p08456: lighting system for an underwater robot concept design review
DESCRIPTION
P08456: Lighting System for an Underwater Robot Concept Design Review. Jeremy Schiele Jonathan Lent Ryan Seeber Justin VanSlyke Benoit Hennekinee. Project Background. The design of an underwater LED lighting system that is multi-platform capable - PowerPoint PPT PresentationTRANSCRIPT
P08456: Lighting System for an Underwater Robot
Concept Design Review
Jeremy SchieleJonathan LentRyan Seeber
Justin VanSlykeBenoit Hennekinee
Project Background
The design of an underwater LED lighting system that is multi-platform capable
Focus on modular, scalable & open source design
Housing design is in conjunction with Thruster design
Funding provided by the Dresser-Rand Corporation
Multi-Spectral Lighting Considerations
Chosen wavelength dependent on absorption and scattering of light by water and materials contained within
Best overall wavelength ~550-600nm
Absorption curve courtesy of Dr. Ientilucci
LED Bulb System
LEDs Design Concepts:
Concept #1 - Single LED advantages: simple, only 1 LED to control
disadvantages: less powerful because only 1 LED per fixture, requires 4 lights, 2 per color
Concept #2- 6 small LEDsadvantages: tiny LED, multiple designs, adaptability, powerfuldisadvantages: more complicated to control
Concept #3 – 2 layersadvantages: intermediate solution, multiple LEDs in a larger housingdisadvantages: large housing design, difficult to design
Concept 2LUXEON REBEL CREE XLAMP XR-E Edison Opto EP5W-2E00
Selection Criteria Weight Rating Weighted Score Rating Weighted Score Rating Weighted Score
Brightness 35% 3 1,05 1 0,35 3 1,05
Low Power 10% 5 0,5 5 0,5 3 0,3
Luminous Efficiency 30% 5 1,5 4 1,2 2 0,6
Size 20% 5 1 4 0,8 4 0,8
Angle 5% 4 0,2 2 0,1 3 0,15
100% 4,25 2,95 2,9
LED Bulb System
Choice of the LED:
For each concept, the Pugh’s Matrix has been established in order to choose the best LED. For the concept chosen, the LEDs are tiny and are able to be surface mounted on an circuit board.
LED DriverThe choice of the LED driver has been
made with the following specifications:
1A output at least, VOUT ≥ 12V, VIN = 24V, Allow PWM Dimming (dedicated
input), Step-down (buck) regulator with
efficiency as high as possible, Switching regulator control, Bulk as tiny as possible.
Linear Technology: - LT3474 - LT3496- LTC3783
National Semiconductor:
- LM3405- LM3404
MAXIM: - MAX5053 - MAX5035 - MAX5024 - MAX16819 - MAX16821 - MAX16831
TI:- TPS63000
LED Drivers that fit the criteria
Schematic of implementation of LEDs & Driver.
LED bulb and Driver schematic
Power Supply Schematic
The lighting system will be controlled over an RS-485 communication line. Inside the enclosure a microcontroller will accept the commands and execute them using the LED circuitry.
Control System
RS-485 Communication
Any computer with a serial port can be used as the master system for testing or in actual applications using this circuit to convert RS-232 to the RS-485 signals.
Circuit design provided by Dr. Reddy
Micro-controller SelectionThe Atmega168 was chosen for the microcontroller. This is an example circuit connecting the microcontroller to RS-485 and the LED circuitry.
Scoring Matrix of micro-controller options
Mounting Hardware
Dual or Single Ball Joint LED Mount Pros
Maximum adjustability Quick one/two screw
adjustment Extension away from ROV
chassis Cons
Less secure in holding a position
Mounting Hardware
Hinge Style LED Mount Pros
Two axes of adjustability Quick and secure method
of adjustment Simple, effective design
Cons Close to ROV chassis-
shares line of sight to object with video
Mounting Hardware
Thruster Hard Mount Extension Pros
Most secure with rigid attachment
Extension away from ROV chassis
Feasible for use with light units too
Cons No adjustability
Mounting Hardware
System: Mounting Hardware Weight HAI LED % Weight Raw ScoreWeighted Score Raw Score
Weighted Score Raw Score
Weighted Score Raw Score
Weighted Score
Security 12.00% 3 0.36 5 0.6 3 0.36 3 0.36 5 0.6Adjustability 15.00% 3 0.45 0 0 3 0.45 5 0.75 0 0Durability 10.00% 3 0.3 4 0.4 2 0.2 1 0.1 5 0.5Modularity 20.00% 3 0.6 3 0.6 4 0.8 3 0.6 2 0.4Scalability 15.00% 3 0.45 2 0.3 3 0.45 2 0.3 3 0.45Compact design 10.00% 3 0.3 3 0.3 3 0.3 2 0.2 2 0.2Stiffness of placement 6.00% 3 0.18 4 0.24 3 0.18 2 0.12 5 0.3Ease of manufacturing 5.00% 3 0.15 4 0.2 4 0.2 3 0.15 4 0.2Ease of adjustability 7.00% 3 0.21 3 0.21 4 0.28 3 0.21 0 0Total 100.00% 3 28 2.85 29 3.22 24 2.79 26 2.65
Single Screw SS Hinge SS Ball Joint Hard mount extension
Commonalities of all designs: Two hole bolt pattern for housing attachment
Allows any mounting system to be used with either housing Allows for quick attachment and detachment
Corrosion resistant material 316L S.S. or anodized Aluminum Prevents seizing of adjustment points Preserves aesthetic look of product
Scalable This option allows the housing to be the same design, yet sized
appropriately for application Theory: assume current is RP-10
Used on RP-1, 10, 100… RP-1 motor housing is RP-10 LED housing RP-10 LED housing is RP-1 motor housing
Interchangeable
This option allows for the same base housing for both thruster and light
End cap is interchangeable for swapping between thruster and light
Housing Design Scalable
Best option if motor diameter is significantly larger then LED diameter Interchangeable
Best option if motor diameter and LED diameter are similar Accounts for difference in length Simplified machining: one program, one size stock material Identical sub-parts: o-rings, clamps, etc. Hot swappable