PIλ-PDμController for Suppression of Limit Cycle in Fractional-Order Time Delay System with Nonlinearities

This paper examines the presence of a limit cycle in a fractional-order time delay plant with separable static and dynamic nonlinearities. A comparison study is performed between 2-DOF integer and fractional-order PI-PD controllers for suppression in amplitude and frequency of this limit cycle oscillations. Due to computational complexity, constrained optimization techniques such as Particle Swarm Optimization (PSO), Ant Lion Optimization (ALO), and Teaching Learning Based Optimization (TLBO) are used to estimate the parametric values of the PI-PD controllers. The parameters of the PI-PD controllers obtained from the applied computational algorithms are compared based upon the Integral Square Error (ISE) minimization.