Test Analysis And Simulation Research On The Lack Of Low Speed Brake Force In High Altitude Area

The high altitude,thin air and poor road conditions in Tibetan areas,which make a bad engine combustion and short life of vehicle parts,increase traffic safety risks.Statistics show that the country's total number of traffic accidents has been declining every year,while the number of traffic accidents in Tibet is increasing each year.The vehicle problem is becoming more and more obvious in high-altitude adaptability.The number of major accidents in Tibet every year and the property losses in accidents are far exceeding the national average,of which were caused by braking system problems in a large part.So it is of great significance studying on the vehicle brake system attenuation for improving the vehicle safety on the plateau regions.In this paper,a shortage of low-speed brake booster phenomenon in the plateau area was studied,combined with the structure and working principle of vacuum booster and requirements for vehicle safety from the plateau climate condition.Influencing factors were analyzed and improvement plans were presented from different angles.A simulation software AMESim was introduced into the research help cutting the study cost and time period.Based on the software,the simulation models of vacuum booster and corresponding improvement systems were built to explore the effectiveness of different improvement scheme.The effectiveness of different improvements were analyzed on the output comparison of corresponding improvement systems which using a low vacuum level as the simulation input.In order to realize details about the vehicle braking performance at low speed in plateau region,I carry out the real vehicle brake test at low speed in plateau area,and.In order to explore the specific braking condition which has a more possibility for brake booster power shortage problem,5 experiment schemes were put forward simulating different braking conditions.Finally,The results of comparison test between the car A and B showed the effectiveness of a certain improvement scheme.According to the comparison between simulation data and experimental data,the improvement scheme has obvious improvement effect on the vehicle braking performance at low speed braking conditions,and effectively improves the overall level of the vacuum line and vacuum recovery rate in the vacuum booster.Study on the improvement of this article on vacuum assist brake system,can provide references to the design and modification work improving the braking stability of plateau vehicle for the relevant enterprises.