Vehicle acceleration performance testing and data processing methods

Abstract

This invention relates to the field of automotive testing technology and discloses a method for testing and processing automotive acceleration performance. Using data acquisition equipment, the method records signals showing the changes in vehicle speed and engine speed over time when the accelerator pedal is fully depressed in different gears during an acceleration test. Through data processing, the method obtains the changes in vehicle acceleration over time, vehicle speed, and engine speed in each gear, thus acquiring the vehicle's acceleration capability in each gear. This invention's method for testing and processing automotive acceleration performance clearly reflects the changes in acceleration capability in each gear over time, engine speed, and vehicle speed, and eliminates human error.

Description

Technical Field

[0001] This invention relates to the field of automotive testing technology, specifically to a method for testing and processing automotive acceleration performance data. Background Technology

[0002] The performance indicators of a car are mainly represented by its top speed, acceleration capability, and maximum gradeability, which are the most basic and important performance indicators for a car.

[0003] In my country, acceleration performance, a key performance indicator, is determined by automobile manufacturers through prototype vehicle testing according to national standards. Current methods primarily involve full-throttle start-up acceleration performance tests and full-throttle overtaking acceleration performance tests, with the result being the acceleration time.

[0004] However, existing methods can only obtain acceleration time and cannot characterize the intermediate process, nor can they determine whether the gear ratio design of each gear is scientific and reasonable, which is not conducive to in-depth analysis of the power performance. Secondly, acceleration time is related to the driver's skill level and varies from person to person. At the same time, commercial vehicles with more gears (especially those without synchronizers) take longer to shift gears during acceleration tests and have larger errors. Therefore, acceleration time alone cannot accurately assess the quality of vehicle power performance. In addition, acceleration data collected by on-board acceleration sensors fluctuates greatly, is prone to divergence, and has insufficient data accuracy. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the above-mentioned technologies by providing a method for testing and processing vehicle acceleration performance, which can clearly reflect the changes in acceleration capability of each gear with time, engine speed and vehicle speed, and eliminate human error.

[0006] To achieve the above objectives, the vehicle acceleration performance testing and data processing method involved in this invention uses data acquisition equipment to record the signals of vehicle speed and engine speed changes over time when the accelerator pedal is fully depressed in different gears during the acceleration test. Through data processing, the changes in vehicle acceleration over time, vehicle speed, and engine speed in each gear are obtained, thus acquiring the vehicle's acceleration capability in each gear.

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

[0008] A) Determine the test conditions;

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

[0010] C) Acceleration test: When the vehicle is driving steadily at the minimum speed in each gear, quickly press the accelerator pedal to the maximum position and stop when the vehicle speed no longer increases. The data acquisition equipment collects the time, vehicle speed and RPM data during this process. The test is repeated in both directions, with at least three tests in each direction.

[0011] D) Data processing: Export test data for each gear from the data acquisition equipment, including time, vehicle speed and RPM, extract the effective acceleration test data segment, extract the acceleration data from it, perform polynomial fitting to obtain the fitting curve, and then differentiate the fitting curve to obtain the real-time acceleration during the acceleration process under the maximum throttle opening state in each gear, thus characterizing the acceleration curve of each gear.

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

[0013] Preferably, 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, and the vehicle is driven at the minimum stable speed of that gear. The accelerator pedal is then quickly pressed to the maximum position, and the vehicle stops moving when the speed no longer increases. 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, and the vehicle is driven at the minimum stable speed of that gear. The accelerator pedal is then quickly pressed to the maximum position, and the vehicle stops moving when the 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 for each gear is obtained by deriving test data from multiple tests.

[0018] Preferably, in step D), an acceleration curve is generated with vehicle speed as the abscissa to obtain the acceleration coincidence point of adjacent gears. Based on the acceleration coincidence point, the corresponding vehicle speed and engine speed at the time of gear shift are determined so that the vehicle always maintains maximum acceleration capability during acceleration 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 curves for each gear, which can clearly reflect the changes in acceleration capability of each gear with time, engine speed, and vehicle speed;

[0021] 2. Based on the acceleration overlap point of adjacent gears, calculate the optimal shift speed or RPM to obtain the shortest time to theoretically reach a certain speed, which facilitates comparison between different vehicle models and eliminates human operation error.

