Automobile acceleration performance test and data processing method

Abstract

The invention relates to the technical field of automobile tests, and discloses an automobile acceleration performance test and data processing method, which comprises the following steps of: recording signals that an accelerator pedal is stepped to the maximum position under different gears and the automobile speed and the engine rotating speed change along with time through data acquisition equipment in an acceleration test process, and performing data processing to obtain the acceleration performance of an automobile. The change of the driving acceleration of the vehicle at each gear along with the time, the vehicle speed and the rotating speed is obtained, and the acceleration capacity of the vehicle at each gear is obtained. According to the automobile acceleration performance test and data processing method, the change of the acceleration capacity of each gear along with time, rotating speed and automobile speed can be clearly reflected, and manual operation errors are eliminated.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile testing, and in particular to an automobile acceleration performance test and data processing method. Background Art

[0002] The dynamic indicators of a car are mainly represented by the maximum speed, acceleration ability and maximum climbing grade, which are the most basic and important performance of the car.

[0003] In my country, the acceleration capability in the dynamic performance index is obtained by automobile manufacturers through prototype testing according to the national test standards. According to the existing methods, the main test contents are full throttle starting acceleration performance test and full throttle overtaking acceleration performance test, and the test results are acceleration time.

[0004] However, the existing methods can only obtain the acceleration time, but cannot characterize the intermediate process. It is impossible to know whether the design of each gear ratio is scientific and reasonable, which is not conducive to in-depth analysis of the dynamic situation. Secondly, the acceleration time is related to the driver's proficiency in operation and varies from person to person. At the same time, for commercial vehicles with a large number of gears (especially those without synchronizers), the gear shifting time during the acceleration test is long and the error is large. Therefore, the vehicle's dynamic performance cannot be accurately evaluated by the acceleration time alone. In addition, the acceleration data collected by the on-board acceleration sensor fluctuates greatly, is easy to diverge, and the data accuracy is insufficient. Summary of the invention

[0005] The purpose of the present invention is to address the deficiencies of the above-mentioned technologies and to provide a vehicle acceleration performance test and data processing method that can clearly reflect the changes in the acceleration capability of each gear over time, rotation speed and vehicle speed, and eliminate human operation errors.

[0006] To achieve the above-mentioned purpose, the automobile acceleration performance test and data processing method involved in the present invention uses a data acquisition device to record the signal of the vehicle speed and engine speed changing with time when the accelerator pedal is pressed to the maximum position in different gears during the acceleration test. Through data processing, the changes in the vehicle's driving acceleration with time, vehicle speed and speed in each gear are obtained, thereby obtaining the acceleration capacity of the vehicle in each gear.

[0007] Preferably, the method comprises the following steps:

[0008] A) Determine the test conditions;

[0009] B) Install the test instrument: Obtain the engine speed signal through the OBD interface, import it into the data acquisition equipment through the adapter cable, and use GPS to record the signal of vehicle speed change over time during the test;

[0010] C) Acceleration test: When the vehicle is running steadily at the lowest speed in each gear, quickly press the accelerator pedal to the maximum position and stop when the speed stops rising. The data acquisition equipment collects the time, speed and rotation speed data during this process. The test is repeated back and forth, and each direction is tested at least three times;

[0011] D) Data processing: The test data of each gear is exported from the data acquisition equipment, including time, vehicle speed and rotation speed, and the effective acceleration test data segment is intercepted, from which the acceleration data is extracted, and polynomial fitting is performed to obtain the fitting curve, and then the fitting curve is derived to obtain the real-time acceleration during the acceleration process under the maximum throttle opening state of each gear, and the acceleration curve of each gear is characterized.

[0012] Preferably, in step A), the test conditions include meteorological conditions, road conditions, fuel and lubricant, vehicle preparation and vehicle preheating.

[0013] Preferably, in step C), when the vehicle is a manual transmission, the vehicle is started, the manual transmission is placed in 1st gear, the accelerator is released, the vehicle is driven at the lowest stable speed of the gear, the accelerator pedal is quickly pressed to the maximum position, and the accelerator pedal is turned off when the vehicle speed no longer increases, and then the manual transmission is placed in other gears and the test is repeated.

[0014] Preferably, in step C), when the vehicle is an automatic transmission, when the vehicle is stationary, the automatic transmission is placed in D gear, the accelerator is released, the vehicle is driven at the lowest stable speed of the gear, the accelerator pedal is quickly pressed to the maximum position, and the accelerator pedal is stopped when the vehicle speed no longer increases.

[0015] Preferably, the automatic transmission selects a sport mode.

[0016] Preferably, in step C), all electrical appliances and windows of the vehicle are turned off during the acceleration test.

[0017] Preferably, in step D), the average acceleration curve of each gear is obtained by deriving test data from multiple tests.

