Research On Energy Recovery Control Strategy Of Electro-hydraulic Braking System

The layered control structure of the braking energy recovery control system is analyzed and determined,which is divided into the upper brake moment distribution layer and the lower actuator control layer.For the e-booster system of lower actuators,the double-closed-loop control structure of inner loop current control and outer loop torque control was adopted,and the motor vector control method was adopted to accelerate the response time of the e-booster system and realize the linear control of the brake fluid pressure by the e-booster system.In view of the upper brake torque and torque distribution between,comprehensive consideration of the electric car braking energy recovery speed tracking requirements,the maximum energy recovery needs,and braking safety performance requirements,to track the expected speed,maximum recycling energy and minimum slip rate as the goal,at the same time considering brake torque and torque constraints,described the upper moment distribution,multiple constraints has become a target for more than a rolling optimization problem,by solving optimization problem to realize the speed tracking,maximum energy recovery,and make sure the safety brake.The effectiveness of the upper control structure and control algorithm was verified by the vehicle e-booster electro-hydraulic braking energy recovery platform.Finally,in order to verify the validity of the braking energy recovery control system,set up in Matlab/Simulink on the lower level controller of braking energy recovery system with AMESim software simulation platform for joint simulation,select multiple sets of conditions,and without considering the lower actuator compared,analyzed the lower influence on the upper controller,actuator and to demonstrate the effectiveness of the lower level controller.In recent years,electric vehicles have been developed rapidly,and braking energy recovery has been widely studied as one of its key technologies.When the electric vehicle is braking,the driving motor is converted to the generator to output feedback torque for braking,generating electricity into the battery,so that the electric vehicle will be a part of the kinetic energy stored,increasing the range of the vehicle.How to realize the joint braking of the driving motor and the braking system according to the state information of the vehicle and the state of the battery to maximize the recovery of this part of energy and guarantee the braking performance is the focus of this paper.This paper is in the international(regional)cooperation and exchange key project of national natural science foundation of China(No.61520106008)"safety oriented rolling optimization of electric vehicle energy efficiency",Major projects of national natural science fund(No.61790564)"limit under the condition of automobile active safety coordination control and application verification",the jilin province industrial innovation special fund project(No.2019 c036-5)"the limit of safety based on prediction research and development of the intelligent vehicle active expansion stability under the condition of control unit and industrialization",Shanghai automobile industry technology development fund2019 production,project(No.1909)the "ultimate recognition technology of intelligent vehicle based on pavement condition safety decision research" Under the auspices of Mechanism and Switching Control,Based on a new type of electro-hydraulic braking system e-booster,the braking energy recovery was studied and analyzed as follows:First consult a large number of literature summary of the current electric car brake system and the advantages and disadvantages of several schemes,the selection of a new type of electro-hydraulic brake system E-booster as the research object,in the high precision simulation software AMESim,set the car electric hydraulic braking energy recovery system simulation platform,automobile brake system model,respectively,7 degrees of freedom vehicle model,system model and the energy recovery system simulation in the process of the automobile brake braking torque distribution and energy recovery.