1 Scope
This document specifies an open-loop test method for the side-wind susceptibility test of vehicles with side-winds generated by fan equipment. This document applies to vehicles of category M,,N, also to passenger car trains, other types of vehicles may be referred to.
Note. The test conditions specified in this document do not represent real driving conditions and can be used to quantify the response of a vehicle subjected to a side wind. The sidewind conditions specified in this document are not a direct simulation of natural wind conditions.
The wind conditions specified in this document are not a direct simulation of natural wind conditions, and the wind speed specified is equivalent to the harsher conditions under natural conditions.
2 Normative references
The contents of the following documents constitute essential provisions of this document through normative references in the text. Among them, the date of the citation, only the date of the corresponding version applies to this document; do not note the date of the citation, its latest version (including all the revision of the list) applies to this document.
GB/T 3730.2-1996 Road Vehicle Quality Vocabulary and Codes (ISO 11761990,1DT)
ISO 8855 Road vehicles - Vehicle dynamics and road holding ability - Vocabulary
ISO 15037-112006 Road Vehicles - Urban Dynamics Test Methods - Part 1: Rondvehicles - Vehicle dynamics test method - Part 1: General conditions for passenger cars
Note: GB/T 40501-2021 General Conditions for Handling and Stability Test of Light Vehicles (ISO 15037-112019, MOD)
3 Terminology and definitions
The terms and definitions defined in ISO 8855 apply to this document.
4 Principles
The movement of a vehicle during travel is disturbed by side winds. The test method specified in this document quantitatively evaluates the side wind sensitivity of a vehicle by measuring a series of parameters that characterise the vehicle's performance in side wind conditions. This is achieved by driving the test vehicle along a straight path through a test area of sidewind generated by a wind turbine and measuring the response of the test vehicle. The steering wheel of the test vehicle is kept fixed if no special test is required.
Two methods of measuring lateral deflection are proposed in this document:
--Direct measurements, which measure the position of the vehicle or the track of the stain left on the road;
--indirect measurement, using the measured vehicle dynamic parameters for calculation.
5 Reference system
The reference system shall be selected in accordance with ISO 15037-1, 2006.
6 Measurement variables
The following variables shall be measured during the test
Not all variables are listed in this chapter
7 Measuring instruments
7.1 General rules
The measurement variables listed in chapter 6 shall be measured by means of appropriate sensors and the time course of the gold shall be recorded by means of a time-based multi-channel recorder. Lateral deflections can be measured directly after the test is completed
Typical measurement ranges for combined sensors and recording systems and shake though large error values are shown in Table 1.
7.2 Sensor setup
7.2.1 General requirements
The requirements of 4.2 in ISO 15037-1:2006 shall be met.7.2.2 Measurement of lateral offset
Lateral deflection may be measured directly by suitable instrumentation or by dye tracing, or indirectly using numerical calculations (see 11.3.3). The dye tracing should be achieved on the test track by means of a water jet. The water jets should be located at a height of 0.02 m from the test surface and can be extended by flexible pipes.
The installation point of the water jets should be located close to the 2 axes of the intermediate coordinate system. If this is not possible, a correction can be made to obtain lateral acceleration data within the tolerance range.
7.3 Data processing
The recording system and data processing requirements contained in ISO 15037-1: 2006, 4.3 shall be complied with.
8 Test conditions
8.1 General requirements
The test conditions shall be in accordance with ISO 15037-1;2o06, 5.1 and 8.2 and 8.3 of this document, and any test deviations shall be recorded in the test report (see Appendix A) together with a graphical description of the respective results (see Appendix B).
8.2 Test paths
The test shall be carried out on an evenly hardened, clean and uncontaminated bath surface. The transverse slope of the test road and the longitudinal slope between any 50 m intervals shall be less than 2.5%.
The test road surface shall be a flat asphalt or concrete surface or other high friction surface.
The test road shall have a width of not less than 5 m from at least 100 m in front of the side wind zone to 100 m behind the side wind zone.
In addition to the specified test road conditions, the test road shall have an adequate buffer zone. 8.3 Climatic conditions
The ambient wind speed should be as low as possible during the test and should not exceed 3 m/s in any direction.
The climatic conditions shall be recorded in the test report (see Appendix A).
8.4 Test vehicle
The requirements of 5.4 of ISO 15037-1, 2006 shall be met.
