THE SELF MOTION OF AN ANTHROPOMORPHIC MANIPULATOR

We adopt the measure of kinematic flexibility to quantify the redundancy of a 4R anthropomorphic manipulator whose primary task is to position the wrist in the Cartesian space. The manipulator possesses one degree of redundancy and its self motion consists of a rotation of the centre of the elbow joint about the axis passing through the wrist and the shoulder joint. By the use of kinematic flexibility we measure and display the range of joint angles pertinent to the self motion throughout the workspace for different ratios between the link lengths. We show that the manipulator is more redundant close the inner singularities where it retains a higher potential to adapt to various secondary tasks.