On the Periodic Noise Affecting Wheel Speed Measurement

This paper addresses the measurement of the wheel angular velocity of wheeled vehicles. The wheel angular velocity measurement is often aected by large periodic disturbances. The paper proposes a model of the origin of that disturbance: even a small oset in the positioning of the encoder can cause large, velocity dependent noise. After having shown that the periodic term is indeed a noise and not part of the actual signal, an adaptive notch filter is discussed. Lyapunov theory is employed to prove the quadratic stability of the time-variant lter. An analysis of both simulation and experimental tests supports the analysis and methods.