Inertial-Optical Attitude Determination and Model Following Control of Maneuvering Spacecraft

摘要

An approach to on-board commanding, estimation, and control of the attitude motion of maneuvering spacecraft, based on control principles is presented. The control law is based on explicit model following. It comprises single-axis models of the spacecraft motion, which generate a target trajectory and associated target control. An algorithm for inertial-optical attitude determination and estimation of gyro parameters (drift rate bias and scale factor error) is outlined. The algorithms were validated in software simulations of an attitude control system of the type used in the Infra Red Astronomical Satellite (IRAS). The control law and state estimator were tested in-flight, in an on-board experiment with the IRAS spacecraft. The control system comprises a strapdown rate-integrating gyro and a slit-type start sensor for optical-inertial attitude sensing, a reaction wheel actuator, and a 16-bit on-board computer.