Study on Development of Handling System for Japanese Pear Havesting

本研究旨在开发日本梨采后处理系统。本研究对日本梨的重量和果皮颜色的测量进行了研究，并制作了一台试验机。对梨的肤色的估计是基于L在过去的实验中测得的颜色系统的数据。为了测量梨赤道部分和底部的果皮颜色，对光源、自然光和人造光的选择以及颜色传感器在探测入射光方面的应用进行了研究。在使用人工光源的情况下，检查了光发射的时间间隔、调制和控制。由于颜色传感器的输出信号受入射光的亮度和色温的影响，因此采用对数放大器将输出信号转换为线性值。色温补偿是通过计算色敏元件的R、G、B三个输出值和勒克斯计的亮度值来实现的。由于这些操作非常复杂且同步，因此尝试了多CPU系统的分散操作。其次，试制了一个称重传感器的三指式机械手。称重传感器被用来测量水果的重量。每个手指有一个关节，由两相混合式步进电机驱动。上指有三个压力传感器，用于检测手指和水果之间的恒定压力。传感器由导电橡胶构成。这些手指由自学习自适应控制系统控制。该控制系统通过实时检测压力传感器的接触力来确定水果的最佳抓取力。

This study aimed to develope the handling system of Japanese pear at harvesting. In this study, the measurement of the weight and the skin color of Japanese pear were investigated and a trial manipulator was made. The estimation of the skin color of pear was based on the data by L^<**>a^<**>b^<**> color system measured in the past experiment. To measure the skin color of pear on the equatorial part and the bottom, it was investigated about the selection of the light source, the natural light or the artificial light, and the application of the color sensor for detecting the incident light. In case of using the artificial light source, the time interval, the modulation, and the control of the light emission were examined. As the output signal of color sensor was affected by the lightness and the color temperature of the incident light, so a logarithmic amplifier was applied to cenvert the output signal to the linear value. The compensation of the color temperature was done by the calculation of three output value of R,G,B from the color sensor and the lightness value by a lux meter. As these operations were very complicated and synchronously, so the dispersive operation with the multi CPU system was tried. Next, three fingers type manipulator with one loadcell was made by trial. The loadcell was used to measure the weight of fruit. Each finger has one joint and was driven by a 2-phase hybrid type stepping motor. The upper finger has three pressure sensors for detecting constact pressure between the finger and the fruit. The sensor was contructed by the electro-conductive rubber. These fingers were controlled by a self learning adaptive control system. This control system can decide the optimum grasping force of fruits by detecting the contact force of pressure sensors at the realtime.