111 research outputs found

    Environmental sensing and modelling\ua0using wireless sensor networks

    Get PDF

    New sensing methods for scheduling variable rate irrigation to improve water use efficiency and reduce the environmental footprint : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Soil Science at Massey University, Palmerston North, New Zealand

    Get PDF
    Figures are re-used under an Attribution 4.0 International (CC BY 4.0) license, or are not copyrighted.Irrigation is the largest user of allocated freshwater, so conservation of water use should begin with improving the efficiency of crop irrigation. Improved irrigation management is necessary for humid areas such as New Zealand in order to produce greater yields, overcome excessive irrigation and eliminate nitrogen losses due to accelerated leaching and/or denitrification. The impact of two different climatic regimes (Hawkes Bay, Manawatū) and soils (free and imperfect drainage) on irrigated pea (Pisum sativum., cv. ‘Ashton’) and barley (Hordeum vulgare., cv. ‘Carfields CKS1’) production was investigated. These experiments were conducted to determine whether variable-rate irrigation (VRI) was warranted. The results showed that both weather conditions and within-field soil variability had a significant effect on the irrigated pea and barley crops (pea yield - 4.15 and 1.75 t/ha; barley yield - 4.0 and 10.3 t/ha for freely and imperfectly drained soils, respectively). Given these results, soil spatial variability was characterised at precision scales using proximal sensor survey systems: to inform precision irrigation practice. Apparent soil electrical conductivity (ECa) data were collected by a Dualem-421S electromagnetic (EM) survey, and the data were kriged into a map and modelled to predict ECa to depth. The ECa depth models were related to soil moisture (θv), and the intrinsic soil differences. The method was used to guide the placement of soil moisture sensors. After quantifying precision irrigation management zones using EM technology, dynamic irrigation scheduling for a VRI system was used to efficiently irrigate a pea crop (Pisum sativum., cv. ‘Massey’) and a French bean crop (Phaseolus vulgaris., cv. ‘Contender’) over one season at the Manawatū site. The effects of two VRI scheduling methods using (i) a soil water balance model and (ii) sensors, were compared. The sensor-based technique irrigated 23–45% less water because the model-based approach overestimated drainage for the slower draining soil. There were no significant crop growth and yield differences between the two approaches, and water use efficiency (WUE) was higher under the scheduling regime based on sensors. ii To further investigate the use of sensor-based scheduling, a new method was developed to assess crop height and biomass for pea, bean and barley crops at high field resolution (0.01 m) using ground-based LiDAR (Light Detection and Ranging) data. The LiDAR multi-temporal, crop height maps can usefully improve crop coefficient estimates in soil water balance models. The results were validated against manually measured plant parameters. A critical component of soil water balance models, and of major importance for irrigation scheduling, is the estimation of crop evapotranspiration (ETc) which traditionally relies on regional climate data and default crop factors based on the day of planting. Therefore, the potential of a simpler, site-specific method for estimation of ETc using in-field crop sensors was investigated. Crop indices (NDVI, and canopy surface temperature, Tc) together with site-specific climate data were used to estimate daily crop water use at the Manawatū and Hawkes Bay sites (2017-2019). These site-specific estimates of daily crop water use were then used to evaluate a calibrated FAO-56 Penman-Monteith algorithm to estimate ETc from barley, pea and bean crops. The modified ETc–model showed a high linear correlation between measured and modelled daily ETc for barley, pea, and bean crops. This indicates the potential value of in-field crop sensing for estimating site-specific values of ETc. A model-based, decision support software system (VRI–DSS) that automates irrigation scheduling to variable soils and multiple crops was then tested at both the Manawatū and Hawkes Bay farm sites. The results showed that the virtual climate forecast models used for this study provided an adequate prediction of evapotranspiration but over predicted rainfall. However, when local data was used with the VRI–DSS system to simulate results, the soil moisture deficit showed good agreement with weekly neutron probe readings. The use of model system-based irrigation scheduling allowed two-thirds of the irrigation water to be saved for the high available water content (AWC) soil. During the season 2018 – 2019, the VRI–DSS was again used to evaluate the level of available soil water (threshold) at which irrigation should be applied to increase WUE and crop water productivity (WP) for spring wheat (Triticum aestivum L., cv. ‘Sensas’) on the sandy loam and silt loam soil zones at the Manawatū site. Two irrigation thresholds (40% and 60% AWC), were investigated in each soil zone along with a rainfed control. Soil water uptake pattern was affected mainly by the soil type rather than irrigation. The soil iii water uptake decreased with soil depth for the sandy loam whereas water was taken up uniformly from all depths of the silt loam. The 60% AWC treatments had greater irrigation water use efficiency (IWUE) than the 40% AWC treatments, indicating that irrigation scheduling using a 60% AWC trigger could be recommended for this soil-crop scenario. Overall, in this study, we have developed new sensor-based methods that can support improved spatial irrigation water management. The findings from this study led to a more beneficial use of agricultural water

