Weed Reaper Roscoe Kane, John Audlin, John Barton and Marcus Ortuno

Background Weeds have been a problem since the advent of agriculture Many methods have been used to reduce losses due to weeds All have been either energy intensive or damaging to the environment

Problem Statement Create an automated system to remove weeds from corn rows The corn will be 5-20” in height The weeds will be 0-3” in height The rows are 30” apart Destroy weeds only more than 6” from a corn plant

General Solution Waypoint navigation using crop row “Feelers” sense weeds 2 axis weed auger

Project Management John Audlin – Navigation Roscoe Kane – Weed Detection John Barton – Programming Marcus Ortuno – Weed Destruction

System Block Diagram

Robotic Navigation Three Main Types –Map Navigation Map of entire operating environment –Waypoint Navigation Follow recognizable ‘landmarks’ to destination –Local Navigation Triangulate position from relative position to a landmark and destination’s relative position to it

Waypoint Navigation ‘Follow’ left-hand row 6-10” between plants Potentiometer angle determines distance from row Control software adjusts path accordingly

Force Calculations Minimum Theta approx. 14 degrees Tension must be anchored at least 1.62” forward of arm hinge

Weed Detection “Feelers” on the ground Along front, 7 rows When feeler is lifted by profile of weed, circuit is closed

Sensor Array

Weed Sensors

Sensor Testing Sensor array was held by hand and dragged over weeds Weeds detected (contact is made) depending on 2 major factors The first is the size of the weed. The second is the height of the array off the ground

Design Implications A more sensitive and/or lower weed sensor will detect smaller weeds. A less sensitive and/or higher sensor will detect let weeds grow before killing A less sensitive sensor will give less false positive readings.

Sensor electrical diagram 7 active low switches with pull up resistors

Programming for the Weed Reaper The program will run through a series of routines: Check the sensors Kill weeds previously detected Adjust relative motor speeds Move forward

Navigation Routine

Weed Detecting Routine

Weed Recall Routine

Kill Routine

Weed Removal Using an X and Z axis rail mount. An attached drill with auger. Auger based from actual weeding application.

Auger Force Diagram

X-axis General Design

X-axis & Gear Force

Z-axis Design

Z-axis Gear Design Dp = 8 Pitch Dia. = 3” Pitch Dia. = # of Teeth / Dp = 24 Teeth Outside Dia. = # of Teeth + 2 / Dp =3.25” Gear is cut every 15°

Gaant Chart

Projected Budget

Questions?