Design and Experimental Study of a Biomimetic Pod-Pepper-Picking Drum Based on Multi-Finger Collaboration

Abstract

In order to reduce ground drop loss during mechanical pepper picking and improve the net recovery rate, a drum snap finger picking device was designed. The picking device is mainly composed of a picking drum and auxiliary picking components; the picking finger arrangement was designed biomimetically and its structure and operating parameters were optimized by the DEM (discrete element method). According to the physical and mechanical characteristics of the pepper and the simplified three-dimensional model of the picking device, a virtual simulation model of the pepper-picking device was established using the EDEM software. Through simulation analysis and using the orthogonal test method, the main factors which affect the ground drop loss rate of pepper and their optimal parameter combination values were determined. The simulation results were verified by a pepper-picking field experiment. Orthogonal tests show that, when the picking drum speed (V′) is 210 rpm, the pepper-feeding speed (V″) is 1100 mm·s−1, the bending angle of each picking spring tooth (C) is 162°, and each group of circumferential fingers has rows, the picking device has a good picking effect. At this time, the ground drop loss rates in both the simulation and field test were 7.50% and 7.85%, respectively, and the drop error was only 4.46%, which was within the allowable range. The design form and parameter optimization simulation method in this paper provide an important reference for the design and optimization of pepper-harvesting machinery.

Development of a Bionic Picking Device for High Harvest and Low Loss Rate Pod Pepper Harvesting and Related Working Parameter Optimization Details

“…Among them, in 1997, E. Palau et al [10] developed a hydraulically-driven single-row pepper harvester, which brushes the peppers from the plants through the reverse rotation of the combing drums and throws the pepper fruits to the conveyor belts on both sides, and the conveyor belts convey the peppers while the fan clears and separates the impurities left in them, and finally conveys the peppers to the bins; in 2018, Byum et al [11] used discrete element simulation software EDEM to analyze the effect of pepper harvesting and picking components on the effect of pepper picking; In 2021, Yuan et al determined the main factors affecting pepper harvesting by analyzing the force on the spiral steel bar in contact with the pepper and conducting a field test [12], and determined the range of factors selected in the optimization test by using a one-way trial. In 2024, Du et al [13] used EDEM to carry out simulation tests on the roller comb-finger-type pepper picking device and carried out simulation analysis through the response surface orthogonal test method to determine the main factors affecting the loss rate of pod peppercorns falling on the ground and their optimal parameter combination values. At present, there is less research on the spiral comb finger picking device, the test results fail to meet the expected performance requirements, the breakage rate and ground loss rate are high, the comb finger structure, material and arrangement still need to be studied, and the structural parameters and movement parameters of the pepper picking device still need to be optimized.…”