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1.
实现以RFID卡仿真磁卡的模块设计 总被引：1，自引：0，他引：1
沈文龙 《福建农林大学学报(自然科学版)》2007,36(4):435-439
设计一种能从射频识别(RFID)卡读取数据,而后又仿真磁卡格式输出的模块,借助这种模块,能在不改变原有应用系统的基础上,将系统的磁卡替换为RFID卡.本文介绍的模块选择H4001作为替代磁卡的RFID卡,模块本身则主要由天线、非接触式射频卡读写基站芯片U2270B和单片机AT89C2051构成.在介绍应用电路的同时,分析了RFID卡、磁卡的相关编码格式,提出实现RFID卡信息读取、磁卡仿真输出的方法和步骤,并给出了相应的程序流程图. 相似文献
2.
The quality of an agrochemical application is a combination of the efficacy of deposit, productivity of the operation, and avoidance of off-site movement. A GPS- and sensor-based system was developed to document the quality of spray applications from a self-propelled sprayer. Confirmation of the spray deposition was accomplished with spray sampling surfaces (water sensitive paper) located at surveyed sampling points in the test fields. An image analysis technique was developed to estimate quantitative and qualitative data, such as relative droplet size spectra, and spray coverage from the cards. Relative performance of two flow control techniques, namely conventional pressure-based control and blended-pulse flow control were documented. Blended-pulse control produced a wider dynamic range and superior consistency of deposit when speed varied over a 3:1 range, or a 6:1 variable rate range was desired. Real-time mitigation of spray drift was accomplished through droplet size changes when sensed weather conditions and sprayer location suggested a potential hazard. 相似文献
3.
Travis Esau Qamar Zaman Dominic Groulx Kenny Corscadden Young Chang Arnold Schumann Peter Havard 《Precision Agriculture》2016,17(6):753-765
The wild blueberry industry is spending over $80 million CAD per year on agrochemicals for 93 000 ha under production in North America. A pressing need to reduce agro-chemical usage and production cost has resulted in the development of a smart sprayer for spot-application of agrochemicals in wild blueberry fields. This paper encompasses the economic analysis to determine the potential savings for spot-applications of agrochemicals using a smart sprayer. The economic analysis compared the smart sprayer with two other commercially available sprayers (basic and swath control). The swath control sprayer and smart sprayer both featured GPS auto-steer and boom section control to reduce over-spray in already applied areas based on GPS position. The basic sprayer used a foam marker for guidance with no swath control management. The smart sprayer featured a machine vision system that automatically detected target areas in the field further reducing agrochemical input by shutting individual nozzles off in non-target areas in the field. The cost analysis was performed to compare the different features of the sprayer technologies, i.e., base sprayer, additional technology, training, usage, repair and maintenance. The additional components installed on the smart sprayer were justified in terms of agrochemicals/water savings via spot-applications, tractor fuel and operator’s time. The application total cost was $2052 ha?1 using the basic sprayer, $1799 ha?1 using the swath control sprayer, and $1138 ha?1 using the smart sprayer over a 2 year production cycle of the selected fields that were used in this study. The payback period ranged from 2.0 years (60 ha field size) to 9.8 years (20 ha field size) using the swath control sprayer. The payback period ranged from 11 months (60 ha field size) to 3.5 years (20 ha field size) when using the smart sprayer. Results revealed that the smart sprayer had significant advantage from both an environmental and economic perspective over the other two sprayers. 相似文献
4.
