Unmanned Systems Technology 019 | Navya Autonom Cab | Batteries | UGVs Insight | UAV Factory UAV28-EFI | Swiss Aerobotics Hummel | UMEX 2018 report | Antennas | Oceanology International 2018 report

36 T here are many different battery technologies for different unmanned applications, depending on the power, weight and temperature requirements, but there are also significant variations within the technologies themselves. Some may provide power for longer but with heavier batteries than others, while other technologies may work in colder environments such as space. And it’s not just traditional batteries that can supply power. Ultracapacitors and hydrogen fuel cells are increasingly viable options for powering unmanned systems. Electric power from batteries and these other sources is increasingly important for providing fully autonomous operation. Instead of a craft having to be refuelled by hand, wireless charging for example allows an unmanned platform to be truly autonomous, returning to a charging site when power is low. More electric cars and trucks are being launched every year with a view to driverless operation, but there is a key trade-off between battery charging time and range. If a battery pack can be charged safely in a matter of minutes then a longer range (whether that be in terms of larger capacity or a higher energy density) is less important. This faster charging time is enabled by different materials for anodes, cathodes and electrolytes, as well as a new generation of sensors within the battery to prevent it from overheating. Structure of a battery In a battery, the positive anode and negative cathode (the electrodes) are separated by an electrolyte that allows metal ions to travel from one to the other – from the anode to the cathode to supply electrons for current, and the other way round when charging. As battery power grows in importance for unmanned systems, Nick Flaherty looks at the range of available and emerging technologies Charge accounts April/May 2018 | Unmanned Systems Technology Lithium-sulphur batteries are being used for unmanned underwater vehicles (Courtesy of Steatite)