Interactive multi-objective programming as a framework for computer-aided control system design
This work reports the development of an approach to computer-aided control system design (CACSD). Of primary concern is the quality of co-operation between the designer and his computer. In order to achieve an effective co-operation, we propose a conceptual view of the CACSD problem to the designer, and develop a framework for the computer. The conceptual view is named Generalized Cooperative Search (GCS), which suggests the designer to treat a CACSD problem as a search problem, in which he and the computer co-operate to locate satisfactory designs among sets of candidates. The framework is Interactive Multi-Objective Programming (IMOP), which defines the level of abstraction as well as the organization of the design facilities in the computer. While IMOP methods and control system design methods provide readily usable tools organized by the framework, a design strategy is developed to guide the designer in their effective use. The strategy is a two-level plan of the design process which helps the designer to conduct his search problems as ones of IMOP. He constructs parametrized sets of candidate designs using the design methods (innovates in level I) and matches his design wishes with the design possibilities amongst these candidates using the IMOP methods (trade-offs in level II). The advantages of this approach are (1) a proper emphasis is put on an effective designer-computer co-operation, the designer is supported rather than forced to follow any planned course of actions; (2) a uniform trade-off among design objectives receive their long due attention and (3) it is pluralistic and different design methods may be combined for their respective strengths. The work conducted is likely to be the first integrated approach to designing control systems by search, and may even be the first which supports the principal design stages (formulation, generation and evaluation) in a co-ordinated as well as most general manner. The proposed approach has a promising prospect of being one for the general areas of computer-aided design in engineering and decision support systems in scientific management.