TRIPLE-GNC
TRIPLE-Guidance, Navigation & Control DFKI subproject: acoustic and visual perception of a miniaturized autonomous underwater vehicle for exploration of subglacial lakes
The aim of the TRIPLE project line is to design and build a system for scientific exploration of subglacial lakes while validating the associated functions in close cooperation with marine and space scientists during an analog demonstration mission in Antarctica. This approach is essential to ensuring the applicability and use of the developed TRIPLE System in future terrestrial missions while laying the foundation for a future planetary mission. The interest here is to use this technology in the future to explore oceans in search of extraterrestrial life on other planets and moons, such as on Jupiter's moon Europa. This moon is particularly interesting as it is believed to provide the three key components for life to exist as we know it: water with a 100-kilometer-deep ocean under the icy crust, minerals on its silicate rocky ocean floor, and energy provided by geothermal activities due to tidal forces.
Project details
In Phase 1 of the TRIPLE project line, the constraints to be met and how to overcome the resulting technical challenges to achieve the project goals have already been investigated. The work focused on the technical challenges and assessed current technical capabilities against defined mission requirements. Specifically, software functions and hardware elements have been conceptualized and tested in simulation and partly experimentally.
In the now following phase 2 of the TRIPLE project line, the concepts from phase 1 shall be transferred into the final design of the nanoAUV as well as the required periphery. The goal of the TRIPLE-GNC subproject is the further development and testing of the Guidance, Navigation and Control (GNC) system of the nanoAUV. Special attention will be hereby given to autonomous exploration and docking with the Launch & Recovery System (LRS, previously: MoDo). The software for the nanoAUV and the LRS will be applied, validated in several tests, and then demonstrated in field trials under ice.
In order to contribute to the defined overall goals of TIRPLE-GNC, the environment perception concept from phase 1 will be further developed at DFKI and applied to the flight model of the nanoAUV. Three further developments are hereby planned:
- The current environment reconstruction software will be further developed using an innovative SLAM approach from various acoustic sensors, namely echo sounders and side-scan sonar (SSS), to support navigation and obstacle detection and avoidance. In addition, three-dimensional mapping of the seafloor and lower ice layer from sonar data will be used for scientific purposes.
- A database will be further developed for spatial and temporal intelligent aggregation, storage, and retrieval of scientific data to determine gradients or possible directions of POIs where organic material might be located.
- An advanced ML-based method for underwater image reconstruction from single or multiple LDR images will be further developed for a non-invasive categorization of the habitats (biotopes) of biological communities (biocenosis).
Furthermore, the docking strategy developed in TRIPLE-MoDo is adapted to the nanoAUV’s flight model and robustified by the DFKI-TEam. This includes the reliable actuation and control of the docking process in the novel active docking station of the (LRS) with softrobotic elements.
In addition, a high-precision hydrodynamic model of the nanoAUV will be identified based on DFKI's previous work by using an ML-based method and integrated into the navigation filter to smooth the noisy velocity solution and hence robustify the navigation.
