Hubble Space Telescope Angular Velocity Estimation During the Robotic Servicing Mission

摘要

In 2004 NASA began investigation of a robotic servicing mission for the Hubble Space Telescope. Such a mission would require estimates of the Hubble Space Telescope attitude and rates to achieve a capture by the proposed Hubble Robotic Vehicle. The Hubble Robotic Vehicle was to be equipped with vision-based sensors, capable of estimating the relative attitude between the Hubble Space Telescope and the Hubble Robotic Vehicle. The inertial Hubble Space Telescope attitude is derived from the measured relative attitude and the Hubble Robotic Vehicle computed inertial attitude. However, the relative rate between the Hubble Space Telescope and Hubble Robotic Vehicle cannot be measured directly. Therefore, the Hubble Space Telescope rate with respect to inertial space is not known. A nonlinear approach is developed to estimate the Hubble Space Telescope rates through an estimation of the inertial angular momentum. The development includes an analysis of the estimator stability given errors in the measured attitude. Simulation test results are given, including scenarios with erroneous measured attitudes. Even though the development began as an application for the Hubble Space Telescope robotic servicing mission, the method presented is applicable to any rendezvous-capture mission involving a noncooperative target spacecraft.