Synthesis of Programmable Mechanisms Using Adjustable Dyads

Abstract

Conventional hard automation such as linkage mechanisms and cam-driven mechanisms provide high speed capability at a low cost, but fail to provide the flexibility required in many industrial applications. On the other hand, for most manufacturing automation applications in high production industries, expensive multi-axis robots are employed for simple repetitive operations that require only limited flexibility. In order to provide a true middle ground between conventional mechanism-based hard automation and overly flexible anthropomorphic robots, we incorporate flexibility in conventional mechanisms, thereby creating “programmable mechanisms” or Adjustable Robotic Mechanisms (ARMs). This paper introduces the concept of ARMs and presents generalized analytical methods for designing adjustable mechanisms based on synthesis of adjustable dyads. The synthesis methods presented here, which are extensions of the well-known Burmester precision point theory, enable one to design multi-purpose mechanisms for multiple sets of precision points, thereby enabling conventional mechanisms to perform multiple tasks. The analytical synthesis method has been implemented in a computer program that generates all adjustable dyad solutions for given sets of precision points. Two or more adjustable dyads are assembled together to form a programmable linkage mechanism that performs multiple tasks. Synthesis formulations and a design example illustrating the analytical and computer-aided synthesis methods are presented.