Suppressing Position-Dependent Disturbances in Repetitive Control: With Application to a Substrate Carrier System

摘要

Positioning systems are often subject to position-domain disturbances: these are periodic in the position domain yet can appear a-periodic in the time domain. The aim of this paper is to develop a position-domain repetitive control approach that allows to attenuate disturbances with arbitrary varying period. The key idea is to implement a memory loop in the position domain on the basis of non-equidistantly distributed observations, which are inherent to the position domain. An experimental validation on an industrial substrate carrier shows a major performance improvement for a large range of velocities.