Transcript ECE 477 Final Presentation Group ?? Fall 2004

ECE 477 Design Review
Team 10  Spring 2007
Outline
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Project overview
Project-specific success criteria
Block diagram
Component selection rationale
Packaging design
Schematic and theory of operation
PCB layout
Software design/development status
Project completion timeline
Questions / discussion
Project Overview: Hazard Rover
• Remote-controlled tank with a robotic arm
• User controls tank and receives status information
from a control website through wi-fi interface
• Wireless webcam streams video back to control
website
• Capabilities:
– Obstacle detection – stop tank when detected
– Light sensor/LED headlight
– Camera tilt movement
• Model of a tank to be used in a hazardous or polluted
area
Project-Specific Success Criteria
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An ability to control the speed and direction of
the vehicle (forward/backward).
An ability to display system status (battery life,
stopped/running) on an embedded web page.
An ability to sense obstacles and stop the
vehicle if it is near an obstacle.
An ability to control the position of a robotic arm
on the vehicle.
An ability to sense ambient light and turn on a
bright LED if there is not enough light.
Block Diagram
WiFi Enabled
Personal
Computer
Vehicle Lighting Unit
LED
Headlight
Camera
movement
servo motor
(tilt)
Light
Sensor
1
Wireless
Webcam
1
GPIO
Built-in
Ethernet
Interface
“PWM”
ATD
Microcontroller
ATD
2
Obstacle
Sensors
X2
Wireless
Bridge
GPIO
3
2
GPIO
DC-DC
Converter
DC Motor
Driver
Tank Drive
motor
To all
components
(5V)
Voltage
Regulator
“PWM”
1
DC Motor
Control
GPIO
2
“PWM”
1
DC Motor
Control
Tank steering
motor
Battery
Robotic Arm
(DC motor)
X3
Component Selection Rationale
• 1. Microcontroller
– Freescale MC9S12NE64
– Built-in ethernet interface
– Has more I/O pins than project requires
• 2. Battery
– 8.4V NiMH Battery Pack
– 4500 mAh, estimated battery life of ~2 hours
before recharge
Component Selection Rationale
• 3. Voltage Regulator (8.4V to 5V)
– Fairchild KA78T05 Positive Voltage Regulator
– All components except microcontroller can
run on 5V
– Capable of providing 5A, ~3 motors
• 4. Voltage Regulator (5V to 3.3V)
– Toshiba TA48033F Voltage Regulator
– DC-DC step voltage for microcontroller
Component Selection Rationale
• 5. Light Sensor
– Jameco CDS Photocell 202391
– Provides variable resistance 1K-1M ohms
• 6. LED Cluster
– SunLED XK4MDW62 LED Cluster
– Provides bright light off of 5V
• 7. Camera Tilt Servo Motor
– HS-422 Servo motor with “C” bracket attachment for
tilt capability
– Runs off 5V
Component Selection Rationale
• 8. DC Motor Control
– Fairchild FAN8082 Motor Driver
– Runs off 5V
– Drives tank steering motors as well as all
robotic arm motors.
• 9. Drive Motor Control
– Tecel D200 High Power H-Bridge Driver
– Runs off 5V, capable of driving the motor
– Noisy component – on separate board
Component Selection Rationale
• 10. Wireless Bridge
– D-Link Wireless Bridge DWL-G820
– Instantly compatible with Ethernet-enabled
microcontroller
• 11. Wireless Webcam
– D-Link Wireless Webcam DCS-G900
– Instantly capable of broadcasting live video
feed to the web
Component Selection Rationale
• 12. Robotic Arm
– Jameco Robotic Arm Trainer Kit
– 5 degrees of freedom, controlled by servo
motors
• 13. Obstacle Detection
– Sharp GP2Y0A02YK Infrared Sensor
– Provides analog signal 0-5V
Packaging Design
LED
Wireless
Camera
Light Sensor
PCB Board
Wireless
Bridge
Battery
9“
15 “
4“
Front
Distance
Sensor
4“
5“
20 “
Rear
Distance
Sensor
Schematic/Theory of Operation
• Microcontroller
Distance Sensor
• The output voltage is a function of distance
from the obstacle
Light Sensor
• The output voltage is a function of amount of
ambient light present
Power Supply
• The 8.4V supply powers all motor drivers: FAN8082
and Tecel D200
• The 5V supply powers all other components except
for the microcontroller
• The 3.3V supply powers the microcontroller
Ethernet Interface
• Built in magnetic filter
FAN 8082
• It drives DC motors and steering motor
Wireless Camera
• It operates independently of the microcontroller
H-Bridge
PCB Layout
Motor Drivers: FAN8082
• Left corner of the
board
• Motor drivers
placed together to
group noise
production
Power Supply and Decoupling capacitors
• The two voltage regulators supply the three voltages
necessary to run the circuit: 8.4V, 5V, 3.3V
• Opposite corner from the microcontroller
Microcontroller and Ethernet
Headers
• Headers for components off the board
• The Tecel 200 has separate board
Software Design/Development Status
• Two parts
– User interface: Using C# on Visual Studio.
• Controller: Keyboard and mouse
• Status display: Battery life, stop, direction
• UDP
– Microcontroller
• Using subset of C on CodeWarrior
• Using OpenTCP stack for webserver
• Polling loop
• PWM, ATD, SCI, EPHY
Software Design/Development Status
Software Design/Development Status
Start/Reset
Read light
sensor
Initialization
Dar
k?
Y
LEDs
on
N
Get flags
Read Front
Distance
Dri
ve
Y
Forward/
reverse
Turn
Clo
se?
N
Ar
m
N
Pan/
Tilt
Y
Move Arm
STOP
Y
N
Read Rear
Distance
Y
Move camera
Clo
se?
N
N
STOP
Y
Project Completion Timeline
Week
PCB/
Schematic
PCB Soldering
Software
Designing
Packaging
Testing
Documentation
2/26
3/5
3/12
3/19
3/26
4/2
4/9
4/16
4/23
4/30
Questions / Discussion