Control Seminar

Practicable Rotation-Matrix-Based Attitude Control

James ForbesAssistant ProfessorUniversity of Michigan - Department of Aerospace

The attitude of a body, such as a spacecraft, underwater vehicle, or
unmanned aerial vehicle, is characterized by the rotation matrix.
Historically, set-point and tracking control of rigid bodies has been
realized by parameterizing the rotation matrix in terms of
quaternions, Euler angles, Rodrigues parameters, or modified Rodrigues
parameters (MRPs). However, such parameterizations are problematic.
For instance, Euler angles, Rodrigues parameters, and MRPs suffer from
singularities. As such, in recent years researchers and practitioners
alike have considered attitude control methods that directly use the
rotation matrix.

In this seminar, practical aspects of rotation-matrix-based attitude
control will be considered. Specifically, the use of unit-vector and
angular velocity measurements directly within a rotation-matrix-based
control law will be presented. Additionally, a rotation-matrix-based
attitude control law that prevents actuator saturation and
simultaneously ensure closed-loop stability will be discussed.

James Richard Forbes received his B.A.Sc. in Mechanical Engineering
(Honours, Co-op) from the University of Waterloo in 2006. While
attending the University of Waterloo James participated in the co-op
program; James had the opportunity to work in the manufacturing,
automotive, rail, and industrial automation (robotics) industries.
James was awarded his M.A.Sc. and Ph.D. degrees in Aerospace Science
and Engineering from the University of Toronto Institute for Aerospace
Studies (UTIAS) in 2008 and 2011, respectively. He was awarded the G.
N. Patterson Award for the most outstanding Ph.D. thesis in 2011. From
May 2011 to August 2013 James was an Assistant Professor of Mechanical
Engineering at McGill University located in Montreal, Quebec, Canada.
While at McGill University he was also an associate member of the
Centre for Intelligent Machines. James is currently an Assistant
Professor of Aerospace Engineering at the University of Michigan. The
focus of his research is the dynamics and control of aerospace systems
including large flexible space structures, spacecraft, unconventional
Mars rovers, and cable-actuated systems.

Sponsored by

Bosch, Eaton, Ford, MathWorks, Toyota, and Whirlpool