Title :
Design of feedforward filters for improving tracking performances of existing feedback control systems
Author :
Tsai, Kuen-Yu ; Schaper, Charles D. ; Kailath, Thomas
Author_Institution :
Inf. Syst. Lab., Stanford Univ., CA, USA
Abstract :
A design procedure for feedforward filters is proposed to improve the tracking performance of existing closed-loop systems. A parametric model is not required because it directly utilizes the frequency response of the closed-loop system, which can be measured accurately. This frequency-shaping approach enables the tradeoff between the quality of model-matching and the size of control efforts by adjusting weighting filters. Time domain specifications can be specified indirectly by approximating them in the frequency domain. The procedure is intuitively simple for SISO systems. Generalization for MIMO systems is possible by formulating convex optimization problems. A feedforward filter is designed and implemented on a nanopositioning system for semiconductor manufacturing, to improve its transient response.
Keywords :
MIMO systems; closed loop systems; control system synthesis; convex programming; feedback; feedforward; frequency response; nanopositioning; tracking; tracking filters; transient response; MIMO systems; SISO systems; closed-loop systems; convex optimization problems; feedback control systems; feedforward filter design; frequency response; nanopositioning system; time domain specifications; tracking performance improvement; transient response; Feedback control; Filters; Frequency domain analysis; Frequency measurement; Frequency response; MIMO; Nanopositioning; Parametric statistics; Semiconductor device manufacture; Size control; Control systems; feedforward systems; frequency domain synthesis; shaping filters; tracking filters;
Journal_Title :
Control Systems Technology, IEEE Transactions on
DOI :
10.1109/TCST.2004.825146
