Surface Actuation and Sensing of a Tensegrity Structure Using Robotic Skins

Abstract

Tensegrity robots comprising solid rods connected by tensile cables are of interest due to their flexible and robust nature, which potentially makes them suitable for uneven and unpredictable environments where traditional robots often struggle. Much progress has been made toward attaining locomotion with tensegrity robots. However, measuring the shape of a dynamic tensegrity without the use of external hardware remains a challenge. Here we show how robotic skins may be attached around the exterior of a tensegrity structure, to both control and measure its shape from its surface. The robotic skins are planar, skin-like membranes with integrated actuators and sensors, which we use to transform a passive tensegrity structure into an active tensegrity robot that performs tasks such as locomotion. In addition, sensors placed on the ends of the tensegrity rods are used to directly measure orientation relative to the ground. The hardware and algorithms presented herein thus provide a platform for surface-driven actuation and intrinsic state estimation of tensegrity structures, which we hope will enable future tensegrity robots to execute precise closed-loop motions in real-world environments.