Vehicle wind resistance coefficient determination method

Abstract

The invention discloses a method for determining the wind resistance coefficient of a vehicle, and belongs to the technical field of aerodynamics. The method specifically comprises the following steps: S1, determining a wind resistance coefficient; s2, collecting data; s3, inputting data; s4, storing the data; s5, processing data and generating an instruction; and S6, result display and warning reminding are carried out. The actual wind resistance coefficient of the vehicle can be determined each time through the obtained vehicle wind resistance coefficient determined each time; the number of times that the vehicle wind resistance coefficient is determined and the number of times that the error between the actual vehicle wind resistance coefficient and the determined vehicle wind resistance coefficient exceeds the error range of the difference value between the actual vehicle wind resistance coefficient determined by the input wind resistance coefficient and the determined wind resistance coefficient in total are determined; and comprehensively analyzing the data to obtain an evaluation index of the method, so that the advantages and disadvantages of the method are obtained according to the evaluation index, the larger the evaluation index is, the better the determination effect of the method is, and otherwise, the poorer the determination effect of the method is.

Description

Technical Field

[0001] The present invention relates to the technical field of aerodynamics, and particularly to a method for determining the wind resistance coefficient of a vehicle. Background Art

[0002] The wind resistance coefficient of an automobile is closely related to factors such as the overall vehicle size, styling design, and aerodynamic accessories. In the traditional vehicle development process, the development of the wind resistance coefficient requires a long cycle of design and verification, with low efficiency, high cost, and low quality in wind resistance development. Some problems in wind resistance development are difficult to be discovered during the initial styling design process, and are difficult to be changed or have too high a change cost in the later stage of styling design, resulting in an increase in project development costs and a slowdown in development progress, which will have an adverse impact on designs that require a short vehicle development cycle and accelerated update iterations. Summary of the Invention

[0003] Object of the Invention: The object of the present invention is to provide a method for determining the wind resistance coefficient of a vehicle, which can solve the problem that some problems in wind resistance development are difficult to be discovered during the initial styling design process, and are difficult to be changed or have too high a change cost in the later stage of styling design.

[0004] Technical Solution: To solve the above technical problems, according to one aspect of the present invention, more specifically, a system for determining the wind resistance coefficient of a vehicle includes: a wind resistance coefficient determination unit, a data acquisition unit, a data input unit, a network transmission unit, a data storage unit, an analysis and processing unit, and a display and reminder unit; Wind Resistance Coefficient Determination Unit: It is used to determine the wind resistance coefficient of the vehicle to be determined by comparing the vehicle length, vehicle width, vehicle height, and wheelbase of the vehicle to be determined with the vehicle length, vehicle width, vehicle height, and wheelbase of the sample data in the database based on the constructed sample database, and obtain the wind resistance coefficient of the vehicle to be determined; Data Acquisition Unit: It is used to collect various data required for the system for determining the wind resistance coefficient of a vehicle during the process of determining the wind resistance coefficient of the vehicle; Data Input Unit: It is used to input data for various data required for the system for determining the wind resistance coefficient of a vehicle during the process of determining the wind resistance coefficient of the vehicle; Network Transmission System: It is used to transmit the data collected by the data acquisition unit and the data input by the data input unit to the data storage unit, and transmit the data collected by the data acquisition unit, the data input by the data input unit, and the data stored by the data storage unit to the analysis and processing unit, and transmit the results of the analysis and processing by the analysis and processing unit and the generated instructions to the display and reminder unit; Data Storage Unit: It is used to store the data collected by the data acquisition unit and the data input by the data input unit; Analysis and Processing Unit: It is used to receive the data collected by the Data Acquisition Unit, the data input by the Data Input Unit, and the data stored by the Data Storage Unit, analyze and process the received data, and generate corresponding instructions according to the results of the analysis and processing; Display and Reminder Unit: It is used to receive the analysis and processing results and the generated instructions of the Analysis and Processing Unit, display the received analysis and processing results, and give a warning reminder when receiving the instructions generated by the Analysis and Processing Unit.

[0005] Furthermore, the Data Acquisition Unit includes: a Frequency Acquisition Module and a Result Acquisition Module; Frequency Acquisition Module: It is used to collect various data on frequencies required by the vehicle drag coefficient determination system; Result Acquisition Data: It is used to collect various data on the drag coefficient results of the drag coefficient determination unit.

