基于电容信号的玉米播种机排种性能监测系统

为了改善玉米播种机排种性能监测的可靠性,利用种子介电性质,研究一种基于电容信号获取与分析的播种性能监测方法。通过对玉米播种机排种过程的运动学分析,获得电容传感器极板长度的约束条件,为传感器设计提供理论性参考。设计了以单片机PIC18F2580、电容转换芯片MS3110及AD7685为核心的快速高精度电容检测电路。通过获取相邻种子的电容脉冲峰值间隔并计算脉冲积分面积,可以得到播种工况下的排种量、漏播量及重播量等参数。试验结果表明:系统对单粒玉米种子的监测精度为97.3%,在模拟播种机前进速度4.0km/h的条件下,系统的播种量监测精度为94.6%,漏播量监测精度为93.5%,重播量监测精度为88.1%。该系统能够有效地监测机具排种性能,有助于提高播种作业质量。

Seed monitoring system for corn planter based on capacitance signal

To improve the reliablity of the seeding performance of corn planter, a monitoring system was developed based on capacitive sensor. In order to obtain constrained conditions of the electrode plate length, corn seed movement discipline and mechanism in the dropping process were analyzed theoretically. The detection circuits mainly consisted of microcomputer PIC18F2580, capacitive convert chip MS3110 and AD7685. The capacitive pluse peaks interval and curve integral were calculated, the information of seeding performance were obtained such as seeding quantity, missing rate and multiples rate. The experiment results showed that the system accuracy for single seed detection was up to 97.3%, and when the simulation velocity of the planter was 4.0 km/h, the system had an accuracy of 94.6% in seeding quantity, 93.5% in missing detection and 88.1% in multiples rate. This system can effectively monitor seeding performance and help to improve sowing quality.