“Back in the 80’s, we were world leaders when it came to drone technology with the early days of the Seeker project and so forth. We’ve fallen a bit behind on the manufacturing but nonetheless we seem to catching up again.”
These were the opening remarks by Paul Mooney, consultant at Port Elizabeth’s Nelson Mandela University, regarding the development of drone technology at the Africa Drones Conference held virtually on 27 and 28 August.
Mooney is the representative of a group called, “MandelaUni Autonomous Operations Group”, that specialises in and accelerates drone development from conceptual level to prototyping. One of their highlight projects is a hybrid power heavy-lift drone or UAV (Unmanned Aerial Vehicle).
The MandelaUni Autonomous Operations Group is an independent lab where post-graduate, masters and PhD students are able to join on a volunteer basis. The group classifies itself as a ‘hub’ with specialised individuals including commercial pilots, ex-military test pilots, development engineers and a full-scale aircraft designer and manufacturer that help fast track the development of autonomous vehicles.
“Ultimately, we want to be a centralized drone unit for the university, we are applying for our ROC [Remote Operator Certificate] at the moment, just at a corporate level. We only want to do work for the students so we are not a competitive, commercial group,” said Mooney.
The MandelaUni Autonomous Operations Group, which was established in 2017/2018, does a considerable amount of production work but also focuses on system integration.
The manufacturing capabilities of the lab include large scale aeronautical design, rapid prototyping and manufacturing, large scale 3D printing, composite fabrications and flight test programmes. Mooney said the lab is able to turn an aircraft out at a rapid rate. The lab can create a test platform within a month of a concept being conceived.
Initially, Nelson Mandela University pushed for the lab to do AI (Artificial Intelligence) projects. “We are hoping to pull the human out of the equation and replace the human with some sort of on-board computer that can make decisions for you,” said Mooney. The first AI project was for a UAV to deliver a payload to a ship that is too big to stop moving. This masters project was able to teach a UAV to recognize shapes, animals, people and ships. Once the aircraft gets given the last coordinates of where the ship was, it gets airborne, flies to the last-known coordinates and starts a search pattern, looking for the ship all by itself. The aircraft is taught to recognize a communication flag on the ship and once it has done so, it begins orbiting the ship, calculating the vessel’s speed and direction. The UAV also has a sensor package that can be dropped next to the shape, animal or human it identifies.
Another UAV the lab developed, also meant to fly out to ships, was a double motor fixed-wing UAV, consisting of two independent motors working side-by-side. “It’s actually two aircraft flying in formation. Each part is completely independent of the part next to it,” said Mooney.
The lab is also experimenting with alternative energy sources for drones. Utilizing a UAV with a four metre wingspan, the lab fitted solar panels to the top of the UAV’s wings to test how long the aircraft could stay in the air with the idea of it being an aircraft relay station. This aircraft would stay at high altitudes and relay information to UAVs moving through lower altitudes. The lab gives the aircraft a simulated airborne time of over seven hours on solar on an average day with a further two hours on battery although it has not been practically tested.
“We’re definitely not at the 24-hour stage yet but to achieve that you have to do things like climb up to 60 000 feet during the day and fly it down during the evening,” added Mooney. The project was successful as the lab now has the data to move onto larger aircraft which Mooney said they are heading towards.
Another AI project the lab worked on with a master’s student was a security rotor wing UAV. The idea behind it is that the UAV can detect objects, people and animals and intercept alarm triggers that are sent to security companies. Upon intercepting the relevant alarm trigger, it’s weatherproof “nest” would open up, the UAV would be airborne in 15 seconds, fly to the GPS coordinates within 30 seconds and provide live feedback of the property to the control room. Using AI, the UAV would attempt to identify the criminal and start to follow them. Due to legalities, it was unable to be tested in a residential area but was tested in a controlled environment. “That technology does work, as soon as we get our clearance that project is ready to go,” stated Mooney.
A big project the lab is currently working on is to get autonomous water-borne drones out to sea for ocean sciences. The drones are long-term data capturers that look like mini-torpedoes with winglets on either side. The drone glides down and flies up through the water by taking in and expelling water. It sinks or glides down at a 45-degree angle to a depth of 6 000 metres (which takes a few hours) and then expels water to become buoyant. The drone then reaches the surface, relays the information gathered via satellite and start its descent again.
Funding is a major challenge for the lab’s AI water-borne “glider” drone. “The biggest problem being in South Africa is money as you can imagine. Money in the right places. So, for us to get these gliders out to sea, we start to hire very large research vessels at hundreds of thousands of rands per day or we take one out at a time in a glorified fishing vessel,” Mooney said.
As a result, the lab is only deploying the glider drone twice a year. MandelaUni Autonomous Operations Group for the past year and a half have been working to try find a solution to the costs of deploying their glider drone. Mooney said the lab is developing two options: the first is a water-borne drone that carries the glider drone 50 km out to sea, deploys the glider drone, follows the glider drone and when the glider drone surfaces, acts as a relay station, relieving the glider drone of communicating the data to satellites.
The second option is a UAV that can carry a glider drone, that weighs between 50 to 100 kgs, 50 km out to sea and gently deploy the glider drone. Mooney said the lab is working on a hybrid powered vertical take-off and landing (VTOL) UAV. This UAV would have petrol-powered motors that can tilt 90-degrees to provide vertical and horizontal thrust while the electric motors are only used for stabilization. The lab’s concept VTOL UAV (at 75% to scale) is seven metres across, uses four electric motors for stability, two 70 kg petrol motors, has a payload of 80 kg and has a range of 100 km.
The lab has tested the take-off, landing and transition from hover to flying of a scaled down version of the VTOl UAV and it was successful. The lab has now began building a 75% to scale version of the aircraft, using electric motors instead of petrol-powered motors for the prototype. To build this aircraft and ones like it, the lab developed their own equipment such as a large-scale milling machine. The VTOL UAV is having its final electrics installed as the lab recently installed batteries from a Nissan Leaf vehicle to the front and rear of the aircraft.
In concluding his presentation, Mooney said a student represented the lab and South Africa for drone technology at WorldSkills (the world championships of vocational skills held every two years) 2019 in Russia. The student placed third out of the 85 countries represented.