DAVE COLLINS Gas is receiving significant global attention, especially in South Africa, where either gas or nuclear, or both, could replace coal as the main source of electricity
The 2014 class of interns at the Denel Dynamics Engineering Academy of Learning (EAL) is now well into meeting the challenge that has been given to it. The EAL is based at the main Denel Dynamics facility in Centurion, south of Pretoria, Gauteng, and serves to take newly graduated engineers and technologists and introduce them to the realities of product and system development, within the framework and ethos of Denel Dynamics. This is achieved by setting each class a challenge – a system that they must develop to demonstration phase within a calendar year and within a tight budget.
“What we’ve done this year is to give them a project to put together a microUAV [unmanned air vehicle] surveillance system, with the mission of relaying video of an object 100 m away from a ground station,” reports EAL manager Shahen Naidoo. “Whether the microUAV should be fixed wing or rotary wing was not specified. That was left up to them. Part of the challenge is that the video images have to be relayed from four directions simultaneously. That is, there must be four microUAVs circling the object, constantly relaying the video, for a period of 60 minutes. In addition, each microUAV has got to fit into a 17" backpack.”
The interns must demonstrate their system by December. They spent the early part of the year undertaking research and developing their concept. They decided that the best type of aircraft to fulfil the requirement was a quadcopter, a type of helicopter which flies using four rotors. Model aircraft-type UAVs are commercially available in this format. “They’re progressing quite nicely,” he says. “They have bought one [quadcopter] UAV for trials purposes.” However, such commercially-available micro aircraft are not suitable for the mission that has to be fulfilled, as they do not meet all of the required specifications. Consequently, the interns are having to develop their own model. Currently, they are building the prototype of their microUAV. Their plan is to build eight in total (so they will have spares to ensure that they can provide the required video for the required time).
This year, the EAL has 22 interns, of which 21 are working on the microUAV system. The 22nd is based at Denel Dyanamics Spaceteq, in Stellenbosch, in the Western Cape, and he is following a different, space-centric course there. Of the 22 interns, 13 are men, nine are women, 13 are African, five are Indian South Africans, two are coloured and two are white. The 21 based in Centurion are divided into three teams, one working on the microUAV airframe, one on the ground control station and the third on the communications, including the video system.
The 2013 class of interns was required to develop an intelligent grenade system, comprising an intelligent grenade launcher firing intelligent grenades. Key requirements to be met included the grenade being able to change course in flight and hit a 0.5 m × 0.5 m window, offset from the weapon’s original trajectory, in five shots or less. The interns could not use compressed gas or pyrotechnics to power the launcher or propel the grenade. In response, they successfully developed a technology demonstrator comprising a spring-powered launcher and a winged and steerable grenade, proceeding through all the stages up to and including flight testing.
In 2012, the then EAL interns designed and developed a Cubesat – a nano satellite with dimensions of 10 cm × 10 cm × 10 cm. Named DynaCube, it is designed to fulfil a scientific mission: to use radiation sensors to study a phenomenon known as the South Atlantic Magnetic Anomaly, where radiation levels are higher than over the rest of the globe at low earth orbit altitudes. (It is believed that it was high radiation levels in the anomaly that crippled South Africa’s Sumbandila satellite.) The company hopes to get DynaCube launched into space and that, once launched, DynaCube would be able to operate for at least a year.