Principles for part setup and workholding in automated manufacturing

Abstract

Abstract The future automation of small batch manufacturing will critically depend on part fixturing. Fixturing involves the workholding components and the associated planning that must be done to properly position and finally clamp a part. In the past, part setup and clamping problems have been dealt with as a craft: human expert machinists, after an accumulation of many years of experience, derive part process planning strategies in a reasonable amount of time. This paper describes work that aims to create a science base for clamping: distinct patterns have been discovered that characterize how expert machinists plan setups and clamp parts. A core set of tradeoffs employed by the experts to clamp and machine parts has been established, and these tradeoffs are parameterized by models based on first principles of mechanical engineering and experimental results. Knowledge based planning methods of template matching, feature interaction guide selection, and attribute value approximation have been identified. The craftmen's knowledge based methods and the analytical tradeoffs are integrated to form setup and workholding guides within a hierarchical framework.