From modeling to control of a variable stiffness device based on a cable-driven tensegrity mechanism. (January 2017)

• Record Type: Journal Article
• Authors: Boehler, Quentin; Abdelaziz, Salih; Vedrines, Marc; Poignet, Philippe; Renaud, Pierre
• Is Part Of: Mechanism and machine theory. Volume 107(2017:Jan.)
• Page Start: 1
• Page End: 12
• Publication Date: 2017-01
• Subjects: Tensegrity mechanism -- Variable stiffness -- Cable-driven mechanisms -- Tension distribution -- Velocity distribution; Machine theory -- Periodicals; Machinery -- Periodicals; Machines -- Périodiques; Génie mécanique -- Périodiques; Machine theory; Machinery; Periodicals; 621.81
• DOI: 10.1016/j.mechmachtheory.2016.09.015
• Languages: English
• ISSNs: 0094-114X

Abstract

Abstract: Cable-driven tensegrity mechanisms are now considered for various applications in which their reconfiguration capacities are required together with their inherent lightness. Moreover, they can exhibit interesting variable stiffness capacities through the modification of their level of prestress when composed of deformable cables. Control schemes that deal with both reconfiguration and stiffness variation have however not been developed in the literature yet. This paper presents two control strategies for that purpose to transform a cable-driven tensegrity mechanism into a variable stiffness device. The mechanism is a planar tensegrity mechanism allowing us to control an angular position and the associated stiffness. Relying on the properties of the mechanism models, the proposed control strategies allow a modulation of the stiffness or of its first time derivative. The interest of both propositions is outlined and an experimental investigation of their characteristics is performed. Encouraging results are obtained in terms of reconfiguration capabilities and stiffness variation. Abstract : Highlights: The model of a tensegrity mechanism is derived, and a variation of its stiffness along its degree of freedom is highlighted. Distribution algorithms are used to control the position and the angular stiffness or its first derivative. The validation of both strategies is conducted on a dedicated setup with demonstration of the efficiency of both approaches.