    A Novel Variable Geometry based Planar Inductor Design for Wireless Charging Application

    Get PDF
    In this thesis, the performance, modelling and application of a planar electromagnetic coil are discussed. Due to the small size profiles and their non‐contact nature, planar coils are widely used due to their simple and basic design. The uncertain parameters have been identified and simulated using ANSYS that has been run utilising a newly developed MATLAB code. This code has made it possible to run thousands of trials without the need to manually input the various parameters for each run. This has facilitated the process of obtaining all the probable solutions within the defined range of properties. The optimum and robust design properties were then determined. The thesis discusses the experimentation and the finite element modelling (FEM) performed for developing the design of planar coils and used in wireless chargers. In addition, the thesis investigates the performance of various topologies of planar coils when they are used in wireless chargers. The ANSYS Maxwell FEM package has been used to analyse the models while varying the topologies of the coils. For this purpose, different models in FEM were constructed and then tested with topologies such as circular, square and hexagon coil configurations. The described methodology is considered as an effective way for obtaining maximum Power transfer efficiency (PTE) with a certain distance on planar coils with better performance. The explored designs studies are, namely: (1) Optimization of Planar Coil Using Multi-core, (2) planar coil with an Orthogonal Flux Guide, (3) Using the Variable Geometry in a Planar coil for an Optimised Performance by using the robust design method, (4) Design and Integration of Planar coil on wireless charger. In the first design study, the aim is to present the behaviour of a newly developed planar coil, built from a Mu-metal, via simulation. The structure consists of an excitation coil, sensing coils and three ferromagnetic cores 2 located on the top, middle and bottom sections of the coil in order to concentrate the field using the iterative optimisation technique. Magnetic materials have characteristics which allows them to influence the magnetic field in its environment. The second design study presents the optimal geometry and material selection for the planar with an Orthogonal Flux Guide. The study demonstrates the optimising of the materials and geometry of the coil that provides savings in terms of material usage as well as the employed electric current to produce an equivalent magnetic field. The third design study presents the variable geometry in a planar inductor to obtain the optimised performance. The study has provided the optimum and robust design parameters in terms of different topologies such as circular, square and hexagon coil configurations and then tested, Once the best topology is chosen based on performance. The originality of the work is evident through the randomisation of the parameters using the developed MATLAB code and the optimisation of the joint performance under defined conditions. Finally, the fourth design study presents the development of the planar coil applications. Three shapes of coils are designed and experimented to calculate the inductance and the maximum power transfer efficiency (PTW) over various spacing distances and frequency

    Nonlinear state and parameter estimation of spatially distributed systems

    Get PDF
    In this thesis two probabilistic model-based estimators are introduced that allow the reconstruction and identification of space-time continuous physical systems. The Sliced Gaussian Mixture Filter (SGMF) exploits linear substructures in mixed linear/nonlinear systems, and thus is well-suited for identifying various model parameters. The Covariance Bounds Filter (CBF) allows the efficient estimation of widely distributed systems in a decentralized fashion

    Addressing training data sparsity and interpretability challenges in AI based cellular networks

