Authors

Abstract

Lycium barbarum L. (L. barbarum) is an economic crop with high added value and profit. Vibration harvesting is a suitable mechanized harvesting method for L. barbarum. It bruises easily during harvesting due to the softness and vulnerability of fresh ripe fruit, resulting in economic losses. This study analyzed the fruit drop and collision during vibration harvesting. High-speed photography was used to obtain the impact speed and angle of the falling fruit, and a kinematic analysis of the collision with the collection surface was conducted. The majority of the fruit had an impact speed of 2-6 m/s and an impact angle of 30-90° with the collection surface. A drop test was conducted to assess fruit bruising, and the impact speed was converted to the drop height. A orthogonal rotation experiment was conducted, and mathematical model was established between the drop height, impact angle, and impact material, and the fruit bruise rate, maximum impact force, recovery coefficient, and impact time. The effects of the factors on the fruit bruise rate, maximum impact force, recovery coefficient, and impact time were analyzed. The test results show that a vibration harvesting device for L. barbarum should be designed to reduce the height between the fruit and the collection surface and utilize a tilted collection surface and high cushioning materials to reduce the fruit bruising. This study provides guidance for subsequent research on the bruising of L. barbarum during vibration harvesting and harvester design.

Abstract in Chinese

枸杞作为一种经济作物，具有较高的附加值和利润。振动采收是枸杞机械化采收的适宜方法，由于枸杞鲜果柔嫩易损，采收过程中容易损伤造成经济损失。本研究针对枸杞振动采收中的果实跌落收集过程进行研究，通过高速摄影技术获取果实振采脱落速度与角度，对果实脱落后碰撞过程进行运动学分析，研究发现绝大多数枸杞果实与收集面的撞击速度在2~6m/s，撞击角度为30~90°。采用跌落试验的方法进行损伤研究，将撞击速度转变为跌落高度。通过三因素三水平二次正交旋转组合试验，建立了跌落高度、碰撞角度、碰撞材料与果实损伤率、最大冲击力、恢复系数和碰撞时间之间的数学模型，分析各因素对果实损伤率、最大冲击力、恢复系数和碰撞时间的影响。分析实验结果发现，较低的跌落高度与碰撞角度，以及添加更具缓冲能力的碰撞材料能够有效减少果实损伤，为后续枸杞损伤研究与采收机的设计提供参考。