Unmanned Systems Technology 014 | Quantum Tron | Radio links and telemetry | Unmanned Aerial Vehicles | Protonex fuel cell | Ancillary systems | AUVSI 2017 Show report

14 Platform one June/July 2017 | Unmanned Systems Technology Bluerobotics has teamed up with Norwegian technology developer Water Linked for a revolutionary low- cost underwater GPS system (writes Nick Flaherty). The Water Linked underwater GPS developers’ kit combines a traditional GPS receiver and compass with an acoustic positioning system to provide positioning information underwater. The system will be used on Bluerobotics’ ArduSub and the BlueROV2 remotely operated vehicles. The system uses Short Baseline acoustic positioning, where the craft has a locator beacon that sends out an acoustic pulse. Near the surface, four receiver hydrophones are lowered into the water from a support vessel. The hydrophones listen for the pulse from the locator beacon and use the difference in the time of arrival to each receiver to triangulate the craft’s position. This has the advantage of working well in shallow water and noisy acoustic environments. Researchers at the Bristol Robotics Lab (BRL) in the UK are developing a robot with a new propulsion technique inspired by flying snakes (writes Nick Flaherty). Some species of snake can travel horizontal distances of up to 50 m from trees by undulating their bodies, and Enrico Werner at BRL is developing a robot system that emulates that motion. Elements of it are being tested in a wind tunnel. The test system uses designs with the same aerodynamic aspects – the Reynolds number – as the flying snakes. The mechanism will be capable of imitating the staggered in-air posture of Once the position relative to the receivers is known, the global position can be found by adding that to the position obtained by a GPS receiver to give the actual global position of the craft as the output. That means photos from inspections can be geotagged, targets with known coordinates can be found easily, and the the snakes and the relative movement of two parallel body segments perpendicular to the gliding direction. Each model can move vertically craft can be programmed to carry out autonomous actions such as holding position in a current or following a set of GPS waypoints. Bluerobotics is tweaking the performance of the system and adding an application programming interface to make it easier to integrate it into an ROV or AUV design. The first systems will ship in June 2017. and horizontally, and rotate around its longitudinal axis. The system would also require a new type of control system, which is part of the three-year project. Price set to plunge for GPS Snake idea could have legs Underwater vehicles Propulsion Acoustic pulses provide a cost-effective underwater positioning capability Building a robot that flies like a snake will provide insights into new propulsion and control systems