| With rapid developments of China’s automobile industry and the rapid increase innumber of cars, China’s energy and environment face serious challenges. Since electricvehicles can meet the comprehensive requirements of the vehicle such as low-emission,zero emission and low fuel consumption, development of new energy vehicles such aselectric vehicles has become an inevitable choice for sustainable development of theauto industry and it is also important direction of technical innovation for automotiveindustries. Regenerative braking of electric vehicle is one of the key technologies of theautomotive energy-saving and environmental protection.Regenerative braking system of electric vehicle is a dynamic transformation underconditions of several targets system, the premise of maximize the recovery of brakingenergy under conditions of safety braking is the excellent Electro-hydraulic brakingsystem and integrated control strategy.Electric vehicle of xiaokang is selected to be study in this paper, in order toimprove the recovery of braking energy under constraints of ensuring good brakingperformance, a system of electro-hydraulic braking system for electricity vehicle is putforward. Theory analysis and modeling, co-simulation and performance evaluation ofthe electro-hydraulic braking system is completed. The main tasks are as follows:①In order to meet the coordination control requirements of the mechanismhydraulic braking force and electrical braking force, electro-hydraulic braking system ofelectric vehicles based on the ABS hardware is supposed on the basis of design analysisof the function of ABS anti-lock braking system in traditional cars. The system useshigh-speed switching valve of the ABS to adjusts braking pressure in the front wheel,power source of the front-wheel braking system is back-pump of the ABS, interface ofbrake master cylinder in front-wheel braking system is connected to a stroke simulator,the system can meet the braking needs of electric vehicles in every braking mode,achieving the pressure coordinate control and braking force distribution in all workingmode.②Key components of the Electro-hydraulic braking system is established basedon AMEsim simulation platform, static and dynamic characteristics analysis of the keycomponents is also completed; Simulation model of electro-hydraulic braking system isfinished at last, static and dynamic characteristics analysis of the system is completed, functional simulation based on the parallel braking force distribution strategy isestablished at last.③To maximize the recovery of braking energy and meet needs of the brakingsafety at the same time, threshold of braking intensity is determined by the analysis ofpower distribution on front and rear axle, braking regulations and braking dynamicsanalysis of the electric vehicle, control strategy of braking force distribution in lowbraking intensity and high braking intensity is formulated; through the process analysisof the ABS antilock braking, ABS antilock braking control strategy based on the logicthreshold,coordinate control strategy of regenerative braking and ABS anti-lockbraking is established at the same time.④In order to meet the simulation platform requirement of the Electro-hydraulicbraking system and pressure coordinate control strategy of braking system. AMEsimand Matlab/Simulink co-simulation platform is proposed to solve the problem,structure program based on co-simulation platform is presented, vehicle model, tire modeland the control strategy model is joint based on Matlab/Simulink/Stateflow; modelof pressure coordinate control system in AMEsim and control strategy model in Matlabis combined, electro-hydraulic braking system based on co-simulation platform is built.⑤On different braking intensity and road conditions, off-line simulation analysisfor the energy recovery effect and the braking performance of the new electro-hydraulicbraking system and control strategies designed above is completed based on AMEsimand Matlab co-simulation platform.Simulation studies and research of the Electro-hydraulic braking technology and itscontrol strategy researched in this paper provide some theoretical basis and technicalreference for electric vehicle; it is of great practical significance for development ofelectric vehicle. |
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