On the correction capability of a deployed tape-spring hexapod

This paper deals with a hexapod using six rolled tape-springs for space applications. The first part focuses on the prototype design, especially on the blades connecting the tape-springs to the platform. The second part presents the finite element model of the deployed hexapod including pre-stressed and condensed tape-springs. It is compared with the experimental modal testing of the prototype and used as a linear elastic model in the third part, which deals with the correction capability of the hexapod. Jacobian matrices, dexterity and correction capability are defined as performance criteria. Designed to guarantee an equivalent spherical junction, the thin blade configuration does not offer a significant better correction capability compared to the thick blade configuration. Moreover, thick blades provides better deployment repeatability, stiffer behavior. Consequently, the investigation highlights that hexapod kinematics can be ensured by tape-spring flexibility which eliminates the need of connecting blades.