Research On The Performance Of The Electric Power Steering System For Electric Forklift

Along with the development of electronic automotive technology, people’sincreasingly high demand on steering has promoted the emergence of electricpower steering (EPS) system. EPS system as a new one of steering systems hasadvantages of simple structure, small volume, light weight, low energyconsumption, low noise, no pollution, and is being widely concerned. With thedevelopment of control technology, EPS system is bound to mature and becomethe mainstream of steering systems. Because of the advantages of EPS system,the range of application of EPS system is constantly expanded. We are likely tofind the shadow of EPS system from small cars to large vehicles, from passengercars to trucks, such as electric forklift. Electric forklift, by virtue of its non-polluting, low noise, compact and flexible features, is used in a lot of occasions,such as warehouses, factories, workshops, ports, airports and hospitals. Therefore,the study on the EPS system for electric forklift has practical significance.Firstly, based on the principle of the EPS system for electric forklift, thestructural characteristics and operating conditions, the operating mode andcontrol strategy of EPS system are determined. Power compensation control isadded to improve the performance of steering. While identifying the performance,including stability, assist characteristics, steering consistency, Steering agilityand road feeling. The first three are research priorities.Under the working principle of system, the simulation model is built usingMatlab/Simulink. Simulation results show that the system has good stability,assist characteristics and steering consistency. Simultaneously, the dynamicperformance of EPS system is improved with the power compensation control.Based on the chip of DSPIC30F4011, the hardware and software of EPSsystem are designed and the permanent magnet brushless DC motor is selected.Then the test bench is set up. The consistent of the results of experiment andsimulation verifies the control strategy proposed is correct. Finally, the EPSsystem is installed on electric forklift for debugging. The result shows that theEPS system can meet the steering requirement of electric forklift.