F Giulietti

Robustness to communication failures within formation flight

Concerns formation flight of unmanned air vehicles. Presents the evolution and finite state machine implementation of a deterministic approach to the problem of management of communication faults and aircraft loss inside a formation in autonomous flight. The aircraft formation is represented as an oriented graph and then a procedure, based on the shortest path theory, provides the optimal solution for the information flow within the formation. In case of faults this procedure run again providing with a sub-optimal solution while the formation geometry is changed by a formation manager that uses reconfiguration maps and heuristic laws to find the new best placement for the aircraft in the formation. Theoretical development and simulation results validating the fault management methodology are presented. The next step is testing of this formation management structure on a formation of flying UAV.

SENSORLESS FORMATION FLIGHT

The paper introduces a control technique for autonomous formation flight that does not require inter-aircraft distance measures to maintain formation stiffness. In a two aircraft formation, the leader induces a wake on its wingman and a neural network structure is synthesized to estimate the relative position. The possibility to derive wake effects estimates in order to train a neural network to recognize them, is described both with inverse modeling and asymptotic state estimation. The effect of aircraft dynamics modeling errors on neural network training have been also investigated. Finally, computer simulations are shown that describe the formation control results achieved with this tech

Waypoint-Based Fuzzy Guidance for Unmanned Aircraft

Abstract The paper presents the development and the simulation results of a GPS-based waypoints Fuzzy Guidance System (FGS). Waypoints are described in a 5-dimonsional space, standard position in 3-dimensions plus desired crossing heading and velocity. The aircraft is assumed to be autopiloted in velocity, heading and flight path. The FGS is based on three standard Mamdani fuzzy controllers that generate separately velocity, heading and flight path references for the autopilots. Simulation results show that, under the FGS guidance, the aircraft correctly crosses all waypoints in the specified sequential order. The FGS handles a non-flyable waypoints set as well, driving the aircraft on flyable trajectories that try to cross the waypoints at the prescribed altitude and with prescribed heading.

Differential inclusion stability analysis of fuzzy gain-scheduling controlled systems

This article proposes a new stability criterion for fuzzy gain-scheduling controlled systems. This approach is based on the differential inclusions theory. The control system design procedure uses linear matrix inequalities techniques to find a fuzzy gain-scheduling controller that stabilizes the nonlinear plant in a closed loop inside the desired state space region.

WakeCAD: Aerodynamics Interference Calculation Toolbox for Aircraft Design, Simulation and Control

The paper describes a toolbox that permits the calculation of the induced velocities generated by a system of lifting surfaces. Theoretical fundaments and application outputs are presented.