Travis Esau Qamar Zaman Dominic Groulx Aitazaz Farooque Arnold Schumann Young Chang 《Precision Agriculture》2018,19(4):770-788
An essential part of the wild blueberry cropping system is the proper management of agrochemical inputs including herbicides, fungicides and insecticides. A machine vision system was developed and mounted on the rear sprayer boom 0.18 m in front of the sprayer nozzles capable of targeting the agrochemical application on an as-needed basis. The three-point hitch mounted sprayer featured 27 nozzles over a 13.7 m boom width and a storage tank capacity of 1135 l. Nine digital color cameras continually take images in real-time while computer software processes the images in 0.15 s to determine the target locations where the nozzles open and spray at speeds up to 1.77 m s?1. Two wild blueberry fields in central Nova Scotia were selected for smart sprayer performance testing with spot-application (SA) of agrochemical as compared to control and uniform application techniques. Chateau® herbicide was applied in a field with an infestation of hair cap moss. Spray droplet comparison showed moss patches were properly targeted using the smart sprayer. SA provided the same coverage performance as compared to uniform on the moss targets with herbicide application savings of 78.5% using the smart sprayer. Harvestable yield results were similar for all application tracks. TruPhos Magnesium and ZincMax foliar fertilizers were tank mixed with Bravo® and Proline® fungicides and applied to compare the difference of SA, control and uniform application. Results showed SA of foliar fertilizer and fungicide led to less premature leaf drop and increased the blueberry stem height, number of branches, stem diameter and fruit buds. SA of foliar fertilizer and fungicide also increased the percent of healthy wild blueberry plants by 57.8% and the harvestable yield by 137.8%. Fungicide application savings using the smart sprayer for SA were 11.6%. 相似文献
5.
[目的]针对生猪养殖阶段特点,设计基于RFID技术的畜产品可追溯系统。[方法]阐述电子标签和读写器的天线设计方法,并采用不同的天线对可追溯系统进行通信测试。[结果]数据传输率等参数设置相同时,外接天线的通讯距离比PCB天线要远;3种外接天线比较而言,同轴天线和壁挂天线的通讯距离较远;500kbps数据传输率时通讯距离在28m范围内,250kbps数据传输率时通讯距离在40m范围内。从硬件成本角度考虑,壁挂天线价格远高于同轴天线,在相同通讯距离要求时,系统选用同轴天线。[结论]在生猪养殖阶段采用该研究设计的有源电子标签和读写器,可提高猪肉产品的安全性,并对彻底实现食品的＂源头＂追踪和提供食品安全的透明化管理提供技术支撑。 相似文献
6.
[目的]针对生猪养殖阶段特点,设计基于RFID技术的畜产品可追溯系统。[方法]阐述电子标签和读写器的天线设计方法,并采用不同的天线对可追溯系统进行通信测试。[结果]数据传输率等参数设置相同时,外接天线的通讯距离比PCB天线要远;3种外接天线比较而言,同轴天线和壁挂天线的通讯距离较远;500kbps数据传输卒时通讯距离在28m范围内,250kbps数据传输率时通讯距离在40m范围内。从硬件成本角度考虑,壁挂天线价格远高于同轴天线,在相同通讯距离要求时,系统选用同轴天线。[结论]在生猪养殖阶段采用该研究设计的有源电子标签和读写器,可提高猪肉产品的安全性,并对彻底实现食品的“源头”追踪和提供食品安全的透明化管理提供技术支撑。 相似文献
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Ultan Mc Carthy Gashaw Ayalew Francis Butler Kevin McDonnell Shane Ward 《Computers and Electronics in Agriculture》2009,69(2):135-141
Undetected RFID tags make the potential benefits of RFID unattainable. This study aimed to determine the most significant factors that affect RFID and particularly its application to the traceability of meat. Experimental parameters included five RFID tag inlays, two levels of conveyor speeds, five variations of beef sample and an empty container, 12 tags per test sample, three distances and two types of reader antenna polarisations. Tag detection rates were determined in three replicates per combination of test parameters. A GLM ANOVA was carried out on tag detection rate. In decreasing order of significance in terms of the effect on mean tag detection rate were distance, sample, inlay design, conveyor speed and reader antenna polarisation. Interaction of these factors also proved significant, in decreasing order of importance were reader antenna * inlay, sample type * distance, inlay * distance, sample type * inlay, sample type * reader antenna, distance * speed, sample type * speed and finally sample type * distance * speed. Linearly polarised antenna preformed better overall at detecting tags, with 63% mean detection rate compared with circularly polarised antenna with 57% mean detection rate. Varying the tag inlay resulted in mean detection rates of between 62% and 88%. Ideal transponder location on package was reader antenna polarisation dependent, but generally tags facing reader antennas exhibited better detection rate. Results revealed that the under side of the package was the most un-detectable transponder location, considering the placement of reader antennas on top, left and right sides of the sample. Conveyor speed also proved significant with a variation from 0.5 to 1.0 m/s resulting in an average detection rate ranging from 62% to 57%, respectively. Circularly polarised antennas are believed to perform better in cases of random tag orientation on products. It can be concluded that RFID systems implementation in the meat supply chain requires a holistic approach where distances, polarisations, inlay type, meat composition and conveyor speed need to be considered. 相似文献
8.
