of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy NONLINEAR CONTROL FOR SYSTEMS CONTAINING INPUT UNCERTAINTY VIA A LYAPUNOV-BASED APPROACH By William MacKunis May 2009 Chair: Dr. Warren E. Dixon Major: Aerospace Engineering Controllers are often designed based on the assumption that a c...

Tethered Space Robot (TSR), which is connected to a mother spacecraft through a peace of tether, is a new space system proposed in the previous work. Expected applications are satellite servicing, retrieval of debris, inspection of space structure, soft landing, and so on. TSR differs from the existing tethered systems. We envision the tethered subsatellite to be a multi-body system, whose atti...

The growing population of space debris poses an increasing threat to spacecraft operating in low Earth orbit. By taking advantage of aerodynamic drag, a gossamer sail can be used to dramatically reduce the time it will take for a satellite to deorbit. In addition to rapid deorbit time, a gossamer sail also offers the capability of stabilizing a satellite’s attitude. The deployment system utiliz...

Applying flat systems technique in attitude fault tolerant control of an under-actuated satellite has been investigated in this article. The main purpose of this study is development and implementation of a new idea in order to recovery of satellite stability and its acceptable performance in actuator fault scenarios. Solving the attitude fault tolerant control problem is based on consideration...

This paper investigates a quaternion-based finite time attitude synchronization and stabilization problem for satellite formation flying. Sufficient conditions are presented for finite time boundness and stability of this distributed consensus problem. More specifically, a nonlinear control law based on a finite time control technique is developed such that the attitude of the rigid spacecraft ...