Fuzzy control design for the trajectory tracking on uncertain nonlinear systems

Based on the concept of sliding-mode control (SMC), the paper designs fuzzy logic controls to achieve the prespecified trajectory tracking for an uncertain nonlinear system. The prespecified trajectory is composed of several nonisoclinal segments in the phase plane and is regarded as the piecewise sliding surface. First, let the uncertain system be approximated by a linguistic fuzzy rule base, then two fuzzy logic controllers are designed to achieve the hitting motion and preserve the system's state traveling on the prespecified trajectory. The main advantage of this control design is that the trial and error of the conventional fuzzy control design disappears. A practical example is given to illustrate the applicability of the algorithm.