| With the rapid growth of the domestic auto industry, for requirements about automotive safety performance become more and more important. Meanwhile, automobile safety testing on a regular basis has become a necessary mean to ensure the safety of urban traffic. However, vehicle safety and braking performance is a Key performance indicator of testing automobile safety. Therefore, more accurate in the detection and faster testing vehicle braking performance is of great significance.Currently, most car performance detection station used plat brake rig and scroll brake rig to combine together to detect automotive brake performance, but compare this two type rigs, in term of time, the former will save more. During testing, it is more close to the car’s real status. It has high efficiency and true brake facts and so on. But when used in had found following insufficient that when measurement sector in on its measurement verification found when calibrated the brake force, the effect would be more larger by additional vertical load. The force sensor sometimes increased and sometimes decreased. At some points the next, for example 600 KN calibration point, when a 500 kg wheel acting on the tester surface, the measurement sensor showing the value 600KN-20 KN, and calibrating sensor showing the value 600KN+10KN, caused by additional vertical load 500 kg error rate is 5%, and out of calibration range which is 3%. So additional vertical load on the board has impacted force sensor, and when doing the vehicle braking performance test, the wheel load acting on the plats will give rise to measurement errors, that can affect the measurement accuracy, and the paper mainly has done some experimental research on this problem.The article experimental research work relies on the existing motor vehicle testing stations. The paper mainly choose two typically manufactures’ plat brake testers to do the experiment. The differences of two manufacturers on the structure and the way to measure the force, one is pulling way and another is pressure measurement. The objective is to explore the affect on the measurement accuracy under static load distribution of platform brake tester. And based on test results, provide a theoretical basis for improvement and design development of such equipment test data and recommendations.In the testing, we found that when perfoming calibration of braking, if test plats loaded at dirrerent locations, there will be indication of calibration instrument and measuring instrument resulting values change, and value changes are not synchronized, or increase or decrease in value. This apparent phenomenon shows the fact that loads affect the measurement accuracy does existing on the test of platform brake test.The paper focuses on the board’s structure and measurement system, and investigates the impact on measurement accuracy by loading. This required mapping existing platform brake test of the overall structure and measure the height sensor installation lacation, an installation height of the calibration device. Order for large deformation analysis of plate structures existed, and the bending by the height of force sensors and calibration sensors. Analyses of the methods used for this purpose are as follows:In the analysis, the paper use Solid Works and Simulation platform to build the content. First use the dimensional CAD software Solid Works to map the structure of platform brake testes. Then build dirfferent force analysis model to find effect factors. Second, mainly from platform brake test itself structure and strength aspects, to analysis load distribution and calibration structure on test precision of effect degree, through using Solid Works to mesh. At last, analysis experiment in the get of data, and compared experiment data and finite element data, find the main factors and stress concentration and structurally weak points, and give improvement suggestions. |
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