A low-CG configuration realization method for increasing the stability of the TR-6 on a slope

Tensegrity robots are novel deformable robots based on tensegrity structures. The 6-strut tensegrity robots (TR-6) are similar to spheres. This characteristic allows them to generate rolling gaits easily, but leads to the rolling down problem when they are on a slope. In this paper, as lowering the center of gravity is an efficient way to improve the stability of the TR-6 on a slope, a low-CG(center of gravity) configuration is generated by self-deformation. However, self-deformation may lead to unexpected rolling. To lower the position of the center of gravity and avoid rolling, a low-CG configuration realization method is proposed that contains two steps. Firstly, the stability of the undeformed configurations are analyzed and the most stable undeformed configuration is selected as the initial configuration. Secondly, the low-CG configuration is generated based on the most stable undeformed configuration by suitable deformation. Comparisons are taken between the undeformed configurations and the low-CG configurations in ODE simulations, and the results show the stability of the TR-6 is increased by applying the low-CG configurations.