A diagram of the minimum necessary internal force required to resist external forces on two-point-grasped objects in two-dimensional space

作者：Ito Satoshi^*; Tanaka Kohta; Sasaki Minoru

来源：Robotica, 2012, 30: 857-864.

DOI：10.1017/S0263574711001135

• Grasping
• Gripping power
• Diagram expression
• Internal force magnitude
• External force direction

This paper considers the magnitude of the gripping power, i.e., the internal force that depends on the grasping posture or object orientation in a two-dimensional grasp by two contact points with friction. Expressing the effect of variations in the object posture as the direction of an external force, we propose an %26quot;internal force diagram.%26quot; The internal force necessary to create a statically stable grasp is depicted in the object coordinate frame. Then, a polar coordinate system is introduced in which the orientation represents the direction of the external force, while the distance from the origin represents the minimum necessary internal force. We demonstrate a method based on friction cone configurations to manually draw the internal force diagram, using only a ruler and a compass. The validity of this drawing method is confirmed by a comparison with computer-generated plots. Finally, the characteristics of the internal force diagram are discussed.

• 出版日期2012-9