SKEDSOFT

Analytical Model

Now, an analysis of motion and contact in a planar gripping process, using the present gripper, is formulated. The contact analysis is presented for the case of single-link contact. The analysis may be extended in a straightforward manner for multiple-link contacts. The analysis is based on the following three assumptions:

1.       Object and links are rigid structures. This assumption does not cause significant errors in the determination of the final outcome of the grasp (i.e., whether or not a grasp is successful, and the final position of the object).

2.       Motors are motion sources. For stepper motors, this assumption is valid during steady state motion if no motor steps are missed, as in the present gripper.

3.       Contact bounce is neglected. This assumption is also valid under the conditions that prevail during the grasping process. In particular, link angular speeds are small, and rubber pads on the link contact surfaces, as well as friction between the object and the supporting surface, will tend to dampen the impact response characteristics.