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

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

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

[0025] 6. It facilitates the verification of dynamic theoretical calculation results and provides guidance for improving the accuracy of dynamic simulation in the design process. Attached Figure Description

[0026] Figure 1 This invention provides an embodiment of the vehicle acceleration performance testing and data processing method for deriving test data for a specific gear.

[0027] Figure 2 This refers to the accelerated data segment defined in this embodiment;

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

[0029] Figure 4 This is the acceleration curve obtained by differentiating the fitted curve in this embodiment;

[0030] Figure 5 The acceleration curves for each gear position in this embodiment are shown.

[0031] Figure 6 This is the optimal shift point obtained in this embodiment. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to specific embodiments.

[0033] A method for testing and processing vehicle acceleration performance, characterized in that: during the acceleration test, the vehicle speed and engine speed are recorded by a data acquisition device when the accelerator pedal is fully depressed in different gears, and the changes are obtained over time. Through data processing, the changes in vehicle acceleration with time, vehicle speed and engine speed in each gear are obtained, thus acquiring the vehicle's acceleration capability in each gear.

[0034] Specifically, it includes the following steps:

[0035] A) Determine the test conditions. In this embodiment, these include weather conditions, road conditions, fuel and lubricating oil, vehicle preparation, and vehicle preheating.

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

[0037] C) Acceleration test: When the vehicle is driving steadily at the minimum speed in each gear, quickly press the accelerator pedal to the maximum position and stop when the vehicle speed no longer increases. The data acquisition equipment collects the time, vehicle speed and RPM data during this process. The test is repeated in both directions, with at least three tests in each direction.

[0038] D) Data processing: Export test data from each gear in the data acquisition equipment, including time, vehicle speed and RPM, extract the effective acceleration test data segment, extract the acceleration data from it, perform polynomial fitting to obtain the fitting curve, and then differentiate the fitting curve to obtain the real-time acceleration during the acceleration process under the maximum throttle opening state in each gear, and characterize the acceleration curve of each gear.

[0039] In step C), when the vehicle has a manual transmission, start the vehicle, put the manual transmission in 1st gear, release the accelerator, and drive the vehicle at the minimum stable speed of that gear. Quickly press the accelerator pedal to the maximum position, and stop when the vehicle speed no longer increases. Then put the manual transmission in other gears and repeat the test.

[0040] When 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 pedal to make the vehicle travel at the minimum stable speed of that gear, quickly press the accelerator pedal to the maximum position, and stop when the vehicle speed no longer increases. If the automatic transmission has different modes, select Sport mode.

[0041] To improve testing accuracy and speed up the testing process, all vehicle electrical components and windows are turned off.

[0042] In step D), during data processing, taking a specific test as an example, the test data for a certain gear level is exported from the data acquisition device, such as... Figure 1 As shown, data including time, vehicle speed, and engine speed is extracted from valid acceleration test data segments, and then acceleration data is extracted from them, such as... Figure 2 As shown, this is a data segment showing the gradual increase in vehicle speed after the accelerator pedal is rapidly depressed from its initial position to its maximum position. Polynomial fitting is performed on the acceleration data for this gear, as shown below. Figure 3 As shown, a fitted curve is obtained, and then the derivative of the fitted curve is calculated to obtain the real-time acceleration during acceleration at maximum throttle opening in each gear, as shown below. Figure 4 As shown, the acceleration curves represent the different gears. The greater the acceleration, the stronger the acceleration capability of that gear; the smaller the acceleration, the weaker the acceleration capability of that gear.

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

[0044] Additionally, by generating an acceleration curve with vehicle speed as the abscissa, the point of coincidence of acceleration between adjacent gears can be obtained, such as... Figure 5 The speed-acceleration curves of a certain medium-duty truck at different speeds are shown. Figure 6 In this diagram, A1, A2, A3, A4, and A5 represent the acceleration coincidence points for second and third gear, third and fourth gear, fourth and fifth gear, fifth and sixth gear, and sixth and seventh gear, respectively. Based on these acceleration coincidence points, the corresponding vehicle speed and engine speed during gear shifts can be determined, ensuring the vehicle maintains maximum acceleration capability throughout the acceleration process. Furthermore, the shortest time required to accelerate to a specific speed can be calculated, avoiding variations in 0-100 km / h acceleration times due to human error. Figure 6 For example, the shift speed between second and third gear is 18 km / h. The acceleration time in second gear is obtained through test data. By analogy, the time when other gears maintain maximum acceleration capability can be obtained. The calculation shows that the acceleration time of this car to 90 km / h is 45.21 seconds.

