仿生无损吸取式苹果采摘装置的设计与试验

Design and experiment of bionic nondestructive handheld suction apple picker

关键词:  苹果采摘装置  仿生设计  无损采摘  吸取式

Key words:  apple picker  bionic design  nondestructive picking  suction type

摘要:

为解决苹果在采摘过程中机械化程度低的问题，根据人手采摘苹果的机理，借鉴章鱼吸盘吸附猎物的方法，研制一种仿生无损吸取式苹果采摘装置。该装置主要由气吸式末端执行器、摆位支撑机构、送果机构、实时在线采摘监控系统以及计重系统等组成。对采摘装置的关键部件进行有限元静力学强度分析和动力学模态分析，以确保设计方案的合理性。模拟采摘和吸取损伤试验结果表明：1）该苹果采摘装置可以采摘3 m高度以下，直径60~90 mm、果梗直径3.3~4.8 mm的苹果。2）该苹果采摘装置采用3关节万向节的气吸式末端执行器便于调整转动，在苹果采摘过程中可以调整末端执行器的采摘位姿与果实的生长姿态保持一致，并避开树叶、树枝造成的障碍，从而以最优位置和最佳角度实现采摘。3）对同一批次大小、质量相近，表面完好的30个苹果进行吸取损伤试验，吸盘吸力不会对苹果表皮造成损伤；对放置了7 d的试验苹果削皮处理后也未发现其内部果肉组织有损伤情况。

Abstract:

In order to solve the low level of mechanization in the process of apple picking,a bionic-nondestructive apple picker was developed based on the mechanism of apple picking by hand and the way of catching prey by using octopus suckers.The apple picker was mainly composed of air suction end-effector,positioning support mechanism,real-time on-line picking monitoring system and quality monitoring system.Finite element static strength analysis and dynamic modal analysis were carried out on the key parts of the picking device to ensure the rationality of the design scheme.The results showed that:1) The prototype could pick apples with 3 m apple tree height,60-90 mm of tree diameter,and 3.3-4.8 mm of apple stem diameter.2) The prototype used an air-suction end-effector with 3-joint universal joint can adjust the position and posture of the end-effector to keep the same as the fruit growth posture,and avoid the obstacles caused by leaves and branches to achieve the best position.3) After stretching the same batch of 30 apples of similar size,quality and intact surface,it was found that the suction force of the prototype didn't cause damage to the apple epidermis,and no damage was found in the internal pulp tissue of the apple after being pared for 7 days.