农业工程学报
農業工程學報
농업공정학보
2014年
9期
102-109
,共8页
岳学军%刘永鑫%洪添胜%徐兴%王叶夫%燕英伟%全东平
嶽學軍%劉永鑫%洪添勝%徐興%王葉伕%燕英偉%全東平
악학군%류영흠%홍첨성%서흥%왕협부%연영위%전동평
单片机%无线传感器网络%控制系统%滴灌%低功耗%果园
單片機%無線傳感器網絡%控製繫統%滴灌%低功耗%果園
단편궤%무선전감기망락%공제계통%적관%저공모%과완
microcontrollers%wireless sensor networks%control systems%drip irrigation%low power dissipation%orchard
针对山地果园布线困难,而大面积滴灌需要分区控制并集中管理的需求,构建了低成本、低功耗、能满足定时分区灌溉与集中管理需求的小型无线滴灌控制装置。装置采用无线通信方式,硬件选用低功耗微控制器与双稳态电磁阀,系统软件采用基于 CC1100无线唤醒机制的低功耗间同步通信算法,具有避免信道拥塞的特点。试验表明,输入电压9 V时,控制系统静态电流为400 mA、无线唤醒工作电流为19 mA、工作周期内平均电流为439 mA;1节鹏辉450 mAh的AA电池可供系统至少可工作38 d;果园内RSSI信号衰减测试表明通信距离超过60 m,最高平均丢包率为23%;有遮挡的环境中数据丢包率将大于无遮挡环境,但接收信号强度相差不大;在果园环境中尝试使用电力线载波适配器、大功率WiFi无线网桥、GPRS DTU 3种远距离通信模块建立总控制器与远程监控端的数据链路,链路试验表明,GPRS DTU与大功率WiFi网桥均能成功建立通信链路。相比之下,GPRS有强的适应性;采用无线控制系统,系统准时开启电磁阀,开启时间误差小于5 min,土壤含水率变化呈现快速上升后缓慢下降的变化,灌溉区域的土壤含水率保持13%以上,可应用于岭南绝大部分山地果园。解决了控制装置的布线工程困难,实现可远程传输滴灌信息和监测滴灌状态,并可进一步实现分区控制与轮灌控制。
針對山地果園佈線睏難,而大麵積滴灌需要分區控製併集中管理的需求,構建瞭低成本、低功耗、能滿足定時分區灌溉與集中管理需求的小型無線滴灌控製裝置。裝置採用無線通信方式,硬件選用低功耗微控製器與雙穩態電磁閥,繫統軟件採用基于 CC1100無線喚醒機製的低功耗間同步通信算法,具有避免信道擁塞的特點。試驗錶明,輸入電壓9 V時,控製繫統靜態電流為400 mA、無線喚醒工作電流為19 mA、工作週期內平均電流為439 mA;1節鵬輝450 mAh的AA電池可供繫統至少可工作38 d;果園內RSSI信號衰減測試錶明通信距離超過60 m,最高平均丟包率為23%;有遮擋的環境中數據丟包率將大于無遮擋環境,但接收信號彊度相差不大;在果園環境中嘗試使用電力線載波適配器、大功率WiFi無線網橋、GPRS DTU 3種遠距離通信模塊建立總控製器與遠程鑑控耑的數據鏈路,鏈路試驗錶明,GPRS DTU與大功率WiFi網橋均能成功建立通信鏈路。相比之下,GPRS有彊的適應性;採用無線控製繫統,繫統準時開啟電磁閥,開啟時間誤差小于5 min,土壤含水率變化呈現快速上升後緩慢下降的變化,灌溉區域的土壤含水率保持13%以上,可應用于嶺南絕大部分山地果園。解決瞭控製裝置的佈線工程睏難,實現可遠程傳輸滴灌信息和鑑測滴灌狀態,併可進一步實現分區控製與輪灌控製。
침대산지과완포선곤난,이대면적적관수요분구공제병집중관리적수구,구건료저성본、저공모、능만족정시분구관개여집중관리수구적소형무선적관공제장치。장치채용무선통신방식,경건선용저공모미공제기여쌍은태전자벌,계통연건채용기우 CC1100무선환성궤제적저공모간동보통신산법,구유피면신도옹새적특점。시험표명,수입전압9 V시,공제계통정태전류위400 mA、무선환성공작전류위19 mA、공작주기내평균전류위439 mA;1절붕휘450 mAh적AA전지가공계통지소가공작38 d;과완내RSSI신호쇠감측시표명통신거리초과60 m,최고평균주포솔위23%;유차당적배경중수거주포솔장대우무차당배경,단접수신호강도상차불대;재과완배경중상시사용전력선재파괄배기、대공솔WiFi무선망교、GPRS DTU 3충원거리통신모괴건립총공제기여원정감공단적수거련로,련로시험표명,GPRS DTU여대공솔WiFi망교균능성공건립통신련로。상비지하,GPRS유강적괄응성;채용무선공제계통,계통준시개계전자벌,개계시간오차소우5 min,토양함수솔변화정현쾌속상승후완만하강적변화,관개구역적토양함수솔보지13%이상,가응용우령남절대부분산지과완。해결료공제장치적포선공정곤난,실현가원정전수적관신식화감측적관상태,병가진일보실현분구공제여륜관공제。
In China, commercial electricity was not available in most mountain orchards. Therefore, low-power systems are required. On the other hand, strong demands for developing automatic irrigation systems also existed in those areas. It's also important to implement the central management strategy for those irrigation systems. Wireless networks could be helpful in transmitting soil moisture information and monitoring irrigation status. Taking advantage of wireless networks in the irrigation system for further implementation of a central control strategy is becoming a hot topic in irrigation engineering. This paper is aimed at providing a low-cost and low-power wireless