Stabilization of a class of time varying systems with control saturations and measurement noise with application to nonholonomic systems

We study the problem of globally stabilizing through saturated smooth time-varying measurement feedback a class of time-varying systems with measurement noise and uncertainties having an upper triangular structure (feedforward form). We propose a novel step-by step design, based on splitting a n-dimensional system Σ into n one-dimensional systems Σ_j, j=1,..., n, finding a smooth time-varying measurement feedback controller C_j for each system Σ_j, and selecting the parameters of each C_j in such a way that altogether the controllers C_j, j=1,...,n, give a controller for the overall system Σ. We apply these results to a three-dimensional system in chained form with uncertainties and disturbances with finite energy.