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

98 June/July 2022 | Uncrewed Systems Technology Focus | Connectors correctly with the right pin clearances and geometries to ensure that end-users can mate and un-mate them as smoothly as with conventional plugs. Considerable design lab resources must accordingly be devoted to them, as extensive trial and error is often needed to qualify the micrometre accuracy of their designs before investing in moulds and tooling to make the final prototypes. And even once their design has been qualified in-house, hermaphroditic connectors remain less tried and tested than the typical male-and-female pairings. It is therefore not uncommon for prototypes to be sent to potential customers for beta testing, to ensure they can work in the various areas and operating conditions of their intended application before investing in tooling for series production. To a lesser extent this is also useful for checking that connectors have not been made too small. One might instinctively reply that such a thing is impossible in the autonomous vehicle world, but given that field technicians at airfields often work with gloves and in a range of outdoor conditions, very small connectors could become highly frustrating to mate and un-mate. In all cases, simulation software such as Dassault’s SolidWorks, Ansys’ High Frequency Structure Simulator and similar are critical to any company looking to design the latest generations of connectors, not only for new high- power connections but high-frequency ones as well, for reliable transmission of RF and Gigabit Ethernet data without losses. Real-world testing can then validate new designs to satisfy the demand for these parameters. Testing For high-end rugged connectors, every unit might be tested before shipping from its factory. Just as an engine might be cycled at all its crank speeds and across its power band in different conditions to assess its safety and reliability, so data can be run through connectors and cable assembles at different bandwidths on rate tables and in environmental chambers to certify that it can weather severe harshness and continue communicating critical information and commands throughout its intended vehicle. Such testing is increasingly enhanced by connector companies taking OEMs’ own subsystems and vehicles, and running the connector tests while integrated with the systems. After all, what better way to model how a connector will perform in the field than running performance tests on the equipment to be fielded? That also helps guarantee that different protocols are transmitted and received correctly, regardless of differences in signal or encryption type. It ensures that connector developers can serve commercial as well as military interests, rather than specialising in the protocols more often used by one or the other. Also especially helpful in this regard is the growing practice of running tests and inspections for quality control on each part of every connector as they progress through the manufacturing line. The sooner a mistake or defect is caught, the easier it is to fix, preventing leaks or short-circuits in the completed and delivered cable assembly. Once fully assembled, the kinds of tests that can be run are largely conventional and well-understood. For instance, submergence tests can identify whether a better O-ring is needed for effective sealing against fluid ingress. Vibration tests on rate tables will reveal the quality of latching or interference fit in the design relative to whether it will be mated on a stable surface or on a high-shock surface such as an engine or e-motor. And a wide range of electrical, radio and optical devices are available for measuring and analysing the ability of copper, coaxial and fibre connectors respectively to ensure the energy efficiency, data fidelity and overall integrity of each unit. Increasingly though, end-users are specifying levels of testing they need performed on their connectors that go quite far above what might be called conventional. These can include measuring how resistance changes over extreme temperature cycling, longer and higher pressure salt spray tests, severe durability testing, and many others that suppliers cannot disclose. An increasing number of connector manufacturers are establishing their own testing labs to cater for the demands from the autonomous world (Courtesy of Omnetics)