Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : saturation function


Design of Adaptive Sliding Mode Controller for Uncertain Pendulum System

Dina H. Tohma; Ahmed K. Hamoudi

Engineering and Technology Journal, 2021, Volume 39, Issue 3A, Pages 355-369
DOI: 10.30684/etj.v39i3A.1546

This work aims to study and apply the adaptive sliding mode controller (ASMC) for the pendulum system with the existence of the parameters uncertainty, external disturbances, and coulomb friction. The adaptive sliding mode controller has several features over the conventional sliding mode control method. Firstly, the magnitude of the control signal is reduced to the minimally acceptable level defined by special conditions concerned with ASMC algorithm. Secondly, the upper bounds of uncertainties are not necessary to be defined before starting the work. For this reason, the ASMC can be used successfully to control the pendulum system with minimum control effort. These properties of the ASMC are confirming graphically by the simulation results using MATLAB 2019. The ASMC achieves an asymptotically stable system better than the Classical Sliding Mode Controller (CSMC). The unwanted phenomenon is called “chattering", which is appearing in the control action signal. These drawback properties are suppressed by employing a saturation function. Finally, the comparison between the results of the ASMC and CSMC showed that ASMC is the better one.

Simple Sliding Mode Controller with Adaptive Fuzzy Saturation Function for Nonlinear Single Input-Single Output System

Hanady A. Jaber; Nahida N.Kadhim; Samyaa Y. Muhammad

Engineering and Technology Journal, 2010, Volume 28, Issue 9, Pages 1747-1756

Sliding mode control algorithm that uses fuzzy saturation function is designed in
this paper for nonlinear system. The fuzzy saturation function is suggested to improve
the accuracy and the robustness of the sliding mode control which are partially lost
when using a fixed boundary layer. The fuzzy saturation function is simple, in the
sense that both the membership functions and the rule base are simple. The overall
control algorithm has stability assurance for the closed-loop controlled system;
therefore, it may be applied to control different systems, in this paper this algorithm is
applied on nonlinear SISO system with 10%parameter uncertainty and nonlinear
disturbance. Simulation results show that the developed algorithm has good control
performance with negligible chattering.