Robust adaptive finite time command filtered backstepping control for uncertain output constrained strict-feedback nonlinear systems

This paper proposes a robust adaptive finite time command filtered backstepping control strategy for uncertain output constrained nonlinear systems in strict-feedback form with uncertain parameters and external disturbances. The robust adaptive finite time control technique is constructed by combining the barrier Lyapunov function (BLF) and the finite time control theory into the command filtered backstepping control method. The designed robust adaptive controller is introduced to solve the issue of the explosion of complexity, the compensating signals are designed to avoid the influence of the known filtering errors caused by the command filters and the output constraint is not violated. The designed robust adaptive control method can guarantees that all the signals in the closed-loop system are practical finite time stable, and the tracking errors converge to a small neighbourhood of the origin in a finite time. Simulation results are given to demonstrate the efficiency of the proposed robust adaptive control approach compared to the robust adaptive finite time command filtered backstepping control method that system output without constraint.