Modification of ROVs for stationary observations and passive acoustics


#1

I was excited to learn about your company and its low-cost Trident ROV and I was wondering about the possibility of modifying units to be better designed for behavioral observations and passive acoustics. I am an expert in fish sound production behavior and over the years have approached various companies about this problem but to no avail. The problem with conventional ROV’s is that they generally have to keep moving, so they are great for exploration and running transects, but not really for undisturbed observation and sampling. They can hoover to maintain station if the currents are not too strong, but only by use of the thrusters. But I think a powerful alternative tool would be an ROV that gives you both ability to control movements for exploration and transects, but which can be set down with thrusters off to allow quiet observation. That has its own problems, but I think is doable, at least in low current environments. Unfortunately for me, I’ve not had funding to pursue this type of development myself, but have been advocating it for years (Rountree’s Fish Ecology Page and Do you hear what I hear?). So my dream unit would allow an ROV to carry one or more hydrophones in addition to cameras, and that could be set down in a stable position on the sea floor so that point-transect and roving transect type observations can be made more closely mimicking what a scuba diver can do. A user interface to allow display of acoustic data would be nice too…

I’d love to discuss the idea if you are interested. I really believe it would be a revolution in the way ROVs are used for in situ observational studies.


#2

Greetings,

Benthic type rovers are, I believe, what you are looking for. They can both fly like a traditional ROV, drive over the bottom surface like a rover, and provide a base for long duration observations. MBARI using them often in this capacity. The Trident is not set up for this type of work, nor would it be a good benthic rover platform. But, that doesn’t mean you can’t modify it. It would be a heavy mod and probably not cost effective over building your own using the 2.x brain kit or investing in heavy kits from vendors.


#3

H Jim,

Thanks for the quick response. I was not familiar with the benthic Rover, what a great device! However its way beyond anything that I could hope to use and way to big. I’m interested in something smaller and more agile that can be used in shallow water (ponds, lakes, rivers, estuaries, coastal marine, from 1 m to 30 m depths). You mentioned that the benthic rover could fly like an ROV, but the description I saw just mentions moving slowly along the bottom like a crawler? Such a large machine probably has a pretty big impact on the bottom habitat.

Rodney


#4

I made a hybrid Openrov 2.8/Bluerov to carry a 360 camera for observations like you mentioned, adding a hydrophone should be pretty straight forward. It’s heavy to keep it more stable in the current and is well armored for banging around on the bottom. I’m still testing and still a little too buoyant for sitting quietly on the bottom but I need it to float back to the surface until I get better with it. Point is you could build yourself something to fit your needs from the 2.8 kit.

A couple test videos. Keep in mind these are just tests runs but should give you some ideas. The 360 only seems to work directly on the YouTube.


https://youtu.be/U5PttA-706A

In this one you can hear the what I think is the camera tilt servo. It can make a little buzz if not centered. The camera does have four spatial microphones. https://youtu.be/13RIcce2AyQ