Adaptive Iterating learning sliding mode control for output tracking of incommensurate fractional-order systems

Abstract

This paper develops a novel controller called adaptive iterative learning sliding mode (AILSM) to control linear and nonlinear incommensurate fractional-order systems. This control applies a hybrid structure of adaptive and iterative learning control into sliding mode method. It can switch between both adaptive and iterative learning control in order to use the advantage of both controller simultaneously and therefore achieve better control performance. This controller is designed in the way to be robust against the external disturbance. It also estimates unknown parameters of fractional-order systems. The proposed controller unlike the conventional iterative learning control for fractional systems does not need to apply direct control input to output of the system and also implemented for incommensurate fractional-order systems. It is shown that the controller perform well in partial and complete observable conditions. Illustrative examples verifies the performance of the proposed control in presence of unknown disturbances and model uncertainties