ENGR 100-600 | University of Michigan

ROV Testing at MHL

Objectives

The showcase run-thru at the MHL has two components; each component is approximately 1 hour (the remainder of the time is used for safety training and transitions). The objectives for each component are listed here:

1. ROV testing in the Towing Tank
   1. Determine the final flotation/ballast configuration of your ROV
   2. Confirm your control systems work
   3. Practice driving your ROV
   4. Get three official speed measurements for each direction you are reporting on
   5. Practice finding sectors on the practice targets
2. Final presentation dress rehearsal
   1. Practice your final presentation
   2. Get feedback on overall flow and tone of presentation
   3. Watch another team practice their final presentation
   4. Give feedback on overall flow and tone of presentation
   5. Revise presentation based on feedback received

General Safety Procedures and Rules

We are extremely fortunate to have a world-class testing facility to use for testing our ROVs. You will receive a safety talk prior to testing your ROVs, but know and follow these rules when at the MHL:

1. This is a working laboratory, please act accordingly
2. Absolutely no running
3. Absolutely no yelling or screaming
4. Listen to all instructions from your IAs, Instructors, and the MHL Staff
5. Wear appropriate lab attire, including close-toed shoes
6. Leave all bags and excess outerwear in the Conference Room
7. Always move deliberately and with purpose, watching your hands and feet, especially when entering and exiting the towing tank area where we will be testing
8. Use only our equipment – do not touch any of the equipment in the hallways
9. Stay only within our designated areas – you are not cleared to go wandering through the MHL; if there is something you would like to see closer, ask Laura to show you
10. Treat all MHL staff members with courtesy and respect – we want to be able to use the MHL next semester

Live-Streaming Cameras

The MHL will have several live-streaming cameras set up to showcase our testing to the world. This is very exciting and is an opportunity to reach many future engineers across the world (feel free to share the link!). If, for any reason at all, you would prefer to NOT be on the live stream, please tell Laura and she will tell the MHL staff to temporarily turn off the applicable cameras. This is NOT a big deal, and you do NOT have to give any explanation for this request.

How To Get to The MHL

The Marine Hydrodynamics Laboratory (MHL) is located on the first floor of West Hall on Central Campus. Go to the Engineering Arch off the Southeast side of the Diag (Fig), and go in the doors where you can see “Aaron Friedman Marine Hydrodynamics Lab” (Fig).

Once you go in the door and go through the double doors, go down the hallway until you get to another set of double doors; these doors have a card reader. Someone will meet you here to let you through. You should first go to the conference room. Fig shows the layout of the parts of the MHL that we will be working in.

Tips for Working at the MHL

Here are some general tips for working at the MHL:

• Bring your safety glasses
• Wear pants and closed toed shoes
• You will get dirty (it’s a working lab), so don’t wear anything you care about
• It’s humid and warm, so wearing a t-shirt (or dressing in layers) is a good idea
• Be on time
• Bring a notebook and writing utensil to record data
• Make sure you know your plan (getting data, how to visually inspect sectors, etc.)
• We recommend leaving all electronics in the conference room, but if you really want your phone so you can take pictures, we strongly recommend that you wear pants with a pocket that zips shut so that there is less of a chance you will drop your phone

Testing in the Towing Tank

You will have approximately one hour of time in the towing tank to test your ROV. Read on for specific safety information and procedures for testing your ROV at the MHL.

Safety Information for the Towing Tank

Your team will be working at one of two stations in the towing tank: the Midtank station or the North End station. Read the safety information for each station so you are familiar with both stations.

Safety Information for the Midtank Area

The midtank door is located at the middle of the towing tank. Aren’t we good at naming things?? Your team will launch your ROV from the back platform of the carriage, as shown in Fig.

When you arrive at this station, we remind you of this additional safety instruction. Please pay attention!

