A continuous model of robot hand preshaping

Most of the existing dextrous robot hand preshape schemes offer grasp choice from a fmite and discrete set of grasp types. Such a discrete set obviously hinders the applicability of pre shaping schemes to complex and versatile task requirements. In this paper, we formulate the continuous spaces of grasps and derive an algo­ rithmic procedure for robot hand preshaping. The proposed procedure consists of a mapping from a task space to a topologic3.l space of hand configurations using a barycentric coordinate system and a barycentric subdivision scheme. A model implementation architecture is discussed. An example showing the preshaping of a four-frnger hand in preparation for pinch grasping is also described. .