CoMap - Cooperative Autonomous Multi-Vehicle Mapping system

Only a small percentage of the world's seafloor has been mapped so far. The mapping of the ocean and sea floors is of vital importance for shipping operations as well as for obtaining a better understanding of our world's oceans and planet. Autonomous underwater vehicles (AUVs) are currently being used worldwide for many applications, including mapping the seabed to find (old) underwater mines, collecting information on biology such as algae to better understand harmful algal blooms, and collecting water temperature data to aid in weather predictions and understand climate change. By being able to travel up to thousands of meters of depth under the water, AUVs are able to map deeper water bodies than autonomous surface vehicles (ASVs) who are limited by sensor range as a constraint of having to operate at the surface of the water. However, localization and navigation can be more difficult and less accurate for AUVs than for ASVs, because GPS signals cannot penetrate the water column and AUVs operate underwater for large periods of time. Furthermore, AUVs typically travel at slower speeds than ASVs, and they require manned vessels to deploy and recover them in operational areas. ASVs can also obtain data for greater coverage ranges, for example in seabed mapping, but because they typically operate farther from the seafloor, the data quality is not always as good as that which can be obtained from AUVs.

As part of one of our key initiatives, Robots helping Robots, Maritime Robotics is collaborating with OceanScan-MST and the faculty of engineering at the University of Porto to create an end-to-end solution of bathymetric mapping with unmanned vehicles. By deploying both ASVs and AUVs, we are building a system that can create seamless maps of water bodies, between shallow and deeper areas. The strengths of individual vehicles are combined to overcome their limitations. The benefits of the ASV-AUV cooperation include

• Improved global positioning of the AUV by having the ASV provide it with localization updates. This is made possible by relative acoustic positioning between the vehicles.
• The ASV can operate at higher speeds and greater ranges than AUVs, whereas AUVs are capable of obtaining higher resolution in the bathymetric data by diving deeper. Individual surveying tasks may be assigned to different vehicle types to utilize these advantages.

Maritime Robotics will be joining OceanScan and the University of Porto to demonstrate the multi-robot system at REP-MUS exercise in Portugal, September 2023.