Impulsive Control for Angular Momentum Management of Tumbling Spacecraft
- Paper number
IAC-05-C1.4.06
- Author
Mr. Shoji Yoshikawa, Mitsubishi Electric Corporation, Japan
- Coauthor
Dr. Katsuhiko Yamada, Mitsubishi Electric Corporation, Japan
- Year
2005
- Abstract
Robotic service for a troubled spacecraft remains technically challenging as symbolically shown by a Hubble Telescope repair mission. One of the key technologies for robotic service is to control the relative motion between the space robot and the troubled spacecraft before the robot captures the spacecraft. Many studies have been done on this topic. They can be categorized into 4 types: a) halting the relative motion between the hand and the contact point, b) halting the relative motion between the robot main body and the spacecraft main body, c) controlling the rotational motion of the spacecraft into a simple motion such as flat spinning, and d) damping the rotational motion of the spacecraft. This paper discusses type d). We assume that we can give an impulse to the contact point of the spacecraft by a space robot arm. In our control scenario, the robot gives an impulse to the contact point, measures and controls the relative position and attitude between the spacecraft, and then gives another impulse until the rotational motion of the spacecraft is well damped. At each contact, the impulse at the contact point generates a torque perpendicular to the direction of the contact point from the center of mass of the spacecraft. In other words, a torque along the contact direction cannot be generated. The rotational motion of the rigid body of the spacecraft is nonlinear. Therefore, the system is nonlinear and under-actuated. We propose to apply an appropriate coordinate transformation to separate the dynamics into two parts. One part is perpendicular to the contact direction and the other part is along the contact direction. The former part consists of two components and it is shown that the latter part includes a product of these two components. A discrete controller is designed to control the former part so that the latter part is damped out through the product. Then we discuss the characteristics of the closed system. We derive the analytical expressions of its stationary response under constant disturbance torques and contact model uncertainty. Based on the derived expressions, the stability margin under the contact model uncertainty is investigated. Numerical simulations are given to validate the proposed approach and derived expressions.
- Abstract document
- Manuscript document
IAC-05-C1.4.06.pdf (🔒 authorized access only).
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