I am going to buy either a DVL or UGPS, and what would you choose between the two options? Maybe there are other suggestions? Currently, I have a Ping2, Pixhawk, and a 30bar depth sensor. I am using BlueOS and Cockpit. The ROV is mainly used for inspecting moorings for floating docks, following freshwater hoses laid in the sea, and picking up old fishing gear. What I am missing right now is knowing where the ROV is located.
Hi @Fjosen -
A DVL is not going to tell you where the ROV is located! It tracks the bottom, and enables station-keeping in position hold mode, and the vehicle can show its location on the map, if you set it - however that location is only as good as your estimate of the vehicle’s initial location, and it’s subject to drift over time…
For your applications, I’d think the DVL would be more useful, but a UGPS or another form of LBL acoustic localization is great for knowing absolute position. When used together, you get the best of both worlds - the fast update rate of DVL with the absolute position of a surface GPS + acoustic localization. I’ve been impressed with Cerulean Sonar’s ROVL systems, especially in the OmniTrack form factor…
The cheapest option would be to install a GPS, and use it to get a position fix with the vehicle at the surface, prior to diving? This can be used in conjunction with a DVL…
As long as the DVL knows the starting location from surface GPS, it should be able to estimate the position fairly accurately? I don’t need centimeter accuracy, within about 2 meters is sufficient.
For example, would a Water Linked DVL A50 together with surface GPS work directly in Cockpit, or do I need additional software on the surface station?
Do I need any additional hardware for this?
The import duties to Norway are so high that I almost have to buy Norwegian products.
Hi @Fjosen -
That’s correct - a couple of meters of drift over the course of about an hour is typical, but can vary based on conditions of course.
Cockpit only serves to show vehicle position - the ArduSub autopilot on the vehicle is receiving the GPS data and DVL output, and coming up with its position estimate. No surface-side software is required to do anything but show the vehicle on the map where it thinks it is!
Setting up a GPS and the A50 DVL should be all you need to do…