Design and Control of a Single-Wheeled Hybrid Aerial-Ground Robot Capable of Robust Terrestrial Maneuvers

Abstract

Micro aerial vehicles (MAVs) have gained popularity for their agility and versatility in various tasks. In recent years, hybrid aerial-ground robots, which are equipped with cross-domain capabilities to expand reachable areas, have been largely developed. Among them, legged configurations excel in rough terrains but they require complex linkages and are usually slower. Conversely, wheeled configurations have shown the potential of aggressive locomotion, which is essential for applications, such as search and surveillance.

In this thesis, we propose a wheeled quadcopter designed for high speeds operations with robustness on uneven terrains. The robot features a simple, reconfigurable passive wheeled leg structure, enabling seamless transitions between flight and two ground modes: a standing mode for efficient environmental monitoring and a cruising mode for robust cruising on the ground. Additionally, it maintains aerial locomotion capabilities.

We develop a detailed dynamical model based on unified equations of motion, proving the passive yaw rate stability that improves trajectory tracking, the efficient turning via roll angle and the enhanced stability on uneven terrains. Controllers are designed based on these dynamics to achieve the desired maneuvers.

We then experimentally demonstrate movements of the robot across various scenarios. The indoor trajectory following experiments demonstrate its high speed turning ability, exhibiting exceptional turning performance, achieving a centrifugal acceleration of 0.55g, over 30 % higher than previous records, due to an inherent yaw stabilization effect. The robot is also deployed to outdoor environments, where it exhibits robust movements towards terrain disturbances and is proven to be capable of reliable navigation on irregular surfaces.

In summary, this thesis contributes to the field by presenting a novel wheeled quadcopter with passive yaw rate stability and robustness for uneven grounds, offering significant advancements in both indoor and outdoor maneuverability.

Date of Award	9 Sept 2024
Original language	English
Awarding Institution	City University of Hong Kong
Supervisor	Pakpong CHIRARATTANANON (Supervisor)