<h2>AAS  96-161</h2><h2>MONOTONIC VIBRATION SUPPRESSION USING REPETITIVE CONTROL AND WINDOWING TECHNIQUES</h2><h4>Y. P. Wang and R. W. Longman, Columbia University</h4><h2> Abstract </h2>Repetitive controllers learn to eliminate errors in following a repetitive command, or errors due to a repetitive disturbance. Many vibration suppression problems fall into this latter category.  In the 1995 Astrodynamics Conference new repetitive control laws were presented based on windowing techniques from digital signal processing. Here we show that these methods can be important in vibration suppression. Repetitive control can in theory produce vibration annihilation, unlike nearly all other passive or active methods. Other active methods usually aim to suppress a given frequency without attempting to eliminate the harmonics.  The windowing techniques developed in this paper have the advantage of offering vibration annihilation up to a chosen frequency, they are simple and have robustness properties, and they do not require much on-line computation making them easy to apply.
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