Positioning Control of Oil Hydraulic Cylinder Using Sliding Mode Control with Disturbance observer.

Recently, the sliding mode control (SMC) is frequently applied to various kinds of systems due to its simple algorithm, adaptability or robustness to complex and nonlinear systems and so on. The disturbance observer is very robust servo system against a disturbance and a fluctuation of plant parameters. In this study, we proposed such a robust servo system based on a combination of disturbance observer and sliding mode control. And also to eliminate the chattering phenomena, we use a sliding mode control with accelerative reaching rule. From the view point of the disturbance reduction, a sliding mode control witin disturbance observer is employed to control the positioning of an oil hydraulic cylinder. The experiments are carried out for several conditions, and the obtained results are compared with those of the slidling mode control without disturbance observer. As a result, it is verified that the introduction of the disturbance observer improves the robustness of conventional sliding mode control.