油菜宽幅播种作业监测系统设计与试验

Design and experiment of the sowing monitoring system for a wide-width rapeseed planter

针对油菜宽幅播种作业过程中播量监测与漏播检测的问题,该研究设计了一种适用于宽幅播种的油菜播种监测系统。该监测系统由播种监测终端与种子流传感检测模块构成,可通过改变连接种子流传感检测模块的数量,适配不同作业幅宽的播种机。种子流传感检测模块将种子穿过感应面生成的单脉冲排种信号并传递给播种监测终端;播种监测终端利用I2C总线对端口扩展用于接收多路油菜种子的排种信号,并生成油菜排种过程的多路种子流排种时间间隔序列,用于实现各行播量、排种频率的计量,并依据相关国家标准对播种作业进行漏播判定。在播种监测终端内构建MariaDB服务器用于对播量、排种频率和漏播状态等播种状态信息进行实时存储、管理,为田间管理与处方作业提供支持。播种监测系统的台架试验表明,在排种频率不高于32.73 Hz时,播量监测的准确率不低于97%,满足播种监测的准确性要求;在排种器不产生严重漏播(漏播指数≤15%)时,漏播指数检测值与高精度的视觉检测试验台的最大偏差为2.21个百分点。结果表明播种监测系统对油菜播种的播种监测与漏播检测的准确性满足使用要求。田间试验表明针对油菜播种的田间播种播量监测准确率不低于96.5%,监测系统在田间作业环境下可稳定工作。该油菜播种监测系统为油菜播种的作业质量评价提供了技术支持。

Sowing is one of the most important processes in agricultural production.The efficiency and quality of sowing also dominate deeply the growth and yield of crops.Precision sowing in mechanized seeding aims to achieve a high yield of crops under reasonable planting density in recent years.It is highly urgent to accurately monitor the sowing amount,frequency,and work quality of planter for visualization and digitalization in precision sowing.A wide-width planter can be expected to significantly improve productivity during large-scale planting,especially for rapeseed production.However,most planters are difficult to adjust the working parameters suitable for agronomic requirements,because the real-time sowing frequency fails to be detected during the traditional sowing,particularly for the small seeds,such as rapeseed.Furthermore,the state-of-the-art precise sensors have increased the cost of the monitoring quite a lot.It is still lacking to deal with the real-time data during the sowing in the current system.In this study,a rapeseed sowing monitoring system was proposed for the wide-width planter(named 2 BMF-12),thereby significantly improving the quality of planting scale and mechanized production.The quality of sowing was also evaluated during the rapeseed sowing.The 2 BMF-12 planter was utilized to support up to 12 rows of sowing at the same time.The monitoring system included 12 seed-sensing devices and a detecting terminal.The seed-sensing devices were placed on the planter under the sowing pipe lines,in order to collect the information of seeds crossing the sensing area and generate electrical signals.The terminal received the electrical signals as external interrupts using multithreading I2 C bus to expand ports,in order to receive more interrupts-channel at the same time.In this case,the terminal was designed to monitor 12 rows,where more rows were set under parallel connecting the chips,named PCF8574 on the I2 C bus.Then,the sowing amount and frequency were measured for each row of the planter.The leakage and qualified index of sowing were thus counted,according to national standards.Local database was used to manage and store in the assigned table of the database once a second.MariaDB server was built in the sowing monitoring terminal for real-time storage and management parameters during the planters running,such as sowing amount,sowing frequency,the leakage,and qualified index.Bench and field tests showed that the seeding monitoring system was stable to real-time detect the status and leakage index during sowing.Specifically,the system error was 2.21 percentage points for the degree of leakage,while there was no severity leakage occurred in the planter.The accuracy rate of the monitoring system was not less than 96.5%for rapeseed sowing,suitable for the farm.This finding can provide for the quality evaluation of rape seeding operations in the future.It can be possible to combine with high-precision Bei Dou positioning satellite and mobile internet,thereby supporting the sowing amount and leaking state maps generating for the sowing in the fields.