Online Safe Flight Envelope Prediction for Damaged Aircraft: A Database-driven Approach

Abstract

This paper proposed a framework of database-driven approach to solve the problem of online safe flight envelope prediction for aircraft safe recovery under abnormal conditions. On occurrence of sudden accidents like structural damages, conventional systems have neither enough measurements for the online reidentification of global damaged models, nor enough time for the onboard safe flight envelope computation. To circumvent these technical bottlenecks and make online applications more feasible in such emergency situations, some information, like global damaged models and the corresponding safe flight envelops, could be stored offline in a database for later online retrieval.

Aviate, Navigate: Functional Visualizations of Asymmetric Flight Envelope Limits

“…Unfortunately, estimating the flight envelope of damaged aircraft is far from trivial. While much research is currently being done on Fault Detection and Isolation (FDI) and post-failure flight envelope estimation [13], [14], [15], [16], [17], [18], [19], [20], [21], [22], fully functioning online systems do not yet exist. One reason for this lack of existing implementations are the high dimensionality of the state space and the corresponding computational complexity.…”

“…A second, more fundamental reason, is that all reachability based envelope prediction methods require an accurate global aerodynamic model, which in general is not available after a failure event. A promising solution to this issue in the form of a database driven envelope prediction method was recently introduced by Zhang et al [22].…”

“…Operators employ skill-based behavior for simple, familiar tasks that require little to no mental effort, e.g., the simple tracking task of keeping the wings level while flying in mild turbulence. hierarchy (AH), which helps to obtain a of the functional means-end relationships the operator objectives and the many ways to [20][21][22]. The work domain analysis (WDA) constraints on different levels of abstraction, argin" within which the aircraft can be ting the objectives.…”

Probabilistic Flight Envelope Estimation with Application to Unstable Over-Actuated Aircraft

“…For nonlinear systems, the distance-fields-over-grids method [10] optimizes the state trajectories toward points in a predefined grid. The flight envelope can also be represented in the form of a level set function [11][12][13] that solves the Hamilton-Jacobi-Bellman partial differential equation (HJB-PDE) resulting from an optimal control problem. These solutions are computed using the 'level-set method', which is a widely-used numerical toolbox for solving nonlinear optimal control problems [14].…”

Aircraft Damage Identification and Classification for Database-driven Online Safe Flight Envelope Prediction

“…Different definitions of the flight envelope are proposed in the literature; see, e.g., [4][5][6][7][8][9]. Widely used to prevent stall and potential structural damage, the conventional maneuvering envelope defines hard constraints on the speed and load factor.…”