Optimization of Interval Type-2 Fuzzy Logic Controller for Uncertain Inverted Pendulum System

In this paper, an uncertain inverted pendulum system is controlled by an IT2 fuzzy logic controller (IT2 FLC) which was optimized by the particle swarm optimization (PSO) algorithm. The IT2 FLC, as an extension of the type-1 fuzzy logic controller (T1 FLC), has better control performance in dealing with uncertainties than T1 FLC. However, IT2 FLC has more complexity because the parameters of the IT2 FLC are more than the parameters of T1 FLC, so it is difficult to select appropriate parameters to get better performance. The PSO algorithm is used to optimize several parameters of IT2 FLC via two cost functions. According to simulations, the performance of the IT2 FLC is optimized by the PSO algorithm is better than the IT2 FLC without optimization, and the IT2 FLC has better performance in dealing with uncertainties than T1 FLC.