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

28 board, we are highly dependent on the power system.” Standard aircraft navigation lights are used. The primary communications between ground station and the craft is an off-the-shelf 2.4 GHz Wave Relay wi-fi system supplied by Persistent Systems, and is a Mobile Ad Hoc Networking (MANET) solution originally developed for military use. The basic concept is that each device in the network, in addition to its regular functioning, acts as a router, forwarding traffic unrelated to its own use. Consider a situation in which a primary transmitter can reach a certain device but not a more distant one, over the horizon. It is conceivable that if the transmitter were positioned at the location of the first device, it could then reach the further device. That is where MANET comes in, with the first device automatically re- transmitting the signal to the second. This infrastructure-less Wave Relay mesh network is self-forming and self-healing. As a back-up there is a more conventional 900 MHz wi-fi link (although that frequency is not authorised for such use in the EU, so there is an alternative available for vehicles being exported there). Thus there are two separate radios on board the craft; two separate links between it and the ground station. Moreover, the SA-400 is designed to allow for easy replacement of the standard communications radios, either with other civilian radios or military radio systems. SA-400 control To control a helicopter, the main rotor has blade pitch control which is activated through an articulated swash plate that pivots on its hub to manipulate the individual rotor blades. To control the direction of force, front/rear/left/right, the blades are manipulated individually depending on their position through the circle of rotation. The input for this action comes from the Cyclic control, which tilts the swash plate in the desired direction. To control the lifting force of the rotor, the blades are manipulated together by moving the swash plate up or down, which will increase or decrease lift throughout the entire rotation. This is accomplished with the Collective control. Spring 2015 | Unmanned Systems Technology Dossier | Scion UAS SA-400 optionally piloted helicopter Foreground left, Steen Mogensen, centre, Jim Sampson, right, Phillip Jones with an SA-400 The SA-400 is capable of a very wide range of missions, from agriculture to naval defence