[0018] Preferably, in step D), an acceleration curve is generated with the vehicle speed as the horizontal coordinate to obtain the acceleration coincidence point of adjacent gears, and the corresponding vehicle speed and engine speed when shifting gears are determined based on the acceleration coincidence point, so that the vehicle always maintains the maximum acceleration capability during the acceleration process, and the shortest time required for acceleration can be calculated.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] 1. Calculate the acceleration curve of each gear, which can clearly reflect the changes of acceleration capacity of each gear with time, speed and vehicle speed;

[0021] 2. Calculate the best gear shift speed or rotation speed based on the acceleration coincidence point of adjacent gears, and obtain the shortest time to reach a certain speed in theory, which is convenient for comparison between different models and eliminates human operation errors;

[0022] 3. Adopt V-box and OBD, the equipment is simple and universal;

[0023] 4. Easy installation, short testing time and high work efficiency;

[0024] 5. Data processing is simple and the results are clearly expressed;

[0025] 6. It is convenient to check the results of dynamic theoretical calculations, which plays a guiding role in improving the accuracy of dynamic simulation in the design process. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 To derive test data of a certain gear in a certain embodiment of the automobile acceleration performance test and data processing method of the present invention;

[0027] Figure 2 is the acceleration data segment determined in this embodiment;

[0028] Figure 3 is a fitting curve obtained by performing polynomial fitting on the acceleration data in this embodiment;

[0029] Figure 4 is the acceleration curve obtained by derivation of the fitting curve in this embodiment;

[0030] Figure 5 is the acceleration curve of each gear in this embodiment;

[0031] Figure 6 It is the optimal shift point obtained in this embodiment. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below in conjunction with specific embodiments.

[0033] A vehicle acceleration performance test and data processing method, characterized in that: a data acquisition device is used to record signals of vehicle speed and engine speed changing with time when the accelerator pedal is stepped on to the maximum position in different gears during the acceleration test, and through data processing, the changes in the vehicle's driving acceleration with time, vehicle speed and speed in each gear are obtained, thereby obtaining the acceleration capacity of the vehicle in each gear.

[0034] Specifically, the steps include:

[0035] A) determining test conditions, which in this embodiment include weather conditions, road conditions, fuel and lubricants, vehicle preparation and vehicle preheating;

[0036] B) Install the test instrument: Obtain the engine speed signal through the OBD interface, import it into the data acquisition equipment through the adapter cable, and use GPS to record the signal of vehicle speed change over time during the test;

[0037] C) Acceleration test: When the vehicle is running steadily at the lowest speed in each gear, quickly press the accelerator pedal to the maximum position and stop when the speed stops rising. The data acquisition equipment collects the time, speed and rotation speed data during this process. The test is repeated back and forth, and each direction is tested at least three times;

[0038] D) Data processing: export test data from each gear in the data acquisition equipment, including time, vehicle speed and rotation speed, intercept valid acceleration test data segments, extract acceleration data from them, perform polynomial fitting, obtain fitting curves, and then derive the fitting curves to obtain the real-time acceleration during acceleration at the maximum throttle opening state in each gear, characterizing the acceleration curves of each gear.

[0039] Among them, in step C), when the vehicle has a manual transmission, the vehicle is started, the manual transmission is placed in 1st gear, the accelerator is released, the vehicle is driven at the lowest stable speed of the gear, the accelerator pedal is quickly pressed to the maximum position, and the accelerator pedal is turned off when the vehicle speed no longer increases, and then the manual transmission is placed in other gears and the test is repeated.

[0040] If the vehicle is equipped with an automatic transmission (except CVT), when the vehicle is stationary, put the automatic transmission in D gear, release the accelerator, and keep the vehicle at the lowest stable speed for that gear. Quickly press the accelerator pedal to the maximum position and stop when the speed stops rising. If the automatic transmission has mode distinction, select the sports mode.

[0041] In order to improve test accuracy, all electrical appliances and windows of the vehicle should be turned off during the acceleration test.

[0042] In step D), when data processing is performed, taking a specific test as an example, the test data of a certain gear is exported from the data acquisition device, such as Figure 1 As shown, including time, vehicle speed and rotation speed, the effective acceleration test data segment is intercepted, and then the acceleration data is extracted from it, such as Figure 2 As shown in , it is the data segment where the vehicle speed gradually increases after the accelerator pedal position is quickly stepped on from the initial position to the maximum position. The acceleration data of this gear is fitted with a polynomial, as shown in Figure 3 As shown, the fitting curve is obtained, and then the fitting curve is derived to obtain the real-time acceleration during the acceleration process under the maximum throttle opening state of each gear, such as Figure 4 As shown, the acceleration curves of each gear are characterized. The greater the acceleration, the stronger the acceleration capability of the gear, and the smaller the acceleration, the weaker the acceleration capability of the gear.

[0043] By exporting the test data of multiple tests and repeating the above process, the average acceleration curve of each gear can be obtained.

