear speed of the vehicle; specifically, the relationship between the linear speed of the vehicle and the left wheel speed and the right wheel speed is expressed as follows:

[0063]

[0064] Among them, V1 is the left wheel speed, V2 is the right wheel speed, and V3 is the car linear speed. The above formula means that the left wheel speed and the right wheel speed are added and divided by 2 to get the car linear speed. According to the logical relationship expressed by the above formula, the model is built, and the Add module and the Gain module are connected to the output end of the left wheel component and the output end of the right wheel component, and the left wheel speed and the right wheel speed are summed and evenly divided to get the car linear speed;

[0065] S204: Define the linear speed direction of the car as the speed in the X-axis direction, and complete the construction of the top-level model block diagram; specifically, since only the linear motion speed of the target car is considered, the X-axis direction speed is defined as the linear speed of the car through the Coordinate Transform module in Simulink to complete the construction of the top-level model block diagram, so that the final output of the top-level model block diagram is the linear speed of the car.

[0066] S300: Modeling the interior of the left wheel assembly according to the relationship between the left wheel speed, the left wheel traction and the left wheel resistance, modeling the interior of the left wheel assembly according to the relationship between the right wheel speed, the right wheel traction and the right wheel resistance, outputting the left wheel speed after simulation of the left wheel assembly, and outputting the right wheel speed after simulation of the right wheel assembly;

[0067] Specifically, after the top-level model block diagram is built, the interior of the left wheel component and the right wheel component are modeled; the specific modeling process is as follows:

[0068] S301: Modeling the left wheel resistance and the right wheel resistance of the target car; specifically, the operation process of modeling the left wheel resistance is to define the relationship expression between the left wheel resistance, the resistance coefficient and the left wheel speed of the target car in Matlab, and the operation process of modeling the left wheel resistance is to define the relationship expression between the right wheel resistance, the resistance coefficient and the right wheel speed of the target car in Matlab. The left wheel resistance is proportional to the resistance coefficient and the left wheel speed. The relationship expression between the left wheel resistance, the resistance coefficient and the left wheel speed is shown in the following formula:

[0069] f1=K*V1

[0070] The right wheel resistance is proportional to the resistance coefficient and the right wheel speed. The relationship between the right wheel resistance, the resistance coefficient and the right wheel speed is shown in the following formula:

[0071] f2=K*V2

[0072] Among them, f1 is the left wheel resistance, f2 is the right wheel resistance, K is the resistance coefficient, V1 is the left wheel speed, and V2 is the right wheel speed.

[0073] S302: The left wheel traction force is used as the input of the left wheel component, and the interior of the left wheel component is modeled according to the relationship between the left wheel speed, the left wheel traction force and the left wheel resistance; the right wheel traction force is used as the input of the right wheel component, and the interior of the right wheel component is modeled according to the relationship between the right wheel speed, the right wheel traction force and the right wheel resistance; the output of the left wheel component is the left wheel speed, and the output of the right wheel component is the right wheel speed; specifically, the target car has only a left wheel and a right wheel, so the mass borne by a single wheel is m / 2, according to Newton's second law F=m*a, it can be known that the left wheel acceleration / right wheel acceleration=2F / m, the wheels of the target car are affected by traction and resistance, so the left wheel acceleration a=(F1-f1) / (m / 2), the right wheel acceleration a=(F2-f2) / (m / 2), the left wheel acceleration is integrated over the running time to obtain the left wheel acceleration, and the right wheel acceleration is integrated over the running time to obtain the right wheel speed, and the relationship between the left wheel speed and the left wheel traction force and the left wheel resistance is shown in the following formula:

[0074]

[0075] The relationship between the right wheel speed, the right wheel traction and the right wheel resistance is shown in the following formula:

[0076]

[0077] Among them, F1 is the traction of the left wheel, F2 is the traction of the right wheel, f1 is the resistance of the left wheel, f2 is the resistance of the right wheel, V1 is the speed of the left wheel, V2 is the speed of the right wheel, and m is the mass of the target car;

[0078] According to the logical relationship expressed by the left wheel speed, the left wheel traction and the left wheel resistance, the internal structure of the left wheel component is modeled based on the functional modules in Simulink. After modeling, the left wheel component takes the left wheel traction as input and outputs the left wheel speed after simulation. According to the logical relationship expressed by the right wheel speed, the right wheel traction and the right wheel resistance, the internal structure of the right wheel component is modeled based on the functional modules in Simulink. After modeling, the right wheel component takes the right wheel traction as input and outputs the right wheel speed after simulation.

