Method for generating actual road driving condition of motor vehicle

Abstract

The invention relates to a motor vehicle actual road driving condition generation method comprising the following steps: S1, obtaining actual road data, and constructing a fierce window used for selecting a fierce driving behavior in the actual road data; s2, processing the actual road data based on the intense window, obtaining an intense driving working condition point, and obtaining acceleration information of the intense driving working condition point; s3, carrying out expansion processing on the intense driving working condition point to obtain a new intense driving working condition point; s4, calculating an acceleration value of the new intense driving working condition point, judging whether the acceleration value exceeds an acceleration threshold value or not, if yes, returning to S3, and if not, entering S5; and S5, generating an intense driving working condition curve based on the new intense driving working condition point. The method has the remarkable advantages in the aspects of cost effectiveness, test efficiency, data accuracy, energy consumption and environmental protection.

Description

Technical Field

[0001] The present invention relates to the field of motor vehicle driving technology, and in particular to a method for generating actual road driving conditions of a motor vehicle. Background Art

[0002] The purpose of real-time driving emissions (RDE) testing is to evaluate the emission performance of a vehicle under actual road conditions to ensure that it meets relevant environmental protection standards. Traditional actual road testing methods mainly rely on field testing to collect data by installing a portable emission measurement system (PEMS) on the vehicle. However, this method has some limitations, including high cost, uncertainty in test conditions, and complexity in data collection. Therefore, the present invention proposes a method for generating actual road driving conditions for motor vehicles. Summary of the invention

[0003] The purpose of the present invention is to solve the limitations of the prior art and provide a method for generating actual road driving conditions of a motor vehicle.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] A method for generating actual road driving conditions of a motor vehicle, comprising:

[0006] S1. Acquire actual road data and construct an aggressive window, wherein the aggressive window is used to select aggressive driving behaviors in the actual road data;

[0007] S2. Processing the actual road data based on the intense window to obtain an intense driving condition point and acceleration information of the intense driving condition point;

[0008] S3, expanding the intense driving condition point to obtain a new intense driving condition point;

[0009] S4, calculating the acceleration value of the new intense driving condition point, and determining whether the acceleration value exceeds the acceleration threshold value, if so, returning to S3, if not, entering S5;

[0010] S5. Generate an intense driving condition curve based on the new intense driving condition point.

[0011] Optionally, constructing the intense window in S1 includes:

[0012] Set limits for aggressive driving behavior and benchmarks for world light vehicle test procedures;

[0013] The aggressive window is constructed by taking the aggressive driving behavior limit line and the world light vehicle test procedure baseline as the upper limit and the lower limit respectively.

[0014] Optionally, the step of processing the actual road data based on the intense window in S2 to obtain an intense driving condition point and obtain acceleration information of the intense driving condition point includes:

[0015] Preprocessing the actual road data;

[0016] Placing the intense window and the actual road data after preprocessing in the same coordinate system, obtaining a vv·a coordinate system scatter plot, where v is velocity and a is acceleration;

[0017] The points in the vv·a coordinate system scatter diagram that fall within the intense window are output as intense driving condition points, and the acceleration information of the intense driving condition points is extracted.

[0018] Optionally, preprocessing the actual road data includes: performing unit conversion and calculation on the actual road data to obtain speed and acceleration.

[0019] Optionally, the expansion processing of the intense driving condition points in S3 includes: performing random number interpolation expansion processing on the intense driving condition points.

[0020] Optionally, the acceleration threshold in S4 is the maximum acceleration value in the acceleration information of the intense driving condition point.

[0021] Optionally, the intense driving condition curve in S5 is obtained by fitting based on the new intense driving condition point, with time as the horizontal coordinate and speed as the vertical coordinate.

[0022] The beneficial effects of the present invention are:

[0023] The invention improves cost-effectiveness, and can use the new working condition extracted and generated by the program to test the vehicle. The new working condition combined with the WLTC working condition is the actual road test working condition of the vehicle, and the new working condition is tested on the bench, so the cost required for the test can be reduced.

[0024] The test efficiency and flexibility of the present invention are greatly improved. Using the intense driving condition extraction and new condition generation program, researchers can quickly adjust the test parameters to explore the vehicle's carbon dioxide emission performance, fuel consumption and power consumption under different conditions.

