Theoretical Overturning Analysis of a 2.6-kW Two-Row Walking-Type Automatic Pepper Transplanter

Abstract

Overturning on uneven and sloped surfaces is an important issue during the operation of agricultural field machinery. In this study, the geometrical (size and location) parameters of a pepper transplanter under development were optimized by theoretical overturning analysis to maintain stability during the operation. A walking-type transplanter was designed to transplant pepper seedlings in a two-row cultivation pattern so that the transplanting could be completed using three primary mechanisms for seeding, i.e., supply, picking, and dibbling. The four-wheel transplanter was designed to work with three different forward speeds (i.e., 0.3 m/s, 0.65 m/s, and 1.3 m/s). Mathematical and 3-D models were constructed both for static and dynamic conditions, and simulation was performed using a commercial software package to minimize the overturning tendency of the transplanter. Considering the plant ridge height and width, the track width and wheelbase of the transplanter were determined to be 725 mm and 680 mm, respectively. The positions of the mechanisms were optimized to maintain the center of gravity (CG) of the transplanter in the middle point of the stability area with a 436.26 mm height from the ground. During the static analysis, the transplanter was overturned laterally and longitudinally at slope angles of 40.67° and 36.26°, respectively. The transplanter overturned when the angles exceeded 29.3° for uphill and 49° for downhill paths, respectively, at the maximum forward speed (1.3 m/s) during dynamic analysis. Also, lateral overturning occurred while one wheel was exposed to obstacles with heights greater than 245 mm at the maximum operating speed. The results of this study would be helpful for designing the layout of the transplanter and the field test of the prototype.