Outland Power Supply - intermittent fault

Last year we purchased an Outland Technology Power Supply for our BlueROV2, and since then we have spent some time on setting it up, but we could never be much confident on it.

There is an intermittent glitch we are not able to track. When immersing the equipment in water, and applying any thruster and/or lights command the system presents a telemetry failure. (Video freezing, failure in the ROV parameter readings, and sometimes video shutdown).

Regarding the known issue with pressure sensor I2C communication interference, we:

  • Installed one ferrite bead to pressure sensor wires;
  • Installed two ferrite bead to pressure sensor wires (as stated in manual);
  • Lengthened the wires, (the sensor wires were short), and done multiple wraps.
  • Completely removed the pressure sensor.

None of above worked.

  • Tried different types of Ground to the top side unit;
  • Swapped tether comms to a spare pair;
  • Bypassed OTPS tether communication with an spare tether (OTPS tether were used only for power);
  • Installed ferrite beads to tether wires;
  • Connected 127V and 220V (it seems to happen less in 127V) (Different locations: home power supply, diesel generators, inverters, offshore O&G platforms)

As an important remark, the system was tested in 3 different ROVs, with the same symptoms. When we revert back to the regular battery power supply, everything works fine.

Has anybody experienced this kind of failure with this system?

Hi @VMartini, sorry to hear about this.

It’s unfortunately not a system I’ve worked with, but I’ve asked internally in case someone else has come across something similar.

Perhaps @Outland have some idea what could be going on?

@VMartini continuing here instead of the email chain you initiated.

Re-cap of steps you already covered:
• You say you’re using a custom version of the BlueROV and a Standard BlueROV (heavy?)
• You say everything works ok on the bench, in dry environment
• We updated BlueRobotics technical manual to include instructions for ferrite bead installation.
• You implemented ferrite bead installation without improvement.
• You say you tried spare tether
• Tried different types of Ground to the top side unit
• Swapped tether comms to a spare pair
• Bypassed the tether communication with a spare tether (OTPS tether were used only for power)
• Connected 127V and 220V (it seems to happen less in 127V) (Different locations: home power supply, diesel generators, inverters, offshore O&G platforms)

As previously requested in email with you and BR support: Please send me the exact configuration of your ROV: I would like to know: How many thrusters, is it a “normal” penetrator configuration or are you using some sort of connectors, what type of tether, how long of a tether, metal or acrylic electronics enclosure?

Next Troubleshooting steps:
• Power OFF topside power supply box
• Disconnect tether from topside power supply box, disconnect tether from Power Supply Enclosure,
Disconnect power supply enclosure from BlueROV
• Power ON Topside power supply box
• Verify ~400vdc output of topside power and 0% GFI bias (see LCD screen readout and also verify
with multimeter on PINS 1 and 2 on MCBH3F connector, see page 7 of 46-0013 manual,
https://bluerobotics.com/wp-content/uploads/2019/12/46-0013-Rev-B3.pdf)
• If you verify ~400vdc output, continue:
• Power OFF Topside power supply box.
• Connect tether to topside power supply box.
• Power ON topside power supply box
• Verify/measure ~400vdc on ROV side of tether.
• Verify GFI bias on LCD screen readout is still 0%
• If you verify ~400vdc output and 0% bias, continue.
• Power OFF topside power supply box
• Connect tether to power supply enclosure
• Power ON topside power supply box
• Measure ~15vdc output of power supply enclosure
• Verify that GFI bias is still 0%

1 Like

• You say you’re using a custom version of the BlueROV and a Standard BlueROV (heavy?)

We are now using it in the standard 6 x thruster version

• You say everything works ok on the bench, in dry environment

Used to work on the bench, but now it happens in wet and dry environment as well. It seemed to have something to do with thruster (or lights) commands, but we noted last time in the work site the same symptoms, with the ROV just standing in the deck, (would it be temperature influence?)

• We updated BlueRobotics technical manual to include instructions for ferrite bead installation.
• You implemented ferrite bead installation without improvement.

And we have completely removed the pressure sensor, just in case.

• You say you tried spare tether
• Tried different types of Ground to the top side unit
• Swapped tether comms to a spare pair
• Bypassed the tether communication with a spare tether (OTPS tether were used only for power)
• Connected 127V and 220V (it seems to happen less in 127V) (Different locations: home power supply, diesel generators, inverters, offshore O&G platforms)

Right!

As previously requested in email with you and BR support: Please send me the exact configuration of your ROV: I would like to know: How many thrusters, is it a “normal” penetrator configuration or are you using some sort of connectors, what type of tether, how long of a tether, metal or acrylic electronics enclosure?

We have tried to set up in the following configurations:

  • Standard 6 thrusters config - acryilic enclosures - regular penetrators (both potted and WLP)
  • Standard 6 thrusters config - aluminum enclosures - regular penetrators (both potted and WLP)
  • Custom 8 thruster config (heavy like) - aluminum enclosures - regular penetrators (both potted and WLP)
  • Tether is 250m lenght

Next Troubleshooting steps:
• Power OFF topside power supply box
• Disconnect tether from topside power supply box, disconnect tether from Power Supply Enclosure,
Disconnect power supply enclosure from BlueROV
• Power ON Topside power supply box
• Verify ~400vdc output of topside power and 0% GFI bias (see LCD screen readout and also verify
with multimeter on PINS 1 and 2 on MCBH3F connector, see page 7 of 46-0013 manual,
https://bluerobotics.com/wp-content/uploads/2019/12/46-0013-Rev-B3.pdf)
• If you verify ~400vdc output, continue:
• Power OFF Topside power supply box.
• Connect tether to topside power supply box.
• Power ON topside power supply box
• Verify/measure ~400vdc on ROV side of tether.
• Verify GFI bias on LCD screen readout is still 0%
• If you verify ~400vdc output and 0% bias, continue.
• Power OFF topside power supply box
• Connect tether to power supply enclosure
• Power ON topside power supply box
• Measure ~15vdc output of power supply enclosure
• Verify that GFI bias is still 0%

We’ll try that out, and let you know the results.

Thanks
– VMartini

@Outland , following the suggested troubleshooting steps, we could not find any anomaly.

Any further step to follow? Could it be any failure in the filtering stage of the switch mode power supply?

I will try to measure with an oscilloscope as soon as get it back to the bench.

@VMartini
Measuring noise will be difficult without proper setup. Also, if you attempt to measure the input without isolating the oscope, you will cause the GFI to trip.

Potential steps/questions:

  1. Power system with OTPS and directly connect laptop to the pi and verify connection
  • Run network tests to verify direct connection.
    • If network test pass and system stable
      • verify the top side Fathom-X board operation. Swap out Fathom-x and USB to ethernet adapter.
      • verify tether, check continuity and use 2 Fathom-X’s to test tether with no vehicle: Use known good Fathom-X boards.
    • If network tests fail
      • Verify the output of the 5V switcher to the Pixhawk and pi
      • Verify the pi has sufficient power. Low power will cause the processor to run at a reduced rate. Does the red light on the RPI flash or is it solid?
  1. What is the quiescent current reading on the OTPS?

Even with all of that, at this point it might be best to get the system back in our hands. Contact me via email (sean@outlandtech.com and CC support@bluerobotics.com) and we can coordinate the returns.