A Hybrid Fuzzy Approach to Optimal Control of Uncertain Systems

A hybrid fuzzy approach to effectively control systems with uncertain model parameters is presented. The approach is based on a combination of classical controller design and fuzzy arithmetic. The uncertainties in the system model are expressed by fuzzy-valued model parameters with their membership functions derived from experimental data or expert knowledge. Subsequently, classical controller design is used to determine the parameters of the controller, making use of fuzzy arithmetic based on the so-called transformation method to evaluate the fuzzy-valued controller equations. By this means, a robust, fuzzy-parameterized linear-quadratic regulator is developed and finally applied to stabilize an inverted double pendulum with uncertain model parameters in its unstable, upright position