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...

Thrust vector control (TVC) is a prime example of an aerospace system in which electromechanical actuators (EMAs) can potentially be effective. Researchers at NASA’s Marshall Space Flight Center are currently developing EMAs to replace the hydraulic servo actuators for use on space vehicles with TVC. The current paper focuses on the control of EMAs in TVC applications and on the optimization of...

An output feedback structured model reference adaptive control law has been developed for spacecraft rendezvous and docking problem. The effect of bounded output errors on controller performance is studied in detail. Output errors can represent an aggregation of sensor calibration errors, systematic bias or some stochastic disturbances present in any real sensor measurements or state estimates....

A novel MATLAB/Simulink based modeling and simulation environment for the design and rapid prototyping of state-of-the-art aircraft control systems is proposed. The toolbox, named APRICOT, is able to simulate the longitudinal and laterodirectional dynamics of an aircraft separately, as well as the complete 6 degrees of freedom dynamics. All details of the dynamics can be easily customized in th...

In aerospace engineering and industry, control tasks are often of a periodic nature, while repetitive control is especially suitable for tracking and rejection of periodic exogenous signals. Because of limited research effort on nonlinear systems, we give a survey of repetitive control for nonlinear systems in this paper. First, a brief introduction of repetitive control is presented. Then, aft...