1. ECE 477 Final Presentation Group 2  Fall 2005

2. Outline Project overview Block diagram Professional components
Design components
Success criteria demonstrations
Individual contributions
Project summary
Questions / discussion

3. Project Overview Trash Removing Autonomous Predator!
Keypad Controller with LCD output
Traverses a User-Defined Pickup Zone
Uses Digital Camera to Identify any kind of Empty Red Cans, Cups, etc…
Ultrasonic Sensor and Wheelbase Work Together to Maneuver Robot Into Position and Around Obstacles
Ultrasonic Sensor to Detect a
“Basket Full” Condition

4. Block Diagram CENTER Servo Motors x5 LCD FRONT REAR 4 1 Ultrasonic
Sensor
Ultrasonic
Sensor
MCU 2 2 2 2
Camera
Power
Supply x2
Keypad 8 6
H-Bridge

5. Professional Components
Constraint analysis and component selection rationale
Patent liability analysis
Reliability and safety analysis
Ethical and environmental impact analysis

6. Constraint Analysis Microcontroller Atmel AVR (Industrial)
SPI, UART and at least 30 general input output pins
Clock speed – due to the fact that most processing takes place while the robot is moving, it had to be fast enough to handle all peripherals while in motion
A minimum of 6 PWM channels
Sufficient number of timers/counters

7. Constraint Analysis Ultrasonic Sensors
Wide angle detection with a range of at least 1 meter

8. Constraint Analysis Scan Type Keypad (Spectra Symbol) Small
Lightweight

9. Constraint Analysis LCD Display (Parallax Serial LCD) Small
No backlight
Interface without the using the SPI (SPI already shared)
Consume as few I/O pins as possible

10. Constraint Analysis Camera CMUcam2+
Descent resolution, so that we can identify the boundaries of the colored object.
Ability to identify a colored object, based on its colors without any MCU image processing required.
Ability to shut the camera down from the microcontroller

11. Constraint Analysis Compass module (Vector 2x) 2 degree accuracy
ability to shut down when not used
ability to operate correctly under some mild electromagnetic interference

12. Constraint Analysis Shovel/Arm
Strong enough to be able to pick up the cans and to support its own weight
Weight must be as low as possible so that it doesn’t hinder the motorized base
Designed in such a way as to be able to pick up cans in most orientations
Aligned in such a way as it doesn’t get in the way of the sensors

13. Constraint Analysis Motorized base with basket
Strong enough motors to be able to carry the weight of the shovel and all the sensors
Ability to rotate 360 degrees with the basket attached
H-Bridge
Handle all four motors
Brake options

14. Constraint Analysis Batteries and Voltage regulation
At least two batteries, due to the large current requirement of the motors and the servos of the shovel
Voltage regulation to assure constant voltage for the microcontroller and peripherals
Efficient voltage regulation that won’t significantly affect the battery life

15. Component Selection Rationale
Atmel ATMEGA128L usage
8 MHz
6 out of 8 PWM Modules (2 for H-Bridge, 4 for Shovel Servos)
2 USART Modules (LCD and Camera)
2 out of 8 ADC Modules (Battery Monitoring)
1 out of 2 16-bit Timers (Ultrasonic Sensors x2)
SPI Module for Vector 2x Compass
45 out of 53 I/O pins used
0% EEPROM of 4Kb Used
6.5% FLASH of 128Kb Used

16. Patent Liability Analysis
Similarity
Moves autonomously over a surface
Difference
Uses collision detection to navigate instead of collision prevention

17. Patent Liability Analysis
Similarities
Detects obstacles
Able to grip objects
Difference
Detects obstacles using infrared devices instead of ultrasonic sensor
Different gripping mechanism

18. Patent Liability Analysis
Similarity
Uses ultrasonic devices for obstacle detection
Problem with designing around the patent
Using infrared sensors for obstacle detection is patented as well
Action required
Acquire license from patent
holder

19. Reliability/Safety Analysis
Reliability Analysis (MTTF analysis) Using MIL-HDBK-217F Military Handbook
Microprocessor Atmel ATMEGA 128L-8A – 47.9 years
Servos Hitec HS 645MG – years
Voltage Regulator LTC – 9 years

20. Reliability/Safety Analysis
Safety Analysis using FMECA
High Criticality (Injury, Damage to Robot)
Erratic behavior of Shovel
Batteries catching fire
Low Criticality (Functionality Failure)
Power Supply Failure
Sensor Failure
Servo and Motor Failure

