Unmanned Systems Technology 023 I Milrem Multiscope I Wireless charging I Logistics insight I InterGeo, CUAV London & USA show reports I VideoRay Defender I OS Engines GR400U-FI I Ultrabeam Hydrographic Ultra-2 I IMUs

34 A ny autonomous platform that needs a person to plug it in to a source of power to recharge it presents a compromise in its benefits, so developers are looking at ways to provide that power wirelessly. Techniques range from using robotic connector systems to inductive and capacitive charging that work at distances of a few centimetres up to several metres. There are even projects looking at using lasers to power UAVs in flight by illuminating solar panels on the craft. What is becoming apparent though is the trade-off between the cost and complexity of the base station and the power receiver in the unmanned system. If the base station is simple and low cost then a lot of them can be rolled out to provide a chain of charging points for craft such as UAVs. However, the receiver in the aircraft has to be as simple as possible, as size and weight are paramount design considerations. This is leading to a growing demand for wireless systems to provide enough power to keep an aircraft flying while it’s charging – eliminating the need for a UAV to land – while minimising the cost of the power delivery system on the ground. There are many similarities between the needs of the different unmanned platforms and the various wireless charging technologies. For example, using capacitive resonant technology to keep a UAV flying while charging is similar to charging a driverless car as it travels along a road. Similarly, the same type of magnetic inductive charging that could be used to wirelessly charge a UAV or UGV from a nearby plate can also be used underwater for a UUV. Many of the wireless charging approaches are based around inductive charging, via either a magnetic field generated by coils or a capacitive field generated by a flat plate of metal. This modulates an electric field at a particular frequency, usually in the megahertz Nick Flaherty looks at the various wireless charging technologies that promise to keep unmanned vehicles in operation for longer No plugs here December/January 2019 | Unmanned Systems Technology Inductive charging from the medical industry has been adapted for UAVs as well as ground vehicles (Courtesy of Wibotic)