[0025] The present invention uses a new operating condition to provide a way to study the operating conditions of actual road fuel consumption and power consumption measurement of existing fuel vehicles, electric vehicles, and hybrid vehicles.

[0026] The present invention has a more obvious role in promoting environmental protection. By analyzing intense driving conditions, it can help manufacturers more effectively evaluate and improve the environmental performance of vehicles, thereby reducing emissions in actual road use. This is of great significance for responding to global environmental challenges and reducing the impact of transportation on the environment.

[0027] In summary, the present invention uses intense driving condition extraction and new condition generation procedures, compared with traditional actual road testing, and shows significant advantages in cost-effectiveness, test efficiency, data accuracy, energy consumption and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 A flow chart of a method for generating actual road driving conditions of a motor vehicle according to an embodiment of the present invention;

[0030] Figure 2 is a vv·a coordinate system scatter diagram of an intense driving condition point according to an embodiment of the present invention;

[0031] Figure 3 A curve diagram of a new intense driving condition point according to an embodiment of the present invention;

[0032] Figure 4 This is an application control panel interface of an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] This embodiment provides a method for generating actual road driving conditions of a motor vehicle, such as Figure 1 As shown, including:

[0036] S1. Acquire actual road data and construct an aggressive window, wherein the aggressive window is used to select aggressive driving behaviors in the actual road data;

[0037] S2. Processing the actual road data based on the intense window to obtain an intense driving condition point and acceleration information of the intense driving condition point;

[0038] S3, expanding the intense driving condition point to obtain a new intense driving condition point;

[0039] S4, calculating the acceleration value of the new intense driving condition point, and determining whether the acceleration value exceeds the acceleration threshold value, if so, returning to S3, if not, entering S5;

[0040] S5. Generate an intense driving condition curve based on the new intense driving condition point.

[0041] Specifically, the intense driving condition extraction and new condition generation process of this embodiment shows significant advantages in cost-effectiveness, test efficiency, data accuracy, energy consumption and environmental protection compared to traditional actual road testing.

[0042] Furthermore, constructing the intense window in S1 includes:

[0043] Set limits for aggressive driving behavior and benchmarks for world light vehicle test procedures;

[0044] The aggressive window is constructed by taking the aggressive driving behavior limit line and the world light vehicle test procedure baseline as the upper limit and the lower limit respectively.

[0045] Specifically, the 95th percentile value v·a of the product of vehicle speed and positive acceleration in a certain road speed group pos

[95] is a trip dynamics parameter for evaluating the intensity of driving. The larger the value, the more intense the driving. pos

[95] Verification line, as the limit line for aggressive driving behavior (v·a pos

[95] limit line); at the same time, referring to the baseline of the World Light Vehicle Test Procedure (WLTC), the aggressive driving behavior limit line and the World Light Vehicle Test Procedure baseline are used as the upper and lower limits respectively to construct the aggressive window.

[0046] Below the WTLC baseline, it is a normal window; WTLC baseline and stroke dynamics v·a pos

[95] The limit line is the intense window; stroke dynamics v·a pos

[95] Above the limit line is the abnormal window.

[0047] Furthermore, the processing of the actual road data based on the intense window in S2 to obtain an intense driving condition point and obtain acceleration information of the intense driving condition point includes:

[0048] Preprocessing the actual road data;

[0049] Placing the intense window and the actual road data after preprocessing in the same coordinate system, obtaining a vv·a coordinate system scatter plot, where v is velocity and a is acceleration;

[0050] The points in the vv·a coordinate system scatter diagram that fall within the intense window are output as intense driving condition points, and the acceleration information of the intense driving condition points is extracted.

[0051] The preprocessing of the actual road data includes: performing unit conversion and calculation on the actual road data to obtain speed and acceleration.

[0052] Specifically, this embodiment uses an intense window to extract the intense driving condition points from the processed actual road data, places the actual road data and the intense window in the same coordinate system, and uses a data processing algorithm to convert and calculate the original actual road test data to obtain a scatter plot in the va·v coordinate system, such as Figure 2 As shown in the figure, it can be seen that among all the actual road conditions, a part of them fall within the intense window. Using the window internal point extraction function, all the intense driving points are output to obtain the intense driving conditions.

