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Control allocation as part of a fault-tolerant control architecture for UAVs
Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2011.
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| Format: | Thesis |
| Language: | en_ZA |
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Stellenbosch : University of Stellenbosch
2011
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| _version_ | 1867614007546871808 |
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| access_status_str | Open Access |
| author | Basson, Lionel |
| author2 | Peddle, I. K. |
| author_browse | Basson, Lionel Peddle, I. K. |
| author_facet | Peddle, I. K. Basson, Lionel |
| author_sort | Basson, Lionel |
| collection | Thesis |
| dc_rights_str_mv | University of Stellenbosch |
| description | Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2011. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/6722 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:45:11.659Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2011 |
| publishDateRange | 2011 |
| publishDateSort | 2011 |
| publisher | Stellenbosch : University of Stellenbosch |
| publisherStr | Stellenbosch : University of Stellenbosch |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/6722 Control allocation as part of a fault-tolerant control architecture for UAVs Basson, Lionel Peddle, I. K. University of Stellenbosch. Faculty of Engineering. Dept. of Electrical and Electronic Engineering. Fault-tolerant control Control allocation system Unmanned aerial vehicles (UAVs) Dissertations -- Electronic engineering Theses -- Electronic engineering Drone aircraft Flight control Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2011. ENGLISH ABSTRACT: The development of a control allocation system for use as part of a fault-tolerant control (FTC) system in unmanned aerial vehicles (UAVs) is presented. This system plays a vital role in minimising the possibility that a fault will necessitate the reconfiguration of the control, guidance or navigation systems of the aircraft by minimising the difference between the desired and achievable aircraft performance parameters. This is achieved by optimising the allocation of control effort commanded by the virtual actuators to the physical actuators present on the aircraft. A simple general six degree of freedom aircraft model is presented that contains all of the relevant terms needed to find the trim biases of the aircraft actuators and evaluate the performance of the virtual actuators. This model was used to develop a control allocation formulation that optimises the performance of the virtual actuators of the aircraft while minimising adverse effects and avoiding actuator saturation. The resulting problem formulation was formulated as a multi-objective optimisation problem which was solved using the sequential quadratic programming method. The control allocation system was practically implemented and tested. A number of failure categories of varying severity were defined and two aircraft with different levels of actuator redundancy were used to test the system. The control allocation algorithm was evaluated for each failure category, aircraft test case and for a number of differing control allocation system configurations. A number of enhancements were then made to the control allocation system which included adding frequency-based allocation and adapting the algorithm for an unconventional ducted-fan UAV. The control allocation system is shown to be applicable to a number of different conventional aircraft configurations with no alterations as well as being applicable to unconventional aircraft with minor alterations. The control allocation system is shown to be capable of handling both single and multiple actuator failures and the importance of actuator redundancy is highlighted as a factor that influences the effectiveness of control allocation. The control allocation system can be effectively used as part of a FTC system or as a tool that can be used to investigate control allocation and aircraft redundancy. AFRIKAANSE OPSOMMING: Die ontwikkeling van ’n beheertoekenning sisteem vir gebruik as deel van ’n fout verdraagsame beheersisteem in onbemande lugvaartuie word voorgelê. Hierdie sisteem speel ’n essensiële rol in die vermindering van die moontlikheid dat ’n fout die herkonfigurasie van die beheer, bestuur of navigasiesisteme van die vaartuig tot gevolg sal hê, deur die verskil te verminder tussen die verlangde en bereikbare werkverrigtingsraamwerk van die vaartuig. Dit word bereik deur die optimisering van die toekenning van beheerpoging aangevoer deur die virtuele aktueerders na die fisiese aktueerders teenwoordig op die vaartuig. ’n Eenvoudige algemene ses grade van vryheid lugvaartuig model word voorgestel wat al die relevante terme bevat wat benodig word om die onewewigtigheid verstelling van die vaartuig se aktueerders te vind en die werksverrigting van die virtuele aktueerders te evalueer. Hierdie model is gebruik om ’n beheer toekenning formulering te ontwikkel wat die werkverrigting van die virtuele aktueerders van die vaartuig optimiseer terwyl nadelige gevolge verminder word asook aktueerder versadiging vermy word. Die gevolglike probleem formulering is omskryf as ’n multi-doel optimiserings probleem wat opgelos is deur gebruik van die sekwensiële kwadratiese programmerings metode. Die beheertoekenning sisteem is prakties geïmplementeer en getoets. ’n Aantal fout kategorieë van verskillende grade van erns is gedefinieer en twee vaartuie met verskillende vlakke van aktueerder oortolligheid is gebruik om die sisteem te toets. Die beheer toekenning algoritme is geëvalueer vir elke fout kategorie, vaartuig toetsgeval, asook vir ’n aantal verskillende beheertoekenning sisteem konfigurasies. ’n Aantal verbeterings is aangebring aan die beheertoekenning sisteem, naamlik die toevoeging van frekwensie gebaseerde toekenning en wysiging van die algoritme vir ’n onkonvensionele onbemande geleide waaier lugvaartuig. Die beheertoekenning sisteem is van toepassing op ’n aantal verskillende konvensionele vaartuig konfigurasies met geen verstellings asook van toepassing op onkonvensionele vaartuie met geringe verstellings. Die beheertoekenning sisteem kan beide enkel- en veelvoudige aktueerder tekortkominge hanteer en die belangrikheid van aktueerder oortolligheid is beklemtoon as ’n faktor wat die effektiwiteit van beheertoekenning beïnvloed. Die beheertoekenning sisteem kan effektief geïmplementeer word as deel van ’n fout verdraagsame beheersisteem of as ’n werktuig om beheertoekenning en vaartuig oortolligheid te ondersoek. 2011-02-28T08:59:34Z 2011-03-14T08:35:01Z 2011-02-28T08:59:34Z 2011-03-14T08:35:01Z 2011-03 Thesis http://hdl.handle.net/10019.1/6722 en_ZA University of Stellenbosch 178 p. : ill. application/pdf Stellenbosch : University of Stellenbosch |
| spellingShingle | Fault-tolerant control Control allocation system Unmanned aerial vehicles (UAVs) Dissertations -- Electronic engineering Theses -- Electronic engineering Drone aircraft Flight control Basson, Lionel Control allocation as part of a fault-tolerant control architecture for UAVs |
| title | Control allocation as part of a fault-tolerant control architecture for UAVs |
| title_full | Control allocation as part of a fault-tolerant control architecture for UAVs |
| title_fullStr | Control allocation as part of a fault-tolerant control architecture for UAVs |
| title_full_unstemmed | Control allocation as part of a fault-tolerant control architecture for UAVs |
| title_short | Control allocation as part of a fault-tolerant control architecture for UAVs |
| title_sort | control allocation as part of a fault tolerant control architecture for uavs |
| topic | Fault-tolerant control Control allocation system Unmanned aerial vehicles (UAVs) Dissertations -- Electronic engineering Theses -- Electronic engineering Drone aircraft Flight control |
| url | http://hdl.handle.net/10019.1/6722 |
| work_keys_str_mv | AT bassonlionel controlallocationaspartofafaulttolerantcontrolarchitectureforuavs |