A Soft-Bodied Aerial Robot for Collision Resilience and Contact-Reactive Perching

TL;DR

This paper introduces a lightweight, inflatable soft-bodied aerial robot (SoBAR) with variable stiffness for collision resilience and contact-reactive perching, demonstrating improved interaction capabilities in unstructured environments.

Contribution

The work presents the design and development of SoBAR, a soft-bodied aerial robot with pneumatic stiffness variation, and a novel fabric-based bistable grasper for impact energy utilization.

Findings

SoBAR can repeatedly endure and recover from multi-directional collisions.

It achieves higher perching success rates on various objects.

The hybrid grasper enables rapid, impact-based shape conforming grasping.

Abstract

Current aerial robots demonstrate limited interaction capabilities in unstructured environments when compared with their biological counterparts. Some examples include their inability to tolerate collisions and to successfully land or perch on objects of unknown shapes, sizes, and texture. Efforts to include compliance have introduced designs that incorporate external mechanical impact protection at the cost of reduced agility and flight time due to the added weight. In this work, we propose and develop a light-weight, inflatable, soft-bodied aerial robot (SoBAR) that can pneumatically vary its body stiffness to achieve intrinsic collision resilience. Unlike the conventional rigid aerial robots, SoBAR successfully demonstrates its ability to repeatedly endure and recover from collisions in various directions, not only limited to in-plane ones. Furthermore, we exploit its capabilities to demonstrate perching where the 3D collision resilience helps in improving the perching success rates. We also augment SoBAR with a novel hybrid fabric-based, bistable (HFB) grasper that can utilize impact energies to perform contact-reactive grasping through rapid shape conforming abilities. We exhaustively study and offer insights into the collision resilience, impact absorption, and manipulation capabilities of SoBAR with the HFB grasper. Finally, we compare the performance of conventional aerial robots with the SoBAR through collision characterizations, grasping identifications, and experimental validations of collision resilience and perching in various scenarios and on differently shaped objects.