[0053] Furthermore, the expansion processing of the intense driving condition point in S3 includes: performing random number interpolation expansion processing on the intense driving condition point. The acceleration threshold in S4 is the maximum acceleration value in the acceleration information of the intense driving condition point. The intense driving condition curve in S5 is obtained by fitting based on the new intense driving condition point, with time as the horizontal coordinate and speed as the vertical coordinate.

[0054] Specifically, since each point in the working condition has speed and acceleration information, if it is directly fitted, the local acceleration in the new working condition curve may be greater than the maximum acceleration in the intense driving point; and for different actual road tests, the length of the intense driving data included is also inconsistent, so it is necessary to expand the data of the extracted intense driving points to obtain new intense driving conditions that can be actually tested.

[0055] When expanding data, first of all, it is necessary to ensure that the inserted speed points are random and the speed range does not exceed the maximum and minimum values ​​in the intense driving condition points; secondly, it is necessary to verify the acceleration of the new intense driving condition after the insertion point to ensure that the acceleration value of the new condition does not exceed the maximum value in the intense driving condition point; finally, it is necessary to ensure that the length of the data after interpolation is consistent and generate new intense driving condition points with time as the horizontal axis and speed as the vertical axis.

[0056] After completing the interpolation processing in S3-S4, the new intense driving condition point is fitted using the fitting function in MATLAB to obtain a curve graph of the new intense driving condition point, such as Figure 3 shown.

[0057] Furthermore, this embodiment develops an application program for the above technical solution, and the control panel interface during the use of the application program is as follows: Figure 4 As shown, after obtaining the original data of the actual road, the data containing only the speed is imported into the program. First, the program will preprocess the speed data to obtain the speed, acceleration, v·a and other information of each point in the actual road test; then the intense window internal point extraction function in the program will extract the intense driving condition points in the test; next, the program will perform data interpolation, expansion and fitting on the extracted intense driving condition points according to the user's needs to obtain new intense driving conditions; finally, the user can obtain the intense driving condition points and the interpolated data through the control panel.

[0058] The embodiments described above are only descriptions of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for generating actual road driving conditions of a motor vehicle, characterized in that: include: S1. Acquire actual road data and construct an aggressive window, wherein the aggressive window is used to select aggressive driving behaviors in the actual road data; S2. Processing the actual road data based on the intense window to obtain an intense driving condition point and acceleration information of the intense driving condition point; S3, expanding the intense driving condition point to obtain a new intense driving condition point; S4, calculating the acceleration value of the new intense driving condition point, and determining whether the acceleration value exceeds the acceleration threshold value, if so, returning to S3, if not, entering S5; S5. Generate an intense driving condition curve based on the new intense driving condition point.

2. The method for generating actual road driving conditions of a motor vehicle according to claim 1, characterized in that: The constructing of the intense window in S1 includes: Set limits for aggressive driving behavior and benchmarks for world light vehicle test procedures; The aggressive window is constructed by taking the aggressive driving behavior limit line and the world light vehicle test procedure baseline as the upper limit and the lower limit respectively.

3. The method for generating actual road driving conditions of a motor vehicle according to claim 1, characterized in that: The step S2 of processing the actual road data based on the intense window to obtain an intense driving condition point and obtain acceleration information of the intense driving condition point includes: Preprocessing the actual road data; Placing the intense window and the actual road data after preprocessing in the same coordinate system, obtaining a vv·a coordinate system scatter plot, where v is velocity and a is acceleration; The points in the vv·a coordinate system scatter diagram that fall within the intense window are output as intense driving condition points, and the acceleration information of the intense driving condition points is extracted.

4. The method for generating actual road driving conditions of a motor vehicle according to claim 3, characterized in that: Preprocessing the actual road data includes: performing unit conversion and calculation on the actual road data to obtain speed and acceleration.

5. The method for generating actual road driving conditions of a motor vehicle according to claim 1, characterized in that: The expansion processing of the intense driving condition point in S3 includes: performing random number interpolation expansion processing on the intense driving condition point.

6. The method for generating actual road driving conditions of a motor vehicle according to claim 1, characterized in that: The acceleration threshold in S4 is the maximum acceleration value in the acceleration information of the intense driving condition point.

7. The method for generating actual road driving conditions of a motor vehicle according to claim 1, characterized in that: The intense driving condition curve in S5 is obtained by fitting based on the new intense driving condition point, with time as the horizontal coordinate and speed as the vertical coordinate.

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