Development of a Manually Drawn Single Row Onion Set Planter Using a 2 DOF Robotic Arm

Abstract

In order to obtain precise planting of onion sets, a manual drawn planter with a two degrees of freedom robotic arm was developed. The key idea was to reduce multiple set droppings to single set droppings per hill. The developed three wheeled planter consisted of suitable hopper for onion sets, conveying system, robotic arm, seed tube, furrow opener and closer, and necessary electronics circuits.  The rotation of DC motor of the conveyor belt was dependent on the output of LDR circuit. Onions coming to the workspace of the robotic arm, interrupted the laser light from falling over the LDR hence stopped the belt movement. The robotic arm, programmed in Arduino platform, approached, picked, carried, and released the onion sets into seed tube. Furrow opener and furrow closer were there for planting onions at proper depth and covering them with soil, respectively. Average hill spacing was found to be 160.2 mm with a standard deviation of 4.4 mm at the operating speed of 0.582 kmph as compared to 237.1 mm and 3.2 mm for 0.85 kmph operating speed. The percentage of missed planting of onion sets was 7.8% at the operating speed of 0.582 kmph as compared to 17.45% at 0.85 kmph.