    Get PDF
    To meet the diverse and stringent communication requirements for emerging networks use cases, zero-touch arti cial intelligence (AI) based deep automation in cellular networks is envisioned. However, the full potential of AI in cellular networks remains hindered by two key challenges: (i) training data is not as freely available in cellular networks as in other fields where AI has made a profound impact and (ii) current AI models tend to have black box behavior making operators reluctant to entrust the operation of multibillion mission critical networks to a black box AI engine, which allow little insights and discovery of relationships between the configuration and optimization parameters and key performance indicators. This dissertation systematically addresses and proposes solutions to these two key problems faced by emerging networks. A framework towards addressing the training data sparsity challenge in cellular networks is developed, that can assist network operators and researchers in choosing the optimal data enrichment technique for different network scenarios, based on the available information. The framework encompasses classical interpolation techniques, like inverse distance weighted and kriging to more advanced ML-based methods, like transfer learning and generative adversarial networks, several new techniques, such as matrix completion theory and leveraging different types of network geometries, and simulators and testbeds, among others. The proposed framework will lead to more accurate ML models, that rely on sufficient amount of representative training data. Moreover, solutions are proposed to address the data sparsity challenge specifically in Minimization of drive test (MDT) based automation approaches. MDT allows coverage to be estimated at the base station by exploiting measurement reports gathered by the user equipment without the need for drive tests. Thus, MDT is a key enabling feature for data and artificial intelligence driven autonomous operation and optimization in current and emerging cellular networks. However, to date, the utility of MDT feature remains thwarted by issues such as sparsity of user reports and user positioning inaccuracy. For the first time, this dissertation reveals the existence of an optimal bin width for coverage estimation in the presence of inaccurate user positioning, scarcity of user reports and quantization error. The presented framework can enable network operators to configure the bin size for given positioning accuracy and user density that results in the most accurate MDT based coverage estimation. The lack of interpretability in AI-enabled networks is addressed by proposing a first of its kind novel neural network architecture leveraging analytical modeling, domain knowledge, big data and machine learning to turn black box machine learning models into more interpretable models. The proposed approach combines analytical modeling and domain knowledge to custom design machine learning models with the aim of moving towards interpretable machine learning models, that not only require a lesser training time, but can also deal with issues such as sparsity of training data and determination of model hyperparameters. The approach is tested using both simulated data and real data and results show that the proposed approach outperforms existing mathematical models, while also remaining interpretable when compared with black-box ML models. Thus, the proposed approach can be used to derive better mathematical models of complex systems. The findings from this dissertation can help solve the challenges in emerging AI-based cellular networks and thus aid in their design, operation and optimization

    Site-specific irrigation: Improvement of application map and a dynamic steering of modified centre pivot irrigation system

