针对果园条开沟连续施肥造成肥料浪费,而挖穴施肥作业过程繁琐的问题,基于普通条开沟施肥机具设计了果园对靶变量排肥系统,该系统主要包括果园穴施肥精量排肥器和对靶变量施肥控制器。利用高速摄影技术获得了不同排肥口截面积排肥下落时间,使用间歇旋转机构实现定量穴排肥,提出了扇叶旋转落肥感知方法并设计了排肥故障监测装置,进而设计了果园穴施肥精量排肥器。使用光电传感器实时感知果树树干以获得排肥位置,利用接近开关感知地轮转速计算行进速度,以STC12C5A60S2单片机为核心设计了对靶变量施肥控制器。搭建了试验平台,进行了实验室试验,结果表明,1~5排肥量挡位下,平均排肥量与理论排肥量最大误差为10 g,最大变异系数为4.6%;平均排肥长度为20.2~40.9 cm;偏移距离绝对值最大为5.5 cm,最小为0.6 cm,偏移距离标准差平均值为4.26 cm;单次排肥故障监测装置最少感知落肥通断信号次数为2次,故障监测准确率达到100%。果园试验表明,针对100棵枸杞树进行对靶施肥,其排肥准确率为97%。该系统实现了果园靶标实时探测、对靶精量排肥控制和排肥故障报警功能,达到了条开沟对靶穴施肥的果园作业要求。
Recently,ditching continuous fertilization and digging fertilization are the two main approaches for orchard fertilization in China. However,orchard ditching continuous fertilization always wastes a large proportion of fertilizer while digging fertilization manually is backbreaking work. Based on common ditching fertilizer devices,an orchard toward-target variable-rate fertilizer system was designed,which mainly included an orchard hole fertilization precision fertilizer feeder and a toward-target variable-rate fertilizer controller. Fertilizer ejecting times of ejectors with different sectional areas were obtained by using a high speed photography,and quantitative hole fertilization was realized through using grooved wheel mechanism. A new fertilizer ejecting monitoring method using a horizontal rotating fan was put forward,and a monitoring device was designed. Then the orchard hole fertilization precision fertilizer feeder was designed and developed. The toward-target variable-rate fertilizer controller was developed based on a microcontroller STC12C5A60S2,a photoelectric sensor used to detect orchard tree trunk was adopted to obtain fertilizer ejecting position,and an approach switch sensor was used to acquire speed by detecting wheel rotation. Laboratory experiments were carried out by using self-made test platform. The results showed that when the application setting was one of the 1 ~ 5 grades,the maximum error between the average amount of ejected fertilizer and theoretical amount was 10 g, with maximum variation coefficient of 4. 6%; the range of average fertilizer length was 20. 2 ~ 40. 9 cm; the maximum andminimum fertilizer position offset errors were 5. 5 cm and 0. 6 cm,respectively,with average standard deviation of 4. 26 cm; in each fertilizer ejecting process,the monitoring device could get the on-off signal two times at least,and the accuracy of fault alarm was 100%. Field experiments showed that the accuracy of fertilizer ejecting was 97% in selected 100 wolfberry trees. This system could con