Simulation and experimental research on electro-hydraulic servo road simulator based on IESO

Abstract

The electro-hydraulic servo (EHS) road simulator is one of the important means to test the reliability of the vehicles and their structural parts, whose simulation accuracy directly affects the test results. An EHS road simulation system is established through simulation and experiment. The nonlinear mathematical model of road simulator is established, and a position control method based on improved extended state observer (IESO) is proposed. The control performance of the road simulator under sinusoidal pavement, C-class random pavement is discussed using the AMESim/Simulink co-simulation and experiment methods. The simulation and experiment results show that the IESO controller has a simple structure, is easy to adjust parameters, fast response speed and relatively small control errors, compared to the typical PID controller. When the amplitude of the sine signal is 10 mm and the frequency ranges from 0.1 to 2 Hz, the maximum absolute errors (M_e) of IESO are reduced by 45.8%, 34.6%, 40.5% and 35.2% respectively. When road simulator simulates the C-class pavement, the M_e, the mean absolute error (μ_e) and the standard deviation (σ_e) of IESO are reduced by 4.7%, 11.6% and 29.1% respectively. The results of this paper can improve the position accuracy of IESO control, which could fulfill the requirements of testing accuracy of the road simulation system.