Application of least mean square algorithms to spacecraft vibration compensation

This paper describes the application of the Least Mean Square (LMS) algorit hm in tandem with the Filtered-X Least Mean Square algorithm for controllin g a science instrument's line-of-sight pointing. Pointing error is caused b y a periodic disturbance and spacecraft vibration. A least mean square algo rithm is used on-orbit to produce the transfer function between the instrum ent's servo-mechanism and error sensor. The result is a set of adaptive tra nsversal filter weights tuned to the transfer function. The Filtered-X LMS algorithm, which is an extension of the LMS, tunes a set of transversal fil ter weights to the transfer function between the disturbance source and the servo-mechanism's actuation signal. The servo-mechanism's resulting actuat ion counters the disturbance response and thus maintains accurate science i nstrumental pointing. A simulation model of the Upper Atmosphere Research S atellite is used to demonstrate the algorithms.