Unmanned Systems Technology 015 | Martin UAV V-Bat | William Sachiti | Sonar Systems | USVs | Desert Aircraft DA150 EFI | SeaCat AUV/ROV | Gimbals

63 techniques, for which it built the MiniC open-frame test vehicle. The goal was to develop advanced onboard diagnosis and recovery capabilities using artificial intelligence, and the use of back-up and recovery mission plans in response to events, for example avoiding an obstacle and continuing with the mission. Next came the Grex project, an effort that ran from 2006-9 to develop coordination and control techniques for groups of cooperating unmanned systems in uncertain environments. This project saw Atlas’ first implementation of multi-AUV control and improved external control and mission re-planning capabilities. Atlas’ SeaBee experimental AUV served as the workhorse and test bed for this programme, working with other AUVs such as AUVortex and Aster from French maritime research organisation Ifremer, the DELFIMx catamaran ASV and a manned vessel. The next significant project in the SeaCat’s evolution was a harbour- mapping project called CView that aimed to develop an inspection system for vertical harbour structures such as piers and ship hulls. The idea was to create composite 3D images of these structures using a high-resolution multi-beam echo sounder and a laser sensor. Supported by the German Ministry of Economy and working with partners including the DFKI Robotics Innovation Center (which integrated a sensor head that Atlas fitted to a modified SeaWolf mine disposal vehicle), the company implemented a set of upgrades to the SeaWolf that were so extensive that the modified vehicle was renamed the SeaCat, effectively becoming the first prototype. The first set of modifications added vertical and horizontal thruster sections aft and forward of the centre section, which itself received a fin to house comms antennas and a recovery eye housing, as well as a new nose with the echo sounder and laser sensors. However, it retained the SeaWolf’s X-shaped tail and four ducted propellers. The SeaCat’s anatomy The next iteration brought it to its current configuration, in which the most obvious change is a new tail section that houses a three-bladed propeller from SPW, a propulsion motor from an undisclosed source and the cruciform assembly of vertical and horizontal stabilisers, rudders and elevators, all operated by individual actuators made in-house. Next is a section housing vertical manoeuvring thrusters for pitch control at very low speeds. After that is the centre section that houses lithium-polymer batteries from BMZ. SeaCat AUV/ROV | Digest Unmanned Systems Technology | August/September 2017 The SeaCat starts a dive in hover mode. Horizontal and vertical manoeuvring thrusters provide good control at low speeds and in tight spaces The SeaCat can be likened to a Swiss Army knife because of the variety of interchangeable sensors in front- mounted modules