Generalized Dynamics of Stacked Tensegrity Manipulators

Tensegrity structures emerged initially as an art form, have recently gained substantial interest among engineering researchers. The distinctive attribute of these structures is using pretensioned tensile elements connected to rigid bars to establish an equilibrium of the whole structure. Thanks to these elements, tensegrity structures are lightweight and yet robust. The main challenge impeding their widespread use is the intricate constrained nonlinear dynamics caused by the tensegrity topology. In this paper, we extend the dynamics of tensegrities by adding damping forces and incorporating forces along the connected strings passing through several nodes. As an experimental platform, a two-stage stacked tensegrity manipulator was constructed. The system was actuated using six actuators and the kinematic information of the system was acquired by measuring the node coordinates using optical motion capture. Afterward, we compared the structure behavior to the simulated one using our dynamics formulation. The results of these experiments show that our dynamics formulation is capable of representing the rich nonlinear dynamics of stacked tensegrity manipulators effectively.