Robust Bang-Bang Control of Disturbed Nonlinear Systems Based on Nonlinear Observers

This paper proposes a robust bang-bang controller(RBC)based on the high-gain nonlinear observer for a nonlinear system with intermittent disturbances.The intermittent distur-bances are able to model the system faults and sudden changes of operating conditions of practical nonlinear systems.A bang-bang constant funnel controller(BCFC)is employed,and the largest control capabilities of the control system is explored to stabi-lize the nonlinear system against the disturbances.The BCFC functions with the estimates of tracking error of control target and its derivatives estimated with a high-gain state observer,which eliminates the requirement on the derivative calculations of the system output tracking error.The error convergence of the observer is verified.The closed-loop stability of the RBC is proved in a bounded-input bounded-state sense.Simulation studies are undertaken with a single-machine infinite-bus(SMIB)power system to test the performance of the RBC.