An Efficient Algorithm for Vibration Suppression to Meet Pointing Requirements of Optical Payloads

Abstract

For several future imaging spacecraft, vibration isolation and suppression of its optical payloads have become a challenging problem. These spacecraft have increased performance requirements for the payload, resulting in increased fine steering and vibration isolation requirements. The vibration sources on the spacecraft, however, are increased due to the new large flexible structures and addition of rotating devices. One promising way to address both issues is through the Stewart platform. By using a hexapod with six actuated struts, it is possible to achieve both fine pointing and vibration control. Traditional vibration control algorithms rely on the knowledge of the plant and are usually computationally intensive. This paper applies a computationally efficient vibration control to the Stewart hexapod problem. This algorithm does not rely on the knowledge of the plant other than to find the adaptation rate coefficient and performs well on highly non-linear plants. A convergence analysis is presented. Results are shown for a voice-coil actuated hexapod.