Abstract
It is useful for control of robot manipulators and for task planning if we have a quantitative measure of manipulating ability in positioning and orienting the endeffectors. Its this paper, a method for estimating the ability of robot manipulators under the environment with obstacles is proposed from the viewpoint of kinematics.
The obstacles which are close to a manipulator bring some restrictions to the motion of the manipulator. In this paper, we discuss two cases; the one is the case that the joint velocity vector must satisfy the equality constraint for the purpose of avoiding the obstacle, and the other is the case that the approaching speed to the obstacle is restricted. For each case, we derive a manipulability ellipsoid and a measure of manipulability. Lastly, as an example, an experiment and simulation results using an eight degree of freedom manipulator are shown. In this experiment, the endeffector is inserted into an inside space through a narrow slit, and the joint angle velocities are controlled so as to keep the proposed manipulability large.