8.5 Vehicle load conditions
8.5.1 General requirements
The test shall be carried out under the minimum load condition defined in 8.5.2 and the maximum load condition defined in 8.5.3, or under other load conditions as required.
The maximum permissible total mass and maximum permissible shaft load, as defined in 4.8 and 4.13 of GB/T 3730.2-1996, shall not be exceeded.
9 Fan equipment
The side wind for the test shall be generated by the fan equipment and shall have an average wind speed of 20 m/s to 3 m/s (under conditions where the ambient wind speed is less than 1 m/s). The profile for calculating the average wind speed shall be along the reference travel line, covering the length of the side wind zone and the height of the test vehicle. The nominal wind angle relative to the reference driving line and the wind speed profile covering the entire length and height range of the side wind zone should be recorded in the test report (see Appendix A). The nominal length of the side wind zone is generally determined by the fan array, which should be not less than 15 m and preferably greater than 25 m, and the nominal length of the side wind zone should be recorded in the test report (see Appendix A).
10 Test procedure
10.1 Preheating
The requirements of 6.1 of ISO 15037-1 ,2006 shall be met.
10.2 Test speed
The test speed is defined as the longitudinal nominal speed, the standard test speed being 100 km/h. Other test speeds may be used, but a step size of 20 km/h is desirable.
During the test, the tolerance of the longitudinal speed before the start of the side wind zone x. shall be within 2 km/h. After the start of the side wind zone x, the accelerator pedal shall be fixed.
10.3 Driving operation
The test shall be carried out with the vehicle driven along the reference line (straight line), with steering corrections allowed to keep the vehicle on the reference line as it approaches the side wind zone. However, the steering wheel shall remain stationary between the point x. 40 m before the start of the side wind zone (see Figure 1) and the point x. 2 s after the start at test speed.
The steering wheel should remain fixed until the vehicle has passed the point of the side wind zone. The difference between the maximum value of the steering wheel angle and the average value should not exceed 2° before the vehicle passes through the side wind zone. It is advisable to fix the steering wheel with an aid that will improve the quality of the test.
10.4 Number of tests
The test shall be carried out not less than 5 times -
10.5 Measurement of lateral position points using the dye tracer method
10.6 Data selection
If the lateral position of the test vehicle changes by more than 0.2 m between 40 m before the start of the lateral wind zone and the start of the lateral wind zone", this data should be excluded to reduce the calculation error caused by the initial conditions.
Note: At this stage, on-board sensors for measuring vehicle position are not as widely available and reliable; therefore it is up to the test observer to decide whether the results of each test round are within the permissible range.
The results of each round can therefore be determined by the test observer to be within the permissible range.
11 Data analysis
11.1 General requirements
Test results should be recorded as peaks or pulses (see Figure 2), if peaks are used, the bandwidth of the measurement system should be taken into account.
11.2 Angular velocity and lateral acceleration of the pendulum
The angular velocity and lateral acceleration of the pendulum are recorded as shown in Appendix B.
If the pulsed values of the angular velocity and lateral acceleration are required, the pulsed values are defined as the average signal value during the period when the signal value exceeds 50% of the peak value (see Figure 2).
11.3 Lateral excursions
11.3.1 General requirements
The lateral offset can be determined by direct measurement of the stained trace or by numerical calculation.
11.3.2 Stain tracing method
The stain tracer method measures the lateral offset by means of the stain trajectory left on the road surface, i.e. the offset at the point of travel at test speed after 2 s from the start of the side wind zone. This lateral offset requires the acquisition of the vertical distance of the stain track from a reference line.
The reference line shall be a line fitting the position of the vehicle at three measurement points including the start of the side wind zone and the measurement point ahead of it.
12 Test report
The test data shall be recorded in the form of a test record as shown in Appendix B.
The course of all the variables listed in Appendix B shall be charted over time in the form of Figure B1. If the test consists of different test vehicle speeds, the data shall be recorded and charted in the form of Figure B.2.
Appendix A (informative) test records
Appendix B (normative) Description of test report results
1 Scope
2 Normative references
3 Terminology and definitions
4 Principles
5 Reference system
6 Measurement variables
7 Measuring instruments
8 Test conditions
9 Fan equipment
10 Test procedure
11 Data analysis
12 Test report
Appendix A (informative) test records
Appendix B (normative) Description of test report results
