P08456: Underwater Light
/public/

Testing & Verification

Table of Contents

Prototype Approximation

The housing prototype will be a rough version of what will be produced after pressure testing is concluded. Any changes made to the final design will first be made to the prototype housing to eliminate the possibility of future failure because of an altered design.

The electronic prototype will use the same components as in the final design. All parts will be the EXACT version as the final light unit because a populated PCB was used at the electronic prototype.

Testing Plans

Testing procedure and Log can be found here:

Testing Procedures Document

Testing Log Book Document

Luminous Flux Test

Purpose: Testing will be conducted to determine what frequency of visible light best penetrates multiple types of water conditions, or if a broad spectrum light (white light) is the best option.

Components:

-Glass Fish Tank
-Light meter w/ luminous flux in lm
-LED Light Source
-Organic & particulate material

Procedure:

1. Fix light meter to one end of a fish tank. Make sure the meter is flush and parallel with the surface to ensure an accurate reading
2. Take a light reading to establish the nominal light value in the room. This value will be a baseline for all measurements here after. This allows you to use the light meter under any lighting conditions
3. Place LED board parallel to the opposite end of the tank and power on white LEDs to approx. 200 mA. The exact current is not required
4. Take light measurement and record intensity (lumens, lm)
5. Increase current to LED my ~25 mA
6. Take light meter reading
7. Repeat steps 5-6 through 800 mA
8. Repeat steps 2-7 with colored LEDs
9. Add particulate in some known quantity (mass, volume/volume water, etc) to the water in the tank. Be sure to keep it agitated
10. Take another reading with the second LED spectrum with this medium.
11. Switch to original LED and take another intensity reading
12. Repeat steps with as many LEDs or interference mediums as desired
13. Compare light intensity percentages for each different LED, setting, and medium as such. % Effectiveness = 100x [Intensity (Medium 1, Setting 1) / Intensity (Clear water, Setting 1)]. The LED with the highest % Effectiveness for each medium would perform the best in that condition, with 100% being exactly the same as if the water were clear

Results:

White LEDs

Satisfactory Value: > 250 Lumens
Ideal Value: > 350 Lumens
Tested Value: 510 Lumens

Colored LEDs

Tested Value: 361 Lumens

Multispectral Capability Test

Purpose: Manual verification of multiple operating modes exhibiting individual light characteristics.

Components:

-Assembled LED Light Unit
-Power Supply
-Communication Board

Procedure:

1. Power LED Light unit on with white light
2. Visually check that primary light mode is functioning
3. Switch to secondary LED mode
4. Visually check secondary light mode is functioning
5. Switch to tertiary LED mode (if one exists)
6. Visually check tertiary light mode is functioning

Results:

Satisfactory Value: White + 1 Color
Ideal Value: White + 2 Colors
Tested Value: White + 1 Color

Enclosure Envelope

Purpose: A minimal size envelope saves space on the ROV's structure, allowing for placement of other tools/accessories. This verification does not involve a test, but rather is a requirement that the light unit has been designed around.

Results:

Satisfactory Value: 3 x 3 x 6 in.
Ideal Value: 2 x 2 x 4 in.
Tested Value: 3 x 3 x 5 in. (2.875 in dia. x 5 in)

Mounting/Removal Time Allowance Test

Purpose: An individual should be able to successfully mount, move, or remove a light unit quickly to facilitate modifying an ROV or any other platform that the light unit is mounted onto. The test for this verification involves using individuals to complete timed trials of one mounting, one removal, and one move of a light unit. Each individual shall have given verbal consent that they wish to participate in this test. Also, it shall be made known to the individual that while the chances are very small, any injury is their own fault and no one from P08456 may be held accountable.

Components:
-Assembled LED Light Unit
-Assembled hinge
-Appropriate Allen Wrench to fit hinge screw
-Stopwatch
-Mounting plate similar to that found on the ROV
Procedure:

To be conducted per individual.

