Time-Varying Underactuated Attitude Control Design With Feedback Linearization Using Two Pairs of Gas Jet Actuators

Research has shown that rigid spacecraft with two controls cannot be stabilized by continuous state feedback. In this paper, aiming at asymmetric spacecraft with two pairs of gas jet actuators, we design smooth time-varying controllers for the underactuated system. These optimal controllers are developed by introducing an assistant state variable and using feedback linearization techniques. Through this approach, the states of the closed-loop systems can converge with exponential rates and this is validated by numerical simulations. Compared with existing control designs for underactuated attitude systems, this approach is much simpler and can be also scaled to other applications.Copyright © 2008 by ASME