On prediction of passive contact forces of workpiece-fixture systems

Cai Hua Xiongand, You Lun Xiong, Michael Yu Wang

Research output: Chapter in Book/Report/Conference proceedingConference PaperOther

3 Citations (Scopus)

Abstract

Prediction of passive forces in a frictional workpiece-fixture system is an important problem, since the contact forces have a strong influence on clamp design and on workpiece accuracy during machining. This paper presents a general method for the computation of the contact forces. First, based on the rigid-body kinematics, an indeterminate system of static equilibrium is defined, in which the passive, frictional contact forces cannot be determined arbitrarily as in an actively controlled robotic multi-finger grasp. Then, we define a locally elastic contact model to describe the nonlinear coupling between the contact forces and elastic deformations at the contact point. This model captures the essence of the passive contact. Further, a set of "compatibility" equations are given so that the elastic deformations among all passive contacts in the workpiece-fixture system result in a consistent set of rigid-body displacement of the workpiece in its global system. Finally, combining the locally elastic contact model and the "compatibility" conditions, we transform the force computation problem into a determinate system of nonlinear equations governing all of the elastic deformations at all of the passive contacts. By solving the resulting nonlinear equations with frictional constraints, we can accurately predict all contact forces in the frictional workpiece-fixtures system. This method is illustrated with example cases. The method presented here may also have an application to other passive, indeterminate problems such as power grasps in robotics.

Original languageEnglish
Title of host publicationASME International Design Engineering Technical Conferences & Computers and Information in Engineering Conference (IDETC/CIE) 2003
PublisherAmerican Society of Mechanical Engineers (ASME)
Pages255-264
Number of pages10
DOIs
Publication statusPublished - 2003
Externally publishedYes
EventASME International Design Engineering Technical Conferences & Computers and Information in Engineering Conference (IDETC/CIE) 2003 - Chicago, United States of America
Duration: 2 Sept 20036 Sept 2003
https://asmedigitalcollection.asme.org/IDETC-CIE/proceedings-abstract/IDETC-CIE2003

Conference

ConferenceASME International Design Engineering Technical Conferences & Computers and Information in Engineering Conference (IDETC/CIE) 2003
Country/TerritoryUnited States of America
CityChicago
Period2/09/036/09/03
Internet address

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