TASK DRIVEN UNIFIED SYNTHESIS OF PLANAR FOUR-BAR AND SIX-BAR LINKAGES WITH REVOLUTE AND PRISMATIC JOINTS FOR FIVE POSITION SYNTHESIS

摘要

This paper deals with the problem of integrated joint-type and dimensional synthesis of planar four-bar and six-bar linkages with revolute (R) and prismatic (P) joints for guiding through five specified task positions of the end-effector. In a recent work, we developed a simple algorithm for analyzing a set of given task positions to determine all feasible planar dyads with revolute and/or prismatic joints that can be used to guide through the given positions. The current paper extends this algorithm to the integrated joint-type and dimensional synthesis of Watt Ⅰ and Ⅱ and Stephenson Ⅰ, Ⅱ, and Ⅲ six-bar linkages with a combination of R and P joints. In the process, we developed a new classification for planar six-bar linkages according to whether the end-effector can be constrained by two dyads (Type Ⅰ), one dyad (Type Ⅱ), or no dyad (Type Ⅲ). We demonstrate this task driven synthesis approach with three examples including a novel six-bar linkage for lifting an individual with age disability from seating position to standing position.