Effect of friction model on simulation of hydraulic actuator

This paper examines the effect of friction model on the simulation accuracy of a hydraulic cylinder by using three friction models: a steady-state friction model, the LuGre model, and the new modified LuGre model. Hydraulic cylinder’s behaviors were measured under sinusoidal input to the servo valve. Simulations were conducted under the same conditions as the experiments. The comparisons of simulated results with measured ones show that the new modified LuGre model can predict accurately the hydraulic cylinder’s behaviors. Meanwhile, the steady-state friction model and the LuGre model cause high-frequency oscillations with large amplitudes in velocity, friction force, and pressures, which is not observed in experiments.