Sensor Technology Ltd: Development of a vertical take-off and landing unmanned aerial vehicle is nearing completion, thanks in part to a non-contact digital torque sensor, TorqSense, which proved the only viable option for use on the test rig. The low-cost, flexible search and surveillance unmanned aerial vehicle (UAV) is intended for military, homeland security, policing and environmental monitoring. It is rugged, immediately deployable and can be launched from the ground, ship or even moving vehicles. The vectored-thrust UAV platform is suitable for any situation requiring safe aerial viewing or sensor measurement. It is being developed by SELEX Sensors and Airborne Systems (S&AS), a Finmeccanica company. “The TorqSense technology has been one of the key enablers for the development and implementation of the novel propulsion system on the Damselfy UAV” said Mark Agnew, Selex’s Chief Engineer for UAV Systems. Leading the project is Ashley Bryant, who started out wanting to build a flyable scale-model replica of the vertical take off Harrier jump jet, but quickly saw the potential for a professional UAV. Using a jet engine was out of the question, a ‘cold fan’ solution the only practical option. “A jet engine combusts fuel to turn its turbine and create thrust,” he explains. “Our cold fan is driven, via a drive shaft, by a miniscule but powerful two-stroke engine. Developing this technology required us to build a unique test rig, with an in-line torque sensor so that there were no out of balance forces coming into play.” ...