Experimental sensorless control for electropneumatic system based on high gain observer and adaptive sliding mode control

International audienceMany 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

Adaptive sliding mode control with moving surface: Experimental validation for electropneumatic system

International audienceIn this work, an Adaptive Sliding Mode Control (ASMC) is proposed for a class of nonlinear MIMO system with external disturbances. Although the Sliding Mode Control (SMC) is known for its precision and robustness against disturbance and uncertainties, it suffers from a chattering phenomenon and the choice of sliding surface parameters. To solve such problems, the SMC discontinuous term was replaced by a proportional derivative term and a moving sliding surface was used. The adaptive parameters were obtained by Lyapunov stability analysis to guarantee the stability of the closed loop system. In order to illustrate the efficiency of the proposed controller, experimental results on electropneumatic system were presented and compared to a classic sliding mode controller

Sensorless Induction Motor Drive Based on Model Reference Adaptive System Scheme Utilising a Fictitious Resistance

This article presents a new development of an indirect stator flux-oriented controller for sensorless speed induction motor drive utilising instantaneous and steady-state values, respectively, of a fictitious resistance symbolised as R_f. The dimension of the fictitious quantity, in this context, is the ohm, which is the difference between the stator d- and q-axis fictitious resistances. However, from the measurement of the stator voltage and currents of the machine, two independent resistance estimators are built. Therefore, the first is considered as a reference model of the induction machine (IM), and the second is considered as an adjustable model. Subsequently, the error between the states of the two models is used to drive a suitable adaptation mechanism that generates the estimation of the speed, for the adjustable model. Furthermore, the structure of the proposed estimator is free from stator resistance and eliminates the requirement of any flux computation. All the detailed simulation study is carried out in MATLAB/Simulink to validate the proposed method and to highlight the robustness and the stability of the proposed model reference adaptive system estimator

Integral backstepping-based output feedback controller for the induction motor

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