Research On Integrated Control Of Regenerative Braking And Anti-lock In Electric Vehicle Based On EHB System

The intelligent brake-by-wire(BBW)system can maximize the recovery of vehicle braking energy,assist the vehicle to achieve autonomous braking in unmanned mode,and implement emergency braking within 120 ms,which is an indispensable key component for the global development of advanced automotive technology.In recent years,the intelligent brake-by-wire system represented by the electro-hydraulic brake system(EHB)system has been popularized and applied on a large scale,but its key technology has been "stuck-necked" by foreign countries,and the supply chain has been monopolized..To this end,based on an EHB system for an electric vehicle,this article focuses on maximizing vehicle braking energy recovery and ensuring vehicle "emergency braking" active safety,and conducts research on integrated vehicle regenerative braking and anti-lock braking.The research content completed in this paper is as follows:(1)Design the "electric servo booster + hydraulic adjustment unit " vehicle Two-box solutions of EHB system,and calculate the dynamic parameters of an electric vehicle,and construct the vehicle kinetic model including the vehicle’s seven degrees of freedom,electric motor,and charging and discharging battery packs.(2)The pedal-coupled electric booster is used as the power source,and the power-assisted transmission scheme of motor + worm gear + screw screw is adopted,and the mathematical model of its servo motor and power-assisted mechanism is established.Based on the three closed-loop control of the brushless DC motor,based on The mapping relationship between the ideal pedal displacement and the oil pressure of the master cylinder,a boost control algorithm that uses the servo motor angle signal to compensate the booster in real time is proposed..(3)Simplify the increase/decrease/hold pressure characteristics of the hydraulic control unit(DSC/ESP)into a mathematical model of pressure adjustment of the brake master cylinder + valve port + brake wheel cylinder,and build wheel cylinder pressure control by means of numerical table query The model uses step pressure tracking and triangular pressure tracking to simulate continuous point braking and slow continuous braking actions respectively,and verify the increase/decrease/hold pressure characteristics of its pressure adjustment.(4)Taking into account the efficiency and braking safety of the vehicle energy recovery,combined with the driver’s total braking demand,ground adhesion coefficient and battery SOC and other constraints,the maximum regenerative braking torque is the inflection point,and the synchronous adhesion coefficient point is the desired point.The integrated control strategy of vehicle regenerative braking and anti-lock braking under light braking,medium braking and high-intensity braking was formulated,and the strategy was verified by Matlab/simulnk platform.