Uncrewed Systems Technology 044 l Xer Technolgies X12 and X8 l Lidar sensors l Stan UGV l USVs insight l AUVSI Xponential 2022 l Cobra Aero A99H l Accession Class USV l Connectors I Oceanology International 2022

102 machines with automated mechanisms for loading pin contacts into their housings. Robotic insertions are far less labour- intensive and often faster than manual loading or ‘swaging’, where contacts are pushed by hand into their through-holes and then cooled. Such machinery can also be quality controlled in an automated fashion using laser or camera scanning of the pins and housings. When it comes to mating wires to pins, although crimping remains the most popular approach and automated crimp machines are becoming more and more widespread, major advances have been made in the designs and techniques related to soldering. Some connector manufacturers now solder 90% of their connections and crimp the other 10%. These often relate directly to advances being demanded in high-end autonomous vehicle connectors. For instance, in very small circular connector designs, which can now feature up to 30 contacts in 14 mm-diameter connectors, it can be difficult to get a close fit using crimping tools. One solution is to design solder cup terminals – arrangements of pin back- ends intended to ease the process of precisely applying the molten solder – in a ‘Christmas tree’ configuration. Here, the central contact is longest and hence sticks out further than those around it, while the contacts become progressively shorter in concentric circles away from it. That allows engineers to solder from the centre, moving outwards for a generally straightforward and easy termination process. This is essential for vehicle manufacturing and assembly suppliers, who need to be able to terminate their conductors in-house, as even the best connector in the world will find little demand if it is too time- consuming and difficult to work with. Comms protocols The reach and rate of advances in the uncrewed vehicles industry are also driving the adoption – and in some cases, creation – of entirely new comms protocols in order to ensure that data is transmitted and received at ever higher bandwidths, speed, fidelity and more. For instance, different standards for USB 3.2 and a number of newer types of CAN bus are among those published in the past several years that are likely to see growing interest for uncrewed air, sea and land vehicles in the years to come. Meanwhile, Gigabit Ethernet has seen widespread uptake for the data speeds and bandwidths it enables, and the new industrial standard SPE (Single Pair Ethernet) is being adopted by military and medical users, as well as across IoT systems. In order to ensure that companies’ inventories of connectors are not rendered obsolete every few years by the advent of new comms standards, connector developers keep track of certain key parameters to help future- proof their designs so that they can still carry more and more advanced and complex protocols. ‘Clearance’ and ‘creepage’ are of paramount importance among these. While the former has been explained above, creepage refers to the minimum distance between pins as measured when running along the physical surface of the insulating material (as opposed to straight-line distance). Minimising these means squeezing pins closer together and potentially fitting more connections into a given space. However, enough space and dielectric material such as PEEK must exist between each contact to ensure arcing does not occur, otherwise connection failures or even fires can occur. And increasingly, new kinds of inserts must be designed and produced to ensure sufficient space and arrangements between contacts to pass protocol standards. Signal integrity engineers continue to experiment with different approaches to optimise pin spacings, material choices and contact types for new data configurations. They are also combining them with more established technologies such as the aforementioned latches, backshells and new solder terminals to better specialise in what the uncrewed sector needs. Conclusion Just as UAVs cannot run well on engines taken from chainsaws or lawnmowers, plugs from existing high-power or high- frequency applications are rarely optimal for use in autonomous vehicles. The connectors industry is therefore growing and innovating fast to match the pace of the world of uncrewed systems. With innovations emerging across the board, it is worth keeping a close eye on new products coming out in the years ahead. Acknowledgements The author would like to thank David Ptacek at Fischer Connectors, Derek Hunt and Travis Neumann at Omnetics, Steven Lassen at LEMO, Damon McMillan at Blue Trail Engineering, and Rustom Jehangir at Blue Robotics for their help with researching this article. June/July 2022 | Uncrewed Systems Technology Pin creepage and clearance must be tracked closely when future-proofing connector designs for new comms standards across Ethernet, USB and other protocols (Courtesy of Fischer)