Research On Control Strategy Of Steer-by-Wire System

Three main key technologies included in Steer-by-Wire system are respectively vehiclestability control, steering wheel road feeling control, reliability design, the further research forvehicle stability control and steering wheel road feeling control are mainly carried out in thepaper.With the help of ADAMS/CAR, a2DOF multi-body dynamics model of Steer-by-Wirevehicle is built, and Steer-by-Wire angle ratio is designed based on constant steady-state yaw rategain, two kinds of step steer simulation are carried out respectively to get Steer-by-Wire systemideal angle ratio, which are constant steering wheel angle different vehicle velocity and constantvehicle velocity different steering wheel angle, the relationship of ideal angle ratio, steeringwheel angle and vehicle velocity is given through Surface fitting.Steer-by-Wire fuzzy control strategy and differential braking fuzzy control strategy areconstructed with the main control variables of yaw rate and sideslip angle, then the dynamicresponses of Steer-by-Wire vehicle under step steer and single lane change two typical drivingconditions are simulated, the simulation results show that Steer-by-Wire vehicle has betterstability and track keeping. Under limited conditions, the integrated control of two controlstrategy above is studied, the results show that control effect of vehicle stability is superior toSteer-by-Wire fuzzy control’s and Differential Braking fuzzy control’s.In order to study steering wheel road feeling control, the steer effort of traditionalmechanical steering system is studied, then two steering wheel road feeling control strategy areconstructed, which are low velocity control and high velocity control, and corresponding steeringportability experiment slalom performances are researched. Results show that two controlstrategies can meet requirements better.