Research On Brake Assist System Based On Brake Level Identification

In recent years,with the number of car ownership has exploded,the incidence of traffic accidents has also shown a rapid growth trend,which has caused widespread concern in society.There are many causes of traffic accidents in actual driving conditions according to statistics from the traffic department,it is found that the wrong driving operation of the driver is the most important cause of many accidents.Therefore,reducing driver errors and improving the active safety of cars have become the key research content of technological innovation of vehicles.Advanced Driving Assistance System(ADAS for short)is an intelligent system that replaces the driver with a computer system to make driving decisions.Its main implementation method is to rely on artificial intelligence,visual perception and positioning systems to work together to realize automobiles intelligent driving.ADAS mainly includes lane line maintenance,automatic parking,driving assistance systems,and brake assistance systems.Therefore,the research of ADAS is of great significance to eliminate driver operation errors and reduce the occurrence of traffic accidents.In order to reduce the driver's driving mistakes and operational burden,this paper has carried out research on the key technologies of the new brake assist system based on brake level identification with intelligent driving technology and ADAS as the background.The main research contents are as follows:1)The basic composition and work plan of the brake assist system are studied.Through the theoretical study of the brake-by-wire,this paper studies the brake assist system based on the electric power-assisted hydraulic brake system,and formulates the brake assist system structure plan and its braking plan.2)Established the control strategy of the brake assist system.Taking the vehicle driving data collected from the actual vehicle road experiment as a sample,the speed and acceleration are divided into different states through the Markov chain and the acceleration state transition probability matrix is calculated to realize the prediction of acceleration;a braking level identification fuzzy controller with acceleration and slip rate as input and braking level as output is designed and the critical braking level is set to divide the braking conditions into two types: normal braking and emergency braking,the target braking pressure and target motor torque of the two braking conditions are calculated respectively and send the brake pressure control signal to achieve braking demand.3)A simulation model of the brake assist system is established.Simulation models such as acceleration prediction model,brake level identification fuzzy controller and target motor torque calculation model are established in MATLAB / Simulink and a simulation model of the electric power assisted hydraulic braking system actuator is established in AMEsim,the feasibility of the brake assist system was verified by Simulink-AMEsim joint simulation experiment.The simulation experiment results show that the designed acceleration prediction model can accurately predict the next acceleration change and the braking level identification fuzzy controller can quickly and accurately identify the braking level.The designed braking system has better pressure-following response characteristics under normal braking conditions and the better stability control effect in emergency braking conditions prove the feasibility of the brake assist system in this paper and provide a certain theoretical basis for the study of new driving assistance systems.