A method and system for wind speed compensation during vehicle testing

Abstract

The present application relates to a kind of wind speed compensation method and system during vehicle testing, comprising the following steps: wind speed sensor is arranged in the set position of test vehicle, and road test is carried out, the wind speed following vehicle speed change value of different positions of test vehicle road test is obtained;Test vehicle is connected with chassis dynamometer, restores test vehicle in the wind speed sensor position determined in road test;Change the size of fan wind force, make the wind speed of different positions of test vehicle consistent with the wind speed obtained in road test.Make the wind speed of different positions of vehicle consistent with the wind speed collected in road test, both can improve the heat dissipation condition when vehicle test, can also carry out wind speed compensation to chassis dynamometer, so that test result is more accurate.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of vehicle testing, in particular to a wind speed compensation method and system during vehicle testing. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] Passenger vehicles need to be tested for their performance after being manufactured, and a chassis dynamometer is usually used to simulate the working conditions of the passenger vehicles running on the road. The chassis dynamometer is a device that is stationary on the ground, and it simulates the movement of the road relative to the vehicle by rotating the drum to perform the test, while in actual road tests, the vehicle moves longitudinally relative to the stationary road surface.

[0004] Therefore, when using a chassis dynamometer to simulate the test of a vehicle, since the vehicle does not move relative to the ground, there is no air flow around the vehicle participating in the test as there is on the actual road, so the heat generated by the vehicle during the test cannot be carried away by the flowing air, and compared with road tests, it is more likely to reach an overheating state of the engine, affecting its thermal load, fuel economy, and emission performance parameters, and also affecting the performance of parts and causing certain safety hazards.

[0005] To solve the above problems, the prior art arranges a cooling fan at the front of the vehicle participating in the test to form cooling during the chassis dynamometer test, but the body of the passenger vehicle is long, and the arrangement of the cooling fan at the front of the vehicle cannot make the flowing air reach the tail smoothly, so the cooling effect is limited. If multiple cooling fans are arranged at different positions of the vehicle, although the cooling effect can be ensured, too many fans will make the wind speed around the vehicle during the test of the vehicle performance using the chassis dynamometer chaotic, and unable to match the real wind speed on the actual road. SUMMARY

[0006] To solve the technical problems in the background art, the present application provides a wind speed compensation method and system during vehicle testing, which first performs a road test on a passenger vehicle to obtain the variation of the wind speed at each position of the vehicle with the vehicle speed during the road test, then fixes the vehicle on a chassis dynamometer to perform a road fitting test and a wind speed fitting test, restores the position of the wind speed sensor, changes the size of the wind force emitted by the fan around the vehicle, and makes the wind speed at different positions of the vehicle consistent with the wind speed collected during the road test, which can not only improve the cooling condition during the test of the vehicle, but also compensate for the wind speed of the chassis dynamometer, making the test result more accurate.

[0007] To achieve the above purpose, the present application adopts the following technical solutions:

[0008] The first aspect of the application provides a wind speed compensation method during vehicle testing, comprising the following steps:

[0009] Arranging wind speed sensors at set positions of the test vehicle, and performing a road test to obtain the change value of the wind speed following the vehicle speed at different positions of the test vehicle during the road test;

[0010] Connecting the test vehicle with a chassis dynamometer, and restoring the wind speed sensor positions of the test vehicle determined in the road test;

[0011] Changing the size of the wind force generated by the fan to make the wind speed at different positions of the test vehicle consistent with the wind speed obtained during the road test.

[0012] Arranging wind speed sensors at set positions of the test vehicle, specifically, arranging wind speed sensors at the positions of the vehicle head and the air inlet grille of the test vehicle.

[0013] The environmental conditions of the road test are that the longitudinal slope error of the test road surface is within ±0.1%, the relative humidity is less than 95%, the temperature is 0-40℃, the average wind speed at a position 1.6m above the test road surface is not greater than 3m / s, and the gust wind speed is not greater than 5m / s.

[0014] Performing the road test, specifically:

[0015] Driving the test vehicle at a set vehicle speed along the test road surface for a set time;

[0016] Placing the transmission of the test vehicle in "neutral" for coasting until the vehicle speed is less than V0;

[0017] Obtaining the time T1 required for the test vehicle to decelerate from the initial vehicle speed V1 to V2 through coasting, and V2 is not less than V0.

[0018] Repeating the road test in the opposite direction to obtain the time T2, and obtaining the average value of the required time.

[0019] Obtaining the resistance and power of the test vehicle according to the vehicle speed of the test vehicle and the average value of the time required for coasting to the set speed.

[0020] Obtaining the change value of the wind speed following the vehicle speed at different positions of the test vehicle during the road test, specifically: during the road test, obtaining the wind speed based on the wind speed sensors arranged at the set positions, and the wind speed changes following the vehicle speed.

[0021] Connecting the test vehicle with a chassis dynamometer, and restoring the wind speed sensor positions of the test vehicle determined in the road test, specifically: connecting the test vehicle to the roller of the chassis dynamometer, and the installation position of the wind speed sensor is consistent with the position of the wind speed sensor during the road test of the test vehicle.

