The Magazine for Underwater Professionals
Italy-based SECO reports on a new field swappable u/w storage unit for an AUV with a synthetic aperture sonar payload
The Centre for Maritime Research and Experimentation (CMRE), an executive body of NATO’s Science and Technology Organisation (STO), is an established, world-class scientific facility that organises and conducts research and technology development centred on the maritime domain, delivering innovative and field tested science and technology solutions to address defence and security needs of the Alliance.
A leader in smart defence, CMRE enables nations to work more effectively and efficiently together by prioritising national needs, and focusing on research and technology challenges, both in and out of the maritime environment, through the collective power of its world-class scientists, engineers and specialised laboratories in collaboration with many partners in and out of the scientific domain.
‘Collaborative Autonomous Mine Countermeasures’ (CA-MCM) is one of the main projects at CMRE, aiming at increasing the capabilities of autonomous underwater vehicles by using synthetic aperture sonar (SAS) to quickly and reliably detect, classify and localise mines. This implies the use of high performance, efficient processing systems installed in underwater robots working in real-time. CMRE has been using central processing unit (CPU) boards produced by SECO since 2013. The PicoITX boards (single board computers) are suitable for integration in underwater vehicles where reliability, reduced footprint, low power consumption and computational power are key factors. As of today these boards have been installed on a wide range of vehicles that are part of the CMRE fleet.
The CMRE CA-MCM project focuses on increasing the efficiency and effectiveness of the full range of mine search missions. Advancing the use of AUVs for mine countermeasures has been achieved in a three-pronged approach:
The research axis has gone from basic way-point following to the development of a machine decision-making capability. Incremental steps taken along the way include the development and implementation of:
The next-generation of AUVs currently developed at CMRE is equipped with a wide suite of sensors with onboard processing capabilities as well as a very high level of autonomy and adaptation to the environment in order to achieve high level mission tasks without human intervention. High computational power, large data acquisition and storage are needed to enable these features. Furthermore, the continuous development on these systems requires even larger storage capacity and very high reconfigurability.
One of the best examples of these vehicles equipped with the PicoITX boards is the MUSCLE, CMRE’s major MCM AUV. With a high-resolution, high-frequency synthetic aperture sonar installed, MUSCLE provides superb image quality of objects on the seafloor, and it has a high level of autonomy, thanks to its real-time processing software running on a dedicated high-end graphics processing unit-based system and advanced decision-making capabilities. Despite its relatively low TRL (technology readiness level), the MUSCLE unmanned vehicle is regularly tested and successfully utilised in operational mine countermeasure scenarios in which a very quick turnaround time from mission execution to post mission analysis and very short mission to mission downtimes are key factors.
CMRE began developing concepts for allowing a quick data transfer on autonomous vehicles in 2014. The challenges in developing an underwater field swappable storage unit are in the use of unconventional underwater connectors (typically not suited for standard data buses) and the miniaturisation imposed by the portability of the system despite its ability to sustain high pressures. The SECO PicoITX boards with dual gigabit Ethernet ports and two SATA3 channels combined with their small form factor seemed a possible solution for such applications. The full integration of one of these boards into a small watertight 300-metre rated case developed and built at CMRE was successfully accomplished in 2015. The system has since passed multiple bench tests and it is now approaching the field-testing stage. The high computational power and the possibility of installing up to eight gigabytes of RAM will allow for some data processing contribution to the overall reduction of the post-mission-analysis time.
The newly built underwater field-swappable storage unit is expected to significantly reduce the mission-to-mission downtime due to the data transfer from hours to minutes. This will make multiple missions in the same day possible and it will bring the operational readiness of the CMRE underwater robots, in particular the MUSCLE AUV, one step further. The quick storage unit swap will also allow the operator to have access to the results produced by the advanced internal processing unit of the MUSCLE AUV during the mission execution.
Thanks to the processing power of the SECO PicoITX boards, the new system has been designed by CMRE to run completely autonomously from the other vehicle’s subsystem and it is capable of retrieving and storing the mission data fully unsupervised. Its use as a secondary storage unit allows for higher data integrity. The SECO PicoITX boards have also been successfully tested with NATO approved storage units used in applications with strong requirements in terms of information assurance.
The availability on the market of different CPUs/SOCs (systems on chip), from ARM to x86 architectures, gives a wide range of options and power consumption versus processing power ratios. As a result, CMRE already envisages using this storage unit on multiple vehicles part of its fleet.