AN OPTIMIZATION-BASED FRAMEWORK FOR SIMULTANEOUS PLANT-CONTROLLER REDESIGN

In this paper we develop a framework for the redesign of computer-cont rolled, closed-loop, mechanical systems for improved dynamic performan ce. A central notion which underlies the redesign framework is that, i n order to achieve the best possible performance from a constrained cl osed-loop system, the plant and controller should be designed simultan eously. The framework is presented as the formulation and solution of a progression of optimization problems which establish the limits of p erformance of the dynamic system under various conditions of interest, thereby enabling the engineer to systematically establish the various redesign possibilities. Using a second order linear dynamic system an d a nonlinear controller as an example, we demonstrate the application of the framework and substantiate the idea that in order to achieve t he best possible performance from a constrained closed-loop system, th e plant and controller should be redesigned simultaneously. We then sh ow how the redesign framework can be used to select the best control s trategy for a robotic manipulator from a dynamic performance standpoin t. Finally, in order to demonstrate that the redesign framework yields solutions which the engineer can implement with confidence, we presen t the experimental verification of the numerical solution of a manipul ator redesign optimization problem.