Fuzzy based adaptive dynamic surface control for a class of nonlinear systems with unknown dead zone

This paper provides an adaptive dynamic surface control for a class of nonlinear systems with unknown dead zone using fuzzy logic system. The dead zone precompensator is constructed to deal with non-symmetrical dead zone parameters and to compensate the effect of the dead zone. The dynamic surface control (DSC) method overcomes the problem of “explosion of complexity” in the traditional backstepping design. Fuzzy logic system (FLS) is used to approximate the nonlinear uncertainty. Adaptation law adjusts these fuzzy parameters online to minimize the approximation error. This new scheme not only eliminates the problem of explosion of complexity in backstepping scheme, but also guarantees the semi-global uniform boundedness of the solution of the closed-loop system, and makes the tracking error converge to a small residual set. Simulation results illustrate that the new scheme is effective.