HYBRID-ROV - Development of a new underwater vehicle for high-risk areas

Recently, the Center for Marine Environmental Sciences MARUM (University of Bremen, Germany) received national funds to design and build a new remote operated underwater vehicle - the HYBRID-ROV (H-ROV). Within the 3 year project the basis of a solely battery powered underwater vehicle capable of working as ROV and AUV shall be developed in the MARUM institute. Predominantly, the proposed use of the H-ROV shall be scientific operations in more risky environmental areas like under-ice operation, near-bottom-work in harsh topography, in between cold water corals or hydrothermal vent fields. Basically, due to higher operational risks in these areas, the vehicle predominately should be operated fully remotely and video controlled via a thin high bandwidth glass fiber. In event of a critical situation, e.g., tangled or blocked fiber underneath the ice, the glass fiber will be disconnected and the vehicle should switch automatically into the autonomous mode, passing back to a save rendezvous-point far out of critical area. If appropriate, it should be possible as well to run the H-ROV in a pre-programmed autonomous AUV mission mode from beginning. In basic configuration it is envisaged to design a flat shaped vehicle of approx. 5×2 m foot print dimensions, capable of standing still and hovering on site. In addition, developers are encouraged to reach 4000 m design-depth and/or rather 4000 m operation range with attached glass fiber. With regards to configuration of lights, cameras and manipulator, a challenge for vehicle design will be the approach to work, as well at the sea floor, as underneath the ice (means over head) without vehicle frame modifications and within one dive. The overall vehicle concept should be modular in order to use several already existing scientific payloads from other underwater vehicles. Finally, as an operational aspect due to its smaller size and system weight of approx. 1.5 metric ton or less, operation of the H-ROV from mid-size vessel or vessel of opportunity is an overall design necessity as well. Despite ongoing design iterations it is already decided to build the complete H-ROV software system on the Open Robot Control Software (OROCOS), an open source project based on C++ framework, in direct cooperation with the German Research Center for Artificial Intelligence (DFKI, RIC, University of Bremen, Germany). In addition, the main telemetry will be based on Schilling Robotics DTS to be consistent with already existing MARUM vehicles like QUEST ROV and the MEBO remotely operated deep sea drill. The whole battery system will be designed on a complete pressure-neutral underwater Li-Ion battery stack, because of an effective weight-/ form-factor and overall energy content of battery stack, due to unnecessary pressure housings. The paper summarizes the initial design of basic components like vehicle, propulsion, batteries, telemetry concept and sensor suite.