1 ECE 477 Final Presentation Group 2 Fall 2005
2 Outline Project overview Block diagram Professional componentsDesign 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 UltrasonicSensor Ultrasonic Sensor MCU 2 2 2 2 Camera Power Supply x2 Keypad 8 6 H-Bridge
5 Professional ComponentsConstraint 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 SensorsWide angle detection with a range of at least 1 meter
8 Constraint Analysis Scan Type Keypad (Spectra Symbol) SmallLightweight
9 Constraint Analysis LCD Display (Parallax Serial LCD) SmallNo 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 accuracyability to shut down when not used ability to operate correctly under some mild electromagnetic interference
12 Constraint Analysis Shovel/ArmStrong 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 basketStrong 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 regulationAt 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 RationaleAtmel 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 AnalysisSimilarity Moves autonomously over a surface Difference Uses collision detection to navigate instead of collision prevention
17 Patent Liability AnalysisSimilarities Detects obstacles Able to grip objects Difference Detects obstacles using infrared devices instead of ultrasonic sensor Different gripping mechanism
18 Patent Liability AnalysisSimilarity 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 AnalysisReliability 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 AnalysisSafety 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 AnalysisOperating 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 AnalysisEnvironmental – 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 AnalysisEnvironmental – 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 considerationsSchematic 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 CodeVisionAVRMicrocontroller Modules: USART LCD and Camera SPI Vector 2x Compass PWM Wheelbase and Servo Motors Timers Ultrasonic Sensors ADC Battery Monitoring
34 Check Front UltrasonicSoftware Design Polling Loop Init Check Keypad Check Distance Check Front Ultrasonic
35 Software Design Main (Polling Loop) START Initialization ErrorDistance Keypad Finish Main (Polling Loop) Pause Turnaround Ultrasonic PickUp TrashID Avoidance
36 Success Criteria DemonstrationsAbility 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 ContributionsTeam Leader – Valentinos Zachariou Team Member 2 – Jeffrey Alvin Team Member 3 – Ricky Kannothra Team Member 4 – Michael Dorsey
38 Team Leader – Valentinos ZachariouWebsite 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 ServoUltrasonic Sensor Keypad Packaging Specifications and Design Paper Patent Liability Analysis Paper
40 Member 3 – Ricky KannothraPCB 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 DorseyModules: 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 LearnedKnow 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 enhancementsUse 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
45
46 Back to PSSC
47
48 Back to PSSC
49
50 Back to PSSC
51
52 Back to PSSC
53
54 Back to PSSC