Grasping with mechanical intelligence

Ulrich, Nathan Thatcher

Many robotic hands have been designed and a number have been built. Because of the difficulty of controlling and using complex hands, which usually have nine or more degrees of freedom, the simple one- or two-degree-of-freedom gripper is still the most common robotic end effector. A new category of device is presented: a medium-complexity end effector. With three to five degrees of freedom, such a tool is much easier to control and use, as well as more economical, compact and lightweight than complex hands. In order to increase the versatility, it was necessary to identify grasping primitives and to implement them in the mechanism. In addition, power and enveloping grasps are stressed over fingertip and precision grasps. The design is based upon analysis of object apprehension types, requisite characteristics for active sensing, and a determination of necessary environmental interactions. Contained are the general concepts necessary to the design of a medium-complexity end effector, an analysis of typical performance, and a computer simulation of a grasp planning algorithm specific to this type of mechanism. Finally, some details concerning the UPenn Hand-a tool designed for the research laboratory-are presented.

Document ID

19900017182

Acquisition Source

Legacy CDMS

Document Type

Thesis/Dissertation

Authors

Date Acquired

September 6, 2013

Publication Date

December 1, 1988

Subject Category

Report/Patent Number

Accession Number

90N26498

Funding Number(s)

Distribution Limits

Public

Work of the US Gov. Public Use Permitted.

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19900017182.pdf

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