Composite fuzzy control of a rotary inverted pendulum

The objective of this paper is to investigate the balance control of a rotary inverted pendulum (RIP). The RIP system is essentially nonlinear and unstable, it is often used to verify many control theory in the field of nonlinear control. The RIP system is an appropriate educational tool. In this paper, the composite fuzzy control (CFC) method is proposed to balance and stabilize the RIP system. This method is to take fuzzy PD controls of the drive arm and rotary arm and then take the fuzzy computation (or summation) of these two controls finally. By analysis, CFC method is essentially state feedback control. Hence, the stability is guaranteed in the matter of state feedback control.