Iterative feedforward control with application to a wafer stage

abstract onl

Batch-to-batch rational feedforward tuning : from learning to identification approaches

Abstract onl

MIMO FIR feedforward design for zero error tracking control

This paper discusses a multi-input multi-output (MIMO) finite impulse response (FIR) feedforward design. The design is intended for systems that have (non-)minimum phase zeros in the plant description. The zeros of the plant (either minimum or non-minimum phase) are used in the shaping of the reference signals whereas the poles of the plant are used in constructing feedforward forces. The FIR coefficients themselves are obtained from data-based optimizations which are the result of iterative machine measurements on an industrial wafer scanner. The resulting experimental results demonstrate the ability to obtain zero error tracking

Iterative feedforward tuning approach and experimental verification for nano-precision motion systems

Feedforward control can significantly improve the performance of industrial motion systems through compensation of the servo error induced by the reference signal. Recently, new feedforward tuning algorithms have been proposed that exploit measured data from previous tasks and a suitable feedforward parametrization to attain high servo performance. The aim of this paper is to formulate a design procedure for motion feedforward tuning. Experimental results on an industrial motion system illustrate the improvement in servo performance obtained by means of the proposed tuning procedure