[0044] In addition, the acceleration curve is generated with the vehicle speed as the horizontal coordinate to obtain the acceleration coincidence points of adjacent gears, such as Figure 5 The speed-acceleration curves of each gear of a certain medium truck are: Figure 6 In the figure, A1, A2, A3, A4, and A5 represent the acceleration overlap points of the second gear and the third gear, the third gear and the fourth gear, the fourth gear and the fifth gear, the fifth gear and the sixth gear, and the sixth gear and the seventh gear respectively. According to the acceleration overlap points, the corresponding vehicle speed and engine speed when shifting gears can be determined, so that the vehicle can always maintain the maximum acceleration capability during the acceleration process. At the same time, the shortest time required to accelerate to a certain speed can be calculated to avoid the difference in acceleration time per 100 kilometers due to human operation errors. Figure 6 For example, the shifting speed between the second gear and the third gear is 18km / h. The acceleration time of the second gear is obtained through the test data. Similarly, the time when other gears maintain the maximum acceleration capacity can be obtained. It is calculated that the acceleration time of this car to 90km / h is 45.21 seconds.

[0045] The automobile acceleration performance test and data processing method of the present invention comprises the following steps: 1. calculating the acceleration curve of each gear, which can clearly reflect the change of the acceleration capacity of each gear with time, rotation speed and vehicle speed; calculating the optimal gear shifting speed or rotation speed according to the acceleration coincidence point of adjacent gears, and obtaining the shortest time to reach a certain speed in theory, which is convenient for comparison between different vehicle models and eliminates human operation errors; adopting V-box and OBD, the equipment is simple and universal; the installation is convenient, the test time is short and the work efficiency is high; the data processing is simple and the result expression is clear; it is convenient to check the theoretical calculation results of dynamics, and has a guiding role in improving the dynamics simulation accuracy in the design process.

Claims

1. A vehicle acceleration performance test and data processing method, characterized in that: Through the data acquisition equipment, during the acceleration test, the accelerator pedal is pressed to the maximum position in different gears, and the signals of vehicle speed and engine speed changing with time are recorded. Through data processing, the changes in the vehicle's driving acceleration with time, vehicle speed and speed in each gear are obtained, and the acceleration capacity of the vehicle in each gear is obtained.

2. The automobile acceleration performance test and data processing method as claimed in claim 1, characterized in that: The steps include: A) Determine the test conditions; B) Install the test instrument: Obtain the engine speed signal through the OBD interface, import it into the data acquisition equipment through the adapter cable, and use GPS to record the signal of vehicle speed change over time during the test; C) Acceleration test: When the vehicle is running steadily at the lowest speed in each gear, quickly press the accelerator pedal to the maximum position and stop when the speed stops rising. The data acquisition equipment collects the time, speed and rotation speed data during this process. The test is repeated back and forth, and each direction is tested at least three times; D) Data processing: The test data of each gear is exported from the data acquisition equipment, including time, vehicle speed and rotation speed, and the effective acceleration test data segment is intercepted, from which the acceleration data is extracted, and polynomial fitting is performed to obtain the fitting curve, and then the fitting curve is derived to obtain the real-time acceleration during the acceleration process under the maximum throttle opening state of each gear, and the acceleration curve of each gear is characterized.

3. The DPF regeneration control method based on user usage conditions as claimed in claim 2, characterized in that: In step A), the test conditions include weather conditions, road conditions, fuel and lubricants, vehicle preparation and vehicle preheating.

4. The DPF regeneration control method based on user usage conditions as claimed in claim 2, characterized in that: In the step C), when the vehicle is a manual transmission, the vehicle is started, the manual transmission is placed in 1st gear, the accelerator is released, the vehicle is driven at the lowest stable speed of the gear, the accelerator pedal is quickly pressed to the maximum position, and the accelerator pedal is turned off when the vehicle speed no longer increases, and then the manual transmission is placed in other gears and the test is repeated.

5. The DPF regeneration control method based on user usage conditions as claimed in claim 2, characterized in that: In the step C), when the vehicle is an automatic transmission, when the vehicle is stationary, the automatic transmission is placed in D gear, the accelerator is released, the vehicle is driven at the lowest stable speed of the gear, the accelerator pedal is quickly pressed to the maximum position, and the accelerator pedal is stopped when the vehicle speed no longer increases.

6. The DPF regeneration control method based on user usage conditions as claimed in claim 5, characterized in that: The automatic transmission is in Sport mode.

7. The DPF regeneration control method based on user operating conditions as claimed in claim 2, characterized in that: In the step C), all electrical appliances and windows of the vehicle are turned off during the acceleration test.

8. The DPF regeneration control method based on user usage conditions as claimed in claim 2, characterized in that: In the step D), the average acceleration curve of each gear is obtained by deriving test data from multiple tests.

9. The DPF regeneration control method based on user usage conditions as claimed in claim 2, characterized in that: In the step D), an acceleration curve is generated with the vehicle speed as the horizontal coordinate to obtain the acceleration coincidence points of adjacent gears. Based on the acceleration coincidence points, the corresponding vehicle speed and engine speed when shifting gears are determined, so that the vehicle always maintains the maximum acceleration capability during the acceleration process, and the shortest time required for acceleration can be calculated.

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