Optimal Suppression of Laser Beam Jitter by High-Order RLS Adaptive Control

• Published in: IEEE transactions on control systems technology Vol. 16; no. 2; pp. 255 - 267
• Main Authors: Orzechowski, P.K., Chen, N.Y., Gibson, J.S., Tsu-Chin Tsao
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.03.2008; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adaptative systems; Adaptive control; Adaptive control systems; Adaptive filters; Applied sciences; Circuit properties; Computer science; control theory; systems; Control theory. Systems; Detection, estimation, filtering, equalization, prediction; Dynamical systems; Dynamics; Electric, optical and optoelectronic circuits; electro-optic systems; Electronics; Exact sciences and technology; Information, signal and communications theory; Integrated optics. Optical fibers and wave guides; Jitter; laser beam control; Laser beams; Lattices; Least squares method; Optical and optoelectronic circuits; optical jitter; Optimal control; Optimization; Programmable control; Recursive; Resonance light scattering; Signal and communications theory; Signal, noise; Steady-state; Steering systems; Telecommunications and information theory; High performance; Transient response; Lattice filters; Jitter; Electrooptical device; Adaptive filter; Experimental study; Real time; Recursive algorithm; Adaptive control; Steady state; Transients; optical jitter; Minimal variance; Least squares method; laser beam control; Optimal control; electro-optic systems; Recursive method; Finite impulse response filter
• ISSN: 1063-6536; 1558-0865
• DOI: 10.1109/TCST.2007.903377

This paper demonstrates high-performance adaptive control for a laser-beam steering system, which exhibits high-order unknown jitter dynamics. The adaptive controller, which is based on a recursive least-squares finite-impulse-response lattice filter, has the distinguishing feature that variable and high-order adaptive filters can be realized in the real-time implementation. Varying the order of the adaptive controller produces both fast adaptation and optimal steady-state performance in the experiment, without the large transients often produced by fixed-order recursive least-squares adaptive controllers. The steady-state performance of the high-order adaptive controller approximates closely the theoretically achievable minimum-variance steady-state performance, which is derived from the identified plant and jitter dynamics. Experimental results also illustrate the capability of the adaptive controller to adapt rapidly to changing jitter characteristics.