Tensegrigami: Origami-Inspired Functional Resilient Structures for Aerial Robots

Description

With the potential to revolutionize our use of robots in a wide range of applications such as reconnaissance and transportation, small, human-friendly micro aerial vehicles have drawn immense attention from researchers. The rapid advancements lead to the increasing adoption of small rotorcraft in multiple domains. Safe flight and collision-free navigation in complex environments, however, remains a major technical barrier.Current efforts to safely navigate largely make use of various sensors to map the surrounding obstacles. State-of-the-art methods usually concern vision-based localization. Complementary to these mapping and avoidance strategies, lightweight protective structures and mechanically resilient airframes have been proposed for flying robots to cope with impacts from collisions or subsequent falls. Nevertheless, the increased footprint or added weight associated with such mechanisms may interfere with the operation of the robots or reduce the already restricted payload capacity.In this proposed research, we aim to develop lightweight, resilient structures for small rotorcraft taking motivation from the tensegrity design principle. By engineering airframes as a set of compressed rigid elements to be stabilized by tensile elements or cables in tension, the resultant airframes become structural components that are not only inherently resilient and lightweight but also functional and compatible with real-world uses. The project is divided into three stages. First, we demonstrate that, with minimal modification, the mechanical resilience of a conventional X-shaped airframe can be radically improved through the addition of tensile members as they markedly alleviate the bending moments present in the rigid structures when the vehicle is subject to impacts. Second, we introduce tensegrigami. The concept of tensegrity is combined with the origami-inspired design paradigm to construct foldable structures of which the rotational degrees of freedom are later confined by inelastic cables. As a result, collision-induced bending moments that may cause structural failures are entirely eliminated. This is accomplished while the vehicles remain highly compact and lightweight. Finally, we propose to adopt elastic cables and shape memory alloy actuators as tensile members. This consequently allows the impact-tolerant tensegrigami robots to reconfigure upon actuation. Such transformations are extremely beneficial to applications such as aerial manipulation or thrust vectoring.It is perceivable that the proposed research will contribute to advances of micro aerial robots by the introduction of functional and resilient mechanisms, raising the safety and capability of small aerial vehicles. Scientific merits will come from (i) the improved mechanical resilience of small rotorcraft from the incorporation of tensile members; (ii) the development of novel origami-inspired tensegrity structures, particularly for applications in flying robots; and (iii) the seamless integration of smart materials to create reconfigurable resilient airframes to further expand the functionalities of small aerial vehicles.