    Get PDF
    Einleitung: Ein Management Konzept für nachhaltige und effiziente Nutzunglandwirtschaftlicher Maßnahmen ist bekannt als teilflächenspezifische Landwirtschaft (PA – Precision Agriculture). Wird das teilflächenspezifische Konzept im Bewässerungsmanagement eingesetzt, wird es teilflächenspezifische Bewässerung genannt (PI – Precision Irrigation). Bei der teilflächenspezifische Bewässerung kann die Bewässerung zwischen den Bereichen eines Feldes auf Grund der Variabilität der Bodeneigenschaften oder dem Anbau von verschiedenen Pflanzen auf dem selben Feld variieren. Die räumliche Veränderung der nutzbaren Feldkapazität als Primärfaktor bedingt die räumliche Veränderung der Bewässerungshöhe und der Bewässerungsfrequenz. Die Bewässerungssysteme verteilen das Wasser bis heute gleichmäßig, so dass die Flächen teilweise überbewässert oder unterbewässert sind. Bezogen auf dieses Problem ist die teilflächenspezifische Beregnung geeignet, das Wasser an der richtigen Stelle zum richtigen Zeitpunkt unter Benutzung des richtigen Bewässerungssystems auszubringen. Folglich sind die Schlüsselziele dieser Arbeit: a) die Abgrenzung von Beregnungsmanagementzonen (IMZs – Irrigation Management Zones) unter Nutzung von sensorbasierten Messungen der elektrischen Leitfähigkeit (ECa – depth-weighted apparent soil electrical conductivity) des Bodens mit EM38 und VERIS 3100, b) die Entwicklung und Evaluierung einer teilflächenspezifischen mobilen Tropfbewässerung und c) Auswertung von drahtlosen  Bodenfeuchtesensoren (EnviroSCAN) und der klimatischen Wasserbilanz (AMBAVModell) zur Bestimmung der Bodenfeuchte bzw. der Bewässerungshöhe.Material und Methoden: EC25-Daten (ECa bei 25° C) wurden unter Verwendung von EM38 und VERIS 3100 Geräten bei Feldkapazität auf einem 16,6 ha großen Feldstück der FAL, Braunschweig, Deutschland, gemessen. Die ECa Daten wurden im Sekundenintervall mit zwei bis drei Metern Messabstand und in Reihenabständen von etwa vier bis sechs Metern gemessen. Zur Erstellung der EC25- und Bodenfeuchte Karten wurde die Software ArcView genutzt, nachdem die Messdaten mit Hilfe des sphärischen Kriging-Verfahren interpoliert wurden. 29 Kalibrierungspunkten wurden mit Hilfe von DGPS lokalisiert, um die beste sensorbasierte Methode zur Abgrenzung der Beregnungsmanagementzonen zu bestimmen. Bodenproben wurden in 0 - 60 cm Tiefe entnommen. Der zweite Bogen der Kreisberegnungsmaschinen wurde für die teilflächenspezifische mobile Tropfbewässerung umgerüstet. Eine kontrollierte Wassermenge konnte, durch Installierung einer Pulstechnik mit Magnetventilen (SV – Solenoid Valve), einem Computer gesteuerten Programm (PLC – Programable Logic Control) und Auswechseln der Düsen durch Siplast Tropfrohre ausgebracht werden. Ein Teil des Feldversuches wurde durch EnviroSCAN Bodenfeuchtesensoren gesteuert und der andere Teil wurde durch das AMBAV-Modell gesteuert, um die Beregnungshöhe zu bestimmen. Die hydraulische Genauigkeit der Siplast Tropfrohre wurde im Labor bei unterschiedlichen Wasserdrücken von 50, 100, 150 und 200 kPa untersucht.Ergebnisse und Diskussion: Die Untersuchung zeigt, dass EC25-Daten von verschiedenen gewerblichen Sensoren auf Grund der unterschiedlichen Gewichtung der Tiefe quantitativ unterschiedlich sind. Das höchste Bestimmtheitsmaß wurde zwischen EM38_h und EM38_v (R2 = 0,55) gefunden. In dieser Arbeit wurde ein gutes Bestimmtheitsmaß zwischen nFK und den VERIS 3100 Werten gefunden. Eine Kalibrierungsgleichung zur Abschätzung der nFK von VERIS 3100-sh zeigte eine hohe Ähnlichkeit zu den nFK Daten auf und hatte das höchste Bestimmtheitsmaß (R2 = 0,77). Die Bestimmtheitsmaße zu EM38-v- und EM38-h-Daten waren niedrig und anscheinend nicht ausreichend, um die räumliche Variabilität der nFK reflektieren zu können. Ein Grund kann die größere Messtiefe von EM38 sein. Sechs Beregnungsmanagementzonen (IMZ1: 99 bis 105, IMZ2: 105 bis 116, IMZ3: 116 bis 127, IMZ4: 127 bis 138, IMZ5: 138 bis 149 und IMZ6: 149 bis 152 mm/60 cm) wurden als optimale Anzahl an Beregnungsmanagementzonen auf dem Versuchsfeld, basierend auf den fuzzy-k-Mittelwerten (Boydell and McBratney, 1999) der zufälligen Einteilung, erkannt. Es wurde gefolgert, dass unter konventioneller Beregnung IMZ1 und IMZ2 überbewässert und IMZ4, IMZ5 und IMZ6 unterbewässert wurden. Das entwickelte Konzept der Pulsbewässerung hat sich als eine zuverlässige Technik bewährt. Die Wasserapplikationsmenge war direkt proportional zur