Motion Planning for a 3-DOF Robot with a Passive Joint

This paper studies motion planning from one zero velocity state to another for a three-joint robot in a horizontal plane witha passive revolute third joint. Such a robot is small-time locallycontrollableon an open subset ofits 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. We describe an algorithm that plans collision-free paths in the robot's configuration space, where the motions correspond to dynamically preferred robot motions. Thus the problem of planning fast trajectories in the robot's sixdimensional state space is reduced to the computationally simpler problems of planningpaths in the three-dimensional configurationspace and time-scaling the paths according to the manipulator dynamics. Implementation on an underactuated manipulator is described.

• Type: Conference
• Year: 1998
• Where: ICRA
• Authors: Kevin M. Lynch, Naoji Shiroma, Hirohiko Arai, Kazuo Tanie
• Keywords: ICRA 1998, Manipulator, Preferred Robot Motions, Robot, Robotics