Operation Manual

Regular Maintenance

• Batteries

  • Types of Batteries that power the BlueROV2 vs power the Vision/AI Module

  • Ensure that the batteries are maintained at storage voltage level if you are storing them for a long period of time. If not, do ensure they are fully charged before each deployment in field trials and ensure that the batteries does not exceed their storage voltage.

• Mechanical Components

  • Like any mechanical system, there are components on the ROV that may need some additional attention and maintenance. The most common ones are the penetrators and the O-ring seals at the end cap that prevent water from entering the tube enclosures. Prior to every deployment and after the robot has been sitting for a while in the lab, check the seals to make sure that they have not become dried or cracked and the grease is still present. If they show signs of cracking/tearing, replace the seals. Make sure to put a dab of O-ring grease on the seals and spread it around before replacing it on the robot. If any of the 3D printed thruster guards or propellers are damaged, please replace them before deployment is attempted.

• Storage Recommendations

  • Store the ROV in place with limited humidity due to the sensitive electronics on board. Do not store the ROV with batteries in the tubes overnight. Allow the ROV to completely drain water after a recent trial and give it a good wipe down to completely dry it before storage. For long term storage, grease all seals and reassemble the robot but leave the pressure relief valve away from the enclosures.

Bench Operation

• Guidelines for bench operation

  • When running on the bench, the ROV’s individual systems (i.e., control module, vision/AI module) can be tested or worked with. As the robot is modular and the individual systems are powered by their own batteries, it is not difficult to remove the computing pieces or use alternate power sources (i.e., power adapter rather than battery)

• Using thruster system out of water

  • Ensure the throttling of the thrusters when performing system check is done at a low speed to minimize damage due to rotation in the air.

• Working with individual components

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* Electronics tray allows ease of access to the Jetson Orin NX, which allows wired connection to the portable monitor for debugging 

• Working on Robot system as a whole

  • Tether used to connect to the ROV via the FXTI and Tether Spool

  • SSH can be used to connect to the individual computing systems

Transporting MARVL-ROV

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• The flexibility of the removable tether that allows for the MARVL-ROV to separate from the Fathom Tether Spool enables the ease of transportation without having to pay attention to the concern of the entanglement of the connected tether or the physical hazards such as tripping.

Sample Packing Lists

• Packing list for field trials

Preparing for Deployment

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• Before deployment, ensure the ballast is in correct configuration; all data is offloaded from the previous trials, so you have sufficient room for new data, and the batteries are charged.
  Begin charging the batteries to full capacity the day before deployment.
  Make sure you remain near enough to the batteries during their charging to monitor their progress and so you can remove them from the charger once charging is complete.

• For a deployment to go smoothly, collect everyone’s experiment plans and put together an agenda to ensure you have the time and manpower to accomplish everything onsite.
  Best recommendation is to start planning this in the week leading up to the trial, finalizing any remaining plans the day before the trial.
  The day before the trial, bench test everything you can as best as possible and verify you have all the materials you will need for the trial in the Pelican Case.
  Charge the batteries for MARVL-ROV and put a freeze on the codebase after successful bench operations to minimize causing unexpected issues due to codebase problems.

• On the day of the trial, it is good to run at least one final bench test to perform a system check that thrusters are functional and video stream is stable.
  Remove the batteries after the system checks, apply necessary ballasting (keep in mind the type of water you are going to test in), and seal the robot for transport to your trial location.
  Pack up any additional equipment you will need for your trial, keeping in mind what the robot will need and what you, as the user, will need.

• Ballasting

  • Buoyancy Foam Configurations in SUTD Pool / One 15 Marina, Sentosa

  • Chlorinated water Configurations vs Saltwater Configurations

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• Pre-deployment Procedure

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* Attach batteries to the XT90 parallel connectors in the 3-inch enclosure, in both control and vision/AI modules. 

* Check internal connections. Boot and test connectivity and systems for the control and vision/AI module at this point.

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* Check the end cap O-ring seals. Re-grease if necessary. 

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* Slide the modules/tray into the enclosures, adding a desiccant packet beneath each module in the enclosures. 

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* Attach and tighten all penetrators and pressure relief valves. If using tether, ensure tether penetrator is connected to the WetLink Cable Splice Kit securely. 




* Use the vacuum pump to check for any leaks in the enclosures. Keep removing air until you achieve an internal pressure of 15mmHg and wait for 10mins. If it drops by a maximum of 1mmHg, it shows that the enclosures have minimal leak issues and are ready for deployment. 

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* Deploy the ROV into the water and check for any streams of bubbles surfacing for potential leakage.

Field Operation Guide

• Notes for Tethered Operation

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* Connect the tether to the robot.  

Spool out the tether, giving the robot enough tether to move around freely, but not so much that it will become entangled in itself and cause knotting issues.
Be careful not to step on the tether at the dry land during operation.
One person should be near the ROV at all times to direct the user that controls the robot to avoid potential obstacles that could be missed from the first-person view (FPV) video feed.
If operating in a lake, river, or ocean, ensure you have someone manning the tether at all times to unwind and observe the currents.
This person must have 2 hands on the tether spool and should constantly be monitoring for any knots that occur and where the tether is in relation to human operators in the water.
Having a designated person manning the tether is less critical in pool operations since currents will not be manipulating the tether but still be careful to keep an eye on it.

* Teleoperation

  * To use remote control, make sure that the topside computer is connected to FXTI and the tether spool via Ethernet. Then, connect a wired Logitech controller to the computer.

  * Boot the QGroundControl application and armed the controller in the interface to initiate the teleoperation.  

• Notes for Tetherless Operation

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* Make sure an operator is with the robot at all times, preferably a diver that could dive underwater alongside the robot.  

If operating in a lake, river, or ocean, it is easiest to have a handful of personnel in the water to monitor the robot.

• Drowning the Robot and Starting Operations

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* Place the ROV in the water and submerge it.   

Carefully brush away any air bubbles that come with placing the robot in the water.
Rotate the robot entirely, turning it over in the water.
Watch for any additional bubbles that form on the surface of the robot or any streams of air coming from the robot.
If this is the case, remove the robot from the water as soon as possible since air bubbles are a strong indicator of a leak that could compromise the ROV.
Once the robot has been checked for leakage and the connection with the BlueOS webpage is stable, the robot is ready to perform operations.
Proceed with your tests and experiments.

Post Deployment Operations

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• Once finished with your trial, rinse the robot thoroughly with fresh, unchlorinated water.
  Dry the robot off with a towel and perform a visual leakage check through the acrylic clear end cap. Be sure to dry thoroughly, drying the thrusters to minimize the accumulation of sediments like salt
  Place towels above the battery enclosures to prevent any droplets of water seeping in and remove the batteries immediately to maintain the battery level at storage level to prevent permanent damage before transportation.
  Transport the ROV back to your lab. Once back to your home base, open the control and vision/AI module enclosures and continue to allow the ROV to dry. Remove the desiccant and save for another trial if it is still blueish in color. If it turns pinkish purple, stockpile to microwave them to remove its humidity.

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• It is also recommended to disassemble the thrusters to check their internal conditions for any signs of corrosion and perform basic cleaning on the surface once every 3 to 6 months. Rotate the propeller with your finger and the brushless motor should rotate smoothly with minimal resistance to show there are no foreign particles obstructing the rotation.