水稻高速插秧机固体颗粒肥料变量施肥装置设计与试验

变量施肥技术是实施科学施肥的重要手段，可使施肥更精准、更有针对性，有效减少农田污染。在水稻高速插秧与同步施肥作业时，施肥量的调节主要采用提前标定方式调控，其调控费时、精度不稳定。为快速准确地调节施肥量，实现变量施肥作业，本文设计了一种自动控制的固体颗粒肥料变量施肥装置，阐述了变量施肥装置总体结构和工作原理，进行了关键部件设计与试验；以单片机STM32为控制核心，构建了施肥量在线检测及智能调控系统。采用试验设计优化方法，对肥料流量在线检测系统性能与主要影响因素进行试验，确定了最佳因素组合；通过试验分别构建了3种主要固体颗粒肥料检测流量与压电片电压之间的关系模型、3种主要固体颗粒肥料实际流量与排肥轴转速之间的关系模型、排肥轴转速与电动推杆工作长度和插秧机前进速度之间的关系模型，并对模型进行试验验证与分析。开展了排肥轴转速分别为20、25、30 r/min肥料质量检测精度试验，当插秧机前进速度为1 m/s匀速条件下，3种肥料总体质量检测精度平均值分别为94.45%、93.85%和93.15%;进行了复合肥施肥量为200、250、300 kg/hm²和尿素施肥量为165、...

Design and Experiment of Solid Particle Fertilizer Variable Rate Fertilization Device for High-speed Rice Transplanter

Variable rate fertilization technology is an important means of scientific fertilization, which can make fertilization more accurate and targeted, and effectively reduce farmland pollution. During high-speed rice transplanting and synchronous fertilization operations, the adjustment of fertilization amount is mainly controlled by pre calibration, which is time-consuming and unstable in accuracy. To quickly and accurately adjust the fertilization amount and achieve variable rate fertilization operations, an automatic control variable rate fertilizer application device was studied and designed for solid particle fertilizer. The overall structure and working principle of the variable rate fertilizer application device was expounded, and the key components were designed and tested. The on-line monitoring and intelligent control system of fertilizer amount were constructed with the single-chip microcomputer STM32 as the control core. By using the optimization method of experimental design, the performance and main influencing factors of the fertilizer flow online detection system were studied, and the best combination of factors was determined. Through the experiment, the change rule models between the detected flow of three kinds of main solid particle fertilizers and the voltage value of piezoelectric sheet, the change rule models between the actual flow of three kinds of main solid particle fertilizers and the rotation speed of the fertilizer discharge shaft, the change rule models between the rotation speed of the fertilizer discharge shaft and the working length of the electric push rod and the forward speed of the rice transplanter were respectively constructed, and the models were tested and analyzed. The results showed that when the forward speed of the rice transplanter was 1m/s and the rotation speeds of the fertilizer discharge shaft were 20r/min, 25r/min and 30r/min, the average detection accuracy of the fertilizer discharge of the three solid granular fertilizers were 94.45%, 93.85% and 93.15%, respectively. When the forward speed of the transplanting machine was 0.6~1.4m/s, the compound fertilizer application rates were 200kg/hm2, 250kg/hm2 and 300kg/hm2 and the urea application rates were 165kg/hm2,195kg/hm2 and 225kg/hm2,the average coefficient of variation of the fertilization rates of the three fertilizers were 3.02%, 3.15% and 2.82%, respectively. Field experiment showed that when the transplanting machine advanced at speed of 1~1.4m/s and the fertilization rates were 180kg/hm2 and 225kg/hm2, respectively, the average accuracy rates of compound fertilizer fertilization in Norway were 94.89% and 97.82%, respectively. Theoretical and experimental analysis showed that the variable rate fertilization device had stable regulation performance and can meet the operational requirements of rice side deep variable rate fertilization.