21. Ethical/Environmental Analysis
Operating Conditions:
Problem: Extreme weather conditions
(rain, sleet, snow, etc…)
Solution: Proper weatherproof casing
Problem: Proper lighting for camera
Physical Injury:
Problem: Sharp edges and pinch points from the arm; numerous circuit boards
Solution: Plastic shovel as opposed to a metal one
Solution: Warning labels on circuit
boards, servo motors, shovel,
wheelbase and user manual

22. Ethical/Environmental Analysis
Environmental – Bad
Six circuit boards
Lead, glass-epoxy, formaldehyde, copper foil, etc…
Two NiMH rechargeable batteries
Rubber wheels
Metal servo and wheel motors
Metal shovel
Plexiglas wheelbase casing

23. Ethical/Environmental Analysis
Environmental – Good
Robot provides a positive impact on the environment
Picking up waste/recyclables
Reducing litter
Instructions in user manual for returning entire product at the end of its lifecycle
Recycle usable parts
Shipping reimbursement
for consumer

24. Design Components Packaging design considerations
Schematic design considerations
PCB layout design considerations
Software design considerations

25. Packaging Design
Lynx Motion 4WD1 Base

26. Schematic Design
Keypad

27. Schematic Design
Voltage Regulator

28. Schematic Design
ISP interface migration and SCK resistor

29. PCB Layout Design

30. PCB Layout Design

31. PCB Layout Design

32. PCB Layout Design
Fly Wire #1: ISP programmer connected to wrong pins of MCU
NAND Gate Removed

33. Software Design C Language using CodeVisionAVR
Microcontroller Modules:
USART
LCD and Camera
SPI
Vector 2x Compass
PWM
Wheelbase and Servo Motors
Timers
Ultrasonic Sensors
ADC
Battery Monitoring

34. Check Front Ultrasonic
Software Design
Polling Loop
Init
Check Keypad
Check Distance
Check Front Ultrasonic

35. Software Design Main (Polling Loop) START Initialization Error
Distance
Keypad
Finish
Main
(Polling Loop)
Pause
Turnaround
Ultrasonic
PickUp
TrashID
Avoidance

36. Success Criteria Demonstrations
Ability to identify empty, red aluminum cans for pickup - demo
Ability to pick up identified object(s) - demo
Ability to automatically traverse the pickup zone, a rectangular grid - demo
Ability to detect a “basket full” condition - demo
Ability to set operation mode using a keypad and display system status using a LCD
display - demo

37. Individual Contributions
Team Leader – Valentinos Zachariou
Team Member 2 – Jeffrey Alvin
Team Member 3 – Ricky Kannothra
Team Member 4 – Michael Dorsey

38. Team Leader – Valentinos Zachariou
Website Design
Component Research
Design Constraint Analysis
Purchased most of the components
Schematic and Theory of Operation
Package Design
Shovel Arm Design
Robot Construction
Helped with PCB Layout
Populated PCB
Helped with Software Design

39. Member 2 – Jeffrey Alvin Modules: SPI Module Compass PWM Module Servo
Ultrasonic Sensor
Keypad
Packaging Specifications and Design Paper
Patent Liability Analysis Paper

40. Member 3 – Ricky Kannothra
PCB Layout Design
Modules:
SPI Module
Compass
PWM Module
Shovel Servos
Timer/Counter Module
Ultrasonic Sensors
Keypad
ADC Module
Battery Monitoring
Software:
Basket Full
Trash Pickup
Repositioning
Avoidance
Check Battery
Reliability and Safety Analysis Report

41. Member 4 – Michael Dorsey
Modules:
USART Modules
Camera and LCD
SPI Module
Compass
PWM Module
Wheelbase
Keypad
Software:
Main Polling Loop
Initialization
Trash Pickup
Turnaround
Avoidance
Reposition
Ethical/Environmental Analysis
Software Design Considerations

42. Project Summary Important Lessons Learned
Know where you can get your components locally
Read component user manuals entirely
Sacrifice individual components for overall functionality
Make wire connections that are properly insulated
Have backup components available
Make sure your package can easily be taken apart for corrections
Expect the unexpected

43. Project Summary Second iteration enhancements
Use wheel encoders to detect distance and direction
Use a turret for the camera
Better wheels (more durable)
Use Interrupt Driven Code
Use GPS for increased functionality (Larger Areas, e.g. football field)
Better weather shielding
Ability to identify a wider
variety of trash

44. Questions / Discussion

46. Back to PSSC

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