Construction of a selective Head-forming Vegetables Harvester with a Microcomputer Controlled Sensor

构建了一种生菜选择性收割机试验装置。它配备了生菜成熟和大小的选择器和处理选择器输出信号的微型计算机。收割机由探测器、微型计算机和由液压系统驱动的刀组成。这些元素都安装在一个副框架上，它被安装在较小的四轮驱动拖拉机的三点联动上。该收割机能够对单排莴苣头进行选择和切割，其运行速度为0.1米/秒。研制了两种类型的探测器。一种是机械压缩测量，另一种是静电容量测量。机械检测器有压缩辊和选择辊，生菜通过。检测的第一个动作是由螺旋弹簧加载的压缩辊将生菜周围的叶子压在生菜头上，并测量生菜头的大小。第二个动作是由螺旋弹簧加载的选择辊压紧莴苣头，测量莴苣头的硬度。另一方面，介电探测器有一对电极板，施加高频电压。莴苣头的表观密度可以作为检测器的输出信号来测量。通过对生菜选择性收获的田间试验，该试验型选择性收获机运行良好。然而，收割机的性能几乎取决于探测器的性能。在采用机械检测仪的情况下，生菜的大小与穗直径的相关性较强，结实度与穗表观密度的相关性较好。电介质检测器的选择精度受极板形状的影响较大，与莴苣头曲率拟合的曲面极板电极的检测精度高于平面极板。少

An experimental selective harvester for lettuce was constructed. It equipped with a selector which detected maturity and size of lettuce heads and a microcomputer which processed the selector output signals. The harvester consisted of a detector, a microcomputer and a knife driven by a hydraulic system. These elements were all mounted on a subframe and it was mounted on the three-point linkage of the smaller four-wheel drive tractor. This harvester could select and cut lettuce heads of single-row, and its travelling speed was 0.1 meter per second.Two types of detectors were developed. One was that of mechanically compression and the other was of electro-static capacity measurement.The mechanical detector had compression and selection rollers between which lettuces passed. The first action of detection was that the compresion rollers which were loaded by a spiral spring compressed the surrounding leaves of lettuce against the head and gaged size of the lettuce head. The second action wa … More s that the selection rollers which was loaded by a helical spring compressed the lettuce head and measured firmness of the head. On the other hand the dielectric detector had a couple of electrode plates to which high-frequency voltage applied. Apparent density of lettuce head could be measured as output signals of the detector.As a result of field tests on selective harvesting of lettuces, the experimental selective harvester operated satisfactorily. However, performance of the harvester almost depended on that of the detector. In case of the mechanical detector stronger correlation was observed between the measured size of lettuce and the diameter of the head, and fairly good correlation between the measured firmness and the apparent density of the head. In case of the dielectric detector selection accuracy was influenced significantly by the shape of electrode plates, and the electrode of curved plates fitted to the curvature of the lettuce head detected much accurately than that of flat plates. Less