Adaptive eccentricity compensation

The paper is devoted to the problem of rejecting oscillatory position-dependent disturbances (eccentricity) with unknown frequency and unknown amplitude. Most of the previous works on eccentricity cancellation assume a time-dependent oscillation, we instead assume that the oscillatory disturbance is position-dependent. This leads us to formulate and to globally solve the adaptive cancellation problem in the spatial domain coordinates (curvilinear abscissa associated to the trajectory of the motion), which is the rate-independent (or space) description of the position. An apparatus with rolling excentricity has been built to test the controller