• Be very cautious when stepping out onto the carriage; use handholds wherever possible and move slowly and deliberately
• Only one person should enter or exit the tank at a time; overcrowding the entryway can result in injury or falling into the tank
• Be very cautious of the overhead power rails (orange bars on the outside-wall ceiling); these are 480 Volts, 3 Phase and can kill you if you make contact with them with any electrically conductive material
  • Work with your ROV from the inside-wall side or middle of the tank, never the outside-wall
• Do not walk the rails! Only IAs, Instructors, and MHL Staff are permitted to do so
• Do not climb the ladder on the carriage; only IAs, Instructors and MHL Staff are permitted to do this
• Please communicate using an indoor voice; shouting is for emergencies only
• If you drop something do not lunge for it, simply let it go. Lunging for a dropped item may end up with you falling in or knocking someone else in
• If someone falls into the tank do not get in yourself! An IA, Instructor or MHL Staff will address this incident
• Do not handle or disturb any of the equipment or materials on the carriage; these are for NA&ME laboratory classes and/or funded research
• When in doubt ask an IA, Instructor, or MHL Staff member

Safety Information for the North End Area

The doors at the north end of the tank will give access to the subcarriage, which is the platform you will use to launch your ROV for the riser inspection task. A view of the subcarriage at the the north end of the tank is shown in Fig.

When you arrive at this station, we will remind you of this additional safety instruction. Please pay attention!

• Be very cautious when stepping out onto the sub-carriage; use handholds wherever possible and move slowly and deliberately
• Only one person should enter or exit the tank at a time; overcrowding the entryway can result in injury or falling into the tank
• Be very cautious of the overhead power rails (orange bars on the outside-wall ceiling); these are 480 Volts, 3 Phase and can kill you if you make contact with them with any electrically conductive material
  • Work with your ROV from the inside-wall side or middle of the tank, never the outside-wall
• Do not walk the rails! Only IAs, Instructors and MHL Staff are permitted to do so
• Do not climb the ladder on the sub-carriage; only the MHL Staff are permitted to do this
• Please communicate using an indoor voice; shouting is for emergencies only
• If you drop something do not lunge for it, simply let it go. Lunging for a dropped item may end up with you falling in or knocking someone else in
• If someone falls into the tank Do not get in yourself! An IA, Instructor, or MHL Staff will address this incident
• Do not handle or disturb any of the equipment or materials on the sub-carriage or outside-wall of the towing tank; these are for NA&ME laboratory classes and/or funded research
• When in doubt ask an IA, Instructor, or MHL Staff member

Preparing for ROV Testing

When it is time for your team to begin its ROV test time, we will bring your team to the “shop area” where we will have all the ROV equipment.

• Work with your IA/Justin to have a payload prepared for your ROV
• Assemble your ROV in the designated area of the MHL & check that all seals, ballast, and zip ties are secure – but remember not to pull the payload wires too tight!
• Have your IA or Justin double check your payload and attach the tether.
  • DO NOT MESS WITH THE PAYLOAD ITSELF. AT ALL.
• When you are ready, tell whoever is with your team that you are ready to go to the towing tank. They will take you to one of two testing stations: Midtank or the North End.
• Carefully carry your ROV, tether with float, and controller down the hall to the station you are assigned.
• When you arrive at your station, we will give you some additional safety instruction. Please pay attention!

Procedures for Getting in the Water

When your team is ready to go in the water, carefully lower your ROV into the water using a boat hook.

Take a few minutes to get your ROV situated in the water:

• Check that your control system still works correctly
• Adjust your ballast/flotation if necessary

Now practice driving the ROV in “deep water”. Let everyone have a chance to drive the ROV and then choose who is going to drive the ROV for the speed measurements and at the Showcase. Have your chosen driver get comfortable with where they are at on the platform.

Remember these additional rules and guidelines when testing in the towing tank:

• Do not drive more than 10 feet past the ROV target, otherwise you will interfere with the team testing at the other station.
• The video transmitter is STRICTLY LINE-OF-SIGHT. If you stand between the antenna and the ROV, you will lose video.
• As you drive your ROV around, your battery will (slowly) deplete. We recommend that you do your official speed trials as soon as you are reasonably comfortable with driving your ROV.

Procedures for Speed Measurements

When you are comfortable with your ROV’s ballast and control systems, tell your peer mentor you are ready to start your speed measurements (if your peer mentor isn’t there, tell your IA).

Longitudinal (Forward/Backward) Speed

Follow these procedures if you are measuring forward or backward speed:

• Have your peer mentor walk out to the designated finish line (30 feet from the starting line)
• Position the front (or back, if you are going backwards) of your ROV at the starting line, which is the front edge of the platform you are using for testing.
• When your peer mentor says, “Go”, travel forward.
• Your time ends when your ROV crosses the finish line at the peer mentor’s location.
• Your peer mentor will record your official times for you, and then report them to the instructional staff.
• You may do as many trials as you want, but you must have AT LEAST 3 qualified trials.
• Your top speed will be calculated by your single fastest time trial.

