REGIONAL STRUCTURES OF FREE-FLOATING ROBOTS: A COMPARATIVE STUDY OF THE WORKSPACE

摘要

In this paper, the workspaces of free-floating single and dual-arm robots with revolute and prismatic jointed regional structures are compared. As is now well known, owing to nonholonomy of free-floating robots and the feature of inertially fixed location of the centre of mass, the workspace of free-floating robots cannot be described in the same way as that of earth-based robots. The only characterization that can be made for free-floating robots is a work envelope beyond which a reference point cannot travel, regardless of the orientation of the base. The points within this work envelope are reachable only for specific orientations of the base. The workspace of earth-based robots with revolute and prismatic jointed regional structures is well documented in the literature. However, to date no attempts have been made to compare the workspaces of free-floating robots with revolute and prismatic jointed regional structures. The specific questions addressed in this paper are: (1) For the same total length of the regional structure of a single-arm robot with R-R-R and P-P-P joints, what distribution of lengths results in large workspace? (2) For the same total length of the regional structure of a dual-arm robot with R-R-R and P-P-P joints, what distribution of lengths results in the largest workspace? (3) For these optimal distributions, how do the workspaces of regional structures with R-R-R joints compare to those with P-P-P joints?