Study Of Dynamic Inspection Method Based On The Vehicle Center Of Gravity Position In The Braking Process

By statistics from a large number of vehicle accidents, it is found that vehicle rollover accidents in all traffic accidents are the most destructive and have the highest casualty rates. The reasons of vehicle rollover in addition except for driver operational factors, special damage to the road, hill, corners and other natural causes, many parameter deviation of the vehicle is also a critical factor. Through the analysis of the rollover accident, under the same conditions, the greater the tread of vehicles and center of gravity, the easier the car will turn on side. It is involved in the most important basic parameters--the position of vehicle’s gravity in the vehicle, which includes the height of the vehicle and the plane coordinates. According to the law for the gravity center of the vehicle, GB has published and revised two times, but there has been no rapid, precise, effective method to detect vehicle center of gravity which is can not see, touch but important. From the point of view of theoretical research, At home and abroad, the main measuring methods include platform supporting force method, quality reaction method, suspension method, the method of swing, zero method etc, these are static measuring methods, measuring the location of the center of gravity is not same with dynamic vehicle real-time state change, do not consider Suspension Deformation effect, and also by the site requirements, equipment weight, high operation danger coefficient, measurement and calculation of slow etc. characteristics influence, measurement method of the center are difficult to be applied to the detection of reality. Domestic and foreign has also been studied by dynamic detection method, but they are very simple, without considering the influence of various factors, can not achieve a variety of models of universal detection.The starting point of this article:study a practical detection method in the combination of the usual research contents of the studying team with the purpose of intelligent, fast and precise detection.In this paper, the theoretic analysis of the vehicle braking state was carried out, and the3-dof kinematics model was set up and the vehicle center of gravity height calculation model was established. Through the data analysis of the axle weight and brake force change during the vehicle brake, the suspension vibration cycle and spring stiffness were calculated. Combining the calculating model, the real-time gravity center and height changes value, the height when the vehicle was static was calculated. By means of Matlab/Simulink platform, the simulation model of the dynamics analysis during vehicle braking was established, and the feasibility of dynamic detection method was verified by the simulation results. Based on the car flat plate braking platform, The measuring device for the wheelbase and axle base was designed, and a set of vehicle center of gravity dynamic detection system was designed, in order to extend the function of the flat plate braking platform, at the same time, the analysis and study on the was carried out the data acquisition, equipment calibration and software debugging. Finally, the dynamic test and static test was carried out and the repeatability of the vehicle dynamic result was analyzed. By comparison the experimental results, the factors leading to error were summarized, to verify the effective and accurate of the dynamic detection method for the gravity center and the practicability and reliability of the detecting system..