USE Network launch I UAV Works VALAQ l Cable harnesses l USVs insight l Xponential 2020 update l MARIN AUV l Suter Industries TOA 288 l Vitirover l AI systems l Vtrus ABI

21 During a master’s course at the Norwegian University of Science and Technology’s Department of Engineering Cybernetics, his interest was particularly captured by courses focusing on marine control systems and the modelling of dynamic processes. “I’ve always been engaged by making things that I can test and quickly see working in practice,” he says. “When you’re building software systems, the nature of programming is such that you can develop, demonstrate [or simulate] and retune new projects, and the speed at which you can do that gets faster every year thanks to advances in processor power.” Gjelstad recalls feeling a particular satisfaction in the creation (and eventual demonstration) of such systems. These enabled autonomous position-holding for vessels of immense inertia, using a combination of motion referencing sensors and environmental information to inform the onboard thrusters how to keep the vessel steady while operating cranes or other heavy equipment. After completing his thesis, on Strapdown Inertial Navigation in Dynamic Positioning (DP), he was awarded his MSc in Engineering Cybernetics in 1982. He would then embark on 22 years’ worth of projects centred on developing and commissioning DP systems aboard different types of ship. These included diving support craft, platform supply boats and pipe-laying vessels, for whom such automation would gradually progress from being rare to ubiquitous, and which can now be regarded as a key stepping stone towards the fully autonomous ships that Kongsberg and others are trialling these days. Triple-redundant navigation Gjelstad began his tenure with Kongsberg after being recruited in 1986 by Kongsberg Albatross, which was founded in 1975 to develop DP systems. His first project saw him join a team of researchers who were developing the world’s first triple-redundant DP system, which would be named ‘ADP703 voting’. “The system was based on TMR [triple modular redundancy], a fault- tolerant technique in which three systems perform a process, the result of which is put through a majority-voting system to produce a single output,” he says. “So if any of them fails, the other two can correct and mask the fault. As far as I know, it was the first time this kind of redundancy had been applied to ship navigation.” He also notes that this marked a milestone in navigation architecture for autonomy, given that almost all triple- redundant autopilots in the UAV and USV realms these days use TMR (typically by incorporating three MEMS IMUs, taking their inertial data outputs as votes, and dismissing whichever one fails to match the other two if there’s a discrepancy). “In 1987, I was made responsible for commissioning the launch version of the ADP703,” he recounts. “Eight computers worked together via Ethernet to perform the processing we needed – such was the state of CPUs [Intel 80186] in the late 1980s – and with no cellphones, e-mail or the internet to quickly access outside literature, hardware, software or other resources that could help. “In the end, the ADP703 formed Bjorn Gjelstad | In conversation Unmanned Systems Technology | June/July 2020 Gjelstad pioneered much of the dynamic positioning technology now used by Kongsberg Maritime on manned ships, USVs and automated vessel projects