Field application uniformity and accuracy of two rate control systems with automatic section capabilities on agricultural sprayers 总被引：1，自引：0，他引：1
Ajay Sharda Joe D. Luck John P. Fulton Timothy P. McDonald Scott A. Shearer 《Precision Agriculture》2013,14(3):307-322
The adoption of automatic section control (ASC) on agricultural sprayers remains popular since it reduces overlap and application in unwanted areas leading to input savings and improved environmental stewardship. Most spray controllers attempt to maintain the desired target rate during ASC actuation (ON and OFF of control sections which change the width of boom-section actually spraying) but limited knowledge exists regarding controller response and nozzle discharge variation during field operation. Therefore, field experiments were conducted using two common self-propelled sprayers equipped with commercially available control systems with ASC capabilities. Pressure transducers were mounted across the spray booms to record real-time nozzle pressure with data tagged with GPS location and time. Nozzle flow was obtained from nozzle pressure to compute nozzle flow uniformity or coefficient of variations (CVs) across the ON boom, off-rate errors (percent difference between actual and target nozzle flow rate) and settling times. Results indicated that nozzle CVs were >10 % for both auto-boom and auto-nozzle control systems, when each of the auto-boom and auto-nozzle sections were turned back ON for 0.5 and 0.2 s, respectively. Further, nozzle off-rate errors exceeding ±10 % occurred in both rectangular and irregular shaped fields. These off-rate errors primarily occurred during ASC actuation while at the same time the sprayer was being accelerated or decelerated. The extended nozzle flow settling times of up to 20 s (delayed response) indicated that the rate controller may require intelligent and enhanced control algorithms to minimize nozzle flow stabilization and thereby a reduction in sprayer off-rate errors during field operation. 相似文献
9.
Radio frequency identification (RFID) offers a way to satisfy the current needs of the produce industry for product identification and cool chain preservation. The main challenges for RFID temperature tracking in produce cool chain monitoring are the produce's high-water content and the cost. Water absorbs radio frequency energy decreasing read range and limiting sensor placement. Whereas cost limits the number of sensors that may be used in a viable system. Therefore, the minimal number of sensor placements that maximize the representation of the temperatures of the product in pallets of high-water content produce must be determined. The objectives of the research presented in this paper were: To identify a location able to represent 85% of the temperatures present in a pallet of bottled water mimicking produce when subjected to heating and cooling conditions similar to the loading-unloading process. And second, to assess the readability and read range of a commercially available RFID battery assisted passive tag in this thermally relevant position so as to determine whether it would be read at the required distance for the supply chain. A single location representing 85% of the temperatures in the pallet was not found; consequently, it was suggested using a location with a temperature that would be the middle point of an interval that gathers the temperature readings of approximately 85% of the measured locations. In addition, results indicate that tag readability and read range in this position vary depending on the configuration of the side of the pallet facing the antennas and the amount of air in the surroundings of the RFID tag. 相似文献
10.
[目的]比较不同喷雾器以及喷头对农药有效利用率和施药效率的影响。[方法]采用诱惑红作为农药喷雾的示踪剂,分析了4种喷雾器及喷头在田间喷雾下的雾滴大小、施药效率、叶片农药的沉积回收率和雾滴田间分布均匀性。[结果]农药的有效利用率方面表现为电动喷雾器>机动喷雾器>手动喷雾器>手动弥雾器;施药效率方面表现为机动喷雾器>电动喷雾器>手动弥雾器>手动喷雾器;农药雾滴田间分布均匀性方面表现为电动喷雾器最好,其余都较差。[结论]为新型植保器械的推广应用提供了理论依据。 相似文献
11.