[0022] The size of the fan is changed to make the wind speed at different positions of the test vehicle consistent with the wind speed obtained in the road test, and the specific method is as follows:

[0023] The road fitting test and the wind speed fitting test are performed on the test vehicle, the size of the fan is changed according to the wind speed obtained in the road test and the corresponding vehicle speed, and the wind speed at different positions of the test vehicle is consistent with the wind speed obtained in the road test.

[0024] The second aspect of the present application provides a system for implementing the above method, comprising:

[0025] The wind speed sensor is located at a set position of the test vehicle and is used to collect the wind speed at different positions of the test vehicle during the road test and the change value of the wind speed following the vehicle speed.

[0026] The chassis dynamometer is used to connect with the test vehicle and simulate the running of the test vehicle according to the vehicle speed of the test vehicle.

[0027] The cooling fan is located at a set position of the test vehicle and changes the wind size through the controller, so that the wind speed at different positions of the test vehicle is consistent with the wind speed collected in the road test.

[0028] Compared with the prior art, the above one or more technical solutions have the following beneficial effects:

[0029] 1. The wind speed value following the vehicle speed obtained in the road test is used to restore the corresponding wind speed according to the simulated vehicle speed during the related test of the chassis dynamometer, so that the wind speed compensation is performed on the key position of the vehicle, and the real road condition is approached.

[0030] 2. In the process of wind speed compensation, the wind speed is obtained from the road test, so that the heat dissipation of the test vehicle in the real road condition is simulated as much as possible, and the influence of the overheating of the parts in the traditional method is improved. DETAILED DESCRIPTION

[0031] The drawings accompanying the specification of the present application form a part of the present application and are used to provide a further understanding of the present application, the illustrative embodiments of the present application and the description thereof serve to explain the present application and do not constitute an improper limitation of the present application.

[0032] Fig. 1 is a wind speed compensation flowchart provided by one or more embodiments of the present application during vehicle testing;

[0033] Fig. 2 is a cooperation schematic diagram of the vehicle, the chassis dynamometer and the wind speed sensor during wind speed compensation provided by one or more embodiments of the present application;

[0034] In the figure: 1. Radiator fan; 2. Test bus; 3. Chassis dynamometer roller; 4. Vehicle head position wind speed sensor; 5. Wind speed sensor at air inlet grille. DETAILED DESCRIPTION

[0035] The application will be further described below in conjunction with the accompanying drawings and examples.

[0036] It should be noted that the following detailed description is exemplary in nature and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0037] It is to be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0038] The following examples give a wind speed compensation method and system during vehicle testing, first road test is performed on the passenger vehicle to obtain the wind speed variation of each position of the vehicle with vehicle speed during road test, when the vehicle is fixed on the chassis dynamometer for road fitting test and wind speed fitting test, the passenger vehicle is restored according to the position of the wind speed sensor during road test, and the power of the vehicle fan around the vehicle is changed according to the wind speed determined during road test and the vehicle speed obtained on the chassis dynamometer, so that the wind speed at different positions of the vehicle is consistent with the wind speed collected during road test, which can not only improve the heat dissipation during vehicle testing, but also compensate the wind speed of the chassis dynamometer, so that the test result is more accurate.

[0039] Example 1:

[0040] As shown in Figs. 1-2 A wind speed compensation method during vehicle testing, comprising the following steps:

[0041] Arranging wind speed sensors at the set positions of the test vehicle and performing road test to obtain the wind speed variation of different positions of the test vehicle with vehicle speed during road test;

[0042] The test vehicle is connected with the chassis dynamometer, and the test vehicle is restored at the wind speed sensor positions determined during road test.

[0043] The size of the fan wind force is changed to make the wind speed at different positions of the test vehicle consistent with the wind speed obtained during road test.

[0044] Specifically:

[0045] According to the requirements of road test, the wind speed sensor is installed at the set position of the passenger vehicle. The embodiment installs the wind speed sensor at the position of the vehicle head and the air inlet grille of the passenger vehicle, as shown in Fig. 2 The wind speed sensor 4 at the position of the vehicle head and the wind speed sensor 5 at the air inlet grille are shown.

[0046] According to the appendix C "determination of running resistance and simulation on the chassis dynamometer" in "GB / T 27840-2021 Measurement method for fuel consumption of heavy commercial vehicle", the road test is carried out, and the "sliding energy change method" is used to test the resistance of the vehicle when running on the test road. During the period, the change value of the wind speed following the vehicle speed at different positions of the vehicle during the road test is collected.

[0047] The same test passenger car 2 is subjected to road fitting test and wind speed fitting test, the test passenger car 2 is connected with the chassis dynamometer roller 3, and the test passenger car 2 is restored according to the position of the wind speed sensor determined during the road test. The embodiment also installs the wind speed sensor at the position of the vehicle head and the air inlet grille (as shown in Fig. 2 The wind speed sensor 4 at the position of the vehicle head and the wind speed sensor 5 at the air inlet grille are shown.

