Abstract
Obstacle avoidance motion planning for a three-axis planar manipulator with a passive revolute third joint from one zero velocity state to another is investigated. This kind of manipulator is small-time locally controllable on its zero velocity states and can follow any arbitrarily path in zero velocity states almost exactly. We constructed positioning trajectory by connecting rotational and translational motion segments which are preferred motion of the manipulator considering its dynamics and can be executed at higher speeds. The way of constructing trajectories makes six-dimensional trajectory planning be reduced computationally as simpler three-dimensional path planning and time-scaling on the specified paths. The algorithm for obstacle avoidance motion planning is presented. The experimental result shows that the manipulator can reach the desired configuration according to the planned trajectory.
