| In this paper, an automobile braking dynamic model,a tire math model and a brake math model are built. An automobile's braking trajectory is simulated, by using MATLAB. Automobile's braking performance experiment on road is designed. The experiment data is fitted by both linear fitting method and quadratic fitting method. Using quadratic fitting curve as the automobile's braking trajectory to compare with the simulation curve. The result shows that simulation result can basically reflect automobile's actual braking trajectory. It also indicates that the math model built is accurate, which can reflect automobile's braking state. Theoretical basis is established for the automobile's brake trajectory test technology.The basic theory of automobile's braking trajectory test is educed: by collecting longitudinal force, lateral force and vertical load of the tire and figuring out longitudinal displacement and lateral displacement of the automobile, the automobile's braking trajectory is obtained. Longitudinal force, lateral force and vertical load's test principle is built.Structure and size of the test flat is designed, material of the test flat is selected and intensity of the test flat is checked. The sensor which is used to collect data is selected. Data collecting system is designed. The system adopts analog signals input modules to collect data and serial communication to transmit data. Basic principle of serial communication and connection method of analog signals input modules is introduced.Automobile's braking trajectory test equipment's software system is designed. To prevent software being copied or modified, logging in system is designed. The data collected by hardware is figures that can not give us visual impression, so braking trajectory test system is designed. Its function is to display the data collected in the form. It can display automobile's longitudinal displacement, lateral displacement and braking trajectory 's numerical value and real time curve.
|
PDF Full Text Request