Robust Servomechanism in Nonlinear Systems

Based on the integral manifold concept, a controller is designed that achieves asymptotic tracking and disturbance rejection in a class of nonlinear systems. If the given nonlinear MIMO plant is exponentially stable and has a nonvanishing I/O gain, we show that the control governed by a low gain nonlinear compensator solves this robust servomechanism problem. We also show how the range of initial conditions determines the servo rate of a successful tracking process.