Inflatable and soft structures offer interesting opportunities for the development of lightweight, compact, and deployable aerial vehicles. In particular, multirotor drones based on inflatable structural frames could combine conventional propulsion and control systems with lightweight and compliant supporting structures. Such configurations may enable drones that can be compactly stored and rapidly deployed, while also providing increased robustness to impacts and collisions.
The structural compliance of an inflatable frame, however, introduces important interactions between structural deformation and flight dynamics. Rotor thrust loads may deform the inflatable arms, modifying the position and orientation of the rotors and therefore the forces and moments acting on the vehicle. These effects depend on the structural stiffness of the inflatable components, which is strongly influenced by their internal pressure. Understanding these interactions is therefore important for assessing the flight performance and controllability of inflatable multirotor drones and for determining whether internal pressure can be exploited as an additional control parameter.
The objective of this thesis is to investigate the coupled structural and flight-dynamic behavior of a multirotor drone equipped with a compliant inflatable frame. A reduced-order structural model will be developed to describe the deformation of the inflatable arms as a function of rotor loads and internal pressure. This model will be coupled with a multirotor flight-dynamics model to evaluate how structural compliance affects rotor orientation, vehicle-level forces and moments, control authority, and flight stability under different operating conditions.
Based on the coupled model, the thesis will identify the combinations of structural stiffness, pressure, and flight conditions that are most critical for vehicle controllability and investigate strategies for accounting for structural deformation within the flight-control system. Particular attention will be given to the possibility of using inflation pressure as a slowly varying control variable to modify structural stiffness and adapt the vehicle response to different flight conditions.
A simple experimental setup consisting of an inflatable arm equipped with a rotor may be developed to characterize the relationship between inflation pressure, rotor thrust, and structural deformation and to support the validation of the reduced-order model.
Required background: basic knowledge of flight dynamics and control, basic MATLAB programming skills. Basic knowledge of structural mechanics and aerodynamics is beneficial but not required.
Contact: marco.belloli@polimi.it, alessandro.fontanella@polimi.it