Athletic Field Marking DeviceAnthony Cortese, Ryan Crump, Matthew Lawler, Patrick Shaughnessy (Team Leader), John Sudia

Project Objective

• To create a semi-automatic device that provides a means of lining an athletic field.

Solution Requirements

• Must accurately paint a straight line between two determined points

• Must have the capability to make error corrections on its own.

• Must operate with as little human interaction as possible

System Goals• The device should be able to complete a line 120

yards long

• The device should require less long term costs than current methods

• The device should require less human labor than current methods

• The device should complete its tasks in a reasonable amount of time

Major Challenges

•Dealing with the accuracy of all of the components in our machine

•Creating a drive system that can correct itself when deviating from the desired path

•Keeping the expense of the product to a minimum

•Working in a multi-disciplinary team atmosphere

Current Spraying Devices

Wide Boom Small Boom

Components of Design Solution

• Guidance System

• Drive System

• Paint Delivery System

Potential Guidance Solutions• Differential RTK GPS

• High accuracy GPS, ranging from 10cm to 1cm• High cost and complex implementation

• Laser Optical Guidance• Utilizes laser scanners which give out X and Y

coordinates and heading • High accuracy but cost prohibitive

• Infrared Sensor• Reflective infrared sensor• Cheap and easy to implement

Potential Drive System Solutions

• Gas Powered Engine• Heavy vibration• Weight issues• Complex integration

• Electric Motor• Cheap and readily available• Easy to control• Simple integration

Potential Paint Delivery Solutions• Compressed Tank

• A compressed tank • Paint modulation control• Spray nozzle• Complex and expensive

• Aerosol Spray Can• Inverted spray can• Solenoid to trigger it• Simple and low cost

Guidance System SolutionRyan Crump

Schedule

Guidance System Solution

• An infrared sensor retrieves location data

• Microcontroller receives and processes data from sensor

• Motor controller receives instructions from the microcontroller and outputs voltage to motors

Guidance: Infrared Sensor

• The Lynxmotion board consists of three reflective infrared sensors

• Our system uses the outermost sensors to determine its location relative to the target line

• These sensors each relay either a ‘0’ or ‘1’ for absence or presence of a line

Guidance: The Handy Cricket

• The Handy Cricket microcontroller processes the digital output received from the sensor

• Based on input, the microcontroller determines device location relative to line

• The microcontroller determines appropriate correction necessary and transmits data to motor controllers

Code Block Diagram

Left sens = 0

Start

Input left sensor

Input right sensor

Right sens = 0

Stop

Input rightsensor

Right sens = 0 No change

Increase rightMotor speed

Increase leftMotor speed

Y

Y

Y

N

N

N

Guidance: Motor Controller

• The motor controller can precisely control the speed and acceleration of the motors for easy path correction

Electrical Schematic

+

-

12

VSolenoid

+ -

12 V

IRSensor

MM

C+-

Microcontroller

MM

C+- +

-

12

V

Digital I/O5V

+ -

+-Signal+-Signal

IRSensor

Serial bus

Sensor input

5V

5V

Relay

Drive & Paint System SolutionsPatrick Shaughnessy

Drive System Solution

Drive System Solution

• Each side is independently powered by a separate DC motor

• That DC motor drives a sprocket connected to its side’s drive train

• That drive train is responsible for transferring power to both wheels

Drive System: Motors

• The motors are ¼ HP, 180 RPM and require a 12 volt/3 amp power supply

• Max torque and lower speeds needed for our application

• 2:1 gear ratio was selected to give more torque and a lower speed

Drive System: Gear Ratio• To achieve our gear ratio, the motor turns a 12 tooth sprocket

which is attached by a chain to a 24 tooth sprocket on the rear axle

Drive System: Drive Train

• The rear axle has an additional sprocket which connects to another sprocket on the front axle in a 1:1 ratio by a chain

• Each axle is supported by two ball bearing mounts attached to the frame

• The 8” diameter wheels are locked onto the axles by a custom wheel mount

Drive System: Drive Train

Paint Delivery Solution• The paint delivery system consists of a linear pull solenoid, trigger and spray paint can

• The solenoid will pull a trigger which will dispense paint from the can

• When it is necessary to halt painting the solenoid will release the trigger ceasing the paint flow

• Width of line is adjustable

Paint Delivery System Pictures

Cost AnalysisThe Handy Cricket: $99.00 ;Prof. Dougherty

Lynxmotion Sensor: $32.00

Gamoto Motor Controller: $99.00 x2 = $198.00

Solenoid: $10.00

Wheels: $8.69 x4 = $34.76

Bearings: $4.64 x8 = $37.12

Sprockets: $22.33

Chains: $21.94 ;Battlebot

Aluminum Frame: $114.00 ;Projects Room

Motors: $85.00 x2 = $170.00 ;Battlebot

Miscellaneous: $20.00

----------

TOTAL: $759.15

Existing Methods: >$1000.00

Conclusion

• While we have not yet completed our project, we have learned some important lessons

• We still view our initial goals as attainable and anticipate reaching them upon conclusion

Concluding Video

Questions?