This dissertation explores methodologies for enhancing the operational capabilities of Uncrewed Aerial Vehicles (UAVs). By tightly integrating design, control strategy, and planning algorithms, we have enabled UAVs to operate in environments that pose significant challenges for traditional flying robots.
The dissertation comprises three parts. The first part focuses on collision-resilient UAVs designed for cluttered environments with obstacles that are difficult to detect and/or avoid. We introduce a vehicle featuring an icosahedron tensegrity structure for resilience to high-speed collisions. The design of the vehicle is guided by a model-based approach, which employs dynamics simulation to predict structural stresses in the system. Furthermore, an autonomous re-orientation controller is presented to facilitate post-collision flight resumption, enabling the vehicle to rotate from any given orientation to ones ready for takeoff.
The second part presents a collision-inclusive, sampling-based motion planning algorithm for narrow and cluttered environments. Incorporating collisions into planning yields two benefits. First, collisions can be exploited for quick changes of movement directions. Second, the allowance of collisions results in more efficient sampling in confined spaces, thereby reducing the planning time needed. The algorithm's effectiveness in narrow environments is demonstrated through Monte Carlo simulations, and the trajectories generated by the algorithm are validated by tracking experiments using the tensegrity aerial vehicle.
The final part broadens UAVs' use to multi-domain environments with a miniature Uncrewed Aerial Underwater Vehicle (UAUV), capable of operation both in air and underwater. A pressure-based depth estimator and a control strategy for water breaching have been developed to facilitate the water-air transition. These tools help the UAUV to create a transition window, ensuring all propellers are exposed to air, and to determine the ideal timing to switch controller modes from water to air, thereby guaranteeing a successful transition.
