LocomotionJad Farah Long Quy Patrick Swann Korhan Demirkaya Ngoc Mai NavigationSteven Weaver Denden Tekeste Ali Alkuwari Marcus Schaffer

Objective

Design & build an autonomous robot with ability to:

Navigate a given course -Pass through gates by sensing beaconAvoid obstacles -Various sensors to plot track of robotControl functions: -High (BEAGLEBOARD) -Low (AVR1 & 2)

Project Requirements

• Various sensors to plot track of robot • Detect ultrasonic beacons within 15 - 25 feet• Fits within a 16”x16”x16” cube• Has clearly labeled emergency stop switch• Travels 1.5 ft/sec• Regulates voltage

Block Diagram

AVR ATmega 1280(PS 1) BEAGLE BOARD

OMAP 3530

(PS 2)

H-Bridge

(24 V)

Motor LEFT

Motor RIGHT

2 PWM

/ 4 Di

rectio

n

1 Digi

tal

Wheel Encoder RIGHT(PS 2)

Wheel Encoder

LEFT(PS 2)

1 Digi

tal

2 2

2 Ana

log

4 PWM

Ultrasonic Sensors

(PS 2)

Flex Sensors

(PS 2)

GPS

(PS 2)

Digital Compass

(PS 2)

2 PWM

Servo Motor (PS 2)

SCL(S

erial

I2C)

SDL(S

erial

I2C)

PS 1 = 7.2VPS 2 = 5 V

2 x 7.2V 2300mAh

Nimh Battery2

24V 4200mAhNimh Battery

24V

AVR ATmega 328(PS 1)

Serial(USB)

RXTX

Block Diagram - Navigation

AVR ATmega 1280 BEAGLE BOARDOMAP 3530Serial(USB)

2 A

nal

og

4 P

WM

Ultrasonic Sensors

Flex Sensors

GPS

Digital Compass

2 P

WM

Servo Motor

SC

L(S

eria

l I2C

)

SD

L(S

eria

l I2C

)

RX

TX

Block Diagram – Locomotion

BEAGLE BOARDOMAP 3530

H-Bridge

Motor LEFT

Motor RIGHT

2 PW

M /

4 Di

rect

ion

Wheel Encoder RIGHT

Wheel Encoder

LEFT

1 Di

gita

l

2 2

AVR ATmega 328 Serial(USB)

Assembly

• aluminum body

• specially designed PCBs

unique wire layout

and alternative

Assembly

Assembly

• switches for logic & motor power

• fuses

Mounting

• Various Sensors • H-Bridge

Mounting

• GPS & Compass• Beagle Board• AVRs

• HBridge + Voltage Regulator

• GPS

• Compass

• UART

• Wheel Encoder

• Daughter board

• Sensors: Beacon, Ultrasonic, & Flex

PCB Design

Motor Control

• Hardware : Wheel Encoders, H-Bridge, dedicated micro controller

•Software : Speed / PID Control

• Multiple speeds

1kHz–slowest speed≈ 0.8 feet/second

3kHz–fastest speed≈ 2.5 feet/second

Beagle Board

• Robot brain – high level control

• Python code

• GPS parsing

• Object avoidance

AVR

• serial coding for sensors

• powered with one 7.2V

GPS & RF

• 300 lines of Python code

• GPS equation estimates coordinates, distance, & direction on map

• RSSI equation to estimate distance of beacons

• 2 UART – 5V & 3.3V output

Sensors

• Turtle’s Body

• Parts Mounted

• Code

• PCB

• Interface Beagle Board & AVR together

Milestones

Budget

Beagle Board $150

AVRs $105

GPS $50

Batteries $82

Sensors $78

Labor Cost $0

Website

http://turtle.sdsu.edu