Unmanned Systems Technology 026 I Tecdron TC800-FF I Propellers I USVs I AUVSI 2019 part 1 I Robby Moto UAVE I Singular Aircraft FlyOx I Teledyne SeaRaptor I Simulation & Testing I Ocean Business 2019 report

31 Tecdron TC800-FF | Dossier current protection, implements safety procedures in case of excessively high or low temperatures and balances the state of charge across all the cells. A charging port on the back of the vehicle can be used to recharge both batteries without removing them, or individually when removed. The first method takes around 4 hours and 20 minutes, while the second takes less than 3 hours and 10 minutes, Breuiller notes. The quoted maximum run time of 6 hours, says Breuiller, is achievable under ideal conditions. He emphasises that several factors influence the running time in a given mission, including the weight of the payload the vehicle is carrying, the nature of the ground over which it is travelling and the operator’s driving style. “We’ve worked with a judicial officer to have the running time certified, under operating conditions that were representative of those under which firefighters use the TC800-FF,” he says. For example, with a 500 kg payload, the running lights on and in steady-state, non-stop driving it can keep going for more than 4 hours and 15 minutes, he says, adding that exhausted batteries can be quickly swapped for fully charged ones in the field, as they are mounted in drawers on the vehicle. The drawers are behind waterproof side covers at the rear of the UGV, and are secured using knobs that screw on and off without the need for special tools. Normally, the power that the TC800-FF delivers and the speed at which it travels are limited by its software to 12 kW and 3 kph, to maximise the reliability and longevity of its components. However, it can deliver up to 26 kW at 3.8 kph and travel at up to 6 kph if necessary. “The worst-case scenario is when we ask the TC800-FF to rotate on its own axis with its 800 kg maximum payload and on a surface with a high level of grip, such as tarmac or concrete,” Breuiller says. Although the Paris Fire Brigade and other customers asked for a 500 kg payload capacity, Tecdron decided to build in a significant margin, which led to the TC800-FF’s 800 kg capacity. Mammana explains, “Moving a huge payload is in itself quite easy, but moving it for several hours is much more difficult. We want to offer a robot that can handle its maximum payload throughout its battery endurance without malfunction.” Navigation and control The TC800-FF’s primary navigation sensor suite integrates a GNSS receiver from SBG Systems that processes both GPS and GLONASS signals supplemented by an inertial measurement unit. The navigation algorithms the vehicle uses are programmed into the embedded computer, and operators can control it via an OpenStreetMaps interface. Tecdron also offers several options for direct remote control, including rugged remote control (RC) units, smartphones and tablets that can display images from cameras and other sensors. Semi-autonomous mode allows operators to have the robot follow a firefighter from point A to point B carrying a load, for example, then repeat the route by itself for as long as required. As yet, the TC800-FF does not have collision avoidance capabilities, but Tecdron is working on that. In either mode, and by default, if all comms are lost or there is no new command within a given time, the TC800-FF stops moving immediately. However, its software will act autonomously by turning the water nozzle to a protective position to save it from fire, for example. In firefighting, the TC800-FF would typically be used in RC mode for tasks such as attacking fires underground, or where there is a high risk of explosion or exposure to dangerous chemicals, gases or radiation. For jobs like these, the vehicle would be fitted with a remotely aimed nozzle fed by a hose that serves as a water cannon, a thermal camera and other sensors appropriate to the specific risks that the firefighters anticipate. Another example would be the use of an extractor fan on the vehicle to clear smoke from the site of an incident. Firefighting is among the most demanding applications to which the UGV can be put, as that obviously exposes it to very high temperatures, water, other fire extinguishing and suppression media along with general dust, grit and dirt. Unmanned Systems Technology | June/July 2019 Capable of working with a variety of radio systems, this remote control device is one of several options for managing the vehicle (Courtesy of Tecdron)