ECE 477 Final Presentation Group 2  Fall 2005

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

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

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

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

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

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

Constraint Analysis Scan Type Keypad (Spectra Symbol) Small Lightweight

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

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

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

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

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

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

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

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

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

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

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 – 182.6 years Voltage Regulator LTC 1174-5 – 9 years

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

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

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

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

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

Packaging Design Lynx Motion 4WD1 Base

Schematic Design Keypad

Schematic Design Voltage Regulator

Schematic Design ISP interface migration and SCK resistor

PCB Layout Design

PCB Layout Design

PCB Layout Design

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

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

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

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

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

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

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

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

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

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

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

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

Questions / Discussion

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