PLANNING FOR DEXTEROUS MANIPULATION WITH SLIDING CONTACTS

Dexterous manipulation refers to the skillful execution of object reorienting and repositioning maneuvers, especially when performed within the grasp of an articulated mechani cal hand. In this paper we study the problem of gaining a secure and enveloping grasp of a two-dimensional object by exploiting sliding at the contacts between the object and the hand. This is done in two steps:first, choosing an initial grasp with which the object can be manipulated away from the support, and second, continuously altering the grasp so that envelopment is achieved. The plans generated by our technique could be executed with only position control. How ever, it would be prudent to incorporate contact force sensing to prevent damage during unexpected events. The main contributions of this paper are the derivation of liftability regions of a planar object for use in manipulation planning; the use of the lifting phase plane in manipulation planning; and the derivation of the quasi-static forward object motion problem, which provides a basis for general three- dimensional manipulation planning with rolling and/or sliding contacts. © 1990, Sage Publications. All rights reserved.