Unmanned Systems Technology 009 | Ocean Aero Submaran S10 | Simulation and testing | Farnborough report | 3W-110xi b2 TS HFE FI | USVs | Data storage | Eurosatory/UGS 2016 report

12 Platform one August/September 2016 | Unmanned Systems Technology Low-profile UGVs, especially those used on other planets, are limited in how far their sensors can see, and in the height of obstacles they can see over, by the height of any masts they can accommodate, particularly if that mast must fold for storage or transport (writes Peter Donaldson). Micromo’s Zippermast is designed to overcome these problems with a design inspired by the zip fastener and the metal tape measure to enable surprisingly tall masts to collapse into short housings. For example, the ZM4 mast is 4 ft high when extended but folds down to just 6 in, while its taller ZM8 sibling extends to just over 8 ft high but folds down to 9.84 in, according to Micromo. Using the metal tape measure’s ability to extend without kinking thanks to its curvature, inventor George Woodruff took three steel tapes and arranged them so that they would link together like the teeth of a zip fastener as they extended, to form a stable mast. Made from spring tempered stainless steel, the tapes are wrapped around coils at 120° to each other when stored. In the centre is a guide spindle with bevelled slots in it that unrolls the tapes to form a mast as it turns, driven by a small dc motor from Faulhaber, and the jagged outer edges of the tapes interlock as they extend, so that the mast supports itself and its load. Micromo emphasises that it can be set in any position between stowed and fully extended without any additional locking mechanism, as the guide spindle can only be moved in rotation. Bavarian UGV builder progenoX uses Zippermast units on its UGVs and is investigating other applications, including on spacecraft. Mast design has it taped Hardware The US Navy has been testing a prototype UUV powered by automotive fuel cells from General Motors (writes Peter Donaldson). The Long Duration Unmanned Underwater Vehicle – Innovative Naval Prototype (LDUUV-INP) has completed pool tests at the Naval Surface Warfare Center in Carderock, Maryland, in preparation for sea trials later this year. The programme aims to develop a vehicle with an endurance of more than 60 days in support of the US Navy’s plans to deploy a squadron of next-generation UUVs by 2020. Working with the US Naval Research Laboratory and the Office of Naval Research, GM provided a proton exchange membrane fuel cell stack from its Project Driveway fuel cell vehicle effort, which has logged more than 3 million test miles on more than 100 Chevrolet Equinox SUVs since 2007. While automotive applications use compressed hydrogen and atmospheric air, UUVs must store both hydrogen and oxygen. No specific details have been released on how this is managed aboard the LDUUV, but chemical storage of hydrogen in metal hydrides and cryogenic storage of liquid oxygen are thought promising. Using a fuel cell developed for cars brings big potential benefits from economies of scale, but the environmental unfriendliness of fracked natural gas as the dominant source of hydrogen might prove politically unacceptable and prevent the automotive industry from achieving such economies. UUV in car fuel cells project Underwater vehicles Using fuel cells from the car sector for the LDUUV could bring economies of scale Zippermast’s design is inspired by the zip fastener and the metal tape measure