Autonomous Beacon Seeking Blimp

Kenton WeigoldMarcin OchmanBrian Schmalzer

Outline Introduction Design Overview

Beacon Blimp

Hardware Software

Difficulties and Risks Testing Strategy Weight Constraints Cost analysis

Introduction Helium-supported, self-propelled

autonomous blimp Maintains an altitude of 1.5 meters Seeks out beacon that broadcasts an

infrared signal at 38KHz Able to detect beacon at least 7

meters Lands within 40cm of target beacon

Beacon LEDs

TSAL6100 - 10 degree beam TSAL7200 - 20 degree beam

555-timer (LM555CM) Create 38KHz pulse

6V Li-Ion Batteries (2CR5) with 5V Voltage Regulator (KA7805)

Drivers (SN74LS244EW) Supply up to 8 IR LEDs each with

sufficient current Hemispherical configuration

Profile View

Sensor Placement

Sensor Operation Two IR detectors for

direction One IR detector for

determining if beacon is found

One ultrasonic range finder for altitude determination

IR Sensor

IR BeaconUltrasonic Range Finder

Profile View

Overhead View

Infrared Sensors Panasonic PNA4611M

5V Operating Voltage Detects pulses of 38KHz at a

wavelength of 940nm Maximum typical reception

distance of 16 meters Typical current consumption

of 2.4 mA Active-Low TTL output (0-5V) <1 gram in weight

Ultrasonic Range Finder MaxSonar-EZ-1

5V Operating Voltage 16cm – 6.45 meter range

<16cm ranges as 16cm 2.5cm resolution Typical current consumption

of 2 mA 49ms sample interval Outputs

Serial Analog (10mV/2.54cm) PWM (147uS/2.54cm)

4.3 grams in weight

Blimp Mobility

Altitude Control Vertical-axis motor

Propulsion/Direction Control Two motors on the horizontal plane capable of

independent rotation in both directions

Profile View Overhead View

Propulsion/Direction ControlAltitude Control

Propulsion Assembly Motors

1.5V Operating Voltage 22mA consumption 6400rpm 4.0gcm torque

U80 High thrust propellers

Total weight of 36 grams

Power Supply 6V Lithium-Ion Rechargeable

Battery (2CR5) 48.5 grams in weight 600 mAh

5V Voltage Regulator (KA7805) Input: 5V-35V Output: 5V up to 1A

1.8V Voltage Regulator Input: 3V-26V Output: 1.8V up to 0.5A

Microcontroller Freescale MC9S12DT256

16-bit device 256KB Flash 4KB EEPROM 12 KB RAM 2 10-bit, 8-ch ATD 16 discrete I/O (Port A, Port B) And more…

User Interface and Emergency Tether

A single power switch will start blimp search pattern

To ensure safe operation, the blimp will always remain tethered

A strong tug will release the power cut-off pin

Permanent Connection

Power Cut-off Pin

Blimp System Diagram

Power Supply

6V Li-Ion Battery(Panasonic 2CR5)

5V Voltage Regulator(KA7805)

+

1 2

-

3

MC Interface

Microcontroller(CSM12D)

Altitude Sensor

Ultrasonic Range Finder(MaxSonar-EZ-1)

+5VGND AN

GND

5V

Range Finder SignalAnalog (10mv/inch)

Bearing IR SetIR Detector

(PNA4612M)IR Detector

(PNA4612M)1 2 31 2 3

Right IR Signal TTL(0-5V)Left IR Signal TTL(0-5V)

L L

ED

R L

ED

Overhead IR SetIR Detector

(PNA4612M)1 2 3

O L

ED

Overhead IR Signal TTL(0-5V)

Propulsion/Direction Control

Propeller Motor

1.8V Voltage Regulator(Tl760M18)

GND

6V

Propeller Motor

H Bridge(ZHB6718)

1 2 3

H Bridge(ZHB6718)

6 2

5 7

+ -

6 2

5 7

+ -

Prop/Direction Signals (8 bits TTL)

1,3,4,81,3,4,8

Altitude Control

Propeller Motor

H Bridge(ZHB6718)6 2

5 7

+ -

1,3,4,8

Alt Ctrl Signals (4 bits TTL)

Port A0-7

Port B0-3 Port B4 Port B5 Port B6

Port AD00

Pow

er S

W

Em

erge

ny

Cut

off

Pin

AlgorithmSystem

Start

Altitude Low?

