| Abstract [eng] |
Fast and efficient car braking is one of the key aspects in road safety, where automobile braking must ensure fast stopping at the appearing of the obstacle. In the master thesis is analyzed what determines the braking distance. Research was made of the scientific literature, presented the analysis of the braking systems, comparison of different braking systems, presented their advantages and disadvantages, as well described the requirements for the braking systems. Investigation was made for describing braking distance which depends on the road traction under different weather conditions. It is also analyzed the influence of different types of tires on different road surfaces. Experiments are conducted with using three multi vans with similar mass, research was made by using decelerometer. It is analyzed how the automobile speed has effect on braking distance. Braking distance was studied depending on the stopping with ABS and without it. The theoretical calculations are made and the results are compared with the results of experimental braking. The results shown that the results are similar with the experimental braking without usage of ABS, however the experimental result with usage of ABS were considerably smaller. In the experimental research, the values of braking deceleration are evaluated and graphically presented. The results of the research shown that vehicle speed and adhesion of the wheel and road surface have the greatest influence on braking distance. After research was done using summer and winter tires on dry road surface, the results shown that braking with summer tires is more effective and the braking distance is less than 10 percent. In all cases results shown that braking with the usage of ABS is more effective and the distance is shorter than 25 percent. Summarizing the study and presenting the conclusions the main determinants are described of the braking system. |
