Performance Modeling and Seed Releasing Characteristics of A Corn Planter Metering Unit Using Response Surface Methodology

The objective of this study was to develop prediction performance functions and determine the seed releasing characteristics of seed meter disks based on metering rate and pitch angle at different levels using Response Surface Methodology (RSM). An AGCO White 9000 planter row unit was tested using two seed shapes and associated disks in controlled laboratory conditions. Experiments were designed based on the two-variable Central Composite Design (CCD), one of the RSM designs. Effects of metering rate and row unit pitch (seed tube tilt angle) in their five levels were investigated, on performance and seed release characteristics. A video recording system allowed simultaneous recording of rear and side views of seed exiting the seed tube on the row unit. A MATLAB program in combination with image processing algorithms was used to analyze video. The performance indicators investigated were quality of feed index (QFI), and multiple and miss indices. Seed release characteristics of interest were side and rear angles and time between seeds. Based on the experimental results, QFI values were found 99.0% (maximum) and 100% (maximum) for using flat and round corn seed disks, respectively. The maximum side angle ranged from 33.5 degrees to 48.3 degrees for the flat seed disk and 33.4 degrees to 47.6 degrees for the round seed disk. The maximum rear angle ranged from 5.1 degrees to 15.1 degrees for the flat seed disk and 6.4 degrees to 17.6 degrees for the round seed disk. In addition to experimental results, model equations were also developed to predict QFI, side and rear angles as functions of metering rate and pitch angle. Quality of feed index functions were maximized and the optimum values of metering rate and pitch angle values were found to be 800 seeds min(-1) and -2.6 degrees for the flat meter disks. The optimum values for the round meter disks were a metering rate of 409.4 seeds min(-1) and a pitch angle of 0 degrees.