Optimization Design and Test of Occlusal End-effector for Picking Citrus
Abstract
Aiming at the difficulty of citrus automatic picking, a terminal actuator using spherical closure for occlusion and shearing of citrus fruit stalks was designed. Firstly, the shearing mechanical properties of citrus fruit stalks were studied, and the effects of five factors on the peak shear force were analyzed, i.e., stalk diameter (2~4 mm), shear speed (20~200 mm/min), stalk angle (0~75°), number of leaves blocked (0~3 pieces), and blade gap (0.5~2 mm). The test results showed that the peak shear force required to shear citrus fruit stalks was increased with the increase of stalk diameter. With the increase of shear speed, the peak shear force was decreased, but not significantly. The stalk angle was one of the factors affecting the peak shear force. Between 0° and 30°, the stalk angle had little effect on the peak shear force, but when it was between 30° and 70°, the peak shear force was increased significantly with the increase of the stalk angle. The blockage of a few leaves had little effect on the peak shear force. Blade clearance was one of the main factors affecting the peak shear force. Large blade clearance had a great impact on shearing thin stalks, which may be difficult to shear off. Controlling the blade clearance within 1 mm was critical for the success rate of the end effector picking. The geometry modeling of the end-effector was carried out, and the parameter optimization model was established with the main constraint condition of controlling the blade gap and the optimization goal of increasing the fruit positioning tolerance. The fruit positioning tolerance was increased from the original 9.2%~48.8% to 26.0%~71.7%. The static analysis of the model was carried out and the selection of the electric push rod was completed. At the same time, the finite element simulation of the model was carried out, and the influence results of the spherical shell deformation on the blade gap were obtained, and the strength of the structure was checked. Finally, the prototype of the citrus picking end-effector was developed, and the field picking and shearing performance test was carried out in the citrus orchard. For the fruit stalk with a diameter less than or equal to 4 mm, the success rate of the fruit stalk breaking was 95%, meeting the requirements of picking citrus.
Keywords: citrus, picking, end-effector, occlusal type, shearing
Download Full Text:
PDFReferences
YANG Hong, WU Xiaoyu, QUAN Jinying, et al. Current situation and development countermeasures of citrus industry in Sichuan Province [J], Southeast Horticulture, 2021 , 9(3) : 55 -60. (in Chinese)
JIN Bo, LIN Longxian. Design and force control of an underactuated robotic hand for fruit and vegetable picking [J] . Journal of Mechanical Engineering, 2014, 50(19); 1 -8. (in Chinese)
PENG Van, LIU Yonggan, YANG Yang, et al. Research progress on application of soft robotic gripper in fruit and vegetable picking [J]. Transactions of the CSAE, 2018, 34(9) ; 11 -20. (in Chinese)
LI Ming, LIU Ping. A bionic adaptive end-effector with rope-driven fingers for pear fruit harvesting [J]. Computers and Electronics in Agriculture, 2023, 211:1 - 14.
FU Longsheng, ZHANG Fanian, GEJIMA Y, et al. Development and experiment of end-effector for kiwifruit harvesting robot [J] . Transactions of the Chinese Society for Agricultural Machinery, 2015, 46(3) ; 1 - 8. (in Chinese)
BAO Xiulan, MA Zhitao, MA Xiaojie, et al. Design and experiment of citrus picking robot in hilly orchard natural environment [J ]. Transactions of the Chinese Society for Agricultural Machinery, 2024,55(4) : 124 - 135. (in Chinese)
JIA Jiangming, YE Yuze, CHENG Peilin, et al. Design and parameter optimization of soft pneumatic gripper for slender fruits and vegetables picking [ J ]. Transactions of the Chinese Society for Agricultural Machinery, 2021, 52 (6); 26 - 34. ( in Chinese)
JI Jiangtao, LI Mengsong, ZHAO Kaixuan, et al. Design and experiment of flexible profiling picking end-effector for Agaricus bisporus [J] . Transactions of the Chinese Society for Agricultural Machinery, 2023, 54( 1 ) ; 104 - 1 15. (in Chinese)
HARRELL R C, SLAUGHTER Г) C, ADSIT P D. A fruit-tracking system for robotic harvesting[ J ]. Machine Vision and Applications, 1989, 2: 69 -80.
YOU К, BURKS T. Development of a robotic fruit picking end effector and an adaptable controller [ C] //American Society Agricultural and Biological Engineers, 2016.
PARK Y, SEOL J, PAK J, et al. A novel end-effector for a fruit and vegetable harvesting robot; mechanism and fie experiment[ J]. Precision Agric. , 2023, 24(3) : 948 -970.
HANNAN M W, BURKS T F. Current developments in automated citrus harvesting[ С Meeting. America ociety of [C] //ASAEAnnual Meeting. AmericanSociety of Agricultural and Biological Engineers, 2004.
Liming, LIU Xudong, ZHANG Kailiang, et al. Design and test of end-effector for navel orange picking robot [ J ]. Transactions of the CSAE, 2018, 34(12) ; 53-61. (in Chinese)
LI Mengting. Design and experiment of citrus harvesting software end-effector[ D]. Ya'an; Sichuan Agricultural Universitv 2022. (in Chinese)
QIN Xuejing. Design of end effector of citrus non-destructive picking mechanism [D]. Chongqing; Chongqing Three Gorg< University, 2021. (in Chinese)
LI Ziyue. Design and experimental study of end-effector for picking robot of spherical fruit[ D], Shiyan; Hubei University Automotive Technology, 2023. (in Chinese)
YU Lang, YU Gaohong, WU Haoyu, et al. Design and experiment of the end-effector with underactuated articulars for citn picking [J] . Transactions of the CSAE, 2023, 39( 17) ; 29 —38. (in Chinese)
WANG Yi. Research on key technology of bite-mode end-effector of citrus harvesting robot [ D]. Chongqing; Chongqir University, 2021. (in Chinese)
WANG Yi, YANG Van, YANG Changhui, et al. End-effector with a bite mode for harvesting citrus fruit in random ste orientation environment [J]. Computers and Electronics in Agriculture, 2019, 157; 454 -470.
WANG Yi, XU Hongbin, ZHANG Mao, et al. Design and experiment of bite-model end-effector for citrus harvesting 1 simulating with mouth of snake[J] . Transactions of the Chinese Society for Agricultural Machinery, 2018, 49( 10) ; 54 -64 ( in Chinese)
Refbacks
- There are currently no refbacks.
