Feedback control for a class of feedforward systems in the presence of measurement noise

This paper investigates state feedback controller design for a class of feedforward nonlinear systems in the presence of measurement noise. Since the control coefficient is uncertain, the control design procedure is more challenging. The measurement noise, i.e., the sensor noise, has bounded magnitude, frequency and phase. A low-pass filter is contained in the proposed controller which is used to attenuate the sensor noise. It is shown that the state of the closed-loop system is bounded whose Ultimate Bound (UB) depends on the magnitude and the frequency of the sensor noise. Finally, a simulation example is given to illustrate that, if the sensor noise enters only partial states, the UBs of the particular states can be made arbitrarily small.