Dynamic modeling, nonlinear analysis, and experimental validation of a multi-locomotion tensegrity mobile robot

The capacity to traverse varied terrains, together with an outstanding stiffness-to-mass ratio, renders multi-locomotion tensegrity robots particularly valued. Nevertheless, the dynamic modeling and nonlinear analysis of these robots present a significant difficulty, stemming from their complex locomotion patterns and the presence of multiple parameters, e.g., actual cable-hole axial length, cable-hole friction, and rest length/stiffness of elastic cables. This article proposes a novel dynamic modeling method for a tensegrity robot. Unlike conventional dynamic modeling methods that neglect the effects of parameters such as actual cable-hole axial length and cable-hole friction, the main novelty of this article resides in an explicit dynamic model that accounts for these multiple critical parameters. Based on the model, nonlinear analysis incorporating kinematic and dynamic nonlinearity is performed to clarify the nonlinear mapping between the multi-parameters and both the kinematic performance and dynamic performance, and the variation patterns of the parameters that yield superior robot performance can subsequently be acquired. Finally, experimental testing on a robot prototype is executed to confirm the presented dynamic modeling method and the obtained theoretical nonlinear analysis results.