Research On Control Strategy And Simulation Of Electric Power Steering System For Forklift

As a typical representative of industrial vehicles,forklifts are widely used in coastal ports,large stations,production departments,warehouses and logistics centers.It is the most important conveyance for pallet and container transportation.Therefore,the electric power steering system of forklift has widely market prospects and important actual value.Forklifts are different from other ordinary vehicles and the load changes frequently.A three-variable characteristic curve for forklift is designed in this article.The three variables refer to the load,the speed and the torque of the steering wheel.Secondly,the target current is determined by the ideal characteristic curve.The PID control strategy and the sliding mode control strategy are used to track the current,and the corresponding Simulink simulation is done.The simulation results show that the current tracking effect under the sliding mode control strategy is better.In order to suppress the external interference signal,the observer is added to the sliding mode control strategy and simulated.The simulation results show that the observer is effective and improves the robustness of the system in the presence of external disturbance.Besides,in order to improve the returnability,a dynamic sliding mode controller is designed.Finally,the road feeling is studied and the simulation results show that the intensity of the road feeling will be affected by the speed,the load and other factors.This EPS system can not only improve the steering convenience at low speed,but also ensure a certain intensity of road feeling at high speed.It can not only ensure a certain intensity of the road feeling with the light load,but also improve the steering convenience with the heavy load.In the other word,it can be well adapted to all kinds of conditions.