Hong Y. Jeon Heping ZhuRichard Derksen Edal OzkanCharles Krause 《Computers and Electronics in Agriculture》2011,75(1):213-221
Automatic variable-rate sprayers require accurate measurement of canopy size. An estimate of canopy size is made by measuring the distance to the canopy at several elevations above the ground; an ultrasonic sensor was used to determine canopy distance in this study. It is sometimes necessary to conduct spray operations during harsh operating conditions. In this study ultrasonic sensors were subjected to simulated environmental and operating conditions to determine their durability and accuracy. Conditions tested included exposure to extended cold, outdoor temperatures, cross winds, temperature change, dust clouds, travel speeds and spray cloud effects. The root mean square (RMS) error in a series of measurements of the distance to a simulated plant canopy was used to test for significant difference among treatments. After exposure to outdoor cold conditions for 4 months, the RMS error in distance measured by the ultrasonic sensor increased from 3.31 to 3.55 cm, which was not statistically significant. Neither the presence of dust cloud nor the changes in cross-wind speeds over a range from 1.5-7.5 m/s had significant effects on the mean RMS errors. Varying sensor travel speed from 0.8 to 3.0 m/s had no significant influence on sensor detection distances. Increasing ambient temperature from 16.7 to 41.6 °C reduced the detection distance by 5.0 cm. The physical location of the spray nozzle with respect to the ultrasonic sensor had a significant effect on mean RMS errors. The mean RMS errors of sensor distance measurements ranged from 2.3 to 83.0 cm. The RMS errors could be reduced to acceptable values by proper controlling the sensor/spray nozzles spacing on a sprayer. In addition, multiple-synchronized sensors were tested for their measurement stability and accuracy (due to possible cross-talk errors) when mounted on a prototype sprayer. It was found that isolating the pathway of the ultrasonic wave of each sensor reduced detecting interference between sensors during multiple sensor operation. Test methods presented herein may be useful in the design of standardized testing protocols for field use distance sensors. 相似文献
12.
An expert system (ES) has been developed to assist citrus spray applicators in planning and evaluating their sprayer operations. The ES is partitioned into two parts: (1) spray planning (procedures and calculations for sprayer calibration as well as suitability of spraying under given weather parameters) and (2) spray evaluation (estimation of overall spray deposition, ground fallout, and drift as percentages of the total spray discharged at orchard scale). The first part is based on established procedures and the second part is built on the previously developed spray deposition model. The latter includes a “What-If” analysis function that gives feedback on changes in input variables and the corresponding outputs. Testing of the ES revealed that the trends in the outputs, reflecting the effects of application rate, travel speed, foliage density, and percent missing trees were in general agreement with literature. The ES was evaluated by five individuals with diverse experience in spray applications. Overall, the ES was found useful for calibration and evaluation of spray applications in citrus. 相似文献
13.
F. Lebeau A. VerstraeteC. Stainier M.-F. Destain 《Computers and Electronics in Agriculture》2011,77(2):161-174
A spray drift model called RTDrift was developed to estimate drift caused by ground sprayer machines. The sprayer was equipped with sensors measuring operational parameters namely spray pressure, boom height and movements, and geolocalisation. Climatic parameters, including wind speed and direction, were measured using a 2-D ultrasonic anemometer mounted on the sprayer. The nozzles spray drop size spectra were characterised using Phase Doppler Interferometer measurements. At every successive boom position, a diffusion-advection Gaussian tilted plume model computed the spray drift deposits for each drop class taking into account evaporation. The contribution of a single nozzle was calculated by integration of the individual puffs with respect to time and summation of the contributions of individual drops classes. The overall drift generated by the sprayer machine was obtained adding the contributions of all the nozzles. Field trials were performed on a fallow field with water and on crops with pesticides in various wind conditions. The ground drift was measured at different drift distances using fluorometric methods. When comparing the results of the model with experimental measurements of deposits, the model produced realistic maps of drift deposits. Some further improvement is needed in the presence of large scale eddies. The model offers potential benefits for the farmer as a real time drift estimator embedded on a sprayer machine. 相似文献
14.
