A SUSPENDED AERIAL MANIPULATION AVATAR FOR UNSTRUCTURED ENVIRONMENTS

Aerial robots possess unique advantages. Being able to fly like birds and to approach the workspace from above, grants aerial robot unparalleled agility. As their applications in inspection continue to be explored, the potential of aerial robots to interact with the environment continues to emerge. However, at the current stage of development, two major challenges hinder their practical applications. The first challenge involves the unknown threats present in unstructured environments where the robot is meant to explore. The requirement for interaction further complicates safety issues and control problem. The second challenge concerns payload limitations and battery duration, as maintaining the aircraft in the hover state consumes most of the system energy, regardless of manipulation. In this context, my Ph.D. dissertation presents the concept and implementation of a novel suspended aerial manipulation avatar, aiming to address the obstacles for aerial robotic systems. My work is mainly reflected in four aspects. i) I developed a robotic upper-body system with a human-like design and enhanced robustness for aerial manipulation applications. By introducing a tendon-driven design, the weight distribution of the arm is optimized, reducing the displacement of the center of gravity from the body center during its movement. The introduction of compliance in the arm and neck joints enables the system to cope with unexpected impacts during interaction, and the integration of soft hands further improves the system's versatility in handling different tasks. ii) To ensure the widespread adoption and ease of implementation of my design, I chose an off-the-shelf hexarotor as the aerial platform. On this line, I developed a methodology to model the system and determine its parameters, aligning with the goal of enhancing portability. Moreover, I implemented an open-source digital twin of the proposed system, facilitating further research and control investigations. iii) I proposed a variable-length suspension design that partially compensates for the overall weight of the system, thereby greatly increasing payload capacity. Simultaneously, it preserves the agility of the aerial base, achieving an enhanced workspace. iv) Furthermore, I implemented an immersive teleoperation scheme, allowing the human operator to engage with the robot as if they were flying and present in the workspace, effectively making the robot an "avatar." This design fully exploits the dexterity of the system, enabling it to handle accidental events in unstructured environments. The four pieces of work described above constitute, in their entirety and integration, the concept of "suspended aerial manipulation avatar" that I propose in this thesis. Building upon the specific implementation, I explored, analyzed and discussed on the system modeling and control. Experimental results effectively validate the proposed design, showcasing its potential in post-disaster rescue and reconstruction scenarios, and highlighting its promising applications in other related fields.