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

Introduction Blimps Anatomy Design Control Sensing

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

HELIUM - Calculating Lift At standard temperature and pressure, mass density of Air : ρair = 1.293 kg/m3 Helium : ρHe = 0.178 kg/m3 Neon: ρHe = 0.9 kg/m3 Wload = [(ρair – ρHe) x volume – Wenv ] Kg Grade A Helium gas = 99.995% He and 0.005% Ne Wload = [(ρair - 0.99995ρHe - 0.00005ρNe) x volume – Wenv ] Kg

HELIUM - Calculating Lift Wload = [1.1149 x volume – Wenv ] Kg Thumb rule : 1m3 of helium can lift 1.1 kg of load

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

Envelop Designs

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

Propulsion DC Brushed motors + Propellers Flapping wings/fins !

Propeller Placements

Propeller Placements

Propeller Placements

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

Sensors Gyros Acceleros GPS Digital Compass Ultrasonic Pressure sensor IR Vision

Sensors Gyros Acceleros GPS Digital Compass Ultrasonic Pressure sensor IR Vision

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, 0-255 and 0-3599 SCL Speed up to 1MHz Weight 0.03 oz. Size 32mm x 35mm Devantech, acroname.com, $57

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 : 1mA @ 3V Sparkfun.com, $60

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

Thank you!