Vertical Speed

Follow these procedures if you are measuring speed going up:

• Put your ROV all the way at the bottom of the trench (you’ll see the trench along the bottom of the towing tank); position the ROV so that it is “facing forward”, i.e. in its normal driving attitude.
• When your peer mentor says, “Go”, travel upwards in whatever fashion your ROV ascends.
• Your time ends when your ROV breaks the surface of the water AND is “facing forward”, i.e. its normal driving attitude.
• Your peer mentor will record your official times for you, and then report them to the instructional staff.
• You may do as many trials as you want, but you must have AT LEAST 3 qualified trials.
• Your top speed will be calculated by your single fastest time trial; we will provide you with a depth measurement.

Follow these procedures if you are measuring speed going down:

• Put the top of the ROV at the water’s surface; position the ROV so that it is “facing forward”, i.e. in its normal driving attitude.
• When your peer mentor says, “Go”, travel downwards in whatever fashion your ROV descends.
• Your time ends when your ROV hits the bottom of the trench AND is “facing forward”, i.e. its normal driving attitude.
• Your peer mentor will record your official times for you, and then report them to the instructional staff.
• You may do as many trials as you want, but you must have AT LEAST 3 qualified trials.
• Your top speed will be calculated by your single fastest time trial; we will provide you with a depth measurement.

Lateral Speed

Follow these procedures if you are measuring lateral (left/right) speed:

• Position your ROV with one side of the ROV touching one of the walls of the towing tank; position the ROV so that it is “facing forward”, i.e. its normal driving attitude.
• Have your peer mentor walk out to a location that is directly across from your ROV
• When your peer mentor says, “Go”, travel across the tank in whatever fashion your ROV can get across the tank.
• Your time ends when the side of your ROV touches the wall at the peer mentor’s location AND is “facing forward”, i.e. its normal driving attitude.
• Your peer mentor will record your official times for you, and then report them to the instructional staff.
• You may do as many trials as you want, but you must have AT LEAST 3 qualified trials.
• Your top speed will be calculated by your single fastest time trial; the tank is 6.7 meters (22 feet) across.

Practicing the Riser Inspection Task

When you are finished with your time trials, if there is still time remaining at this station, you may continue testing your ROV. We recommend doing dry (or should we say “wet”??) runs for the riser inspection task that you will do at the next station. Fig shows an example of what you can try out with your ROV with these practice targets.

We recommend picking sets of random sectors and then “inspecting” them for damage to practice inspecting all views of the sector.

When You Are Finished Testing

When you have completed your testing (or if your time at this station is up), take your ROV equipment back to where you orginally set up the ROV. Detach the payload system and return it to Justin, pack everything up, clean up your area, and get Justin or your IA to check your area.

Check out with your IA and once they are happy with your clean up, you are free to return to the conference room.

Final Presentation Dress Rehearsal

A dress rehearsal is a performance that is the “real thing” except that the expected audience isn’t there. It’s a chance for the performers to practice everything ahead of time and build confidence for the actual performance. A dress rehearsal might have no audience at all, or the audience might be a group of people who have no expectations of quality so that the performers can be in front of people but not be stressed about the audience’s reaction. For example, a local high school’s theater group invites students from the nearby elementary school to their dress rehearsals. The elementary school kids get to see a free play, and the high school students get to practice in front of a bunch of people knowing that the little kids will be happy no matter what happens!

A team presentation, as you’ve experienced in this class, is absolutely a performance. We want all of you to feel as confident as you can going into your final presentation. This dress rehearsal will also serve as an internal deadline for your team so that you have your final presentation slides done with enough time to get feedback on your presentation and make revisions before you do the “real thing”.

We also want you all to continue getting experience giving useful feedback to your peers; this is a crucial engineering skill. So, each team will give their presentation and also watch another presentation.

The two teams that are not currently testing their ROVs in the towing tank will be in the MHL conference room. Each team will give their presentation and provide feedback on the other team’s presentation. This conference room is the same place that you will give your actual final presentation on Saturday, so this is truly a real dress rehearsal!