Robotic grasping of complex shapes: is full geometrical knowledge of the shape really necessary?

This paper aims at contributing to a sub-symbolic, feedback-based theory of robotic grasping where no full geometrical knowledge of the shape is assumed. We describe experimental results on grasping 2D generic shapes without traditional geometrical processing. Grasping algorithms are used in conjunction with a vision system and a robot manipulator with a three-fingered gripper is used to grasp several different shapes. The altorithms are run on the shape as it appears on the computer screen (i.e. directly from a vision system). Simulated gripper finger with virtual sensors are configured and positioned on the screen whose inputs are controlled by moving their position relative to the image until an equilibrium is reached among the control systems involved. When in steady state, the algorithms output a position and orientation for the real gripper. This information is then used both to drive the manipulator and to map the object onto its final location.