The Role of Theory in Control Practice

Most control theory research is focussed on control law design, though this task requires only a small fraction of the effort necessary to "control" a system and may not be critical in making it successful. Other (often more important) issues are the design of the system itself, so that it is easy to control, developing a model to serve as a basis for control law design, the proper placement and use of actuators and sensors, scheduling the control law to account for nonlinearities, providing graceful performance degradation in the event of actuator saturation or actuator/sensor failure. The successes and failures of modern control theory in addressing these issues will be described and the definition of research goals for a practical theory will be attempted.