Experimental sensorless control for electropneumatic system based on high gain observer and adaptive sliding mode control
Résumé
Many advanced techniques are applied to obtain robust and accurate control for pneumatic actuators. These strategies need that all states are measured, which is not always the case. For this reason, in this paper, the observability problem of pneumatic actuator is treated. Since the cylinder pressure are not simultaneously observable on according to the cylinder dynamic nature. Firstly, a high gain observer is proposed to estimate the velocity of the rod and the pressure on one side of cylinder from the measurement of the pressure on the other side of the cylinder and the position of the rod. Then, an adaptive sliding mode control is presented in order to compensate the estimation error of the proposed observer and reduce the chattering phenomenon of classic sliding mode control. Real implementation on pneumatic benchmark is carried out due to simplicity of the proposed observer. Experimental results show the applicability of the high gain observer and its effectiveness.