Gerhards R. Sökefeld M. Timmermann C. Kühbauch W. Williams M. M. 《Precision Agriculture》2002,3(1):25-35
A four-year study of site-specific weed control is presented in this paper. Weed seedling distribution was sampled and mapped prior to and after post-emergence herbicide application in four fields planted with maize, sugar beets, winter wheat and winter barley, rotating on one site. Herbicides and other weed control strategies were applied site-specifically according to the spatial variation of weed populations. Different decision algorithms were used for chemical weed control methods in each crop. A weed treatment map was created to direct location and dosage of herbicide application. The sprayer was coupled with a differential Global Positioning System (DGPS). The solenoid valves of the sprayer were opened automatically when the tractor entered a weed patch characterized in the weed treatment map. For site specific herbicide application, a patch sprayer was developed that allowed variable rate application and the selective control of each section of the spray boom. 相似文献
15.
针对短波天线辐射效率难以现场监测的问题,研究一种基于外场场强测量的短波天线辐射效率监测方法。该方法结合天线仿真与测量技术,通过域变换法解析介质半空间位型并矢格林函数,采用RWG矩量法(RWG-MoM)离散平面分层介质C类混合位电场积分方程（MPIE）,得到天线辐射功率的相对分布。测量天线外场场强,得到场点电磁功率面密度作为样本估计天线辐射功率,由辐射功率与输入功率的比值计算得到天线辐射效率。以短波双极天线为例,基于现有的飞艇场强测量平台,进行室外远场场强的测量,实验得到的归一化场强方向图与仿真结果吻合较好,通过该方法计算得到的天线辐射效率与公开文献一致性较好,实现了短波天线辐射效率的监测。 相似文献
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During phytosanitary treatments aimed at minimizing product losses, selective spraying systems can be employed. These systems consist of a group of detection–action devices which manage the spraying. In this work, the technical feasibility of a low-cost ultrasound detection system prototype has been assessed for pesticide spray application on greenhouse crops. The prototype is based on a commercially-available car parking assistance system, which has been modified to amplify the signal and activate an electro-valve for spray control. This system was fitted into a self-propelled machine with two vertical spray booms. A laboratory test was carried out to evaluate the system limitations (detection range, response time, optimal sensor location); and once the feasibility of the system was known, a field test was conducted. Inside the greenhouse, the same parameters were determined for canopy presence. The system’s capacity to start and stop spraying at the beginnings and ends of the crop lines was also analysed. In addition, the minimum crop line surface with no plant mass that triggers system activation was determined. The results show that the detection range was 0–0.4 m with an average response time of 1.67 s. Based on these parameters, the optimal sensor location was determined for the different forward velocities. In conclusion, the results show that this system is suitable for plant detection at a forward speed of 0.9 m s?1, allowing growers to stop spraying automatically at the ends of the crop lines and where plant mass absence is greater than 1.0 lineal meter. 相似文献
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[目的]明确无人机不同喷液量对大豆一年生禾本科杂草的防治效果。[方法]以背负式静电喷雾器常量喷雾为对照,研究植保无人机喷施不同喷液量5%精喹禾灵EC对大豆一年生禾本科杂草的防治效果。[结果]5%精喹禾灵EC制剂用药量为1 050 m L/hm2,植保无人机喷液量为7 500~12 000 m L/hm~2时对大豆安全,植保无人机喷液量为9 000、10 500 m L/hm~2时对夏大豆田一年生禾本科杂草的防治效果较好,与背负式静电喷药450 kg/hm~2时效果相当。[结论]试验结果为无人机的大面积推广应用提供了理论依据。 相似文献
20.
针对温室内手动施药劳动强度大、容易造成施药人员中毒等问题,利用GSM网络技术平台,设计基于手机信息发送指令的自走式弥雾机远程控制系统。该系统采用GSM模块和手机及单片机之间的双向通信实现手机对弥雾机行走速度和喷雾流量设定,运用Keil C51V9.00软件编程,对动作流程进行决策,控制弥雾机自动喷药。试验结果表明:该系统响应时间约为3s,弥雾机停止工作时,有一定的响应距离,最大为0.59m;当行走速度为4~12cm/s,喷雾流量50~300mL/min时,雾滴分布变异系数为3%~5%,喷雾均匀性较好。该远程控制系统可以满足在温室大棚内的使用要求,与传统施药方法相比,简化了植保机械的操作过程,有利于减轻劳动强度,保障人身安全。 相似文献