1. Give individual instructions that they are to mount the light unit onto the plate
2. Hand over LED light unit, allen wrench, and mounting plate
3. Simultaneously instruct them to start and start the stop-watch.
4. When they have notified you that they are complete, stop the stop-watch and record the time it took to complete operation
5. Repeat steps 1-4 for moving LED light unit from one location on ROV to another
6. Repeat steps 1-4 for removing LED light unit from simulated ROV
Results:
Satisfactory Value: < 90 sec per operation
Ideal Value: < 60 sec per operation
Tested Value:
24 sec (moving)
11 sec (removal)
14 sec (mounting)

O-Ring Sealing Test

Purpose: This test is crucial to the success of the light unit. An o-ring failure would cause a critical failure of the light unit and put a continuous draw on the on-board batteries.

NOTE: This test can be conducted in parallel with the Pressure Resistance test. When pressure testing is concluded, and housing is inspected, if there is water inside housing, but no physical damage due to pressure change, the fault must lie at the sealing surfaces. This condition would mandate an inspection of the o-rings and sealing surfaces.

Results:
Satisfactory Value: < 400 ft.
Ideal Value: < 500 ft.
Tested Value: 910 ft

Control Duality Test

Purpose: To verify that both the motor unit and LED light unit can be fully operated using a single control program. This test also acts to verify that the GUI and its supporting programming is working properly.
Components:
-Assembled LED Light Unit
-Assembled Thruster Unit
-Communication board
-Computer w/ GUI loaded
Procedure:
1.Hook up all connections between components, communication board, and computer
2.With only one program open, activate each light and each motor individually to demonstrate two types of components running off of commands from a single program
Results:
Satisfactory Value: Positive Verification
Ideal Value: Positive Verification
Tested Value: _______________________

Pressure Test

To be conducted at Hydroacoustics Inc. (HAI) with the aid of D. Scoville.

Purpose: Pressure testing with housing submerged in water will verify the assembled components ability to withstand the required pressure and check for leaks at the sealing surfaces.

Components:
-Assembled LED Housing
-Assembled Thruster Housing
-Pressure Vessel
Procedure:
1.Place Housing in pressure vessel; securing all bolts on perimeter of lid
2.Open top air escape valve; completely fill chamber with water
3.Connect Nitrogen supply line to pressure chamber valve
4.Using pressure gauge on chamber, pressurize to desired simulated depth:
400 psi (~950 ft. seawater)
5.Hold pressure for 5 minutes
6.After 5 minute period open release vales outside building (water will spray out of pressurized chamber)
7.Remove bolts; open lid and remove tested housing
8.Dry off outside of tested housing thoroughly and inspect for any damage: cracking, indentations, etc.
9.Open tested housing and inspect for any water penetration on inside surfaces
10.If moisture or water is detected inside housing, modifications to sealing forces need to be made.
Results:
Satisfactory Value: < 170 psi
Ideal Value: < 216 psi
Tested Value: 400 psi

Built In Specifications

Certain critical specifications set in the project verifications specs are not tested because they have been built into the design of the light unit from the beginning of the design iteration process. The verification of these components can be seen in the individual product data sheets or are inherent to the project itself. The preservation of open architecture and open source information are inherent to the RIT Multidisciplinary Senior Design curriculum and is upheld by all teams participating in it. All information is publicly available on the EDGE website (www.edge.rit.edu).

The following specs are can be verified by the data sheets, or have driven the design from the beginning and are intrinsic to it.

1) Microcontroller voltage is ideally 3.3 volts, and satisfactory at 5 V, the microcontroller selected used a 5 V power supply, and will only work with such.

2) The Board voltage is also specified to be 5 and 3.3 V at the ideal and satisfactory level. The voltage able to be pulled at many points in the board is 5 volts as provided by the power regulator selected for this project.

3) The LED Voltage in the final design is 24 volts, this is the satisfactory number and was chosen to limit the amount of power conditioning required for the 24 volts supplied by the batteries.

4) The LED current ideal value is 0.7 Amperes (satisfactory is 1.0 Amperes). T Because our light unit has a variable current to the LEDs, and its maximum rating is 1.0 Amperes, so it can not physically go over that without causing harm to the LEDs. The white LEDs are estimated to provide the required amount of light at 0.350 amperes, which is well below the 0.7 Amps ideal target.

A more complete schedule of MSD-II can be found here:

MSD-II Schedule word doc.

MSD-II Schedule bitmap image


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