Unmanned Systems Technology 002 | Scion SA-400 | Commercial UAV Show report | Vision sensors | Danielson Trident I Security and safety systems | MIRA MACE | Additive manufacturing | Marine UUVs

30 the flight controller. We tell it to start the engine and it starts the engine – that has nothing to do with the autopilot.” It follows that core control of the SA- 400 is concentrated in two modules – an autopilot and a flight controller. In addition, says Jones, “The control electronics include sensor interface boards and things like that. We run a lot of Ethernet between different sensor types and different systems. Then there is an advanced GPS and there are the two radios to talk back down to the ground, a primary link and a back-up. “For the flight controller we are using a standard off-the-shelf single-board computer, albeit one that has a lot of I/O. Aside from its primary function of interfacing between all onboard systems, the flight controller acts as a data logger, although all the data from the various onboard sensors is constantly sent to the ground station in real time via the radio links. The onboard logger is simply a back-up for data logging. “So long as the radio link is open then all the data is sent to the ground station. At any time the operator at the ground station can monitor those inputs, and all the data is logged there, so we can go back and replay everything that went on, should we have an issue with anything. But if at any time we lose the data link between ground control and the aircraft, that data is still being stored on board the aircraft.” The SA-400 is designed primarily to operate in autonomous mode rather than as a remotely piloted aircraft. In the normal manner of autonomous aerial craft, it will automatically follow a predetermined course defined by waypoints. While it can also be remotely controlled within line of sight or via onboard cameras in First Person View style, Mogensen says it isn’t normally operated by Scion UAS in that way. Autonomous operation is no mean feat. As Mogensen remarks, “The pilot can see, sense, smell and so on, but once you take him out of the equation you actually lose about a million sensors and a data processor.” The SA-400’s landing gear is essentially a bent tube on each side of the craft. “But we do have load cells there, to use as a weighing scale,” notes Mogensen. “The autopilot needs to know when the skids are off the ground. This triggers a state change in the autopilot, which is required since trying to fly Spring 2015 | Unmanned Systems Technology Prior to the establishment of Scion UAS in 2011, the founders started the design of a small rotorcraft which became known as the SA-200 Weasel. Further developed by Scion UAS following the formation of the company, this design was based on feedback received from the US Air Force after the completion of the Yellow Jacket project in 2010. The SA-200 is a general-purpose unmanned rotorcraft which is sized such that it can be transported in the back of a pickup truck, and is designed to be launched from its carrier within 10 minutes. It is envisaged for roles such as pipeline and wind turbine inspection, mineral exploration, security and other tasks calling for a camera in the sky. Another possibility is the use of chemical sensors, for example one that allows the identification of radiation on sea-going vessels or one that allows leaks to be found in a natural gas pipeline, through odour recognition. The SA-200 project went on the back burner when Scion UAS won the contract for the larger SA-400, but will be restarted this summer. The SA-200 Weasel Start of another mission for the SA-400 – without pilot