Research On Braking Control Of Electric Vehicle Assisted Driving System Considering Energy Recovery

In order to improve the comprehensive performance of the assisted driving system of battery electric vehicle,this dissertation analyzed the requirements of system distance strategy,braking recovery and multi-objective optimization with the goal of improving the following,economy,safety and comfort of the system,and studied the assisted driving system research.First of all,this dissertation took ‘perception,decision-making and control' as the main idea and combined with hierarchical control to design the overall architecture of the assisted driving system.The multi-mode controller was designed by method of fuzzy control,and the corresponding constraint range was designed for each mode.Secondly,high-precision battery electric vehicle model was established in AMESim.At the same time,the VCU model of assisted driving system was established in Simulink,thus the AMESim & Simulink co-simulation platform was built.Thirdly,variable time headway strategy was established based on a simple road adhesion coefficient recognition algorithm and relative motion information.The safety distance model was built through the dynamic analysis of emergent condition.Moreover,this dissertation designed the braking force distribution strategy under multi-source information fusion framework.An adaptive model predictive controller was built under the model predictive control framework,and a fuzzy controller was designed based on the real-time relative motion information to make real-time decision and optimize the weight coefficients of control targets.Finally,the simulation and real driving experiments were carried out on the AMESim & Simulink co-simulation platform and HIL experimental platform.Results showed that the proposed variable timeheadway strategy can update the desired inter-distance in real time according to the relative motion information,and real-time performance was effectively improved.At the same time,the adaptive weight optimization strategy can adjust the control target weight timely,which improves the robustness of the system.The proposed braking force distribution strategy can provide more recovery energy and significantly improve the economy of the system.