Research On Vehicle Braking Distance Under Rainfall

When cars are driving on the road,various road conditions and sudden dangerous conditions will affect drivers' safety.For protecting driver safety,drivers need to have clear understanding of braking distance of cars.Because braking distance of cars are affected by their own mechanical systems and driving environment,braking distance in different driving environments varies widely.Therefore,research on braking distance of cars can help drivers to improve driving safety in some special environments,and it is significant to ensure the safety of drivers and people near cars.Because cars are affected by weather and road surfaces when it is raining,braking distance required is different from normal road conditions.This article mainly analyzes drivers' reaction time,road adhesion coefficient,and lack of visibility due to rainfall.It can effectively improve braking distance of cars under raining,reduce occurrence of traffic accidents,and protect drivers' life and property safety for internal and external personnel.Firstly,it analyzes the influence of various factors on the braking distance of the car during rainfall,including vehicle speed,water film thickness,tire performance.Through regression analysis of the adhesion coefficient under various working conditions,the regression model of automobile adhesion coefficient under rainfall conditions is obtained.By comparing with the existing theoretical model of adhesion coefficient,it is determined that the adhesion coefficient model obtained in this paper is available.The influencing factors adopted are driving speed,water film thickness,tire tread depth and tire flatness ratio.The model of the obtained adhesion coefficient is input into Car Sim and the relevant parameters of the vehicle are set for simulation test.The regression model of the braking distance of the vehicle is obtained by processing and analyzing the test data.Secondly,the existing driving data is processed and analyzed to determine the range of the driver reaction time when encountering unexpected situations;Based on the existing research results on driver response time,the effect of vehicle speed on driver's perceived reaction time is studied,and a model of driver's perceived reaction time is established.The relationship between visibility during rain and driver's sight distance judgment was also studied.A fuzzy reasoning method is used to establish a model for the driver's visual distance judgment error.Finally,based on drivers' reaction time model,braking distance model,and drivers' line-of-sight judgment error model under rain conditions,a joint simulation model are built using Simulink and Car Sim software to establish the driver's safe braking distance model under rain model.The analysis of the simulation results shows that joint simulation model built in this paper is effective.The research content of this paper can be used to calculate the safe braking distance required by the driver under rain conditions,and provide important theoretical reference and guidance for the driver's driving safety under rain conditions.