irrigation solution for small-scale orchard growers to realize automatic time-control irrigation. The system was composed of several nodes, each node of hardware consisted of a MSP430F2132 micro controller, a short range RF transceiver (CC1100, Texas Instrument), an RS-232 interface for long distance communication module, an LCD (liquid crystal display, JLX12865-0086PC) module, a 9 V Battery module, a valve driving circuit and a soil moisture sensor (Decagon EC-5 or other) interface. Time synchronization communication protocol was designed for system nodes;therefore, the whole system could enter the sleep mode when there was no irrigation task. Furthermore, the WOR (wake on radio) feature of the RF module also helped to reduce power consumption of the nodes when the nodes were woken up for synchronization. The system power consumption test was performed under 9 V battery voltage; the quiescent current consumption is 400 μA. While the WOR current consumption was 19 mA, the current consumption of the system was 439μA on average. Calculations also indicated that the charge of daily operating a pulse solenoid valve covers only a tiny portion in a whole node's daily charge. The battery discharge experiment in the conditioning of 100 mA const current revealed that the selected battery module could provide a charge of 400 mAh. In the test, output voltage dropped from 9 V to 5 V. According to the estimation, the system could run for at least 38 days without changing batteries. Communication tests in mountain orchards showed that the minimum packet loss rate when nodes were randomly distributed was 6.19%, the effective communication distance with 3 dBi antenna on each node reached 70m. The RSSI (received signal strength index) did not show a significant difference in the experimental orchard compared with open field RSSI experiment results, but the packet loss rate was much higher when in the deep orchard. The test of long distance communication module showed that the PLC (power line communication) Module (Zinwell PWQ-5101) had few chances to establish a successful data link while the GPRS and high power WiFi module held a stable data link between the remote monitoring terminal and the control system. The system was utilized for irrigation control, irrigation valves were turned on every day at 8:00 am, the collected soil moisture showed a rapid increase when valves were turned on and decreased slowly after irrigation valves were turned off, the time control error was less than 5 minutes and soil moisture rate was maintained above 13%during experiment periods. These tests proved that this system could be suitable for mountain orchards in southern China.