Intelligent control for swing up and balancing of an inverted pendulum system

This paper describes implementation of swing-up and balancing control for a rotational inverted pendulum system. The authors' focus is on three aspects of fuzzy control in the overall control design: direct, supervisory, and auto-tuning fuzzy control. For a swing-up control, the authors utilize an energy pumping strategy, enhanced by introducing a fuzzy supervisory mechanism. For balancing control, an LQR-based linear control strategy is generalized to a nonlinear direct fuzzy control design. For improved performance when disturbances affect the pendulum system, the authors develop a new scheme, the auto-tuned fuzzy controller, which has the capability to vary its resolution on-line. All controllers are tested on an experimental apparatus, and performance comparisons are drawn.