First underwater ROV in our fleet: BlueROV2 with modifications

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BlueROV2 original configuration

Already more than 2 months have passed since the BlueROV2 (https://bluerobotics.com/) arrived. The BlueROV2 is the most basic of the ROV’s that will be part of our operational fleet for underwater surveys and inspections. Furthermore, it will be the backbone of our training program. The BlueROV2 is a remarkable little machine that is well crafted and a good platform for further development. And that is the first thing that we did :).

In our elite products (the UX-series currently under development) the main thrusters are ones that are produced by Blue Robotics and used on their BlueROV2. They are in itself, well made and well designed. However, for our special type of operations in underground flooded environments we needed something even better. That is where our part-time team member Tim Rhodes, http://highlandtechnologyservices.co.uk/,  provided a helping hand. With years of experience developing systems for submersible ROVs and robots he re-designed the thrusters (more on that later).

First, a bit more about the BlueROV2.

BlueROV2

The BlueROV2 is a small ROV which is highly configurable. It runs on a platform called ROS. ROS is a very common platform for research and development of robotic systems. Our UX-1 robots have been built on ROS as well and our flagship UX-Neo and others will be using ROS as well. Another benefit is that our team have been building simulations using ROS for the UX-1’s. This means that the BlueROV2 can be easily integrated in our simulation framework which is part of our training program.

Special modifications

The BlueROV2, like most ROVs and similar submersibles, has been developed for marine, or otherwise open surface environments. Our speciality lies in surveying flooded underground structures, like abandoned mines, tunnels and caves. To accommodate for these environments some small modifications were essential.

BlueROV2 original configuration

Notice how in the originally assembled version the flood lights were all attached on the outside of the frame. Working in underground environments, that is a definite “No-no”. There is no question that those lamps will be nocked off, probably already in its first dive.

In the images below we show how a small modification means the lights will be much more protected from any close encounters with the walls

BlueROV2 new light layout
BlueROV2 new light layout side view

Tether adjustment

Another modification for more practical deployment in the field was the cable attachment. As can be seen in the image, the tether is well-connected in a sturdy configuration. However, the configuration also means that the tether needs to always be connected.

Work is currently underway to add an additional connector between its looped connection and the pressure chamber. This will allow for the easy detachment of the tether when needed.

BlueROV2 permanent tether

New Thruster design

The last modification is not specific to the BlueROV2. It is actually a completely new design for a thruster that can withstand high salinity environments with more ease. In some old mine workings, it is highly likely to encounter very saline environments. The thrusters that are being used for the UX’s are not designed for those situations. Although they can operate there, in our surveys they will need to be able to withstand that for several hours over multiple days. This would pose a significant risk for those operations. Hence, the thrusters were in need of a re-design.

Thruster design

Unfortunately, we can’t disclose too much information in this post, but will give an idea about our new thrusters. The design took the components within the same dimensions as the Blue Robotics thrusters. This will allow for relatively easy replacement of the thrusters with the new designed ones. It also means the new thrusters can be tested within the BlueROV2 frame to run extensive tests and diagnostics to compare performance, before building and integrating 8 thrusters on the UX robots.

3D printed thruster components_1
3D printed thruster components_2
3D printed thruster components_3

The new thruster components have all been 3D printed and are now ready for assembly. Once that has finished they will be integrated and tested with the BlueROV2 to compare performance with the originals. Once they have passed those tests, they will be shipped to Porto to be fitted on the UX robots.