Selection of actuation mode for tensegrity mechanisms: The case study of the actuated Snelson cross

Abstract

Tensegrity mechanisms are self-stressed and deployable mechanisms which provide interesting properties such as high resistance-to-mass ratio and compliance. Despite a growing interest for these mechanisms in robotics, the actuation selection of such mechanisms is still poorly discussed. In this paper, the influence of the actuation type and position, i.e. actuation mode, within the structure is assessed for a widely considered tensegrity mechanism, the Snelson cross. Actuation strategies of interest are proposed and performance criteria are defined to achieve fair comparison of the mechanisms. Performance maps are generated and the most interesting results are discussed. Finally, building blocks providing elementary motions are identified and compliant equivalences of conventional joints are proposed for the design of more complex tensegrity-based devices.