The system – which carries 400 kilograms of fuel (about 880 pounds) and is capable of refueling another UAV – is operated by a computer in the refueling UAV.Unmanned aerial vehicles are often used in military operations and surveillance missions. But a major unsolved problem facing the UAV operation has been one of refueling for long missions. Manual refueling is expensive and time consuming, and if the mission is over hostile territory, can be very dangerous.

But at the Technion – Israel Institute of Technology, a group of Israeli students, guided by their professors, have found an alternative: a system that enables refueling from one UAV to another. This automated UAV to UAV refueling procedure allows vehicles to remain airborne an additional 36 hours without refueling.

Guided by Professors Benjamin Landkof and Robert Zickel, 10 Technion students in the Aerospace Engineering program worked on the task over the past year. The project was presented last week at the 47th Israel Annual Conference on Aerospace Sciences in Tel Aviv and at the Technion.

According to student Dotan Weinstein, the project was conceived as part of a class assignment.

“The project was part of a required course for undergraduate students at the Technion, to enable us to acquire additional expertise in receiving instructions, overcoming problems and team work,” he told ISRAEL21c. “The idea is to invent an innovative system over the course of a full year that goes from concept, first idea, continues with surveys, and ends with the implementation of the chosen idea after the integration of all the adjustments.”

The team spent the first semester carrying out surveys, and upon their conclusion, decided to focus on developing a refueling system and not a UAV refueler.

“We initially decided to develop an unmanned refueling UAV in order to duplicate the endurance of UAVs. We assumed that it would be low-cost, and based it on the existing platform, like one of the observatory UAV’s without the cameras and the other equipment. We made some videos and eventually decided only to develop the refueling instrument and not the refueling UAV,” said Weinstein.

First developed in the 1920s, midair refueling had a slow start. While now most combat aircraft are capable of such refueling, it is still considered to be complex and done manually.

“We developed an algorithm that took the camera signal and calculated how we should drive the boom toward the receptacle,” explains Weinstein, referring to the ‘boom and receptacle’ technique of aerial refueling in which a long shaft around a tube, called a boom, is fitted to the receptacle in the receiving aircraft.

The camera focuses a small red light that marks the target, calculates the distance between the pipe and the fuel opening. It then instructs the wings that guide the fuel pipe towards the opening. The camera is also able to extend its length, from six to twelve inches, if necessary.

The system – which carries 400 kilograms of fuel (about 880 pounds) and is capable of refueling another UAV – is operated by a computer in the refueling UAV.

While companies like Boeing are testing similar systems, there is currently no system on the market that can refuel one UAV using another unmanned aerial vehicle. According to the Technion, the results of the student project aroused interest at a recent conference on ariel refueling.

While not yet ready for market, the Technion system would not be difficult to adapt into a working product according to Weinstein. “It’s very partial because we made some assumptions and we simplified the problem but I think that if someone would want to develop it, he can. He has a base.”

Perhaps next year’s Technion class will take care of that.