Published online by Cambridge University Press: 06 September 2002
This paper proposes a new orientation representation of planar manipulators by resorting to polar coordinates. Connecting the end-effector point to the first joint of a manipulator with a virtual adjustable link, the length of the adjustable link corresponds to a workspace point and is related to the orientation of the end effector link by a virtual angle in the form of a transcendental equation. Plotting this link length against the virtual angle in polar coordinates, the orientation of a manipulator can be represented in a compact form, and the range of partial dexterity can be identified. The characteristics of the new representation is hence revealed and related to the assessment of an orientation capability of a manipulator. Based on this representation, a desirable task can be presented and a manipulator can be synthesised with the required orientation.