Design and Development of Calibration Unit for Precision Planter

The critical parameters for plant population with desired planting geometry include uniform distribution and precision placement of seeds.R&D efforts in metering of single seeds at predetermined intervals are carried in this paper.Proximity sensor technique based seed spacing evaluation system that measure time intervals between seeds and transmission ratio between two velocities is use to determine planter seed spacing uniformity.The calibration unit includes frame light barrier sensor that consists of square crosssection window including transmitter and receiver with innovative microcontroller technology in its casing along with the inductive type gear tooth sensor that calculates rpm of roller.For acquiring the data serially to personal computer the system includes circuitry to interface the sensors with the AT89S52 microcontroller.Mechanical mechanism of motor/roller/ SMU is controlled using V/F drive through PC itself.Calibration of whole system is based on ISO defined standard parameters that are Quality of feed index, multiple index and Miss index.This calibration unit can be used instead of grease belt stand to rapidly obtain quantitative evaluations of planter seed spacing uniformity in the laboratory.