Two Strategies for Fractional Sliding Mode Control of Integer Order Systems by System Augmentation: Application to a Servomotor

摘要

This paper investigates new alternatives of sliding mode control (SMC) derived by introducing fractional dynamics into integer order systems. This is based on system augmentation, that is, the definition of pseudo-states for the integer order system corresponding to fractional (in fact, rational) order derivatives of the system states. Two strategies to design the fractional sliding mode controller are proposed: 1) particle swarm optimization (PSO), and 2) pole placement (PP) for ideal sliding motion. For illustration purposes, both the speed and the position control of a servomotor are considered. Simulation results are given to show the applicability of the proposed strategies.