Filter based saturated controller design for a class of nonlinear singularly perturbed systems

This paper describes a novel method to design a saturated controller for a singularly perturbed systems (SPS). These systems frequently exhibit complexity and uncertainty that may have negative impacts on the performance. Further, the SPS are characterised by a substantial time scale difference between fast and slow dynamics. In order to overcome these difficulties, the singular perturbation approach is used to design a nonlinear saturated controller which has a filter and disturbance observer. A strategical approach is presented based on contraction theory to achieve convergence of all closed-loop states of the system. For the analysis and design of these systems, contraction theory offers a rigorous mathematical framework that ensures system trajectories will converge even in the presence of singular perturbation and uncertainties. The suggested approach is validate on pitch angle control of the Twin Rotor MIMO System (TRMS) to replicate the real time situations.