Reachability analysis for base placement in mobile manipulators

Abstract

Abstract This article addresses the problem of base placement for mobile robots using a reachability analysis. A simple geometric solution is proposed to determine the appropriate base locations from which the robot can reach a stationary or moving target point. This leads to a simple criterion for automated base placement, thus relieving the operator from the tedious and repetitive procedure for continuously positioning the robot base manually during the execution of the end‐effector task. For robots with one degree‐of‐mobility such as tracked robots, the feasible base locations consists of a region on the translational axis, the boundaries of which are derived in this article. The results are used to obtain the base locations so that the robot can reach a vertical line, a square surface, and a cubic volume. Using the proposed method, two experimental studies at the JPL Surface Inspection Laboratory are described: scanning a surface and reaching inside an opening. The results of the article are extended to mobile robots with two and three degrees‐of‐mobility such as rover‐mounted arms and gantry robots, and a simple numerical example is given for illustration. © 1995 John Wiley & Sons, Inc .