[0045] This invention relates to a method for testing and processing vehicle acceleration performance. 1. It calculates the acceleration curves for each gear, clearly reflecting the changes in acceleration capability of each gear with time, engine speed, and vehicle speed. Based on the acceleration overlap points of adjacent gears, it calculates the optimal shift speed or engine speed, obtaining the shortest theoretical time to reach a certain speed, facilitating comparisons between different vehicle models and eliminating human error. It utilizes V-box and OBD, making the equipment simple and universal. Installation is convenient, testing time is short, and work efficiency is high. Data processing is simple, and results are clearly expressed. It facilitates the verification of dynamic performance theoretical calculation results and provides guidance for improving the accuracy of dynamic performance simulation during the design process.

Claims

1. A method for testing and processing vehicle acceleration performance data, characterized in that: Using data acquisition equipment, the signals of vehicle speed and engine speed changing over time when the accelerator pedal is fully depressed in different gears during the acceleration test are recorded. Through data processing, the changes in vehicle acceleration over time, vehicle speed, and engine speed in each gear are obtained, thus acquiring the vehicle's acceleration capability in each gear. This includes the following steps: A) Determine the test conditions; B) Install test instruments: Obtain engine speed signal through OBD interface, import it into data acquisition equipment through adapter cable, and record the vehicle speed change signal over time during the test through GPS; C) Acceleration test: When the vehicle is driving steadily at the minimum speed in each gear, quickly press the accelerator pedal to the maximum position and stop when the vehicle speed no longer increases. The data acquisition equipment collects the time, vehicle speed and RPM data during this process. The test is repeated in both directions, with at least three tests in each direction. D) Data Processing: Export test data for each gear from the data acquisition equipment, including time, vehicle speed, and engine speed. Extract effective acceleration test data segments, extract acceleration data from them, perform polynomial fitting to obtain the fitted curve, and then differentiate the fitted curve to obtain the real-time acceleration during the acceleration process at the maximum throttle opening in each gear. Characterize the acceleration curve of each gear. Generate acceleration curves with vehicle speed as the abscissa to obtain the acceleration coincidence point of adjacent gears. Based on the acceleration coincidence point, determine the corresponding vehicle speed and engine speed at the time of gear shifting, so that the vehicle always maintains the maximum acceleration capability during the acceleration process, and at the same time, calculate the shortest time required for acceleration.

2. The vehicle acceleration performance testing and data processing method as described in claim 1, characterized in that: In step A), the test conditions include weather conditions, road conditions, fuel and lubricating oil, vehicle preparation, and vehicle preheating.

3. The vehicle acceleration performance testing and data processing method as described in claim 1, characterized in that: In step C), when the vehicle has a manual transmission, start the vehicle, put the manual transmission in 1st gear, release the accelerator, and drive the vehicle at the minimum stable speed of that gear. Quickly press the accelerator pedal to the maximum position, and stop when the vehicle speed no longer increases. Then put the manual transmission in other gears and repeat the test.

4. The method for testing and processing vehicle acceleration performance as described in claim 1, characterized in that: In step C), when the vehicle is an automatic transmission, when the vehicle is stationary, put the automatic transmission in D gear, release the accelerator to make the vehicle travel at the minimum stable speed of that gear, quickly press the accelerator pedal to the maximum position, and stop when the vehicle speed no longer increases.

5. The method for testing and processing vehicle acceleration performance as described in claim 4, characterized in that: Select Sport mode for the automatic transmission.

6. The method for testing and processing vehicle acceleration performance as described in claim 1, characterized in that: In step C), all electrical appliances and windows of the vehicle are turned off during the acceleration test.

7. The method for testing and processing vehicle acceleration performance as described in claim 1, characterized in that: In step D), the average acceleration curve for each gear is obtained by exporting test data from multiple tests.

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