Control Theory Research Group

C. D. Johnson, PhD, Distinguished Professor
Field of interest: Control of Dynamical Systems in the Face of Uncertain Disturbances and Parameter Variations.

Y. B. Shtessel, PhD, Professor
Field of interest: Sliding Mode Control with Applications to Space and Flight Control.

For the past 35 years Dr. Johnson has been actively involved in the development of new approaches to the design of high-performance stabilization, set-point regulation, servo-tracking, guidance laws and adaptive control systems for rockets, missiles and other dynamical systems which must operate in environments with uncertain, persistently-acting disturbances and parameter-variations. These research efforts have led to the development of a wide variety of new control techniques including the theories of: subspace-stabilization control, disturbance-accommodating control, Chebyshev-minimax control, optimal bang-bang control, optimal linear-saturating control, optimal disturbance-utilizing control, linear adaptive control, inter-sample control for discrete-time systems, "smart" active-control of vibrations and structures, inverse-system realization methods, new methods for real-time system identification and deconvolution, singular-solution methods in optimal control, optimal real-time allocation of scarce resources, and exact time-varying eigenvalue methods for linear time-varying dynamical systems. Dr. Johnson published over 200 technical papers

Presently, Dr. Shtessel has been working on a wide variety of research topics encompassing Nonlinear Nonminimum Phase Output Tracking and Adaptive Control on Sliding Modes.  Breakthrough has been achieved in nonminimum phase output tracking on traditional and higher order sliding modes in causal systems. The results are obtained by using dynamic extension of the stable system center and a sliding manifold as a dynamic operator. New results on a higher order sliding mode (HOSM) observer design for nonminimum phase nonlinear systems have been achieved as well. Novel adaptive sliding mode control algorithms that allow not overestimating the sliding mode control gains in systems with bounded disturbances and unknown bounds have been developed. Dr. Shtessel published over 300 technical papers. He produced 8 PhD and 22 MS (with thesis) students.  Dr. Shtessel applied his theoretical developments in sliding mode control and observation techniques to a large variety of tasks, including (a) Attitude tracking and bending mode control of a launch vehicle. (b) Damaged aircraft reconfigurable anti-windup control. (c) Integrated autopilot/guidance system for hit-to-kill missile interceptors. (d) Output tracking in multiple-modular nonminimum phase boost and buck-boost DC-DC and AC-DC electric power converters. (e) Robust control of tight formations of unmanned air vehicles. (f) The robust feedback stabilization of the blood glucose concentration level in diabetic patients. (g) Preserving a connectivity in mobile communication, data-gathering networks that consist of uncontrolled and controlled agents.

Courses in Control Theory
EE-425/505 "Introduction to Control and Robotic Systems
EE-410/510 "Advanced Control"
EE-605   "Classic Control Design"
EE-607 "Robotic Systems Control"
EE-700 "Sample Data Control"
EE-701 "Advanced Linear Control Theory"
EE-703   "Modern Control Design"
EE-704 "Nonlinear Control Systems"
EE-705 "Theory of Optimal Control"
EE-706 "Stochastic Control Theory"
EE-720 "Computer-Aided Design of Control Systems"
EE-721 "Control Engineering for Large Scale Systems"
EE-722 "Sliding Mode Control"

Contact Information email:

Dr. C. D. Johnson
Electrical and Computer Engineering Department
The University of Alabama in Huntsville
Huntsville, AL 35899
Phone: (256) 824-6293
Fax: (256) 824-6803
Dr. Yuri Shtessel
Electrical and Computer Engineering Department
The University of Alabama in Huntsville
Huntsville, AL 35899
Phone: (256) 824-6316
Fax: (256) 824-6803