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Initial Design Review Team “Chip”. Tim Quinn Henry Mossell Desiree Cerretani. Background. Barns Get Dirty Quickly Maintenance Takes Up a Lot of Time Disease Prevention is Important Every Barn is Shaped Differently Lots of Obstacles Moving Cows Corners Workers
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Initial Design ReviewTeam “Chip” Tim Quinn Henry Mossell Desiree Cerretani
Background • Barns Get Dirty Quickly • Maintenance Takes Up a Lot of Time • Disease Prevention is Important • Every Barn is Shaped Differently • Lots of Obstacles • Moving Cows • Corners • Workers • Rough Surfaces for Floors • Various Depths of Debris • Debris May Be Dry or Wet
Problem Statement As a Group We Were Given a Task to Engineer a Solution to Pick Up Woodchips Off of Barn Floors.
Solution Statement Our Solution is to have MARV “Chip”, navigate the barn floor, avoiding obstacles, while successfully sucking up woodchips from a primary nozzle located in the front and a secondary nozzle/squeegee in the back. The vacuum source is a stand alone central vacuum system with hose reel located at a fixed location within the barn.
Solution Statement • Verro • Autonomous • Small Capacity • Thorough Cleaning in 60 to 90 Minutes • $800-$1200 • Roomba • Autonomous • Small Capacity • Most Expensive Version Can Clean 4 Rooms With One Charge • $200-$600 • Billy Goat • Human Run • Large Capacity • 32.75” Wide Nozzle • Weighs 285lbs • 2090 CFM @ 3600 RMP • $3,299.99
Hose Reel Intelligent retraction Robot “Chip” Primary Cleaning Vacuum Nozzle Secondary Cleaning Squeegee Onboard Microprocessor Obstacle Negotiation Wireless Communication 12 Vdc Operation Autonomous System Overview Diagram 120 Vac Hose Reel Vacuum Hose Suction Only Central Vac Unit 5 hp 150 mph 16 Gallon Control Hose in/out
Mechanical System Overview • Nozzle is pushed through debris • Wheels mounted on the front • Squeegee mounted behind the caster • Bumper mounted above nozzle opening
Mechanical Design Concepts Hose Bend Radius Nozzle Rear Squeegee Bumper Nozzle
Mechanical Design - Nozzle 0.125” Dia x 4 2.5” Dia 16”x1” mouth opening 8” rise
Nozzle Engineering • Flow Rate Calculations • 2.5” Dia tube • V=150mph = 2640in/sec • A= πr² • A= π(1.25)² = 4.91in² • Q=V A • Q = (2640in/sec)(4.91in²) • Q = 12959in³/sec
Actual Nozzle • 14” X 1” mouth opening • Squeegees focusing chips • 20” Total width of floor cleaning • readily accessible • Cost effective for this experimental application
Squeegee & Secondary Nozzle 8.0” 2” Dia 4.0” 20.0”
Squeegee & Secondary Nozzle • squeegee • Single layer rubber door sweep • collects any shaving missed by primary nozzle • arc shape focuses shavings to the center • secondary nozzle mounted in the center of the arc to collect
Mechanical Design - Bumper #45 Compression Spring Mounts 23 “ 3 “ 13 “
Mechanical Design – Hose Reel • Can hold 175ft of 1 in hose • Using approximately 30ft of 2 in hose • Dimensions of the cart: 35" H x 22" W x 20" D • Large 7 inch wheels • Weighs about 13.75 pounds • Top handle folds over
Hose Reel State Machine Start/ Neutral MARV is turning Motor shuts off Sensor sees change in voltage (Let hose out) 00 00 Motor Forward Motor Reverse Take In Hose Let Out Hose 01 10 Sensor sees change in voltage (Reel in hose) MARV is turning Motor shuts off • Hardwired line from MARV to hose reel • Software will detect MARV turning and change direction of the motor on hose reel • Hose reel will be timed so that the hose is properly let out and retracted
Electrical Design Concepts Right Motor Motor Controller 12 Volt Supply Left Motor Left Bumper Optical Switch Left Bumper Optical Switch Left Bumper Optical Switch Left Bumper Optical Switch Microprocessor Onboard computer Left Ultrasonic Sensor Left Ultrasonic Sensor Left Ultrasonic Sensor Left Ultrasonic Sensor IR Transmitter 1 9 Volt Supply Right Bumper Optical Switch Right Bumper Optical Switch Right Bumper Optical Switch Right Bumper Optical Switch Push Button Infrared Receiver IR Transmitter 2 Right Ultrasonic Sensor Right Ultrasonic Sensor Right Ultrasonic Sensor Right Ultrasonic Sensor Sensors and Inputs Normal Navigation
Electrical – Sensor Bumper • Optical Switches • Bumper • 5 V operation • Normally Closed • Optek OPB390 • Indicating LED Red Vf 1.8 V • R1 Current Limiting 37 mA • (VCC-LED Vf)/R1 • (5-1.3)/100= 0.037 A • Biased Device On • R2 Drop 1.89 V • Vce 1.23 V • Vled 1.88 • Device Off • Vc 3.48 V • Ve 0 V R2 R1 Red
Electrical – Sensor Normal • IR Gate • 9 Volt Power • 3 W IR LED
Software Design Concepts Obstacle Negotiation • Front bumper pushed back- optical limit switch • Back up • Turn Clockwise 15˚ • Move forward • Check clear - Ultrasonic • Turn Counter Clockwise 15˚ • Turn Clockwise 15˚ Wall • Moving normal • IR detector trigger • Counter++ • Stop • If counter/2modulus!=0 • Turn left wheel • Moving Normal • IR 2detector trigger • Counter++ • Stop • If counter/2modulus==0 • Turn right wheel
State Machine Run == 1 IR Sensor Triggered IR Sensor Triggered Drive FWD Start Detect IR1 Detect IR2 0000 0000 1100 1000 0100 Motor RT Reverse LT Bumperpressed ==1 Motor LT Reverse RT Timer Expired Bumper Hit Timer Expired Ping Return Not Detected 0000 Avoid Step 6 1000 Avoid Step 5 Backup Straight 1100 0011 Ping Return Detected Avoid Step 4 Turn To Avoid Ping Return Not Detected Ping Return Detected 0100 0100 Avoid Step 1 Avoid Step 3 Avoid Step 2 1100 1100 1000 Ping Return Detected Ping Return Not Detected
Motion Path - Normal IR Gate 1 Robot Hose Reel IR Gate 2 Vacuum Unit
Project Assignments • Tim Quinn • Primary Nozzle • Squeegee • Normal Navigation • Desiree Cerretani • Hose Reel • Normal Navigation • Henry Mossell • Front Bumper • Obstacle Negotiation