[0006] Furthermore, the Data Input Unit includes: a Drag Coefficient Input Module, an Error Range Input Module, and a Warning Threshold Input Module; Drag Coefficient Input Module: It is used to input the actual drag coefficient of the vehicle for which the drag coefficient is to be determined; Error Range Input Module: It is used to input the error range of the difference between the actual drag coefficient and the determined drag coefficient of the vehicle for which the drag coefficient is to be determined; Warning Threshold Input Module: It is used to input the warning thresholds for the analysis and processing results of the Analysis and Processing Unit.

[0007] Furthermore, the Analysis and Processing Unit includes: a Data Reception Module, a Data Processing Module, and an Instruction Generation Module; Data Reception Module: It is used to receive the data collected by the Data Acquisition Unit, the data input by the Data Input Unit, and the data stored by the Data Storage Unit; Data Processing Module: It is used to analyze and process the various data received by the Data Reception Module to obtain the analysis and processing results; Instruction Generation Module: It is used to generate corresponding instructions according to the analysis and processing results of the Data Processing Module.

[0008] Furthermore, the Display and Reminder Unit includes: a Result and Instruction Reception Module, a Result Display Module, and a Warning Reminder Module; Result and Instruction Reception Module: It is used to receive the analysis and processing results and the generated instructions of the Analysis and Processing Unit; Result Display Module: It is used to display the analysis and processing results of the Analysis and Processing Unit received by the Result and Instruction Reception Module; Warning and reminder module: used to give a warning and reminder when the result and instruction receiving module receives the instructions generated by the analysis and processing unit.

[0009] According to another aspect of the present invention, a method for determining the aerodynamic drag coefficient of a vehicle is provided. This method is implemented based on the above-mentioned system for determining the aerodynamic drag coefficient of a vehicle, and specifically includes the following steps: S1. Determination of the aerodynamic drag coefficient: Based on the constructed sample database, by comparing the vehicle length, vehicle width, vehicle height, and wheelbase of the vehicle to be determined with the vehicle length, vehicle width, vehicle height, and wheelbase of the sample data in the database, the aerodynamic drag coefficient of the vehicle to be determined is determined, and the aerodynamic drag coefficient of the vehicle to be determined is obtained. S2. Data collection: Collect various data required for the system for determining the aerodynamic drag coefficient of a vehicle during the process of determining the aerodynamic drag coefficient of the vehicle. S3. Data input: Input the various data required for the system for determining the aerodynamic drag coefficient of a vehicle during the process of determining the aerodynamic drag coefficient of the vehicle. S4. Data storage: Store the data collected by the data collection unit and the data input by the data input unit. S5. Data processing and instruction generation: Analyze and process the collected data, input data, and stored data to obtain an analysis and processing result, and generate corresponding instructions according to the analysis and processing result. S6. Result display and warning reminder: Display the analysis and processing result, and give a reminder when receiving the corresponding instruction.

[0010] Furthermore, in step S5, when performing the analysis and processing, the aerodynamic drag coefficient of the vehicle determined each time, the actual aerodynamic drag coefficient of the vehicle determined each time, the total number of times of determining the aerodynamic drag coefficient of the vehicle, and the number of times that the error between the actual aerodynamic drag coefficient of the vehicle and the determined aerodynamic drag coefficient exceeds the error range of the difference between the actual aerodynamic drag coefficient of the vehicle determined by inputting the aerodynamic drag coefficient and the determined aerodynamic drag coefficient can be obtained, and the above data is comprehensively analyzed to obtain the evaluation index of this method:

[0011] Thus, the superiority and inferiority of the method can be obtained according to the evaluation index. The larger the evaluation index, the better the determination effect of this method; on the contrary, it means that the determination effect of this method is worse. Among them, is the evaluation index, is the aerodynamic drag coefficient of the vehicle determined each time, is the actual aerodynamic drag coefficient of the vehicle determined each time, is the total number of times of determining the aerodynamic drag coefficient of the vehicle, The number of times that the error between the actual aerodynamic drag coefficient of the vehicle and the determined aerodynamic drag coefficient of the vehicle exceeds the error range of the difference between the actual aerodynamic drag coefficient of the vehicle determined by the input aerodynamic drag coefficient and the determined aerodynamic drag coefficient.

