Research On Design And Simulation Of The Mechanical Emergency Brake Assist System For Sedan

With an increasing number of the vehicle population, the low security can’t satisfypeople’s high demands any more. The vast majority of drivers are not able to step onbreak pedal at once or hesitate over braking in case of emergency resulting in increasingbraking distance. Emergency brake assist, as one of the active safeties, can settle theproblem that deficiency of pedal effort or hesitating over braking. Therefore, emergencybrake assist plays an indispensable role in reducing braking distance as well as improvingdriving safety.The paper in study of emergency brake assist based on a project introduces amechanical emergency brake assist through upgrading the common vacuum booster, andcontains simulation study. The main points are as follows:1. Represents the working principle of vacuum booster, simplies the structure based onthe simulation platform, studies force analysis of part of the structure, and establishes themodal of vacuum booster via AMESim. The results indicate that the trend of input andoutput simulation curve is basically identical with the experiment curve. Therefore, it canrealize input and output characteristics from vacuum booster via AMESim.2. Represents the structure and working principle of emergency brake assist based oncommon vacuum booster, designs the key parts for brake assist, confirms the designprinciple and span of parameters respectively, and then checks them kinematically anddynamically according to the working principle of brake assist.3. Simplies the structure of brake assist after confirming mechanical brake assist. Then,it confirms the method in studying the characteristic of input and output, and meanwhilechooses parameters concerned and their span to design several experiment plans. The resultindicates that it’s necessary to consider the span of parameters given the significant effectof pretightening forces on return spring of brake master cylinder and piston push rod onoutput force. 4. Sets up dynamical modal in CarSim and combines brake assist in Simulink withCarSim. In hard braking cars with BA need shorter braking time than those without BA infour cases that is high attachment coefficient road, middle attachment coefficient road, lowattachment coefficient road, split cohesion coefficient road and rough road.