The autonomous landing of an unmanned helicopter on a moving platform

Fourie, Christopher Kurt (2015-12)

Thesis (MEng)--Stellenbosch University, 2015.

Thesis

ENGLISH ABSTRACT: This work details the design and implementation of an autonomous landing system for an unmanned helicopter. The system was broken down in to two separate systems - an autonomous navigation and control system design for an X-Cell .90 Aerobatic Helicopter, and a safe-landing system utilising ship motion prediction to discern ideal landing periods for autonomous helicopter landings. The helicopter control system is based on a successively closed control system architecture optimized for the X-Cell .90 Aerobatic Helicopter. A state-machine is used to implement fully autonomous landing behaviour, with tracking and landing modes tested for full autonomous landings on a moving platform. Results are given for both hardware-in-the-loop simulated landings, as well as practical landings. Successful practical landings were demonstrated on a target moving at 11 kph. A quiescent period detection system was developed based on data obtained from the South African Navy. This system makes use of a prediction technique to provide advance warning of quiescent periods as well as the ship's deviation from such periods. A classifier based on multiple predictors was implemented to provide an aggregate prediction on whether it is safe for a helicopter to land. Performance, while conservative, illustrated that such a system is feasible and suitable for further development.

AFRIKAANSE OPSOMMING: Hierdie werkstuk behandel die ontwerp en implementering van 'n outonome landingstelsel vir 'n onbemande helikopter. Die stelsel is verdeel in twee afsonderlike substelsels - 'n outonome navigasie- en beheerstelsel ontwerp vir 'n X-Cell .90 akrobatiese helikopter, en 'n veilige landingsisteem wat skipbeweging voorspel om ideale landingsperiodes te herken vir outonome helikopterlandings. Die helikopter beheerstelsel is gebasseer op 'n opeenvolgende lus-sluiting argitektuur wat vir die X-Cell .90 akrobatiese helikopter geoptimeer is. 'n Toestandmasjien word gebruik vir die implementering van volle outonome landingsgedrag, met getoetsde volging en landingsmodusse vir volle outonome landings op 'n bewegende platform. Resultate word voorsien vir beide gesimuleerde hardeware-in-die-lus landings sowel as praktiese landings. Suksesvolle landings was gedemonstreer op 'n platform wat teen 11 kph beweeg het. 'n Statiese tydperk voorspellingsstelsel is ontwikkel om relatief statiese periodes in beweging op te spoor, gebasseer op data van die Suid-Afrikaanse Vloot. Die stelsel maak gebruik van 'n voorspellingstegniek om 'n vroegtydige waarskuwing van statiese periodes sowel as afwyking van die skip te gee. 'n Klassifiseerder wat gebasseer is op verskeie voorspellers is geïmplementeer om 'n gekombineerde voorspelling vir veilige landingstoestande te voorsien. Konserwatiewe prestasies illustreer dat so 'n stelsel haalbaar en vir verdere ontwikkeling geskik is.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/98000
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