Camellia oleifera oil is easily absorbed by the human body and has a high development prospect in the research and development of new drugs. However, the labor intensity involved in picking has limited the development of the camellia oil industry. Vibratory mechanized harvesting is considered to be an effective way to solve harvesting difficulties. In this study, the whole process of accelerating the mechanical vibration picking is analyzed theoretically, according to different vibration positions (height), and a vibration picking experiment is carried out. The ratio of the optimal excitation location to the years of growth of Camellia oleifera was found to be between 16 and 20. It was observed that with the increase of camellia growing years, this ratio gradually decreased, and its optimal vibration position showed an increasing trend. Further, when the excitation time was greater than 8 s, the fruit removal rate did not continue to increase, but the buds and leaves falling continued to decrease. This study can effectively improve the efficiency of camellia oil fruit picking and reduce the drop-off of camellia buds and leaves.

: In order to solve the problem of high missed rate of camellia fruits and high damage rate of flower buds during vibratory picking, through the study on the biological characteristics of camellia tree, the crown of camellia tree was divided into upper and lower canopy at the maximum canopy diameter. A kind of vibration plate type camellia fruit picking machine was designed. The structure and working principle of the whole machine were described. Through the analysis of the factors of camellia fruit abscission, it is concluded that frequency, amplitude and working time are the main factors affecting the magnitude of inertia force. Through preliminary research and coupling simulation, the horizontal range of each factor is determined: operation time is 5 s, 10 s, 15 s, frequency is 3 Hz, 5 Hz, 7 Hz and amplitude is 50 mm, 60 mm, 70 mm. Orthogonal tests were carried out on the upper and lower canopies successively, and the comprehensive scoring method was used to analyze the orthogonal test results. The results showed that the optimal combination of working parameters for picking camellia in the upper canopy was A 3 B 3 C 2 , that is, the operation time was 15 s, the amplitude was 70 mm and the frequency was 5 Hz. Under this condition, the missed picking rate of camellia fruits was 8.21% and the rate of flower buds damage was 9.12%. The optimal combination of working parameters for picking camellia fruits in the lower canopy was A 3 B 1 C 3 , that is, the operation time was 15 s, the amplitude was 50 mm and the frequency was 7 Hz. Under this condition, the rate of missing picking of camellia fruits was 6.84% and the rate of flower buds damage was 6.92%.

为研究振动参数对油茶果采摘的影响,本文建立了油茶"果实-枝条"双摆动力学模型,通过求解动力学模型得出系统固有频率为0.42、7.18 Hz;根据对油茶果实和花苞受力分析,得出油茶果实和花苞振动脱落所需的平均加速度分别为427.15、1936 m/s2;利用ADAMS动力学仿真软件对油茶果冠层振动采摘进行了仿真试验,利用Design-Expert 11.0.4软件对试验数据进行分析和优化并进行田间试验验证,理论优化结果为振动时间8.09 s、振动频率8.15 Hz、振幅50 mm时,油茶果实采收率为93.41％,油茶花苞损伤率为14.10％.田间试验结果表明,针对湘林210品种油茶树,当冠层振动时间8 s、振动频率8 Hz、振幅50 mm时,油茶果实采收率和花苞损伤率平均值分别为92.37％、14.38％,与理论优化值的差值分别为1.04、0.28个百分点.

为了解决油茶果采摘过程中采净率低、花苞损伤率大的问题,通过研究不同品种油茶果结合力和油茶枝条特性,设计了一种扭梳式油茶果采摘末端执行器,在采摘作业时该执行器可以对油茶果产生多种作用力.阐述了该末端执行器的结构和工作原理,并对关键部件进行了设计,分析了末端执行器的作业过程和油茶果脱落的影响因素.对不同品种油茶果的结合力和枝条扭转进行测试,得出抗拉力主要集中在10 ～25 N之间、抗剪力主要集中在5～15N之间、抗扭力矩主要集中在0.015 ～0.030 N·m之间,不同品种油茶枝条扭转模量在2～7 MPa之间.单因素试验表明,在扭梳组件转速为25 ～ 35 r/min、梳辊转速为75 ～ 85 r/min、作业时间为8～12s工况下,采摘性能较优.试验表明,最优工作参数组合为扭梳组件转速35 r/min、梳辊转速85 r/min、作业时间12s,此时油茶果采净率平均值为93.37％,花苞损伤率平均值为13.16％.

针对油茶果机械化采摘漏采率高、损伤率大的问题,设计了一款摇枝式油茶果采摘机.根据摇枝式采摘工作原理,完成了关键部件的结构设计,计算分析了采摘头夹持油茶枝的夹持力,对油茶枝和油茶果振动过程进行力学分析,建立力学方程并求解.结果 表明,夹持油茶枝时最大压力为2 826 N,振动对树枝产生的径向力约为57.5 N、法向力约为78.2 N,夹持和振动都不会对枝条造成损伤.为保证采摘机安全性,对横梁架进行了静力学分析,经计算其弯曲变形为0.000 5 mm,远小于最大许用弯曲挠度.设计了四因素三水平正交试验,结果表明,最佳作业参数组合为:采摘装置的采摘时间10s、电机输出频率35 Hz、采摘头的振幅5 cm及采摘爪的夹持位置(夹持油茶枝的夹持中心到油茶树冠层距离)10 ～ 20 cm,此时油茶果采净率为95.2％,花苞损伤率为17.2％.对摇枝式油茶果采摘机进行了田间试验,对枝条的损伤基本符合采摘要求.