Öffnungsdauer des Ventils, und das System war in der Lage, die Wassermenge entsprechend des Bewässerungspulses zu variieren. Weiterhin war es in der Lage, 15 Reihen mit jeweils 15 Düsen zu steuern. Es gab keine offenkundigen Probleme mit dem gepulsten Wasserabgabesystem in den durchgeführten Feldversuchen. Die Kreisberegnungsmaschinengeschwindigkeit und Pulstechnik zur Bereitstellung verschiedener Wassermengen hatten einen geringen nachteiligen Einfluss auf die Gleichmäßigkeit der Beregnungshöhe. Die Gleichmäßigkeitskoeffizienten wurden durch sinkende Pulszeiten und steigende Kreisberegnungsmaschinengeschwindigkeiten gesenkt. Die Kontrolleinheit war wie erwartet in der Lage die Bodenfeuchtedaten mittels Fernmesstechnik von dem EnviroSCAN Sensor zum zentralen Modem zu senden. Obwohl der EnviroSCANBodenfeuchtigkeitssensor empfindlich und kompliziert zu benutzen und zu kalibrieren ist, wurden die Bodenfeuchtigkeitsdaten fast störungsfrei von der Kontrolleinheit empfangen, gespeichert und zum Mobiltelefon gesendet. Für die Übertragung auf den PC wurde die Software „Kurznachricht Pro 2.2“ genutzt. Anschließend wurde die differenzierte Bewässerungshöhe kalkuliert. Die Ergebnisse zeigen, dass die EnviroSCAN-Sensoren in der Lage sind, den Verlauf der Bodenfeuchte während der Wachstumsperiode erfolgreich zu verfolgen. Weniger gut arbeitet der Sensor, um die Feuchtigkeitsverhältnisse auf sandigen Böden (unter 40 cm Tiefe), trotz bodenspezifischer Kalibrierung zu bestimmen. Während dessen hat sich das AMBAV-Modell als eine Alternative zum kostenintensiven EnviroSCAN erwiesen, das in der Lage ist, die Bodenfeuchtigkeit in der Wurzelzone der Graspflanzen als eine preiswerte und verlässliche Methode zu simulieren. Das Tropfbewässerungssystem sollte auf verlässlichen Testergebnissen und nicht auf Herstellerangaben beruhen. Die Laborexperimente zeigten, dass der Einfluß des Betriebsdrucks auf den Durchfluss am Siplast Tropfer hoch signifikant war und der Tropferdurchfluß stark vom Betriebsdruck abhing. Die CV-Werte wurden auf dem ISO-Standard basierend als gut eingestuft. Aus den Laborexperimenten wurde herausgefunden, dass der in-line Siplast Tropfer eine hohe Ausbringungsgleichmäßigkeit und einen geringen Variationskoeffizienten aufweist. Das Rohrmaterial des Siplast Tropfer ist hart und unflexibel. Es sollte nach weiteren Produkten gesucht werden, die flexibler sind und somit die Kulturen schonen. Die ökonomische Analyse dieser Arbeit zeigt, dass der Kapitalbedarf pro Hektar unter teilflächenspezifische mobile Tropfbewässerung um etwa 338 € und 250 € höher liegt als bei entsprechender Tropfbewässerung in Deutschland und im Iran. Die jährlichen Fixkosten sind geringer, als bei der Tropfbewässerung (111 und 128 [€/(ha x Jahr)] in Deutschland oder im Iran). Obwohl die teilflächenspezifische mobile Tropfbewässerung teurer ist als die Beregnung mit Kreisberegnungsmaschinen, verursacht sie weniger Wasser- und Energiekosten als die Kreisberegnungsmaschinen und hat das Potenzial den Ertrag qualitativ und quantitativ, sowie den landwirtschaftlichen Gewinn zu steigern. Die Ergebnisse zeigen, als wichtige Folge des Verfahrens, dass die teilflächenspezifische mobile Tropfbewässerung nicht notwendiger Weise eine wassersparende Technologie ist, aber es kann den Wasserbedarf optimieren. Der Energiebedarf kann um 70 % und der Wasserbedarf kann um 25 % durch die teilflächenspezifische mobile Tropfbewässerung gegenüber der Kreisberegnungsmaschine gesenkt werden. Die Modellbetrachtungen zeigten, dass durch die teilflächenspezifische mobile Tropfbewässerung im Vergleich mit der konventionellen Kreisberegnungsmaschine bei Salat, Zuckerrübe,  Kartoffel und Erdbeere etwa 575, 378, 462 und 588 kWh Energie pro Hektar gespart werden können.Schlussfolgerung: Die sensorbasierte Messung der elektrischen Leitfähigkeit bei Feldkapazität von nicht salzigen Böden ist eine preiswerte, schnelle und das Bodengefüge nicht zerstörende Alternative, um die Beregnungsmanagementzone räumlich abzugrenzen und ist den Methoden der Bodenprobenahme und Luftbildauswertung vorzuziehen. Feldstudien mit größeren Bewässerungssystemen und Felder mit verschiedenen Bodentypen, Topographie oder Pflanzenbeständen sind weiterhin zu untersuchen, um die Genauigkeit des Bewässerungskonzeptes zu validieren. Vor dem Hintergrund, dass teilflächenspezifische Bewässerung in den Anfängen steckt und eine weitere Verbreitung dieser Technologie zu erwarten