[0079] S400: Continue modeling according to the relationship between the displacement of the trolley and the linear velocity of the trolley, and construct a top-level model, the output of which is the displacement of the trolley. Specifically, after the internal modeling of the left wheel assembly and the right wheel assembly is completed, the linear velocity of the trolley is integrated with respect to the running time to construct an overall top-level model; the relationship between the displacement of the trolley and the linear velocity of the trolley is expressed as follows:

[0080] X=∫V3dt

[0081] Among them, V3 is the linear velocity of the car, and X is the displacement of the car;

[0082] The specific modeling process is to continue modeling according to the logic expressed by the relationship between the car displacement and the car linear velocity, connect the integral module to the output end of the car linear velocity in the top-level model block diagram, and build a complete top-level model so that the output of the top-level model is the car displacement.

[0083] Preferably, after the top-level model is established, a scope module can be placed at the end of the left wheel assembly and the right wheel assembly, the resistance coefficient, mass and wheel radius of the target vehicle are defined in the workspace, and the step module is used to simulate the external force provided to the left wheel traction assembly and the right wheel traction assembly. The left wheel traction assembly outputs the left wheel traction, and the right wheel traction assembly outputs the right wheel traction. After the left wheel assembly is simulated, a curve graph of the left wheel speed and the running time is output and displayed through the scope module. After the right wheel assembly is simulated, a curve graph of the right wheel speed and the running time is output and displayed through the scope module.

[0084] Specifically, the left wheel assembly and the right wheel assembly can be simulated independently; Figure 5 As shown, the simulation process is introduced below by taking the simulation of the left wheel assembly as an example. The resistance coefficient of the road surface is taken as 0.2. In the MATLAB workspace, the mass of the car is defined as 2.5kg, the resistance coefficient is 30, and the wheel radius of the car (left wheel radius and right wheel radius) is 0.15m. Then, the step module in Simulink is used to simulate the external force input. The scope module is placed at the end of the left wheel assembly. Then, the left wheel assembly starts to simulate. During the simulation, the external force continues to increase. When the traction force is equal to the resistance, the simulation ends. After the simulation ends, double-click the scope module at the back end of the left wheel assembly. The scope module pops up a curve chart of the left wheel speed and running time. The curve chart is as shown in the figure. Figure 5 As shown, according to Figure 5 It can be observed intuitively from the curve graph that when external force is applied to the left wheel, the speed of the left wheel continues to increase, and when the speed remains unchanged, the speed remains stable at 0.17.

[0085] Preferably, a scope module is placed at the end of the top-level model, the drag coefficient, mass and wheel radius of the target car are defined in the workspace, and a step module is used to simulate the external force provided to the left wheel traction component and the right wheel traction component. After the top-level model is simulated, the scope module is used to output and display the curve graph of the car's linear speed and the car's displacement and the running time.

