Combined Optimal Design and Control With Application to an Electric DC Motor

Abstract

In the design and optimization of artifacts requiring both mechanical and control design, the process is typically divided and performed in separate steps. The physical structure is designed first, a control strategy is selected, and the actual controller is then designed. This article examines how this separation could affect the overall system design and how the combination of the separate problems into a single decision model could improve the overall design, using an electric DC motor as a case study. The combination is challenging since the two problems often have different design criteria, decision objectives, and mathematical model properties. Furthermore, the two problems are often fully coupled in that the physical structure depends on the controller and the controller depends on the physical structure. A Pareto analysis is suggested as a rigorous way to compare a variety of design scenaria.

Optimal Codesign of Nonlinear Control Systems Based on a Modified Policy Iteration Method

“…Similar research work has been carried out under the names of integrated structure and control design [1], [2], optimal redesign [3], [4], and simultaneous design [5], [6]. The codesign problem can find a great number of engineering applications, such as aerospace crafts [5], [6], smart buildings [2], [4], and electromechanical devices [7].…”

An iterative approach to the optimal co-design of linear control systems

“…Bode (1945); Freudenberg and Looze (1985); Serön et al (1997). Indeed, co-design problems can find a great number of applications, such as the optimal design and control of aerospace crafts (Hale et al, 1985;Messac, 1998), smart buildings (Lu and Skelton, 2000;Skelton and Kim, 1992), electromechanical devices (da Silva et al, 2009;Peters et al, 2011;Reyer and Papalambros, 2002), and robotics (Ravichandran et al, 2006).…”

On Measures of Coupling Between the Artifact and Controller Optimal Design Problems

“…These concepts were demonstrated in the optimal design of an electric DC motor and its controller [10,11]. The existence of coupling was determined by the existence of interaction variables, but was not quantified to determine its strength.…”

“…In previous work by Reyer et al [10,11], the concept of coupling in "co-design", or combined optimal design of an artifact and its controller, was introduced. These concepts were demonstrated in the optimal design of an electric DC motor and its controller [10,11].…”