ist, könnten die zusätzlichen Kosten für industrielle Ausrüstungsteile gesenkt werden. Beträchtliche Forschung und Entwicklung ist noch nötig, um die möglichen Vorteile der teilflächenspezifischen Beregnung und der Flüssigdüngung besser zu realisieren, um ein positives ökonomisches Ergebnis für den Erzeuger zu sichern.Introduction: A management concept for sustainable utilization and the efficient use of agricultural inputs is known as “Precision Agriculture” (PA). The PA concept, when applied to irrigation management is known as Precision Irrigation (PI). In PI, the need for irrigation may differ between zones of a particular field due to the spatial variation of soil properties or the cropping of different plants on the same field. Spatial variation of total available water content (TAWC) as a primary factor causes spatial variation of irrigation depth and frequency within fields. While moving irrigation systems apply water at constant rates, some areas of the field may receive too much water and others not enough. In this regard, precision irrigation (PI) is capable of applying water in the right place in the right amount at the right time using the right irrigation system. Therefore the key objectives of the present study were a) Delineation of irrigation management zones (IMZs) using sensor-based soil electrical conductivity (ECa) measurement with the aid of EM38 and VERIS 3100, b) Developing and evaluating a precision mobile drip irrigation (PMDI) and c) Evaluating wireless EnviroSCAN sensors and AMBAV-models to measure the soil moisture content.Materials and methods: EC25 data (ECa in 25° C) were collected using EM38 and VERIS 3100 at field capacity on a 16.6 ha non-saline field in the FAL, Braunschweig, Germany. ECa data were obtained in 1-s intervals corresponding to a 2 to 3 m data spacing on transects spaced approximately 4 to 6 m apart. An ArcView (ESRI) software program was used to create the EC25 and TAWC maps after the readings were interpolated using a spherical kriging model. 29 calibration points taken at a depth of 0 - 60 cm depth were located using DGPS based on the ECa spatial variability pattern and with the objective of covering the whole range of ECa values present to determine the best sensor-based method to monitor TAWC. The second span of the centre pivot irrigation machine (CP) was modified to PMDI and controlled for variable-rate water application with a pulsing technique by installing solenoid valves (SV), programmable logic control (PLC) and using a Siplast drop tube instead of sprinklers. One quarter of the study field was controlled by the EnviroSCAN soil moisture sensor and another quarter was controlled by the AMBAV-model to determine irrigation depth. In addition, the hydraulic performance of the Siplast drop tube was evaluated in the laboratory by collecting discharge rates at different pressure of 50, 100, 150 and 200 kPa.Results and discussion: This study showed that, while qualitatively similar, EC25 data obtained with different commercial sensors were quantitatively different because of different depth-weighted response functions. The highest coefficients of determination (R2) were generally found between EM38_h and EM38_v (R2 = 0.55). In this study, a better value of R2 between TAWC and the VERIS 3100 readings was found. The R2 value from VERIS 3100-sh data for TAWC estimation was maximally (0.77) and matched the TAWC data quite well, whereas R2 values to EM38-h and EM38-v data were low and apparently could not adequately reflect the spatial variability of the TAWC due to the higher influence of the EM38 on deeper layers. Six IMZs (IMZ1: 99 to 105, IMZ2: 105 to 116, IMZ3: 116 to 127, IMZ4: 127 to 138, IMZ5: 138 to 149 and IMZ6: 149 to 152 mm/60 cm) were identified based on fuzzy-k-means unsupervised classification as an optimum number of IMZs within the study field. It was concluded that under conventional uniform irrigation, IMZ1 and IMZ2 were over-irrigated, whereas IMZ4, IMZ5 and IMZ6 were under-irrigated. The developed concept of pulse irrigation was a feasible and a viable technique. Water application was directly proportional to the fraction of time the valve was opened as the system was capable of controlling fifteen banks of fifteen nozzles. There were no apparent problems with the pulsing water delivery system where the field tests were conducted. CP speed and the pulsing technique used to deliver variable amounts of