Automated trajectory generation and airport selection for an emergency landing procedure of a CS23 aircraft

Arno Fallast,Bernd Messnarz

doi:10.1007/s13272-017-0252-5

Arno Fallast, Bernd Messnarz

Open Access

https://doi.org/10.1007/s13272-017-0252-5

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Abstract

Aircraft in general aviation usually are operated in single pilot mode. Especially, in case of an incapability of the pilot to control the aircraft, an automated emergency procedure is desirable in order to reduce the risk of fatalities. The finding of a solution for an emergency landing maneuver includes preselecting possible landing sites with regard to the available aircraft capabilities and creation of feasible trajectories to these sites. A search tree in four-dimensional search space with an efficient implementation of a rapidly exploring random tree algorithm (RRT*) is created. The algorithm performance is increased by use of basic geometrical sets to construct the final route as a combination of Dubins path segments. To further reduce the route length, a gradient based local optimization routine is added after completion of the RRT* algorithm. At the moment of creation, terrain avoidance is verified and accordance with legal airspace structure is considered. An emergency procedure is created by combining a selected landing site and a flyable trajectory to this site. Each of these combinations is scored, and the most promising emergency landing procedure is chosen and delivered to flight management system of the aircraft. The flight management system controls a full-authority auto-flight system that is capable of performing en-route flight and auto-land procedures as well.

Highlights

Within the project eSAFE—emergency Safe Return for CS23 Aircraft—a unique technique for automatic flight guidance including emergency landing in case of a pilot’s sudden inability of flight is developed.The project contains the adoption of a Diamond Aircraft DA42 to Fly-By-Wire capabilities, the implementation of flight control computer as well as sensor and actuator hardware and the development of control and trajectory planning algorithms.The adoption of the Diamond Aircraft DA42 was performed in the LUFO IV Project FLYSMART simultaneously performed at Diamond Aircraft
A first scope of investigation was to prove the stability of the program and to gather data for an adaption of the search parameters. These simulation runs where conducted with a fixed starting point and variation of search algorithm parameters such as number of iterations and number of neighbors to consider for the connection and rewiring process mentioned in the algorithm process
The rapid exploring random tree (RRT)* algorithm that is chosen for the actual implementation is proven to yield an optimal solution if such an solution exists [3]

Summary

Introduction

Within the project eSAFE—emergency Safe Return for CS23 Aircraft—a unique technique for automatic flight guidance including emergency landing in case of a pilot’s sudden inability of flight is developed.The project contains the adoption of a Diamond Aircraft DA42 to Fly-By-Wire capabilities, the implementation of flight control computer as well as sensor and actuator hardware and the development of control and trajectory planning algorithms.The adoption of the Diamond Aircraft DA42 was performed in the LUFO IV Project FLYSMART simultaneously performed at Diamond Aircraft. Within the project eSAFE—emergency Safe Return for CS23 Aircraft—a unique technique for automatic flight guidance including emergency landing in case of a pilot’s sudden inability of flight is developed. The project contains the adoption of a Diamond Aircraft DA42 to Fly-By-Wire capabilities, the implementation of flight control computer as well as sensor and actuator hardware and the development of control and trajectory planning algorithms. To enable fullauthority flight and outo-land functions, the DA42 with a redundant flight computer, sensor and actuator system that is designed with a scope on eligibility for certification and fulfills the legal required redundancy and reliability demands. By using the available sensors, the execution of the emergency procedure is based only on on-board equipment. The DA42 had two different pilot control sets included: One pilot (the test pilot) controlled the aircraft solely by means of a fly-by-wire sidestick in the cockpit. The other (the safety pilot) maintained control over the conventional, mechanically connected

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