油菜精量排种器种子流传感装置设计与试验  

Design and experiment on seed flow sensing device for rapeseed precision metering device

作　　者：丁幼春[1] 杨军强[1] 朱凯[1] 张莉莉[1] 周雅文[1] 廖庆喜[1] 

机构地区：[1]华中农业大学工学院,武汉430070

出　　处：《农业工程学报》2017年第9期29-36,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家重点研发计划项目(2016YFD020060602);湖北省技术创新专项重大项目(2016ABA094)

摘　　要：针对油菜精量播种过程中缺乏小粒径种子流传感而导致播量监测困难的问题,设计了一种油菜精量排种器种子流传感装置。运用高速摄影技术及碰撞动力学模型,记录并分析油菜种子与聚偏氟乙烯压电薄膜的碰撞轨迹,为传感装置的导管、压电薄膜倾角、出种口位置等关键结构参数提供依据。基于油菜种子与压电薄膜的碰撞信号特征分析,设计了沉槽基板-压电薄膜感应结构,将碰撞信号的衰减时间从9缩短至1 ms,提高了对高频种子流检测的时间分辨率,同时能够有效抵抗机械振动带来的干扰影响。对微弱碰撞信号进行放大、半波整流、电压比较、单稳态触发转化为单脉冲信号,通过单片机定时计数采集处理,实现油菜种子流排种频率与排种总量的实时检测,并利用无线收发模块定时发送给监测显示终端,实现播量数据的实时显示与保存。油菜精量排种器台架及数粒仪高频排种试验表明:在排种频率8.1~32.9 Hz范围内,检测准确率不低于99.5%。田间播种试验表明传感装置能够实时检测精量排种器的排种频率与排种总量,在无排种时计数为零,正常播种状态时检测准确率不低于99.1%,机械振动及粉尘对传感装置没有影响。该传感装置为油菜精量播种过程播量监测、漏播检测以及补种提供有效支撑。Precision seeding plays an important role in intelligent agricultural machinery development due to its advantages of saving seeds, reducing labor intensity, improving operation efficiency and increasing farmers＇ income. In the planting process, seed metering device is in a closed status and sowing quantity affects crop yield directly, and thus sowing quantity monitoring become one of the development trends in intelligent precision seeding. In recent years, various methods for precision seeding such as photoelectric sensor detection, high-speed photography, and capacitance sensing have been proposed to improve seeding performance for the corn, rice, soybean and other large seeds. Few studies have focused on the sensing method of small seeds such as rapeseed because of its small size, light weight and high frequency seeding. Thus, the development and application of monitoring technology about precision sowing for small seeds are limited. In this study, a seed flow sensing device for rapeseed precision metering device was designed and tested. Specifically, collision trajectory between rapeseed and PVDF （polyvinylidene fluoride） piezoelectric film was recorded and analyzed using high-speed photography and collision dynamics. These data provided a quantitative reference for the design of key structures in terms of the height of catheter, sloping angle of piezoelectric film, position of seed-output, etc. The sensing structure of sinking groove substrate and piezoelectric film was designed based on the analysis of characteristics of impact signal between rapeseed and piezoelectric film. The structure could limit the free oscillation amplitude of the piezoelectric film that could weaken the peak voltage of the free oscillation effectively. The decay time of impact signal was reduced from 9 to 1 ms, which improved the time resolution for high frequency seed flow detection and effectively eliminated the interference caused by mechanical vibration. The signal conditioning circuit turned weak signal into single pulse s

关 键 词：机械化 设计 监测 油菜精量排种器 油菜种子流 碰撞 传感装置 

分 类 号：S223.25[农业科学—农业机械化工程]