Date post: | 19-Dec-2015 |
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Ground Control
Andrew BourgeoisAaron Minard
Background
http://streamsurfers.netfirms.com/faq/faq0001_how_it_works.htm
Data transmitted at the speed of light in a straight line.
Satellites used to avoid curve of the earth
If not geostationary, moves across the sky.
SatPC32
Calculates the tracks of earth orbiting satellites.
Calculations are based on the SGP4/SDP4 model, highly accurate.
Simplified General Perturbations Satellite Orbit Model 4 (NASA/NORAD)
SatPC32
CubeSat Satellite
Developed by Cal Poly and Stanford University 10cm3 and has a mass of 1kg Powered by photovoltaic cells and rechargeable
batteries Usually launched piggyback to commercial
satellites Costs $30,000 to $50,000 to build and the same
amount to ride piggybacked on a commercial satellite.
Problem
Track a low orbit satellite from horizon to horizon
Move a 3 meter satellite dish
Interface to SatPC32
Solutions
Gears and motor
Motor controllers to interface with SatPC32
Digital Encoders to control position of the dish
Use/Modify existing designs for elevation and azimuth control
System Diagram
Micro-controller
MC
MC
A E
Limit SwitchRS232 (2x)
Analysis
COMING SOON
Analysis
Horse-Power
deg Gear Ratio 2 3 4 5 6 7 8 9 10
5 0.262501 0.175 0.13125 0.105 0.0875 0.075 0.065625 0.058333 0.0525
10 0.13125 0.0875 0.065625 0.0525 0.04375 0.0375 0.032813 0.029167 0.02625
15 0.0875 0.058333 0.04375 0.035 0.029167 0.025 0.021875 0.019444 0.0175
20 0.065625 0.04375 0.032813 0.02625 0.021875 0.01875 0.016406 0.014583 0.013125
25 0.0525 0.035 0.02625 0.021 0.0175 0.015 0.013125 0.011667 0.0105
30 0.04375 0.029167 0.021875 0.0175 0.014583 0.0125 0.010938 0.009722 0.00875
35 0.0375 0.025 0.01875 0.015 0.0125 0.010714 0.009375 0.008333 0.0075
40 0.032813 0.021875 0.016406 0.013125 0.010938 0.009375 0.008203 0.007292 0.006563
45 0.029167 0.019444 0.014583 0.011667 0.009722 0.008333 0.007292 0.006481 0.005833
Elevation
Azimuth
ElectricalPosition Encoders
AC
MCMC L.S.
24Vdc FUSE
5Vdc
Micro-controller
A
E
L.S.
FUSE
FUSE
Programming
Material Costs
Mechanical Materials
Steel
2" x 2" x 12' Square Tube $54.48
1" x 1" x 8' Square Tube $17.28
24" x 24" x 1/4" Steel Plate $129.56
1" x .12"th x 6" Round Tube $64.71
1" x 6' Round Stock $55.97
total $322.00
Questions?