Online safety calculations for glide-slope recapture

As unmanned aerial vehicles (UAVs) increase in popularity and usage, an appropriate increase in confidence in their behavior is expected. This research addresses a particular portion of the flight of an aircraft (whether autonomous, unmanned, or manned): specifically, the recapture of the glide slope after a wave-off maneuver during landing. While this situation is rare in commercial aircraft, its applicability toward unmanned aircraft has been limited due to the complexity of the calculations of safety of the maneuvers. In this paper, we present several control laws for this glide-slope recapture, and inferences into their convergence to the glide slope, as well as reachability calculations which show their guaranteed safety. We also present a methodology which theoretically allows us to apply these offline-computed safety data to all kinds of unmanned fixed-wing aerial vehicles while online, permitting the use of the controllers to reduce wait times during landing. Finally, we detail the live aircraft application demonstration which was done to show feasibility of the controller, and give the results of offline simulations which show the correctness of online decisions at that demonstration.

[1]  Frank L. Lewis,et al.  Aircraft Control and Simulation , 1992 .

[2]  Marilyn Jager Adams,et al.  Situation Awareness and the Cognitive Management of Complex Systems , 1995, Hum. Factors.

[3]  Mark R. Greenstreet.  Verifying Safety Properties of Differential Equations , 1996, CAV.

[4]  P. Saint-Pierre,et al.  Set-Valued Numerical Analysis for Optimal Control and Differential Games , 1999 .

[5]  Ronald Fedkiw,et al.  Level set methods and dynamic implicit surfaces , 2002, Applied mathematical sciences.

[6]  T. John,et al.  Hybrid Control of Unmanned Aerial Vehicles for Autonomous Landing , 2003 .

[7]  Ian M. Mitchell,et al.  Overapproximating Reachable Sets by Hamilton-Jacobi Projections , 2003, J. Sci. Comput..

[8]  Alexandre M. Bayen,et al.  Computational techniques for the verification of hybrid systems , 2003, Proc. IEEE.

[9]  Jiawei Zhang,et al.  An approximation algorithm for scheduling aircraft with holding time , 2004, 2004 43rd IEEE Conference on Decision and Control (CDC) (IEEE Cat. No.04CH37601).

[10]  J. Sprinkle,et al.  Encoding aerial pursuit/evasion games with fixed wing aircraft into a nonlinear model predictive tracking controller , 2004, 2004 43rd IEEE Conference on Decision and Control (CDC) (IEEE Cat. No.04CH37601).

[11]  S. Sastry,et al.  Vision based terrain recovery for landing unmanned aerial vehicles , 2004, 2004 43rd IEEE Conference on Decision and Control (CDC) (IEEE Cat. No.04CH37601).

[12]  S.S. Sastry,et al.  Deciding to land a UAV safely in real time , 2005, Proceedings of the 2005, American Control Conference, 2005..

[13]  Alexandre M. Bayen,et al.  A time-dependent Hamilton-Jacobi formulation of reachable sets for continuous dynamic games , 2005, IEEE Transactions on Automatic Control.