The dynamic modelling and control system of a tethered aerostat for remote sensing applications

Fourie, Daniel Andries (2009-12)

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2009.

Thesis

ENGLISH ABSTRACT: Aerostats and Stratolites could play a major role in expanding current satellite and other technologies in the near future. A study was made on the development of aerostat platforms and the current state of Stratolite development. The aim was to develop an airship system that is capable of maintaining a specific position regardless of the presence of wind. The various applications of such a geostationary platform are discussed. A dynamic model of an airship was developed and a simulation was implemented in software. This was done to study the possibility of developing aerostats like these. A tethered airship system was developed and built to demonstrate that it is possible to control the position of an airship. The airship system uses current technology in an unique combination to fulfil the requirement of remaining stationary despite the influence of wind. Various control system design techniques were used to implement the controllers. Linear models of the airship system were identified practically and used to design the controllers. The controllers were tested in simulation as well as practically and the results of these tests are given. It was concluded that there exists potential for the development of Stratolite systems, although there exists a fair amount of challenges and obstacles that would need to be overcome before this technology could be implemented.

AFRIKAANSE OPSOMMING: Aerostats en Stratolites kan ’n besondere rol speel in die uitbreiding van huidige sateliet- en ander aardwaarnemingstoepassings. ’n Studie is gemaak oor die ontwikkeling van Aerostat platforms en die huidige stand van Stratolite ontwikkeling. Die mikpunt was om ’n lugskipstelsel te ontwikkel wat in staat is om ’n spesifieke posisie te handhaaf ten spyte van die invloed van wind. Die verskeidenheid van toepassings, waarvoor so ’n geostasionêre platform gebruik kan word, word genoem. ’n Dinamiese model van ’n lugskip is ontwikkel en die stelsel is in sagteware gesimuleer. Dit is gedoen om die moontlikheid te ondersoek om sulke Aerostats in die toekoms te ontwikkel. ’n Lugskipstelsel, wat aan die grond geanker word met ’n kabel, is ontwerp en gebou. Die stelsel is gedemonstreer en daar is bewys dat dit moontlik is om die posisie van die lugskip te beheer. Die lugskip gebruik huidige tegnologie wat in ’n unieke kombinasie saamgevoeg is om te illustreer dat dit moontlik is vir die lugskip om stasionêr te bly ten spyte van wind. Verskeie beheerstelsels ontwerptegnieke is gebruik om die beheerders mee te implementeer. Lineêre modelle van die lugskip is prakties geïdentifiseer en is gebruik om die beheerders te ontwerp. Die lugskip se beheerders is in simulasie sowel as prakties getoets en die resultate van hierdie toetse word gegee. Die projek bevestig dat daar ’n potensiaal bestaan vir die praktiese ontwikkeling van Stratolite stelsels. Daar is egter ’n hele paar uitdagings en probleme wat eers uit die weg geruim sal moet word, voordat hierdie tegnologie ’n alledaagse werklikheid sal word.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/2984
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