Multimodal aerial-tethered robot for tree canopy exploration

Abstract

Forest canopies are the biggest habitat for terrestrial life, yet our understanding of environmental processes and biodiversity inside the canopy continues to be limited due to labour and resource intensive data collection. Existing aerial and climbing robots also struggle to access these complex environments, while animals easily navigate them using multiple means of locomotion. Following this insight we present a robot with multimodal mobility obtained by combining aerial and tethered locomotion. After the robot is deployed at the top of the tree, it can descend with the tether and maneuver around leaves and branches with its thrusters. The tether increases robustness and safety and allows for resting as well as emergency retrieval of the system. The aerial locomotion grants the system the ability to move in a conical 3D space constrained by the tether. We modelled the static system and validated the impact of design parameters on it. A simple control architecture for teleoperation is discussed and its performance is analyzed. The proposed multimodal mobility is demonstrated in preliminary outdoor tests, which show how our robot can move within the canopy while continuously monitoring the environment.

Into the ice: Exploration and data capturing in glacial moulins by a tethered robot

“…Kirchgeorg and Mintchev (2022) show that for the center of gravity being below the center of thrust the system experiences dynamics of a double pendulum, leading to oscillations of the robot's pitch angle. For the presented tethered robot, it is assumed that its center of gravity is positioned below the thrusters.…”

“…Lately, a novel class of tethered robot systems has emerged. Following a tethered design with two thrusters to control the robot's pose in free air makes these systems promising candidates for moulin exploration (Kirchgeorg & Mintchev, 2022;Polzin et al, 2023).…”

Design, Modeling, and Control of AVOCADO: A Multimodal Aerial-Tethered Robot for Tree Canopy Exploration

“…2B and main parameter definitions and characteristics are summarized in Table I. Compared to our previous work [19], we have reworked and improved the mechanical design of the platform. The new robot incorporates a soft, 3D printed shell (Varioshore TPU) that protects all internal components, including propellers, from damage in case of collision with obstacles.…”

“…Taking inspiration from arboreal animals' multimodal mobility, we presented a novel robot that exploits tethered and aerial locomotion to achieve the task of navigating through a tree canopy in our previous work [19]. The robot is anchored to the top of the canopy (Fig.…”

“…In this article, we present the system design and dynamic modeling of the aerial-tethered robot AVOCADO as well as the implementation of a controller for onboard autonomy with validation in simulation and real world experiments. We elaborate on the initial contributions of our work on the aerialtethered robot for tree canopy exploration presented at IROS 2022 [19] and extend it with the following contributions:…”