[0086] Specifically, the top-level model can be simulated as a whole. After consulting the data, it is known that the resistance coefficient of snow is 0.2, and the resistance coefficient of cement ground is 0.4-0.7. Assuming that the target car is driving on the snow, the mass of the car is defined as 2.5kg, the resistance coefficient is 0.2, and the wheel radius (left wheel radius and right wheel radius) of the car is 0.5m in the MATLAB workspace. Then, the step module in Simulink is used to simulate the external force to generate left wheel traction and right wheel traction. The scope module is placed at the end of the top-level model. Then, the top-level model starts to simulate. When the traction is equal to the resistance, the simulation ends. After the simulation ends, double-click the scope module to pop up the curve graph of the car linear speed and car displacement and running time. The curve graph is as follows Figure 6 As shown, from Figure 6 It can be observed intuitively from the curve graph that in the time period of 0-1, the input of the left wheel traction and the right wheel traction are both 0. In this time period, the wheels are only affected by resistance, so the car linear speed and car displacement in this time period are both 0. Starting from time 1, the car linear speed of the target car gradually increases. At the end of the simulation, the car linear speed basically remains unchanged at 2, and the car displacement is around 16.

[0087] Assume that when the target car is driving on a cement floor, take the resistance coefficient of the cement floor as 0.6, define the car mass as 2.5kg, the resistance coefficient as 0.6, and the car wheel radius (left wheel radius and right wheel radius) as 0.5m in the MATLAB workspace. Then, use the step module in Simulink to simulate the external force to generate left wheel traction and right wheel traction. Place the scope module at the end of the top-level model. Then, the top-level model starts to simulate. After the simulation is completed, double-click the scope module to pop up the curve graph of the car's linear velocity and car displacement versus running time. The curve graph is as follows: Figure 7 As shown, from Figure 7 It can be observed intuitively from the curve graph that in the 0-1 time period, the inputs of the left wheel traction and the right wheel traction are both 0. In this time period, the wheels are only affected by resistance, so the car linear speed and the car displacement in this time period are both 0. Starting from time 1, the car linear speed of the target car gradually increases. At the end of the simulation, the car linear speed basically remains unchanged at 1.7, which is slower than the speed of driving on the snow. When the simulation ends, the car displacement is around 11; the top model can be tested multiple times by changing the resistance coefficient; the above simulation results can effectively prove that the surface with a large resistance coefficient can stop the car in a shorter distance than the surface with a small resistance coefficient, indicating that the road surfaces with different resistance coefficients have different vehicle motion properties; it provides a reference for subsequent in-depth research on the impact of comprehensive factors such as vehicle traction, resistance, and speed on the vehicle driving state.

[0088] In the description of this specification, the terms "connection", "installation", "fixation" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0089] In the description of this specification, the description of the terms "one embodiment", "some embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0090] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A Simulink vehicle modeling method based on different road resistance coefficients, characterized in that: include: S100: simplifying the target car model, wherein the target car is simplified to a car having only left and right wheels, and only the linear motion of the target car is considered; S200: establishing a top-level model block diagram in Simulink according to the relationship between the linear speed of the trolley and the speeds of the left wheel and the right wheel, wherein the output of the top-level model block diagram is the linear speed of the trolley; S300: Modeling the interior of the left wheel assembly according to the relationship between the left wheel speed, the left wheel traction and the left wheel resistance, and modeling the interior of the right wheel assembly according to the relationship between the right wheel speed, the right wheel traction and the right wheel resistance, and outputting the left wheel speed after simulation of the left wheel assembly, and outputting the right wheel speed after simulation of the right wheel assembly; S400: Continue modeling according to the relationship between the displacement of the trolley and the linear velocity of the trolley, and construct a top-level model, wherein the output of the top-level model is the displacement of the trolley.

2. A Simulink vehicle modeling method based on different road resistance coefficients according to claim 1, characterized in that: The step S200 includes: S201: Build the left wheel component and the right wheel component that are not modeled internally in Simulink; S202: the left wheel assembly is connected to the left wheel traction assembly, the right wheel assembly is connected to the right wheel traction assembly, the left wheel traction force generated by the left wheel traction assembly is used as the input of the left wheel assembly, and the right wheel traction force generated by the right wheel traction assembly is used as the input of the right wheel assembly; S203: Sum and evenly divide the left wheel speed output by the left wheel assembly and the right wheel speed output by the right wheel assembly to obtain the linear speed of the vehicle; S204: Define the linear speed direction of the car as the speed in the X-axis direction, and complete the construction of the top-level model block diagram; the relationship between the linear speed of the car and the speed of the left wheel and the speed of the right wheel is shown in the following formula: Among them, V1 is the left wheel speed, V2 is the right wheel speed, and V3 is the linear speed of the car.

