Active Disturbance Rejection Control of an Electro-Hydrostatic Actuator

Active Disturbance Rejection Control (ADRC) is widely applied in automatic machines, like electric motors, proved effective in performance enhancement. However, there is little report in its application in Electro-Hydrostatic Actuators (EHAs), where hydrostatics and power electronics coupled heavily. This paper gives both theoretical and experimental study on ADRC application in an EHA for the thrust vector control of a launcher. The mathematical model and state space model of the system were established and the system disturbances were estimated and compensated. The performances were compared to the counterpart using traditional proportional-integral-differential (PID) algorithm. It shows that ADRC is more effective than PID in rejecting system disturbances and model uncertainties，significantly reducing tracking errors and improving EHA dynamics.

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