Research On Brake Force Assisting Technology For Automotive Electronic Stability Control System

With the continuous development of automotive technology,people pay more and more attention to driving safety and pedestrian safety,and promote the continuous innovation of active safety technology.Automotive electronic stability control system is one of the hotspots in active safety of automobiles today.It can control the vehicle to make it in a stable driving state.Now it has been widely applied to all kinds of vehicles.The matching rate of ESC in domestic cars has increased year by year,and has almost become a standard function.Therefore,various value-added functions based on the ESC hydraulic circuit system have emerged as the times require,such as hydraulic brake assist(HBA),hill descent control(HDC),automatic vehicle hold(AVH),autonomous emergency braking(AEB),and hill hold control(HHC),more than ten functions.The realization of these value-added systems mentioned above is based on the active pressurization function of the ESC hydraulic circuit system.Brake force assisting technology can assist drivers to control vehicle during braking and driving through active pressurization,which plays an irreplaceable role in reducing the possibility of accidents and reducing the severity of accidents.Brake force assisting technology has very important significance.The research of brake force assisting technology in this paper mainly includes the realization of two functions,hydraulic brake assist and hill descent control.The main research contents are as follows:Firstly,the research of driver’s intention recognition and ramp recognition technology was carried out before the control strategy was designed.Secondly,the design of HBA and HDC control strategy is carried out by the combination of Matlab/Simulink and Stateflow state machine theory modeling.Thirdly,the feasibility of control strategy of HBA and HDC system is verified through the offline joint simulation method of CarSim and Simulink.According to the previous control strategy to build the control model in Simulink and set the corresponding vehicle model in CarSim.During the test,the driver’s emergency braking condition was set in CarSim to test the HBA function.When testing the HDC,different slopes were set in CarSim for testing.The simulation results show that the control strategy designed in this paper has achieved a good control effect.Then,the HIL test is carried out on the hardware in the loop test bench that is composed of the RapidECU rapid prototyping controller produced by Huahai Technologies Co.,Ltd.and the Simulator produced by dSPACE company.The control model built by Simulink will be imported into RapidECU,and the CarSim vehicle model will be downloaded to Simulator.The vehicle braking system is replaced by the brake system bench.The control strategy is optimized by testing the feasibility of the control strategy again by the hardware-in-the-loop simulation.Finally,the RapidECU is connected to the vehicle as a controller to carry out the real vehicle test to verify the control performance of the HBA control strategy on the real vehicle,and further optimize the control strategy.