Modeling and analysis of a four-leg tensegrity mechanism

In this paper, we present an innovative four-leg tensegrity mechanism designed for cooperative robotic applications. This lightweight mechanism has two degrees of freedom (2-DoFs) and is co-actuated by three cables. The novelty of the proposed mechanism is based on the use of a central leg to constrain torsion. This central leg eliminates torsional compliance and the need to use an additional motor to control the tension of a fourth central cable. Our study includes a detailed analysis of the kinematics, the Geometric Workspace (GW), the static behavior and the Wrench Feasible Workspace (WFW), together with the optimization of some geometric design parameters. We also present a modeling approach based on a reduced form of the static Newton–Euler equations derived from an analysis of the free-motion space. Through this work, we aim to address key challenges in tensegrity robotics, advancing the field, and opening up new avenues of exploration.