3. A Simulink vehicle modeling method based on different road resistance coefficients according to claim 2, characterized in that: The step S300 includes: S301: Modeling the left wheel resistance and the right wheel resistance of the target vehicle; S302: The left wheel traction force is used as the input of the left wheel component, and the interior of the left wheel component is modeled according to the relationship between the left wheel speed, the left wheel traction force and the left wheel resistance; the right wheel traction force is used as the input of the right wheel component, and the interior of the right wheel component is modeled according to the relationship between the right wheel speed, the right wheel traction force and the right wheel resistance; the output of the left wheel component is the left wheel speed, and the output of the right wheel component is the right wheel speed; The relationship between the left wheel speed, the left wheel traction and the left wheel resistance is shown in the following formula: The relationship between the right wheel speed, the right wheel traction and the right wheel resistance is shown in the following formula: Among them, F1 is the traction of the left wheel, F2 is the traction of the right wheel, f1 is the resistance of the left wheel, f2 is the resistance of the right wheel, V1 is the speed of the left wheel, V2 is the speed of the right wheel, and m is the mass of the target car; The mass of the target car borne by the left and right wheels is m / 2. The difference between the left wheel traction and the left wheel resistance divided by the mass borne by the left wheel is the left wheel acceleration, and the left wheel acceleration is integrated over the running time to get the left wheel speed; the difference between the right wheel traction and the right wheel resistance divided by the mass borne by the right wheel is the right wheel acceleration, and the right wheel acceleration is integrated over the running time to get the right wheel speed.

4. A Simulink vehicle modeling method based on different road resistance coefficients according to claim 3, characterized in that: Modeling the left wheel resistance and the right wheel resistance of the target car includes: Define the relationship between the left wheel resistance, resistance coefficient and left wheel speed of the target car, and define the relationship between the right wheel resistance, resistance coefficient and right wheel speed of the target car; The relationship between the left wheel resistance, the drag coefficient and the left wheel speed is shown in the following formula: f1=K*V1 The relationship between the right wheel resistance, the drag coefficient and the right wheel speed is shown in the following formula: f2=K*V2 Among them, f1 is the left wheel resistance, f2 is the right wheel resistance, K is the resistance coefficient, V1 is the left wheel speed, and V2 is the right wheel speed.

5. According to the Simulink vehicle modeling method based on different road resistance coefficients according to claim 4, the step S400 comprises: The linear velocity of the car is integrated with respect to the running time to construct a top-level model, wherein the output of the top-level model is the displacement of the car; The relationship between the displacement of the trolley and the linear velocity of the trolley is shown in the following formula: X=∫V3dt Among them, V3 is the linear velocity of the car, and X is the displacement of the car.

6. A Simulink vehicle modeling method based on different road resistance coefficients according to claim 2, characterized in that: Also includes: A scope module is placed at the end of the left wheel assembly and the right wheel assembly, and the resistance coefficient, mass and wheel radius of the target vehicle are defined in the workspace. A step module is used to simulate the external force provided to the left wheel traction assembly and the right wheel traction assembly. After the simulation of the left wheel assembly, a curve graph of the left wheel speed and the running time is output and displayed through the scope module. After the simulation of the right wheel assembly, a curve graph of the right wheel speed and the running time is output and displayed through the scope module.

7. A Simulink vehicle modeling method based on different road resistance coefficients according to claim 6, characterized in that: Also includes: A scope module is placed at the end of the top-level model, and the resistance coefficient, mass and wheel radius of the target car are defined in the workspace. The step module is used to simulate the external force provided to the left wheel traction component and the right wheel traction component. After the top-level model is simulated, the scope module is used to output and display the curve graph of the car's linear speed and displacement versus the running time.

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