文档介绍：Mechanism and Machine Theory 44 (2009) 822–834
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Mechanism and Machine Theory
journal homepage: ate/mechmt
Kinematics of pantograph masts
. Nagaraj a,1, R. Pandiyan a,2, Ashitava Ghosal b,*
a ISRO Satellite Centre, Bangalore 560 017, India
b Department of Mechanical Engineering, Indian Institute of Science, Bangalore 560 012, India
article info abstract
Article history: This paper deals with the kinematics of pantograph masts. Pantograph masts have wide-
Received 1 April 2008 spread use in space application as deployable structures. They are over constrained mech-
Received in revised form 5 April 2008 anisms with degree-of-freedom, evaluated by the Grübler–Kutzback formula, as less than
Accepted 14 April 2008
one. In this paper, a numerical algorithm is used to evaluate the degree-of-freedom of pan-
Available online 22 May 2008
tograph masts by obtaining the null space of a constraint Jacobian matrix. In the process
redundant joints in the masts are obtained. A method based on putation,
to obtain the closed-form kinematics equations of triangular and box shaped pantograph
Keywords:
masts, is presented. In the process, the various configurations such masts can attain during
Deployable pantograph masts
Degree-of-freedom deployment, are obtained. The closed-form solution also helps in identifying the redundant
Jacobian matrix joints in the masts. The putations involving the Jacobian matrix also leads to
Closed-form solutions a method to evaluate the global degree-of-freedom for these masts.
Ó 2008 Elsevier Ltd. All rights reserved.
1. Introduction
Deployable structures is a generic name for a broad category of prefabricated structures that can be transformed from a
pact configuration to a predetermined expanded form in which they are stable and can carry loads. The study of
deployable/collapsible mast has applications in space industry that requires a highly collapsible and portable mechanis