[0012] Furthermore, in the step S5, the analysis and processing can be obtained by analyzing and processing the aerodynamic drag coefficients determined by running multiple times with the same input conditions and parameters, the actual aerodynamic drag coefficient of the vehicle under this condition, the number of groups for comparison, and the number of times of the same input conditions and parameters for each group to obtain the stability index of the determination process:

[0013] Thus, the operation stability of the determination process can be obtained according to the stability index. The larger the stability index, the better the operation stability of the determination process; on the contrary, it indicates that the operation stability of the determination process is worse; where, is the stability index, and are two adjacent aerodynamic drag coefficients determined by running multiple times with the same input conditions and parameters, is the actual aerodynamic drag coefficient of the vehicle under this condition, is the number of groups for comparison, is the number of times of the same input conditions and parameters for each group.

[0014] Furthermore, in the step S5, the condition for generating an instruction is that when the evaluation index is lower than the warning reminder threshold of the input evaluation index or the stability index is lower than the warning reminder threshold of the input stability index, a corresponding warning reminder instruction will be generated to give a warning reminder for the corresponding situation.

[0015] Beneficial effects: When performing analysis and processing through this method, the vehicle drag coefficient determined each time can be obtained, the actual drag coefficient of the vehicle can be determined each time, the total number of times of determining the vehicle drag coefficient, and the number of times that the error between the actual drag coefficient of the vehicle and the determined vehicle drag coefficient exceeds the error range of the difference between the actual drag coefficient of the vehicle determined by the input drag coefficient and the determined drag coefficient. By comprehensively analyzing the above data, the evaluation index of this method can be obtained, so as to obtain the superiority and inferiority of the method according to the evaluation index. The larger the evaluation index, the better the determination effect of this method; otherwise, it means that the determination effect of this method is worse. The analysis and processing can obtain the stability index of the determination process by comparing the drag coefficients determined by running multiple times under the same input conditions and parameters, the actual drag coefficient of the vehicle under this condition, the number of comparison groups, and the number of times of the same input conditions and parameters for each group, so as to obtain the operation stability of the determination process according to the stability index. The larger the stability index, the better the operation stability of the determination process; otherwise, it means that the operation stability of the determination process is worse. At the same time, when the evaluation index is lower than the warning reminder threshold of the input evaluation index or the stability index is lower than the warning reminder threshold of the input stability index, corresponding warning reminder instructions will be generated to warn of the corresponding situation to remind the operator to discover problems in time. Description of the Drawings

[0016] Figure 1 It is a schematic diagram of the system principle. Detailed Implementation Manner

[0017] To make the technical solutions of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] Embodiment 1 First step, determination of the drag coefficient: Through the drag coefficient determination unit in the constructed sample database, by comparing the vehicle length, vehicle width, vehicle height, and wheelbase of the vehicle to be determined with the vehicle length, vehicle width, vehicle height, and wheelbase of the sample data in the database, the drag coefficient of the vehicle to be determined is determined, and the vehicle drag coefficient of the vehicle to be determined is obtained.

[0019] Second step, data collection: The number collection module and result collection module of the data collection unit collect various data on the number required for the vehicle drag coefficient determination system and various data on the drag coefficient results of the drag coefficient determination unit.

[0020] Step 3, Data Input: Input the actual drag coefficient of the vehicle for which the drag coefficient is determined, the error range between the actual drag coefficient of the vehicle for which the drag coefficient is determined and the determined drag coefficient, and the warning threshold for each analysis and processing result of the analysis and processing unit through the drag coefficient input module, error range input module, and warning threshold input module of the data input unit.

[0021] Step 4, Data Storage: Store the data collected by the data collection unit and the data input by the data input unit through the data storage unit.

[0022] Step 5, Data Processing and Instruction Generation: Receive the data collected by the data collection unit, the data input by the data input unit, and the data stored by the data storage unit through the data receiving module of the analysis and processing unit, and analyze and process each data received by the data receiving module through the data processing module to obtain the analysis and processing results. At the same time, generate corresponding instructions through the instruction generation module according to the analysis and processing results of the data processing module.

[0023] During the analysis and processing, the evaluation index of this method can be obtained by obtaining the drag coefficient of the vehicle determined each time, the actual drag coefficient of the vehicle determined each time, the total number of times of determining the vehicle drag coefficient, and the number of times that the error between the actual drag coefficient of the vehicle and the determined drag coefficient of the vehicle exceeds the error range between the actual drag coefficient of the vehicle for which the drag coefficient is determined and the determined drag coefficient input, and comprehensively analyzing the above data:

[0024] Thus, the superiority and inferiority of the method can be obtained according to the evaluation index. The larger the evaluation index, the better the determination effect of this method; on the contrary, it means that the determination effect of this method is worse; where, is the evaluation index, is the drag coefficient of the vehicle determined each time, is the actual drag coefficient of the vehicle determined each time, is the total number of times of determining the vehicle drag coefficient, is the number of times that the error between the actual drag coefficient of the vehicle and the determined drag coefficient of the vehicle exceeds the error range between the actual drag coefficient of the vehicle for which the drag coefficient is determined and the determined drag coefficient input.

[0025] At the same time, the analysis and processing can obtain the stability index of the determination process by analyzing and processing the drag coefficients determined by running multiple times with the same input conditions and parameters, the actual drag coefficients of the vehicle under this condition, the number of comparison groups, and the number of times of the same input conditions and parameters for each group.

[0026] Thus, the operational stability of the determination process is obtained based on the stability index. The larger the stability index, the better the operational stability of the determination process; conversely, it indicates that the operational stability of the determination process is worse. Among them, is the stability index, and are two adjacent air resistance coefficients determined by running multiple times using the same input conditions and parameters, is the actual air resistance coefficient of the vehicle under this condition, is the number of groups for comparison, is the number of times of the same input conditions and parameters for each group.

[0027] Moreover, when the evaluation index is lower than the warning reminder threshold of the input evaluation index or the stability index is lower than the warning reminder threshold of the input stability index, corresponding warning reminder instructions will be generated to give a warning reminder for the corresponding situation Step 6, Result display and warning reminder: The result and instruction receiving module receives the analysis and processing results of the analysis and processing unit and the generated instructions through the result display and reminder unit, and the result display module displays the analysis and processing results of the analysis and processing unit received by the result and instruction receiving module. At the same time, when the instruction generated by the analysis and processing unit is received by the result and instruction receiving module, a warning reminder is given through the warning reminder module.

[0028] Embodiment 2 When performing analysis and processing, obtain = 37.1, = 36.5, = 0.6, = 100, = 7. At this time, it can be calculated that:

[0029] = 1.9 At this time, compare 1.9 with the warning reminder threshold of the input evaluation index If 1.9, no warning reminder is given. If .9, a warning reminder is given for the relevant situation.

[0030] Embodiment 3 When performing analysis and processing, obtain , . At this time, it can be calculated that:

[0031]

[0032] At this time, compare 0.975 with the warning reminder threshold of the input stability index If 0.975, then give a warning reminder about the relevant situation. If 0.975, then no warning reminder will be given.

[0033] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the appended claims.

Claims

1. A system for determining a vehicle drag coefficient, characterized in that: include: Drag coefficient determination unit, data collection unit, data input unit, network transmission unit, data storage unit, analysis and processing unit, and display and reminder unit; Drag coefficient determination unit: used for determining the drag coefficient of the vehicle to be determined based on the constructed sample database by comparing the vehicle length, vehicle width, vehicle height and wheelbase of the vehicle to be determined with the vehicle length, vehicle width, vehicle height and wheelbase of the sample data in the database, and obtaining the vehicle drag coefficient of the vehicle to be determined; Data acquisition unit: used for collecting various data required by the vehicle drag coefficient determination system in the process of determining the vehicle drag coefficient; Data input unit: used for inputting data required by the vehicle drag coefficient determination system in the process of determining the vehicle drag coefficient; Network transmission system: used to transmit the data collected by the data collection unit and the data input by the data input unit to the data storage unit, and to transmit the data collected by the data collection unit, the data input by the data input unit and the data stored by the data storage unit to the analysis and processing unit, and to transmit the analysis and processing results and the generated instructions of the analysis and processing unit to the display and reminder unit; Data storage unit: used for storing the data collected by the data collection unit and the data input by the data input unit; Analysis and processing unit: used for receiving the data collected by the data collection unit, the data input by the data input unit and the data stored by the data storage unit, analyzing and processing the received data, and generating corresponding instructions according to the results of the analysis and processing; Display and reminder unit: used to receive the analysis and processing results and the instructions generated by the analysis and processing unit, and to display the received analysis and processing results, and to issue a warning reminder when receiving the instructions generated by the analysis and processing unit.

2. A vehicle drag coefficient determination system according to claim 1, characterized in that: The data collection unit includes: a frequency collection module and a result collection module; Frequency collection module: used to collect various frequency data required by the vehicle drag coefficient determination system; Result collection data: used to collect data on the drag coefficient results of the drag coefficient determination unit.

3. A vehicle drag coefficient determination system according to claim 1, characterized in that: The data input unit includes: a drag coefficient input module, an error range input module and a warning threshold input module; Drag coefficient input module: used to input the actual drag coefficient of the vehicle for determining the drag coefficient; An error range input module: used for inputting an error range of a difference between an actual drag coefficient of a vehicle for which drag coefficient determination is to be performed and a determined drag coefficient; Warning threshold input module: used to input the warning threshold of each analysis and processing result of the analysis and processing unit.