[0048] The wind speed at different positions of the test passenger car 2 at different speeds has been determined by road test, then the simulation speed of the test passenger car 2 on the chassis dynamometer is obtained, the cooling fan 1 is set at the required position (in this embodiment, it is set at the position of the vehicle head), the wind power generated by the controller is changed, so that the wind speed at different positions of the test passenger car 2 is consistent with the wind speed collected during the road test, thereby simulating the influence of air resistance on the test passenger car 2 under road test, restoring the wind speed at the key position of the vehicle, reducing the damage of the parts of the vehicle caused by overheating during the test, and improving the safety of the test.

[0049] The sliding energy change method can be used to test the influence of the resistance of the vehicle on the power during the road test, and the resistance under the test condition is derived from the air resistance and the friction between the tire and the ground. When the chassis dynamometer is used subsequently, since the vehicle is stationary relative to the ground, only the resistance caused by the friction between the tire and the ground can be simulated, and the resistance caused by the air flow is ignored. At the same time, since there is no air flow, the parts of the test vehicle are more likely to overheat. The embodiment uses the "wind speed value following the change of vehicle speed" obtained during the road test to restore the simulated speed and the "corresponding speed and wind speed during the road test" during the related test of the chassis dynamometer, thereby restoring the wind speed at the key position of the vehicle, which is closer to the real road condition, and simulates the real road condition to cool the test vehicle.

[0050] Embodiment two:

[0051] The system for realizing the above method comprises:

[0052] A wind speed sensor is arranged at a set position of the test vehicle to collect the wind speed and the change value of the vehicle speed at different positions of the test vehicle during the road test;

[0053] A chassis dynamometer is arranged to be connected with the test vehicle to simulate the running test vehicle according to the vehicle speed of the test vehicle;

[0054] A cooling fan is arranged at a set position of the test vehicle, and the wind power is changed by the controller to make the wind speed at different positions of the test vehicle consistent with the wind speed collected during the road test.

[0055] The above merely describes the preferred embodiments of the present application and is not intended to limit the present application. Various modifications and changes can be made by those skilled in the art. 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 wind speed compensation method during vehicle testing, characterized in that, Includes the following steps: Wind speed sensors were placed at designated locations on the test vehicle, and road tests were conducted to obtain the wind speed variation values ​​at different locations as the vehicle speed changed during the road test. The test vehicle is connected to the chassis dynamometer to restore the wind speed sensor position determined during the road test. Specifically, the test vehicle is connected to the rollers of the chassis dynamometer, and the installation position of the wind speed sensor is consistent with the position of the wind speed sensor during the road test. The fan's output power was adjusted to match the wind speed at different locations on the test vehicle with the wind speed obtained during the road test. Specifically, road fitting and wind speed fitting tests were performed on the test vehicle. Based on the wind speed and corresponding vehicle speed obtained during the road test, the fan's output power was adjusted to match the wind speed at different locations on the test vehicle with the wind speed obtained during the road test.

2. The wind speed compensation method during vehicle testing as described in claim 1, characterized in that, Wind speed sensors were placed at designated locations on the test vehicle, specifically at the front of the vehicle and at the air intake grille.

3. The wind speed compensation method during vehicle testing as described in claim 1, characterized in that, The environmental conditions for the road test are as follows: the longitudinal slope error of the test road surface is within ±0.1%, the relative humidity is less than 95%, the temperature is 0°C-40°C, the average wind speed at a height of 1.6m above the test road surface is no greater than 3m / s, and the gust wind speed is no greater than 5m / s.

4. The wind speed compensation method during vehicle testing as described in claim 3, characterized in that, Perform road tests, including: The test vehicle travels along the test road at a set speed for a set time. The test vehicle's transmission was placed in "neutral" and coasted until the vehicle speed was less than V0; Obtain the time T1 required for the test vehicle to decelerate from its initial speed V1 to V2 via coasting, where V2 is not less than V0.

5. The wind speed compensation method during vehicle testing as described in claim 4, characterized in that, Conducting road tests also includes: Repeat the road test in the opposite direction to obtain time T2, and get the average value of the required time.

6. The wind speed compensation method during vehicle testing as described in claim 5, characterized in that, The resistance and power of the test vehicle are obtained by averaging the vehicle speed and the time required to coast to the set speed.

7. The wind speed compensation method during vehicle testing as described in claim 1, characterized in that, The wind speed at different locations during the road test of the test vehicle is obtained as the vehicle speed changes. Specifically, during the road test, the wind speed is obtained based on the wind speed sensor placed at a set location, and the wind speed changes as the vehicle speed changes.

8. A system for implementing the method of any one of claims 1-7, comprising: The wind speed sensor is located at a designated position on the test bus and is used to collect the wind speed changes as the vehicle speed changes at different locations during road testing. The chassis dynamometer is used to connect to the test bus and simulate the operation of the test bus based on its speed. The cooling fan is located at a designated position on the test bus. The fan speed is adjusted by a controller to ensure that the wind speed at different locations on the test bus is consistent with the wind speed collected during the road test.

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