Form-closure of planar mechanisms: Synthesis of number, configuration, and geometry of point contacts

Ramakrishna, K and Sen, Dibakar (2018) Form-closure of planar mechanisms: Synthesis of number, configuration, and geometry of point contacts. In: MECHANISM AND MACHINE THEORY, 130 . pp. 220-243.

PDF MEc_Mac_The_136_220_2018.pdf - Published Version Restricted to Registered users only Download (3MB) | Request a copy

Abstract

This paper presents a study on restraining the motion of planar mechanisms using point contacts between the links of the mechanisms. First-order form-closure (FFC) and second-order form-closure (SFC) of 1- and 2-degrees-of-freedom (d.o.f.) smooth planar motions are studied. It is shown geometrically that two and three point contacts are sufficient for FFC of an object which is capable of executing 1- and 2-d.o.f. motions respectively. These results are applied for FFC of planar mechanisms. A theory for contact curvature based SFC of 1- and 2-d.o.f. motions with a single point contact is presented. It is derived that the instantaneous point-path curvature of points on a specific line of a 2-d.o.f. moving plane is always bounded. Using this result, a procedure is chalked out for immobilizing land 2-d.o.f. mechanisms with a single contact. Illustrations of immobilizing four-bar and 2R-mechanisms are presented. Rapid prototyped model of the four-bar mechanism and stoppers is fabricated and the SFC theory is verified. (C) 2018 Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	MECHANISM AND MACHINE THEORY
Publisher:	PERGAMON-ELSEVIER SCIENCE LTD
Additional Information:	Copy right for this article belong to PERGAMON-ELSEVIER SCIENCE LTD
Keywords:	Form-closure; Envelope theory; Curvature theory; Immobilization; Multi-d.o.f planar mechanisms
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	27 Nov 2018 15:44
Last Modified:	25 Aug 2022 04:34
URI:	https://eprints.iisc.ac.in/id/eprint/61167

Actions (login required)

View Item