Reconfiguration of a four-bar mechanism using phase space connections

Zhang, J. and McInnes, C. R. (2016) Reconfiguration of a four-bar mechanism using phase space connections. Mechanical Systems and Signal Processing, 81, pp. 43-59. (doi: 10.1016/j.ymssp.2016.03.024)

Abstract

Linkage mechanisms are perhaps the simplest mechanical structures in engineering, but they can exhibit significant nonlinearity which can in principle be exploited. In this paper a simple smart structure model is developed based on such nonlinearity to investigate the reconfiguration of a four-bar mechanism through phase space connections. The central idea is based on heteroclinic connections in the mechanism phase space between equal-energy unstable equilibria. It is proposed that transitions between such equal-energy unstable (but actively controlled) equilibria in principle require zero net energy input, compared to transitions between stable equilibria which require the input and then dissipation of energy. However, it can be difficult to obtain such heteroclinic connections numerically in complex dynamical systems, therefore an objective function approach is used to seek transtions between unstable equilibria which approximate true heteroclinic connections. The instability inherent in the model is therefore actively utilised to provide energy-efficient transitions between configurations of the mechanism. It will be shown that the four-bar mechanism then forms the basis for an elastic model of a smart buckling beam.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: McInnes, Professor Colin
• Authors: Zhang, J., and McInnes, C. R.
• College/School: College of Science and Engineering > School of Engineering > Systems Power and Energy
• Journal Name: Mechanical Systems and Signal Processing
• Publisher: Elsevier
• ISSN: 0888-3270
• ISSN (Online): 1096-1216
• Published Online: 06 April 2016
• Copyright Holders: Copyright © 2016 Elsevier B. V.
• First Published: First published in Mechanical Systems and Signal Processing 81:43-59
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher