Journal of Aeronautics & Aerospace Engineering
Open Access

Nonlinear Lyapunov control improved by an extended least squares adaptive feed forward controller and enhanced Luenberger observer

5^th International Conference and Exhibition on Mechanical & Aerospace Engineering

October 02-04, 2017 Las Vegas, USA

Matthew Cooper and Peter Heidlauf

Air Force Institute of Technology, USA

Scientific Tracks Abstracts: J Aeronaut Aerospace Eng

Abstract :

Three adaptive approaches for a non-linear feedforward controller are combined with and sinusoidal trajectory planners in a spacecraft attitude control system. Physics-based feedforward control, trajectory generation, observers, feedback control, and system stability are discussed in relation to the nonlinear dynamics under simulation. The adaptive feedforward controllers compared include an adaptive controller, a Recursive Least Square (RLS) Method, and an Extended Least Squares (ELS) Method. A novel approach to incorporate ELS in adapting an idealized feedforward controller was developed and compared to the standard RLS optimal estimator. For a large slew maneuver, the controller configuration with ELS feedforward, PID feedback, and sinusoidal trajectory outperformed the baseline adaptive controller. Mean error was decreased by 23.4%, error standard deviation by 34.0%, and maximum error by 33.0%. Mean control effort was similar for all controller configurations. This improvement is due to corrections for miss-modeled dynamics, which occur during spacecraft launch, collisions with debris, or due to fuel slosh and loose components

Biography :

Matthew Cooper completed his M.S. in Electrical Engineering and M.S. in Aeronautical Engineering at the Air Force Institute of Technology and his B.S. in Electrical Engineering at Penn State. He has worked as an Electrical Systems Integration Engineer at BAE Systems, as a Geospatial Intelligence Project Engineer at the National Air and Space Intelligence Center, and is currently at the AFRL Advanced Laser Division. Peter Heidlauf completed his M.S. in Aeronautical Engineering at the Air Force Institute of Technology and his B.S. in Mechanical Engineering at the Rose-Hulman Institute of Technology. He is an Autonomous Control Aerospace Engineer at the AFRL Power and Control Division