An adaptive neuro-fuzzy controller for vibration suppression of a flexible structure in aerial refueling

Air-to-air refueling (AAR) has been commonly used in military jet applications. Recently, civilian applications of AAR have been garnering increased attention due to the high cost of air travel, which is largely dictated by the cost of jet fuel. There are two types of AAR approaches: probe-drogue and flying boom systems. This work explores the probe-drogue AAR system in commercial applications. Typical AAR applications deploy a drogue connected to a long flexible hose behind a moving aircraft tanker. The drogue is connected to a probe in a receiver aircraft before initiating fuel transfer and is retracted back into the tanker when the fuel transfer is completed. In order to ensure a safe and efficient refueling operation sophisticated systems need to be developed to accommodate the turbulences encountered, particularly in respect to vibration reduction of the flexible hose and drogue. The objective of this work is to develop a probe-drogue system for helicopter AAR applications. The first project is to make a preliminary design of a new AAR system for helicopter refuelling from a modified AT-802 tanker aircraft. [...

Antidisturbance Vibration Suppression of the Aerial Refueling Hose during the Coupling Process

In autonomous aerial refueling (AAR), the vibration of the flexible refueling hose caused by the receiver aircraft’s excessive closure speed should be suppressed once it appears. This paper proposed an active control strategy based on the permanent magnet synchronous motor (PMSM) angular control for the timely and accurate vibration suppression of the flexible refueling hose. A nonsingular fast terminal sliding-mode (NFTSM) control scheme with adaptive extended state observer (AESO) is proposed for PMSM take-up system under multiple disturbances. The states and the “total disturbance” of the PMSM system are firstly reconstituted using the AESO under the uncertainties and measurement noise. Then, a faster sliding variable with tracking error exponential term is proposed together with a special designed reaching law to enhance the global convergence speed and precision of the controller. The proposed control scheme provides a more comprehensive solution to rapidly suppress the flexible refueling hose vibration in AAR. Compared to other methods, the scheme can suppress the flexible hose vibration more fleetly and accurately even when the system is exposed to multiple disturbances and measurement noise. Simulation results show that the proposed scheme is competitive in accuracy, global rapidity, and robustness

Electro-thermal modelling of large PV array degradation for thermography and peak power conditioning monitoring

Photovoltaic (PV) panels started their long technological development journey at the hands of legendary pioneers such as Edmond Bequerel. He discovered the key solar energy principles in 1839 and following this Heinrich Hertz was credited with the discovery of the photoelectric effect in 1887. Nikolas Tesla developed key patents in 1901 and Albert Einstein published a paper in 1905. This work in 1954 lead to Bell Laboratories producing the first commercial PV cell and since then PV cells have advanced to astronomical levels. This project aimed to model the effects of degradation of photovoltaic panels. The goal was to observe the effects that PV cell failure has on the cells internal resistance, and then determine what effect this had on the performance of the panel’s output. Field trials were also undertaken to detect this heating using an infrared thermograph and to also relate the temperatures to the simulated results. Results showed that any increase in panel temperature above 25°C caused the panel’s output to reduce up to 63% at 90°C. The physical detection of heating or hot spots was successful with six out of the thirty-six arrays having cells with increased temperatures. Additionally, the maximum cell temperature scanned was 61°C which was a 24°C increase from the nominal of the rest of the PV array

Aeronautical engineering: A continuing bibliography with indexes (supplement 262)

This bibliography lists 474 reports, articles, and other documents introduced into the NASA scientific and technical information system in Jan. 1991. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics

Aeronautical Engineering: A cumulative index to the 1984 issues of the continuing bibliography

This bibliography is a cumulative index to the abstracts contained in NASA SP-7037(171) through NASA SP-7037(182) of Aeronautical Engineering: A Continuing Bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, foreign technology, contract, report number, and accession number indexes

Proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress

Published proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress, hosted by York University, 27-30 May 2018

Aeronautical engineering. A continuing bibliography with indexes, supplement 114

This bibliography lists 394 reports, articles, and other documents introduced into the NASA scientific and technical information system in September 1979