农业工程学报
農業工程學報
농업공정학보
2014年
24期
11-21
,共11页
农业机械%种子%实时控制%精量播种%时变窗口%漏播检测%排种频率%排种时间间隔
農業機械%種子%實時控製%精量播種%時變窗口%漏播檢測%排種頻率%排種時間間隔
농업궤계%충자%실시공제%정량파충%시변창구%루파검측%배충빈솔%배충시간간격
agricultural machinery%seed%real time control%precision planting%time changed window%miss detection%seeding frequency%seeding time intervals
为了快速准确地反映不同漏播状态类型,针对油菜精量排种器漏播实时检测问题,在界定了“稀疏缺苗”和“断条”2种不同漏播类型的基础上定义了稀疏缺苗系数与断条系数,分析了两系数的二维平面分布,提出了一种采用排种盘转速与排种脉冲同步检测、排种频率与时间间隔双重阈值约束的检测方法。该检测方法利用MSP430单片机的时间捕捉中断资源,在由排种盘转速脉冲序列信号确定的时间窗口内,通过光纤传感器感应获得排种序列的排种频率与排种时间间隔2类统计指标,依据设定的漏播严重程度评判系数,建立了漏播状态评判规则。在气力式油菜精量排种器上试验结果表明:该检测方法能够根据排种盘转速的变化自行调整检测时间窗口,对“稀疏缺苗”和“断条”漏播状态判断准确率可达100%,对于油菜精量联合直播机在田间不同作业速度下,该方法能够有效实现精量排种器漏播的实时检测,在考虑地轮滑移情况下检测结果滞后距离低于(84*型孔数)mm。该方法不仅有效解决了小粒径精量排种器重播条件下漏播的检测,而且对播量不足进行了约束,提高了漏播检测的实时性,为后期实现精准自动补种创造了有利条件。
為瞭快速準確地反映不同漏播狀態類型,針對油菜精量排種器漏播實時檢測問題,在界定瞭“稀疏缺苗”和“斷條”2種不同漏播類型的基礎上定義瞭稀疏缺苗繫數與斷條繫數,分析瞭兩繫數的二維平麵分佈,提齣瞭一種採用排種盤轉速與排種脈遲同步檢測、排種頻率與時間間隔雙重閾值約束的檢測方法。該檢測方法利用MSP430單片機的時間捕捉中斷資源,在由排種盤轉速脈遲序列信號確定的時間窗口內,通過光纖傳感器感應穫得排種序列的排種頻率與排種時間間隔2類統計指標,依據設定的漏播嚴重程度評判繫數,建立瞭漏播狀態評判規則。在氣力式油菜精量排種器上試驗結果錶明:該檢測方法能夠根據排種盤轉速的變化自行調整檢測時間窗口,對“稀疏缺苗”和“斷條”漏播狀態判斷準確率可達100%,對于油菜精量聯閤直播機在田間不同作業速度下,該方法能夠有效實現精量排種器漏播的實時檢測,在攷慮地輪滑移情況下檢測結果滯後距離低于(84*型孔數)mm。該方法不僅有效解決瞭小粒徑精量排種器重播條件下漏播的檢測,而且對播量不足進行瞭約束,提高瞭漏播檢測的實時性,為後期實現精準自動補種創造瞭有利條件。
위료쾌속준학지반영불동루파상태류형,침대유채정량배충기루파실시검측문제,재계정료“희소결묘”화“단조”2충불동루파류형적기출상정의료희소결묘계수여단조계수,분석료량계수적이유평면분포,제출료일충채용배충반전속여배충맥충동보검측、배충빈솔여시간간격쌍중역치약속적검측방법。해검측방법이용MSP430단편궤적시간포착중단자원,재유배충반전속맥충서렬신호학정적시간창구내,통과광섬전감기감응획득배충서렬적배충빈솔여배충시간간격2류통계지표,의거설정적루파엄중정도평판계수,건립료루파상태평판규칙。재기력식유채정량배충기상시험결과표명:해검측방법능구근거배충반전속적변화자행조정검측시간창구,대“희소결묘”화“단조”루파상태판단준학솔가체100%,대우유채정량연합직파궤재전간불동작업속도하,해방법능구유효실현정량배충기루파적실시검측,재고필지륜활이정황하검측결과체후거리저우(84*형공수)mm。해방법불부유효해결료소립경정량배충기중파조건하루파적검측,이차대파량불족진행료약속,제고료루파검측적실시성,위후기실현정준자동보충창조료유리조건。
Loss sowing is one of the important indicators of measuring metering device quality and performance. Seeding faults such as the lack of seeds in the seed box, clogged seeding holes, transmission fault, and faster rotation speed of seeding plates will lead to loss sowing during the seeding operation. Numbers of continuous clogged seeding holes will cause periodic blank misses in a row and lots of discontinuous clogged seeding holes will produce periodic sparse misses. Both misses affect crop yield seriously. In recent years, lots of miss detection methods such as the time-interval method and seeding-frequency method have been studied on the precision planting to improve seeding performance, but few studies focus on the loss sowing detection in real time, especially for small seeds such as rapeseeds. In this study, pointing to the problem of how to detect the misses of small seed precision planting in real time, based on the concepts of sparse miss coefficient and blank miss coefficient, and the relation between two coefficients of two-dimensional plane and loss sowing, one double-threshold (including seeding frequency and seeding time interval) decision method has been put forward, in which a standard seeding pulse sequence has been developed to sense the seeding speed. The detection system utilizes time capture interrupts of MSP430 to acquire the seeding signals including seeding frequency and seeding time intervals by a fiber optic sensor within the time window determined by the finite pulse sequence of seeding speed. Based on the sequences of seeding frequency and seeding time intervals, two statistic parameters have been counted. With one setting coefficient which indicates the degree of miss, the two parameters can be used to decide the miss type. Tests were carried out on the JPS-12 test-bed of the pneumatic rapeseed precision metering device. During the platform tests the negative pressure was set to 900 Pa, the positive pressure was set to 500 Pa, and the speed of seed conveyor belt was 1.9 km/h. The loss sowing detection effect of pneumatic rapeseed precision metering device with 20 holes and 40 holes had been tested at the different rotating speed such as 12, 15, 18, 21, 24, 27, 30 r/min. One threshold coefficient of loss sowing was set to decide whether the metering device had produced miss and which type the miss was. During one time window, which was defined as the time of the seeding plate rotating a definite number of rounds, the detection system calculated the sparse miss coefficient and blank miss coefficient from the information of seeding frequencies and seeding intervals. Additionally, the field test was carried on precision the combine planter of 2BYM6/8 for both rapeseed and wheat seed driven by a DFH-LX954 tractor. During the test, the planter was set at three different level of working speeds, and each speed lasted for 8 m. The tests of the pneumatic rapeseed precision metering device showed that: it is effective and necessary to establish two coefficients (sparse miss coefficient and blank miss coefficient) to detect sparse miss and blank miss especially under both situations of multiple seeding and inadequate seeding. The accuracy of the loss sowing detection was 100%. Meanwhile, this method can accurately detect the loss sowing of the rapeseed precision planter at different working speeds in the field. The miss detection method can adapt the time window for the variation of seeding speed and shows a good real-time detection performance. Concerning the slip of copying land wheel, the standard distance delay of miss detection is less than 84 k mm, which makes it possible to re-seed automatically in the miss place at the right time.