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Upgraded to Heavy Configurations, Seems very slow

I upgraded the standard bluerov to heavy and as the subject said, lost much of the speed and fine control. It seems to be spending a lot of power orienting. It is slightly positively buoyant and a little off center in buoyancy front to back.
I have also installed a gripper and a sonar. I have moved the sonar opposite the gripper to better balance and even out the water resistance.

Even with these add ons, it appears slow. Perhaps moving at equivalent to 25% on the un upgraded version.

I checked the direction of the thrusters, which seems ok. Am I missing something? I almost want to unload the heavy configuration.

Hi @wje,

The extra mass can slow things down a bit, but it shouldn’t be that significant. Any chance you’ve reduced the gain without realising it?

Nope, that would be an easy fix but no luck, I know that much.
At 100 it is closer to the old 25 it maybe 50

And never is close to the zippy 100 gain on the old one.

I have the old power module, have not got around to installing the power sense module. Could this make a difference?

William J Edwards
Professor and Chair of Biology
Niagara University

Worth a shot at least :slight_smile:

It’s most likely a parameter or powering issue. Accordingly:

  1. Is your battery at a reasonable level of charge/do you have a suitable power supply?
  2. Assuming it’s not the battery, could you send through a parameter file so we can compare it to a normal one? Alternatively, if you haven’t set anything special you might want to try just loading the default BlueROV2 Heavy parameters.
  3. If neither of those help, could you do a test to see what the highest forward speed is that you can achieve (check the “Ground Speed” parameter in QGC)? Our BlueROV2 Technical Details specify an estimated max forward speed of 1.5 m/s for the standard BlueROV2 - it would be helpful to quantify how fast your heavy config is actually going.

ArduSub doesn’t intentionally try to limit the power of the thrusters unless the operator sets a low gain, or custom frame parameters with maximum factors that are below 1. The power sense module is there to give the operator warnings about low battery voltage and to predict remaining run-time, so this shouldn’t cause any issues beyond you not knowing that information.

The ESCs that run the thrusters can thermally throttle (covered in the ESC Technical Details), but that doesn’t start occurring until they’re over 140℃ (284℉), so is unlikely to occur at all, and if it does occur it won’t be until the ROV has been run at high throttle for an extended period.

If you’ve got an old power module, you might also have an old BEC, and you should get our new one. The old bec and power modules were both trouble makers.

Consider that this might be a cpu thing also. Does it act any different if you unplug the ping360?

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