4. A vehicle drag coefficient determination system according to claim 1, characterized in that: The analysis and processing unit includes: a data receiving module, a data processing module and an instruction generating module; Data receiving module: used for receiving data collected by the data collection unit, data input by the data input unit and data stored by the data storage unit; Data processing module: used to analyze and process the data received by the data receiving module to obtain the analysis and processing results; Instruction generation module: used to generate corresponding instructions according to the analysis and processing results of the data processing module.

5. The system for determining a vehicle drag coefficient according to claim 1, characterized in that: The display and reminder unit includes: a result and instruction receiving module, a result display module and a warning reminder module; Result and instruction receiving module: used for receiving the analysis and processing results and the generated instructions of the analysis and processing unit; Result display module: used for displaying the analysis and processing results of the analysis and processing unit received by the result and instruction receiving module; Warning reminder module: used to issue a warning reminder when the result and instruction receiving module receives the instruction generated by the analysis and processing unit.

6. A method for determining a vehicle drag coefficient, characterized in that: The method is implemented based on a vehicle drag coefficient determination system according to any one of claims 1 to 5, and specifically comprises the following steps: S1. Determine the drag coefficient: Based on the constructed sample database, determine the drag coefficient of the vehicle to be determined by comparing the vehicle length, vehicle width, vehicle height and wheelbase of the vehicle to be determined with the vehicle length, vehicle width, vehicle height and wheelbase of the sample data in the database, and obtain the vehicle drag coefficient of the vehicle to be determined; S2. Data collection: collecting various data required by the vehicle drag coefficient determination system in the process of determining the vehicle drag coefficient; S3. Data input: inputting various data required by the vehicle drag coefficient determination system in the process of determining the vehicle drag coefficient; S4, data storage: storing the data collected by the data collection unit and the data input by the data input unit; S5. Data processing and instruction generation: Analyze and process the collected data, input data, and stored data to obtain analysis and processing results, and generate corresponding instructions based on the analysis and processing results; S6. Display of results and warning reminders: Display the results of the analysis and processing, and issue reminders when corresponding instructions are received.

7. A method for determining a vehicle drag coefficient according to claim 6, characterized in that: In step S5, when performing analysis and processing, the evaluation index of the method can be obtained by obtaining each determined vehicle drag coefficient, each determined vehicle actual drag coefficient, the total number of vehicle drag coefficient determinations, and the number of times the error between the actual vehicle drag coefficient and the determined vehicle drag coefficient exceeds the error range of the difference between the actual vehicle drag coefficient determined by the input drag coefficient and the determined drag coefficient, and comprehensively analyzing the above data: Thus, the merits of the method are obtained according to the evaluation index. The larger the evaluation index is, the better the determination effect of the method is. On the contrary, the smaller the evaluation index is, the worse the determination effect of the method is. To evaluate the index, is the vehicle drag coefficient determined each time, Determine the actual drag coefficient of the vehicle for each run. is the total number of vehicle drag coefficient determinations performed, The number of times that the error between the actual drag coefficient of the vehicle and the determined drag coefficient of the vehicle exceeds the error range of the difference between the actual drag coefficient of the vehicle determined by the input drag coefficient and the determined drag coefficient.

8. The method for determining a vehicle drag coefficient according to claim 6, characterized in that: In step S5, the analysis process can be performed by analyzing the drag coefficient determined by multiple runs using the same input conditions and parameters, the actual drag coefficient of the vehicle under the conditions, the number of groups for comparison, and the number of times each group is subjected to the same input conditions and parameters to obtain a stability index of the determination process: 。 9. Thus, the operational stability of the determination process is obtained according to the stability index. The larger the stability index is, the better the operational stability of the determination process is. Conversely, the worse the operational stability of the determination process is. is the stability index, and For two consecutive drag coefficients determined using the same input conditions and parameters, is the actual drag coefficient of the vehicle under this condition, is the number of groups to be compared, The same input conditions and parameters were repeated for each group.

10. The method for determining a vehicle drag coefficient according to claim 6, characterized in that: In step S5, the condition for generating the instruction is that when the evaluation index is lower than the warning threshold of the input evaluation index or the stability index is lower than the warning threshold of the input stability index, a corresponding warning instruction will be generated to issue a warning for the corresponding situation.

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