Jenny December 1, 2014 In Response to NASA BAA # NNH14ZDA001N Development of ROV for Ross Ice Shelf Expedition Sanjana Belani Caleb Irvin Ryden Lewis Emily Thayer Ryan Wilkie neptune, inc ©
Jenny
December 1, 2014In Response to NASA BAA # NNH14ZDA001N
Development of ROV for Ross Ice Shelf Expedition
Sanjana BelaniCaleb IrvinRyden LewisEmily ThayerRyan Wilkie
neptune, inc©
Objectives
● Design a Remotely Operated Vehicle to collect data beneath the Ross Ice Shelf in Antarctica
● Build a scale model of this ROV● Provide calculations for a full
scale model of the ROV● Turn Valve 180° http://www.destination360.com/antarctica/ross-ice-shelf
Requirements
The ROV must:● not exceed a total system mass of 15.0 kg● not exceed the dimensions : 58cm x 40cm x 30cm ● be able to move in 6 directions of motion● Incorporate required components and meet design
requirements
Design - Jenny
Jenny
● Meets size requirements● Easily maneuverable in any direction● Average speed of .595 m/s● Neutrally buoyant● Capable of being scaled up to full scale
Description
● Dimensions: 49 cm x 31 cm x 29 cm● PVC frame● Five buoys and two Gatorade bottles for
buoyancy● Zip ties secure components ● Camera on front, right side
Design
31 cm
29 c
m
49 c
m
Design
(Rear view)
Payload
Design
(Top view)
Buoys
Design
(Front view)
Bottles
Camera
Design
(Rear view)
Thrusters
Thruster Placement
● Located in rear corners● Allows pitch to be easily
changed● Tight turn radius● Each controlled
individually by switches or buttons
Circuit Diagram
Advantages
● Design allows for easy addition/removal of components
● Four rear facing thrusters maximize speed ● Inner frame securely protects payload ● Wide surface area to turn the valve
Mass Budget
Component Mass (grams)
Payload <10,000.0
Frame 1464.5
Thrusters 944.7
Buoyancy 289.6
Total <13,291.5
CalculationsOur ROV is neutrally buoyant so the force of buoyancy is equal to the weight of the ROV.
∑F = FB - FG
0 = FB - FG
FB = FG
FB = 130.38 N
FG= m×gFG= (13291.5g/1000g)(9.81m/s2)
FG= 130.38 N
Calculations
DragD = T = 25.22 N
ThrustForward = 25.22 NBackwards = 8.19 N
Calculations
Top SpeedForward Vtop speed =
√(T/(.5AROVCD⍴)
= 0.663 m/s
Reverse Vtop speed =
0.377 m/s
Max PowerForward Prequired=VT/ηoverall
= 66.88 W
Reverse Prequired = 12.35 W
Calculations
Center of Gravity
XCG = 19.1225
YCG = 16.304
ZCG = 1.78
Testing
● Temperature ≃ 20˚C● Density: 998 kg/m3 ● Achieved average velocity
of 0.595 m/s ● Neutrally Buoyant ● Stable
Full Scale Environment
Fluid: Sea waterDensity:1028 kg/m3
Water temperature: -2.16˚CAdditional considerations: Sea currents, Increased pressure and buoyancy, Limited lighting
Full Scale Materials
● Frame: High-Strength Steel
● Propellers: Stainless Steel
● Buoyancy: Syntactic Foam
● Power Source: Lithium-ion battery
Full Scale Calculations
Full Scale Dimensions:λ = 2.5
Ls = 1.23 m
Ws = 0.78 m
Hs = 0.73 m
Full Scale Calculations
Full Scale Top Speed:
Vs = Vm × λV
= 0.483 m/s
Full Scale Thrust:
TS= TM x λT = 86.12 N
Power:
Ps= Pmx λpower = 166.3 W
Recommendations
● Housing for the camera● More secure protection for thrusters● More sophisticated controls
Conclusion
● Model meets all requirement● Has a calculated speed of 0.663 m/s and a
recorded speed of 0.595 m/s● Highly maneuverable ● Compact design
Questions?
neptune, inc©
Contact: [email protected]
image from: http://www.percyjacksonmovies.com/wp-content/gallery/logos/black.png
Center of Gravity
XCG=((236.175*49)*4+10000*16.3)/(944.7+10000)
XCG = 19.1225
YCG=(212.5*7.75)+2(236.175*15.5)/(944.7+212.5+10000)
YCG = 0.804
(31/2) + YCG = 16.304
ZCG= (212.5*29)+(236.175*29*2)/(212.5+944.7+10000)
ZCG = 1.78