Over the last eight years, the Robotics and Mechatronics (RAM) research
team at the Center for Advanced Manufacturing at Clemson University has
been engaged in the design and the experimental validation of advanced
model-based controllers for mechatronic systems (e.g., electric motors,
robot manipulators, overhead cranes, active magnetic bearings, flexible
cables/beams, etc.). The primary philosophy of the RAM group is the design
of model-based controllers using well established mathematical
representations (i.e., ordinary or partial differential equations) which
describe the dynamic behavior of the mechatronic systems as thoroughly as
possible. This design philosophy is based on the belief that enhanced
closed-loop performance of mechatronic systems can be achieved by designing
model-based controllers as opposed to controllers based on simplified,
reduced, and/or linearized models. Due to the inherent difficulties
associated with the dynamic structure, previous control design methods
often utilized simplifying assumptions to aid in the control synthesis;
however, recent Lyapunov-based control design techniques, such as
integrator backstepping or boundary control, have formed a theoretical
basis for the design of high-performance control strategies. In addition,
since these techniques are Lyapunov-based, they can be often be redesigned
to compensate for parametric uncertainty (i.e., adaptive controllers) or to
estimate system states that are difficult or costly to measure (i.e.,
partial-state feedback (PSFB) and output feedback (OFB) controllers).
To substantiate the closed-loop stability and the performance of a given
mechatronic system under a proposed control, the model-based control
algorithms are accompanied with stability proofs. Specifically, by
utilizing Lyapunov-type stability analysis arguments, we are able to
predict closed-loop system performance (i.e., asymptotic or exponential
envelopes for the system's transient performance). In order to validate the
theoretical results, several of the proposed control algorithms have been
experimentally tested at the RAM research facilities. To support the
real-time implementation of these algorithms, we have developed several
mechatronic workstations which provide real-time control support for
digital signal processing/windows-based and Pentium/QNX-based hardware
platforms.
In this presentation, Professor Dawson will illustrate the boundary control
design approach by presenting the development and analysis of
Lyapunov-based controllers for flexible rotors and flexible link robots. In
order to validate the theoretical results, experimental implementation for
the boundary control algorithm will also be presented.
Biosketch
Darren M. Dawson was born in 1962, in Macon, Georgia. He received an
Associate Degree in Mathematics from Macon Junior College in 1982 and a
B.S. Degree in Electrical Engineering from the Georgia Institute of
Technology in 1984. He then worked for Westinghouse as a control engineer
from 1985 to 1987. In 1987, he returned to the Georgia Institute of
Technology where he received the Ph.D. Degree in Electrical Engineering in
March 1990. In July 1990, he joined the Electrical and Computer Engineering
Department and the
Center for Advanced Manufacturing (CAM) at Clemson
University where he currently holds the position of Professor. Under the
CAM director's supervision, he currently leads the Robotics and
Mechatronics Laboratory which is jointly operated by the Electrical and
Mechanical Engineering departments. He is a senior member of the Institute
of Electrical and Electronic Engineers and Sigma Xi. Dr. Dawson has served
the control and robotics community in the following capacities: Present
Associate Editor, IEEE Transactions on Control System Technology, Past
Associate Editor Automatica, The International Federation of Automatic
Control (IFAC) Journal, Served on the International Program Committee for
the Symposium on Implicit and Nonlinear Systems, 1992, the International
Program Committee for the 3rd IEEE Mediterranean Symposium on New
Directions in Control and Automation, the International Program Committee
for the 4th IEEE Mediterranean Symposium on New Directions in Control and
Automation, and is presently serving on the International Program Committee
for the 7th IEEE Conference on Control Application, 1998.
Dr. Dawson's work has been recognized by several awards including the
National Science Foundation Research Initiation Award in 1991, the NCR
Undergraduate Teaching Award in 1992, the Office of Naval Research Young
Investigator Award in 1994, the National Science Foundation Young
Investigator Award in 1994, the McQueen-Quattlebaum Faculty Achievement
Award in 1994, the Georgia Institute of Technology Council of Outstanding
Young Engineering Alumni Award in 1995, the Sigma Xi Excellence in
Research Award in 1995, Clemson University Provost's Award for Scholarly
Achievement, 1997, and the Clemson University Alumni Award for Outstanding
Achievement in Research, 1997.
Professor Dawson research interests include: i) Nonlinear Control
Techniques for Mechatronic Systems such as Electric Machinery, Robotic
Manipulator Systems, Overhead Cranes, Rapid Isothermal Processing of
Electronic Materials, Magnetic Bearings, and Mechanical Friction, ii)
Boundary Control of Distributed Parameter Systems such as Paper Handling
and Textile Machines, Flexible Beams/Robots/Rotors, and Cable Structures,
iii) Robust and Adaptive Control of Uncertain Nonlinear Systems, iv)
Partial State Feedback and Output Feedback Control Techniques and v)
Realtime Hardware and
Software Systems for Control Implementation.