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Title: Control system design for autonomous air-to-air refuelling
Author: Bhandari , Ujjar
ISNI:       0000 0004 5915 2164
Awarding Body: University of Bristol
Current Institution: University of Bristol
Date of Award: 2014
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A wide range of Unmanned Air Vehicle applications have been identified over the last decade, both for civilian and military usage. The Air-to-Air Refuelling capability is perceived as an advantage to future support and deployment of mid-large scale Unmanned Air Vehicles to meet operational requirements. Despite Autonomous Air-to-Air Refuelling drawing a lot of attention and research in general, bow wave effects in an Air-to-Air Refuelling scenario have received little attention. Some existing studies have discussed and attempted to model the effect of the bow wave from a comparatively large receiver (B-2, C-17) onto the tanker (KC-135) during boom refuelling. However the effects of bow wave from the receiver aircraft onto the drogue in a probe and drogue refuelling system have received very little attention. This thesis analyses the effects of the receiver's bow wave on the drogue in a probe and drogue based Air-to-Air Refuelling activity, with results suggesting its critical influence on the capture rates of Autonomous Airto- Air Refuelling simulation. This work has developed a state of the art literature survey of Air-to-Air Refuelling including the developments in the sensor models, numerical modelling concepts, control methodologies and simulation and test facilities. By performing multiple random simulations a novel way of quantifying capture rates in aerial refuelling simulations has been developed. Compensating the bow wave effects through the use of position offset is simple yet effective solution emerging from this work. This method was found to restore the loss in performance in the Autonomous Air-to-Air Refuelling simulation which results from the bow wave interactions. On the other hand, the ability to optimise these position offsets for a given condition makes it suitably applicable to different flight conditions. Another major contribution is the various capture strategies presented in this thesis which demonstrate several ways of approaching the drogue in the capture phase for successful engagements. Results demonstrate further gains in terms of capture rates by avoiding drogue chasing in the simulations. Additional unconventional and innovative concepts to drogue capture are also discussed. This work forms part of the Autonomous Systems Technology Related Airborne Evaluation & Assessment programme in the UK.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available