Control of nonlinear systems with time varying output constraints
This paper presents output tracking control for strict feedback nonlinear systems with time varying output constraint. A Barrier Lyapunov Function (BLF) which depends explicitly on time, is employed at the outset to prevent the output from violating the time varying constraint. Specifically, we allow the barrier limit to vary with the desired trajectory in time. Through a change of coordinates for the tracking error, we then eliminate the time dependence, therefore simplifying the analysis. We show that asymptotic output tracking is achieved without violation of the time varying constraint, and that all closed loop signals remain bounded. The performance of the proposed control is illustrated through a simulation example.
ICCA 2009