The reachability and dexterity of elbow and dual‐elbow robot manipulators

The objective of this article is to highlight the reachability and dexterity of dual‐elbow manipulators and provide a comparative evaluation of their capabilities. By necessity, dual‐elbow robots are compared to elbow manipulators, the de facto standard of industrial applications. Although it is well established that the ideal elbow and dual elbow geometries are comparable in terms of workspace optimization, it is shown that the corresponding realistic geometries exhibit distinct properties. Realistic dual‐elbow and elbow manipulators are investigated and the effects of manufacturing distortions on the flexibility and workspace utilization of the two geometries are quantified and contrasted. Realistic dual‐elbow geometries are shown to provide, in general, better reachability and dexterity, especially for manipulators with a large structural frame, and to be less sensitive to parallelism errors. © 1992 John Wiley & Sons, Inc.