A.G.I.L.E

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A.G.I.L.E
Autonomously Guided Intelligent Lawn Equipment

• Team Members
• Brad Ramsey
• Derek Rodriguez
• Dane Wielgopolan
• Project Managers
• Dr. Joel Schipper
• Dr. James Irwin

ECE Department
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PRESENTATION OUTLINE

• PROJECT OBJECTIVES
• PREVIOUS WORK
• PRELIMINARY LAB WORK
• EQUIPMENT INFORMATION
• PARTS LIST
• SCHEDULE OF TASKS FOR NEXT SEMESTER

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PROJECT OBJECTIVES

• Design a lawnmower navigation system
• Detect the field boundaries using RF
• Track vehicles position and orientation
• Movement using closed loop motor control
• Detect and avoid objects (static/dynamic)
• Safety shutoff switch

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LITERATURE REVIEW

• Find previous projects and their pros and cons
• University of Florida project path ideal example
• Series of 3 projects add up to ours
• What can we do better?

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Florida Project One

• Project name LawnNibbler
• Student researcher Kevin Hakala
• Operating Components
• Electric weed trimming platform
• RF Wire Boundary
• (proof of concept) Local Positioning System
• No results for completed mower published

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Florida Project Two

• Project name LawnShark
• Student researcher Rand Chandler and Katherine
  Meiszer
• Operating Components
• Electric Toro Lawnmower
• Local Positioning System
• Ultrasonic sensors (2)
• No results for completed mower published

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Florida Project Three

• Project name Autonomous Lawn Care Applications
• Student researcher Michael Gregg
• Operating Components
• Proof of Concept platform (no mowing)
• RF wire containment
• Obstacle avoidance
• Collision Detection
• Random Movement Programming
• No results for completed mower published

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What makes us different

• Three cumulative projects compacted into one
• Added Components for a better outcome
• Wall following (physical and RF fence)
• Efficient mowing pattern
• Off unit computer processing
• Unnecessary computer on mower
• Utilize an existing computer
• Easy to update software
• Design and Create Electric RF dog fence

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GOALS

• Obtain a chassis
• Drive control system
• Build sensors
• Detect and avoid objects
• Mower/PC communication
• Efficient Algorithm

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SPECIFICATIONS

• Max Speed 2 ft/s
• Response Time lt150ms
• Mowing Coverage 120 ft²/min _at_ 2 ft/s
• 12v 7.2 Ah Batteries x2
• Heading Accuracy 1 of error (ideal)

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SYSTEM BLOCK DIAGRAM
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CHASSIS

• Maneuverable
• Symmetrical
• Dual DC Motors
• Differential turning
• Dimensions
• Length 12.5
• Width 18.5
• Height 7

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POWERTRAIN

• Dual Pittman 12v DC motors
• Gear ratio 65.51
• Max RPM _at_no load 4916
• Max shaft RPM _at_no load 75
• Rotary encoder
• 500 CPR
• 2 channels
• Wheels
• 6 Diameter
• Direct drive
• Power
• Dual 12v 7.2Ah Batteries

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MOTOR CONTROL

• User input average speed
• Speed averaged between wheels
• Rotary encoder feedback
• PI control
• PWM
• Control system modeled in Simulink

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SIMULINK MODELING

• Single motor model
• Microcontroller

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MICROCONTROLLER

• MICROPAC 535 (EMAC)
• 8051 architecture
• 3 timers
• 3 serial ports (up to 230.4K baud)
• 10 external interrupts
• 4 PWM I/O ports
• 8 A/D
• 24 digital I/O

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OBJECT DETECTION

• Ultrasonic sensors
• Coverage area maximized for front sides

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ULTRASONIC SENSORS

• Devantech SRF05 Ultrasonic Range Finder
• Interfaced to microcontroller
• Multiplexer used to save digital I/O pins
• 1 digital input/2 digital outputs for all
  sensors

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DIGITAL COMPASS

• R117-COMPASS
• Interfaced to microcontroller

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SAFETY

• Safety switch on mower
• Remote shutdown
• User shutdown in software
• Lost connection to PC
• Bump switches
• Last line of defense
• Uses 3 pushbutton switches
• Bumper connected to buttons
• Interfaced to digital input on µC
• Triggers high priority interrupt
• Kills mower blade

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BOUNDARY DETECTION

• Dog fence
• Transmitter
• Radio Frequency
• 8 kHz Sine Wave
• Dual receivers

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RF CONTAINMENT WIRE

• Better known as an electric dog fence
• Band pass receiving filter

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SOFTWARE

• C/Assembly on EMAC
• C On PC
• EMAC will acquire data
• Remote PC
• Receive user settings
• Process data
• Implement algorithm

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SOFTWARE FLOW CHART
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BASIC ALGORITHM

• North-South pattern
• Uses dog fence
• Minimal areas missed
• Ideal for square field
• Starts with border

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DATA SYNCHRONIZATION

• Data synchronized between µC and PC
• Serial to 802.11 converter
• Any LAN connected PC can connect and run the
  software
• Sets up a virtual com port on the LAN PC
• Data rates up to 230400 Baud

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PARTS LIST

• Mowjoe chassis (motors, frame, batteries)
• C80515 EMAC 8051 based microcontroller
• ES1AWB (RS-232 to Wi-Fi)
• Windows based PC
• Digital compass
• Devantech R117 for prototype
• Would like a more accurate one
• Ultrasonic sensors X4
• Devantech SRF05
• RF sensors X2
• Dog fence components

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GANTT CHART
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GANTT CHART
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Joel says Any Questions?