Increase Altitude.Yes

Altitude High?

Decrease Altitude.

No

Yes

Overhead Detected?

ShutdownDecrease Altitude.Yes Landed?

No

Yes

Left IR Detect?

Right IR Detect?

Turn Left

Turn Right

Yes

Yes

No

No

No

Right or Left IR Detect?

Yes

Turn RightNo Increase Loop

Proceed ForwardLoop

Count = Loop

No

Yes

Set Loop to 1

No

Right IR Detect?

No

Yes Proceed Straight

Increase Loop Count

Set Loop count to 0

Turn Right

Difficulties and Risks IR Pollution/Reflections

Infrared Guards Digital Filter/Software Filter

Weight Limitations Strip non-essential components

Maintaining Neutral Buoyancy Maintain helium pressure Ballast

Difficulties and Risks (cont) Air Currents

Avoid areas with noticeable air currents

Inverted Airfoil Effect Mount Fins Use short thrust bursts

Insufficient Power Reduce power consumption Increase battery power

Testing Strategy Module Tests/Interface Tests

IR Ultrasonic components Propulsion Power

Integration Tests Blimp Beacon

Bench Tests Field Tests

Weight ConstraintsPart Qty Individual

Weight (g)Total Weight (g)

IR Sensors 3 <1.0 1.0

Ultrasonic Range Finder 1 4.3 4.3

H-bridges 3 <1.0 1.0

Blimp Propeller Assembly/Motors/Propellers 1 33.0 36.0

Freescale CSM12D 1 38.0 38.0

Indicator LEDs 3 <1.0 1.0

Li-Ion Battery 1 48.5 48.5

1.8V Voltage Regulator 1 1.0 1.0

5.0V Voltage Regulator 1 1.0 1.0

Envelope 1 63 63

Weight available for Additional Logic Components/Interconnections, mounts, and landing gear.

N/A   ~55.2

Total     250

Cost AnalysisPart Supplier Qty Individual Cost Total Cost

IR Sensor (PNA4612M) www.digikey.com 3 $1.27 $3.81

Ultrasonic Range Finder (MaxSonar-EZ-1) www.acroname.com 1 $25.00 $25.00

IR LED (TSAL6100) Reynolds Electronics 30 $0.70 $21.00

IR LED (TSAL7200) Reynolds Electronics 30 $0.65 $32.50

H-bridges (ZHB6518CT) www.digikey.com 3 $3.70 $11.10

RC Toy Blimp (includes motor mounts an motors)

www.rctoys.com 1 $59.95 $59.95

Propellers (U80) FXAeromodels 3 $1.75 $5.25

Freescale CSM12D Freescale 1 $120.00 $0.00

6V Li-Ion Batteries and Charger (KIT2CR5)

Thomas Distributing 1 $29.97 $29.97

Additional 6V Li-Ion Battery (2CR5) Thomas Distributing 2 $14.97 $29.94

1.8V Regulator (TL760M18) Radio Shack 2 1.65 $3.30

5.0V Regulator (KA7805 Radio Shack 1 1.65 $1.65

Indicator LEDs Team 3 $0.14 $0.00

Additional Logic Components/Interconnects

Team N/A $N/A $0.00

Drivers (SN74LS244EW) Mouser Electronics 6 $0.77 $4.62

Clock (LM555CM) Mouser Electronics 1 $0.27 $0.27

Helium Party City N/A ~$0.30/cu.ft. $3.00

Total Cost N/A N/A N/A $231.36

Questions/Comments