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Optimal estimation and sensor selection for autonomous landing of a helicopter on a ship deck
Thesis (MEng)--Stellenbosch University, 2014.
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| Format: | Thesis |
| Language: | en_ZA |
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Stellenbosch : Stellenbosch University
2015
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| _version_ | 1867613933736558592 |
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| access_status_str | Open Access |
| author | Irwin, Shaun George |
| author2 | Jones, Thomas |
| author_browse | Irwin, Shaun George Jones, Thomas |
| author_facet | Jones, Thomas Irwin, Shaun George |
| author_sort | Irwin, Shaun George |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MEng)--Stellenbosch University, 2014. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/95894 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:44:01Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2015 |
| publishDateRange | 2015 |
| publishDateSort | 2015 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/95894 Optimal estimation and sensor selection for autonomous landing of a helicopter on a ship deck Irwin, Shaun George Jones, Thomas Stellenbosch University. Faculty of Engineering. Department of Electrical and Electronic Engineering. Complete state sensor models Attitude estimators Unmanned helicopters Automated landing Helicopters -- Landing Theses -- Electronic engineering Dissertations -- Electronic engineering UCTD Thesis (MEng)--Stellenbosch University, 2014. ENGLISH ABSTRACT: This thesis presents a complete state estimation framework for landing an unmanned helicopter on a ship deck. In order to design and simulate an optimal state estimator, realistic sensor models are required. Selected inertial, absolute and relative sensors are modeled based on extensive data analysis. The short-listed relative sensors include monocular vision, stereo vision and laser-based sensors. A state estimation framework is developed to fuse available helicopter estimates, ship estimates and relative measurements. The estimation structure is shown to be both optimal, as it minimises variance on the estimates, and flexible, as it allows for varying degrees of ship deck instrumentation. Deck instrumentation permitted ranges from a fully instrumented deck, equipped with an inertial measurement unit and differential GPS, to a completely uninstrumented ship deck. Optimal estimates of all helicopter, relative and ship states necessary for the autonomous landing on the ship deck are provided by the estimator. Active gyro bias estimation is incorporated into the helicopter’s attitude estimator. In addition, the process and measurement noise covariance matrices are derived from sensor noise analysis, rather than conventional tuning methods. A full performance analysis of the estimator is then conducted. The optimal relative sensor combination is determined through Monte Carlo simulation. Results show that the choice of sensors is primarily dependent on the desired hover height during the ship motion prediction stage. For a low hover height, monocular vision is sufficient. For greater altitudes, a combination of monocular vision and a scanning laser beam greatly improves relative and ship state estimation. A communication link between helicopter and ship is not required for landing, but is advised for added accuracy. The estimator is implemented on a microprocessor running real-time Linux. The successful performance of the system is demonstrated through hardware-in-the-loop and actual flight testing. AFRIKAANSE OPSOMMING: Hierdie tesis bied ’n volledige sensorfusie- en posisieskattingstruktuur om ’n onbemande helikopter op ’n skeepsdek te laat land. Die ontwerp van ’n optimale posisieskatter vereis die ontwikkeling van realistiese sensormodelle ten einde die skatter akkuraat te simuleer. Die gekose inersie-, absolute en relatiewe sensors in hierdie tesis is op grond van uitvoerige dataontleding getipeer, wat eenoogvisie-, stereovisieen lasergegronde sensors ingesluit het. ’n Innoverende raamwerk vir die skatting van relatiewe en skeepsposisie is ontwikkel om die beskikbare helikopterskattings, skeepskattings en relatiewe metings te kombineer. Die skattingstruktuur blyk optimaal te wees in die beperking van skattingsvariansie, en is terselfdertyd buigsaam aangesien dit vir wisselende mates van skeepsdekinstrumentasie voorsiening maak. Die toegelate vlakke van dekinstrumentasie wissel van ’n volledig geïnstrumenteerde dek wat met ’n inersiemetingseenheid en ’n differensiële globale posisioneringstelsel (GPS) toegerus is, tot ’n algeheel ongeïnstrumenteerde dek. Die skatter voorsien optimale skattings van alle vereiste helikopter-, relatiewe en skeepsposisies vir die doeleinde van outonome landing op die skeepsdek. Aktiewe giro-sydige skatting is by die posisieskatter van die helikopter ingesluit. Die proses- en metingsmatrikse vir geruiskovariansie in die helikopterskatter is met behulp van ’n ontleding van sensorgeruis, eerder as gebruiklike instemmingsmetodes, afgelei. ’n Volledige werkingsontleding is daarna op die skatter uitgevoer. Die optimale relatiewe sensorkombinasie vir landing op ’n skeepsdek is met Monte Carlo-simulasie bepaal. Die resultate toon dat die keuse van sensors hoofsaaklik van die gewenste sweefhanghoogte gedurende die voorspellingstadium van skeepsbeweging afhang. Vir ’n lae sweefhanghoogte is eenoogvisie-sensors voldoende. Vir hoër hoogtes het ’n kombinasie van eenoogvisie-sensors en ’n aftaslaserbundel ’n groot verbetering in relatiewe en skeepsposisieskatting teweeggebring. ’n Kommunikasieskakel tussen helikopter en skip is nie ’n vereiste vir landing nie, maar word wel aanbeveel vir ekstra akkuraatheid. Die skatter is op ’n mikroverwerker met intydse Linux in werking gestel. Die suksesvolle werking van die stelsel is deur middel van hardeware-geïntegreerde simulasie en werklike vlugtoetse aangetoon. 2015-01-13T11:48:10Z 2015-01-13T11:48:10Z 2014-12 Thesis http://hdl.handle.net/10019.1/95894 en_ZA Stellenbosch University xx, 108 p. : ill. application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Complete state sensor models Attitude estimators Unmanned helicopters Automated landing Helicopters -- Landing Theses -- Electronic engineering Dissertations -- Electronic engineering UCTD Irwin, Shaun George Optimal estimation and sensor selection for autonomous landing of a helicopter on a ship deck |
| title | Optimal estimation and sensor selection for autonomous landing of a helicopter on a ship deck |
| title_full | Optimal estimation and sensor selection for autonomous landing of a helicopter on a ship deck |
| title_fullStr | Optimal estimation and sensor selection for autonomous landing of a helicopter on a ship deck |
| title_full_unstemmed | Optimal estimation and sensor selection for autonomous landing of a helicopter on a ship deck |
| title_short | Optimal estimation and sensor selection for autonomous landing of a helicopter on a ship deck |
| title_sort | optimal estimation and sensor selection for autonomous landing of a helicopter on a ship deck |
| topic | Complete state sensor models Attitude estimators Unmanned helicopters Automated landing Helicopters -- Landing Theses -- Electronic engineering Dissertations -- Electronic engineering UCTD |
| url | http://hdl.handle.net/10019.1/95894 |
| work_keys_str_mv | AT irwinshaungeorge optimalestimationandsensorselectionforautonomouslandingofahelicopteronashipdeck |