1. Mohit Bhoite and Saurabh Palan
MEAM 610
BLIMPS
Mohit Bhoite and Saurabh Palan

2. Introduction
Blimps
Anatomy
Design
Control
Sensing

3. Anatomy of a Blimp
“A blimp, or non-rigid airship, is an airship without an internal supporting framework or keel.” - wiki
Stabilizers
Envelop
Motors
Propellers
Gondola

4. HELIUM - Calculating Lift
At standard temperature and pressure, mass density of
Air : ρair = kg/m3
Helium : ρHe = kg/m3
Neon: ρHe = 0.9 kg/m3
Wload = [(ρair – ρHe) x volume – Wenv ] Kg
Grade A Helium gas = % He and 0.005% Ne
Wload = [(ρair ρHe ρNe) x volume – Wenv ] Kg

5. HELIUM - Calculating Lift
Wload = [ x volume – Wenv ] Kg
Thumb rule : 1m3 of helium can lift 1.1 kg of load

6. Latex Balloons vs. Rigid Envelops
Which one is better?
Balloons have internal pressure much higher than atmospheric => unnecessary helium mass => no extra lift
Rigid envelops will have pressure equivalent to atmospheric pressure => better efficiency

7. Envelop Designs

8. Envelop Designs Off-the-shelf Options Cost $25, 7cu feet $12
$4, 3’ dia

9. Propulsion
DC Brushed motors + Propellers
Flapping wings/fins !

10. Propeller Placements

11. Propeller Placements

12. Propeller Placements

13. Controller Architecture
Sensors
Main Controller
(uP, uC)
Motor Driver
Motors, Servos
Camera
Wireless Link

14. Sensors Gyros Acceleros GPS Digital Compass Ultrasonic Pressure sensorIR
Vision

15. Sensors Gyros Acceleros GPS Digital Compass Ultrasonic Pressure sensorIR
Vision

16. Digital Compass Devantech, acroname.com, $57 Specifications Voltage 5v
Current
20mA Typ.
Resolution
0.1 Degree
Accuracy
3-4 Degrees approx (after calibration)
Output 1
Timing Pulse 1mS to 37mS in 0.1mS increments
Output 2
I2C Interface, and
SCL Speed
up to 1MHz
Weight
0.03 oz.
Size
32mm x 35mm
Devantech, acroname.com, $57

17. Digital Compass I2C interface 2.7 to 5.2V supply range
1 to 20Hz selectable update rate
True drop-in solution
0.5 degree heading resolution
1 degree repeatability
Supply current : 3V
Sparkfun.com, $60

18. Pressure Sensors Barometric pressure sensing for altitude measurement
Can achieve resolution of about 10cm at sea level
Pressure decreases at the rate of 100 millibars per 800 meters
$55

19. Thank you!