Structural Characterization of a First-Generation Articulated-Truss Joint for Space Crane Application

Structural Characterization of a First-Generation Articulated-Truss Joint for Space Crane Application
Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
Total Pages: 28
Release: 2018-10-22
Genre: Science
ISBN: 9781729013786

A first-generation space crane articulated-truss joint was statically and dynamically characterized in a configuration that approximated an operational environment. The articulated-truss joint was integrated into a test-bed for structural characterization. Static characterization was performed by applying known loads and measuring the corresponding deflections to obtain load-deflection curves. Dynamic characterization was performed using modal testing to experimentally determine the first six mode shapes, frequencies, and modal damping values. Static and dynamic characteristics were also determined for a reference truss that served as a characterization baseline. Load-deflection curves and experimental frequency response functions are presented for the reference truss and the articulated-truss joint mounted in the test-bed. The static and dynamic experimental results are compared with analytical predictions obtained from finite element analyses. Load-deflection response is also presented for one of the linear actuators used in the articulated-truss joint. Finally, an assessment is presented for the predictability of the truss hardware used in the reference truss and articulated-truss joint based upon hardware stiffness properties that were previously obtained during the Precision Segmented Reflector (PSR) Technology Development Program. Sutter, Thomas R. and Wu, K. Chauncey and Riutort, Kevin T. and Laufer, Joseph B. and Phelps, James E. Langley Research Center RTOP 506-43-41-02...

Parallel Robots

Parallel Robots
Author: J.-P. Merlet
Publisher: Springer Science & Business Media
Total Pages: 367
Release: 2012-12-06
Genre: Technology & Engineering
ISBN: 9401095876

Parallel robots are closed-loop mechanisms presenting very good performances in terms of accuracy, rigidity and ability to manipulate large loads. Parallel robots have been used in a large number of applications ranging from astronomy to flight simulators and are becoming increasingly popular in the field of machine-tool industry. This book presents a complete synthesis of the latest results on the possible mechanical architectures, analysis and synthesis of this type of mechanism. It is intended to be used by students (with over 100 exercises and numerous Internet addresses), researchers (with over 500 references and anonymous ftp access to the code of some algorithms presented in this book) and engineers (for which practical results and applications are presented).