农业工程学报
農業工程學報
농업공정학보
2013年
23期
15-22
,共8页
黄东岩%贾洪雷%祁悦%朱龙图%李洪刚
黃東巖%賈洪雷%祁悅%硃龍圖%李洪剛
황동암%가홍뢰%기열%주룡도%리홍강
监测%农业机械%种子%播种机%PVDF压电薄膜%单片机
鑑測%農業機械%種子%播種機%PVDF壓電薄膜%單片機
감측%농업궤계%충자%파충궤%PVDF압전박막%단편궤
monitoring%agricultural machinery%seed%planter%PVDF Piezoelectric Film%chip microprocessor
为了能够在恶劣的环境中实时自动监测播种机的排种状况，提高监测的可靠性，采用聚偏二氟乙烯（polyvinylidence fluoride，PVDF）压电薄膜传感器将排种器单粒落粒物理量转变成脉冲电压信号，设计了以单片机STC89C52为核心的监测系统，该系统可根据传感器输出的相邻脉冲电压信号的时间间隔与机具的前进速度，计算出播种机的排种量，排种速度，播种面积，漏播率等性能指标。试验台试验结果表明，在排种器每秒落粒数分别为5、8.75、10时，系统对排种量监测精度为95.3%、96%、92.5%，对漏播量监测精度为90.4%、91%、90.2%；田间试验结果表明，在播种机前进速度分别为3、4、5 km/h时，系统对排种量监测精度为95.2%、93.8%、90.4%，对漏播量监测精度为93.3%、93.1%、89.7%。该系统满足排种器实时监测要求，有助于提高播种作业质量。
為瞭能夠在噁劣的環境中實時自動鑑測播種機的排種狀況，提高鑑測的可靠性，採用聚偏二氟乙烯（polyvinylidence fluoride，PVDF）壓電薄膜傳感器將排種器單粒落粒物理量轉變成脈遲電壓信號，設計瞭以單片機STC89C52為覈心的鑑測繫統，該繫統可根據傳感器輸齣的相鄰脈遲電壓信號的時間間隔與機具的前進速度，計算齣播種機的排種量，排種速度，播種麵積，漏播率等性能指標。試驗檯試驗結果錶明，在排種器每秒落粒數分彆為5、8.75、10時，繫統對排種量鑑測精度為95.3%、96%、92.5%，對漏播量鑑測精度為90.4%、91%、90.2%；田間試驗結果錶明，在播種機前進速度分彆為3、4、5 km/h時，繫統對排種量鑑測精度為95.2%、93.8%、90.4%，對漏播量鑑測精度為93.3%、93.1%、89.7%。該繫統滿足排種器實時鑑測要求，有助于提高播種作業質量。
위료능구재악렬적배경중실시자동감측파충궤적배충상황，제고감측적가고성，채용취편이불을희（polyvinylidence fluoride，PVDF）압전박막전감기장배충기단립락립물리량전변성맥충전압신호，설계료이단편궤STC89C52위핵심적감측계통，해계통가근거전감기수출적상린맥충전압신호적시간간격여궤구적전진속도，계산출파충궤적배충량，배충속도，파충면적，루파솔등성능지표。시험태시험결과표명，재배충기매초락립수분별위5、8.75、10시，계통대배충량감측정도위95.3%、96%、92.5%，대루파량감측정도위90.4%、91%、90.2%；전간시험결과표명，재파충궤전진속도분별위3、4、5 km/h시，계통대배충량감측정도위95.2%、93.8%、90.4%，대루파량감측정도위93.3%、93.1%、89.7%。해계통만족배충기실시감측요구，유조우제고파충작업질량。
During the process of seeding, once the fault cannot be identified, there will be a large area of missed planting and loss of agricultural production. It is very important to improve the reliability of the seed monitoring system. In this paper, a seed monitoring system was developed based on a PVDF piezoelectric film sensor. The system is simple, with strong applicability. The sensor with the cantilever structure has little effect on the seed coefficient of variation. The system can work in harsh environments. According to the sensor output signal and the forward speed of the machine, the amount of seeding, the speed of seeding, seeding acreage, leakage rate, and other performance indicators can be gained. An alarm will be given once there is the phenomenon of a missing seed or blocking. According to the alarm signal, the tractor driver stops to check the planter. A PVDF piezoelectric film sensor is installed in the seeding tube under the seed-metering device. During the process of seeding, seeds sideswipe the PVDF piezoelectric film one by one. The stricks of seeds make deformations of the piezoelectric film. At the same time, the piezoelectric polarization is generated inside the film. Positive and negative charges are gathered on the upper and lower surfaces of the piezoelectric film respectively. The charges generate a voltage signal. When the seed-metering device fails, the piezoelectric sensor will not be subject to stricks of seeds, and the voltage signal disappears. Therefore, the voltage signals generated by the piezoelectric sensor can be used to determine whether there is a missed planting phenomenon. In order to avoid rebounds of the seed on the sensor, the sensor is installed in a 30? angle with the vertical direction. The piezoelectric film sensor is soft, thin, and highly sensitive. The sensor is near to the seed-metering device, the collision of seed and the sensor is rapid, so the phenomenon of blocking is prevented at the installation position for the sensor. The system hardware is composed of a monitor and an alarm circuit. The central processors of the monitor and alarm are two single-chip microcomputers, and the type is STC89C52. The signals of the PVDF sensor and the hall sensor are collected by the monitor circuit. The alarm circuit is mainly used for processing the human-computer interaction. Two single-chip microcomputers communicate by a wireless data transmission module NRF24L012. The information of seeding performance gathered by the monitor is transmitted to the alarm through the wireless transmission. The alarm circuit displays the alarm signals. The system was applied for both a bench test and a field test. When the amounts of seeding are 5, 8.75 and 10 seeds per second, the system accuracy for amount of seeding is 95.3%, 96%, and 92.5%respectively, the system accuracy for missed planting is 90.4%, 91%, and 90.2%respectively. A large amount of seeds does not affect the system’s accuracy. When the planter forward speed is 3, 4 and 5 km/h, the system accuracy for the amount of seeding is 95.2%, 93.8%, and 90.4%respectively, the system accuracy for missed planting is 93.3%, 93.1%, and 89.7% respectively. The system has a strong ability of anti-interference. Equipment vibrations do not affect the accuracy of the system. This system can effectively monitor seeding performance, and help to improve sowing quality.
