中文摘要：

为改善现有收获设备的采收性能,降低伤果率,提高采摘率,必须对果实采收设备引起的果实运动情况进行准确评估,以确定导致果实损伤的主要阶段和关键因素。该文建立和分析了果实—树体的动力学模型,通过试验和计算验证了果实脱落的理论条件是果实所受法向惯性力要大于果柄与果实间的结合力,并设计了一种扁球型电子果实（orange impact recording sensor,OIRS）,利用它检测记录三维激振采收系统在收获砂糖桔时所产生的机械冲击,对该系统引起的果实运动进行分析。在野外振动采收试验记录的数据中,电子果实记录到振动阶段的最大机械冲击加速度均值为217 g,平均冲击加速度达到123 g;而下落阶段的最大机械冲击加速度均值为155 g,平均冲击加速度仅为76 g。结果表明：在振动阶段果实损伤的可能性更高,可通过调整采收机的工作参数,降低潜在的伤果风险;而下落阶段果实与地面接触时产生的较高冲击也会导致果实损伤,收获设备表面可铺设缓冲减震材料,以此降低果实的坠落损伤。研究结果表明利用电子果实能够有效检测三维激振采收系统在果实收获过程中所产生的机械冲击,用于机器系统的伤果评估。

英文摘要：

At present, the main way of fruit harvesting is still dominated by manual picking. Although the workload of the laborer can be reduced by the use of mechanical equipment in the process of fruit harvesting, the unstable harvesting rate and the high proportion of fruit damage are hindering the development of harvesting equipment, especial in fruit harvesting machines, which are the key factors to improve harvesting machine. In order to improve the performance of harvesting equipment in the market of agricultural machinery, it is necessary to make accurate evaluation of the fruit motion in process of picking with fruit harvesting equipment, and then determine the main stages and key factors leading to fruit damage. In this paper, a flattened electronic fruit based on Orange Impact Recording Sensor（OIRS） was designed to detect the mechanical impact caused by the three-dimensional vibration harvesting system and analyze the fruit motion. The dynamics model of sugar orange was built and analyzed, which was equivalent to solve nonhomogeneous linear ordinary differential equation with constant coefficients. The dynamics model was solved and the theoretical condition of fruit abscission from tree body was obtained. The fruit falling process was recorded by high-speed photography in the detachment test of electronic fruit, and the amplitude and binding force of fruit were measured. All the parameters in the theoretical model were calculated, and the result of 17.2511.6 N was obtained, which demonstrated that the normal inertia force of fruit was greater than that of binding force when the fruit was detached from the tree. So the theoretical model of fruit abscission was verified. Three-axis accelerometer was embedded in the OIRS, and was used to detect and record the acceleration in the process of harvesting. And the final resultant acceleration values from three directions were obtained with the method of FFT（Fast Fourier Transformation） by MATLAB. Four vibration harvesting experiments were carried out in orchard