This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Web of Science (20) Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Lynch, K. M. Articles by Tanie, K. Search for Related Content Social Bookmarking                         What's this?

Collision-Free Trajectory Planning for a 3-DoF Robot with a Passive Joint

Mechanical Engineering Department, Northwestern University, Evanston, IL 60208, USA

Naoji Shiroma

Institute of Engineering Mechanics and Systems, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8573, Japan

Hirohiko Arai

Kazuo Tanie

Robotics Department, Mechanical Engineering Laboratory, Namiki 1-2, Tsukuba, 305-8564, Japan

This paper studies motion planning from one zero-velocity state to another for a three-joint robot in a horizontal plane with a passive revolute third joint. Such a robot is small-time locally controllable on an open subset of its zero-velocity section, allowing it to follow any path in this subset arbitrarily closely. However, some paths are "preferred" by the dynamics of the manipulator in that they can be followed at higher speeds. In this paper, the authors describe a computationally efficient trajectory planner that finds fast, collision-free trajectories among obstacles. The planner decouples the problem of planning feasible trajectories in the robot’s six-dimensional state space into the computationally simpler problems of planning paths in the three-dimensional configuration space and time scaling the paths according to the manipulator dynamics. This decoupling is made possible by the existence of velocity directions, fixed in the passive link frame, which can be executed at arbitrary speeds. Results of the planner have been implemented on an experimental underactuated manipulator. To the authors’ knowledge, it is the first implementation of a collision-free motion-planning algorithm for a manipulator subject to a second-order nonholonomic constraint.

Key Words: underactuated manipulator • trajectory planning • locally controllable nonholonomic system • passive joint • decoupling motions

The International Journal of Robotics Research, Vol. 19, No. 12, 1171-1184 (2000)
DOI: 10.1177/02783640022068011


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?