A Game Theoretic Approach to the Design of Multi-Agent Process Planning Systems

University Of Minnesota-Twin Cities, Minneapolis MN

Investigators

Abstract

The objective of this research project is to suggest how manufacturing process planning systems should be designed. In automated manufacturing, process planning is the intermediate step that transforms a design into an ordered list of instructions for fabrication. For instance, in machining, a block of homogeneous metal (the stock or initial workpiece) must be transformed by removing material appropriately. For each step, the position of the workpiece, how it is held in place (fixturing), the specific tool to be used, the tool access direction, and the precise tool path must be specified. A computer aided process planning system takes a computer file defining the design in a standard format---the output of a computer aided design system---and finds computerized instructions for computer assisted manufacturing equipment to make the desired artifact. Increasingly, such process planning systems contain multiple artificially intelligent agents (or distributed decision makers). Process planners (and multi-agent systems in general) define particular games. The examination of such games helps one to understand how process planners and multi-agent systems work, why they can fail, and how they can be improved. Game-theoretic mechanism design analyzes how games can be designed so that the desired outcomes arise as equilibria in the games. The proposed research will first use existing results in game theory and mechanism design to study process planners and multi-agent systems. Then new results will be derived for network and distributed games and the potential disaggregation of agents will be analyzed. The goal is to establish rigorous theoretical principles, based on strategic optimization behavior, to guide the design of multi-agent process planning systems and multi-agent systems in general. If successful, this research project will provide principles to improve the design of process planning systems. Process planning can be time-consuming and expensive; when it fails, it can lead to further costs and delays due to redesign. Moreover, process planning is a crucial step in a manufacturing industry (machining) that typically represents about five percent of gross domestic product in developed economies. Hence, it is important to design process planning systems well, so that they successfully find feasible---and, ideally, good, where "good'' means relatively inexpensive to manufacture to tolerance specifications---process plans quickly on average when the design is manufacturable (and don't waste excessive amounts of time and resources if the design is not manufacturable). Broader impacts include involvement of students (including those from underrepresented groups) in this research and the initiation of a new course at the University of Minnesota on game theory for engineers. Moreover, the project is inherently interdisciplinary and involves novel applications of game theory in manufacturing.