Basic manipulation considerations for the articulated body mobile robot

Abstract

Some methods of mobile manipulator control for the articulated body mobile robot "KORYU (KR)" are analyzed. KR is a class of mobile robot composed of serially connected "unit segments", configuring a long articulated body which resembles a train or a snake in shape. This configuration has an intrinsic advantage of making possible the use of the body's degrees of freedom (DOF) not only for "locomotion", but also for "manipulation". In order to demonstrate this characteristic we built a real mechanical model called KR-II, equipped with a 2 DOF manipulator in its foremost part. In the paper, two configurations for augmenting the number of this manipulator DOF are considered. The first method "fixed manipulator" considers the robot fixed to the ground, so that the manipulation control issue can be studied using well-known standard manipulator control theories. In the second method "mobile manipulator" special attention is paid to integrating manipulation tasks with body locomotion (steering) freedom. We verify that mobile manipulation can be smoothly integrated with a steering control method already developed in earlier works. Experimental results are shown to demonstrate the validity of the proposed augmented manipulation configurations and respective control methods.