Good morning, Blue Robotics community,
As detailed below, we power our BlueROV via a separate power system on the Seattle Aquarium vessel, and I have two questions about the potential for integrating powerful lights into our ROV and powering them via shore-power:
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Does anyone know of companies selling very bright (e.g., greater than 5,000 lumens) lights that could be integrated into and powered by the ROV? And if so, . . .
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Does anyone have experience integrating lights into the BlueROV2 such that we can control them (i.e., turn them on and off) from the laptop / ROV control?
I’ve seen a couple somewhat similar threads (e.g., here, here, and here), with the latter link mostly kicking back 404 errors.
Context
We conduct formal benthic surveys using our x2 BlueROV2, and you can find a recent BR post summarizing some of our survey methods, imaging approach, and AI/ML methods of image analysis here on the forums (and the main landing pad for our work is here on GitHub). We require relatively powerful downward-facing lights to maximize camera settings (e.g., shutter speed, ISO) to capture high-resolution photos with our GoPro. Unfortunately, swapping batteries on externally mounted lights is one of our main rate-limiting steps, and the lights add substantial weight and drag to our vehicle.
Current system, power consumption, and power available
We power our main ROV with x2 12.6V Victron Lithium-Ion 200Ah batteries on the Seattle Aquarium vessel (pictured below), and we use Outland’s Topside Power Supply to feed power to the ROV.
We currently use x4 externally mounted and battery powered Kraken 18,000 lumen lights, but we step these down to 80% capacity, or ~14,400 lumens. We use x4 lights to give even coverage across our field of view (see example downward-facing image below). Given that they use ~ 1 watt per 80-100 lumens, a conservative estimate would put their power consumption at 180 watts for 14,400 lumens. 180 x 4 = 720 watts. The OTS system can deliver a max of 1000 watts to the ROV. Fortunately, our ROV surveys consume relatively little power, as we slowly motor the ROV forward at 20-30% of thruster power; our analyses of the TLOG indicate we consume less than 100 watts of power at any point in time (when surveying, and when we’d want the lights on).
So, given (1) the topside power available (x2 12.8V 200Ah lithium-ion batteries), (2) the OTS maximum of 1000 watts to the ROV, and (3) the relatively small power consumption of the ROV itself (when surveying, and when we’d want the lights on), we’d like to explore options of integrating more powerful lights directly into the ROV and powering them from the vessel.
Our wish list
The current lights have a wide beam angle (~120 degrees), and as you can see from the photo of the ROV underwater, there’s a lot of light that spills out of frame (relative to our cameras field of view, see also below). Therefore, an optimal solution would involve lights that have a narrower beam angle (e.g., 70-100 degrees), enabling a more efficient use of our lumens, and likewise enabling us to utilize less powerful (lower lumen) lights. As a conservative rule of them, we likely wouldn’t want to consume more than 180 watts per light, and I’d be very curious to learn about options ranging from 50-150 watts. We could likely get away with ~8-10k lumen lights if they were narrower, enabling greater efficiency across our field of view.
We’d likely want x4 lights, similar to our current mounting system, so I’m uncertain if hoping for daisy-chained lights is too much to ask for, as the number of available ports in our backplate will be a limiting factor.
A final consideration is control. We’d want to turn these lights on and off from the topside laptop / controller, likely requiring a microcontroller board that can plug into the Navigator.
What do you all think? Is anyone aware of any companies or products that might be appropriate for our application? And does anyone have any experience integrating non-BR lights into the BlueROV2?
Thanks in advance, everyone!
Zach