irrigation had little adverse effect on system uniformity and the nozzle flow rate. Uniformity coefficients were reduced by decreasing the pulsing level and increasing CP speed. The control unit was able to monitor wireless soil moisture sensors via radio telemetry and communication from the EnviroSCAN sensors to the central ISM modem, which worked as expected. Although the EnviroSCAN soil moisture sensor was found to be delicate and intricate to use and calibrate, soil moisture data were easily sent from the control unit and received by the mobile phone and then transferred to an Excel table on a computer using easy and suitable “Kurznachricht Pro 2.2” software to calculate irrigation depth. The results suggest that EnviroSCAN sensors are able to follow the general trends successfully as soil water content measured by sampling changed during the growing season, but are not a reliable sensor to repeat moisture conditions on sandy soils (at greater depths than 40 cm ) despite its soil-specific calibration. Meanwhile, an AMBAV model as a cheap and reliable alternative instead of the expensive EnviroSCAN sensor was capable of determining and simulating soil moisture in the root zone of grass crops. Drip irrigation design should be based on reliable data sets, but not on data supplied by the manufacturer. The laboratory experiments showed that the effect of operating pressure on the discharge of Siplast emitters was highly significant and the emitter discharge was strongly influenced by the operating pressure, while some deviation from the design flow rate claimed by the manufacturer occurred. CV values were classified as good, on the basis of the ISO standard. Based on the laboratory experiments, it was found that the in-line Siplast emitter has high emission uniformity and a low coefficient of variation. In spite of high emission uniformity and a low coefficient of variation of the Siplast drop tube, it must consist of hard and inflexible material. To have a shorter drip tube installed on CP, using an in-line drop tube lateral with higher emitter discharge at low operation pressure and less emitter distance is proposed. The economic analysis of this study showed that although capital requirement per hectare under PMDI is about € 338 and € 250 more than for drip irrigation in Germany and Iran, respectively, it causes perceptibly less annual fixed cost than drip irrigation (111 and 128 [€/(ha x year)] cheaper than drip irrigation in Germany and Iran, respectively). Although PMDI causes more annual fixed expenses than CP irrigation, it has less total irrigation cost per hectare and year than CP and drip irrigation and has the potential benefit to increase yield quantity, quality and farming benefit. The results showed as an important policy implication that PMDI is not necessarily a water saving technology and it does not necessarily involve a reduction in total water use, but that it can optimize water consumption. Given a reduction of energy and water consumption of 70 % and 25 %, respectively, achieved by the PMDI as compared with the CP, results showed that about 575, 378, 462 and 588 kWh energy per hectare can be saved by PMDI in comparison with the conventional CP irrigation of lettuce, sugar beet, potato and strawberry.Conclusion: Sensor-based ECa measurement at F.C. in non-saline soil can be used as a cheap, rapid and non-destructive alternative to delineate IMZ instead of using soil sampling and aerial photography methods. Field studies using larger irrigation systems and fields with different soil types, topographic or crop characteristics are recommended to validate the precision irrigation concept and to realize and ensure a positive net economic return to the producer. With due attention to the success of PI in the early stages and developments in industrial technology in the coming years, the extra costs of industrial accessories could be minimised

    Precision Agriculture Technology for Crop Farming

    Get PDF
    This book provides a review of precision agriculture technology development, followed by a presentation of the state-of-the-art and future requirements of precision agriculture technology. It presents different styles of precision agriculture technologies suitable for large scale mechanized farming; highly automated community-based mechanized production; and fully mechanized farming practices commonly seen in emerging economic regions. The book emphasizes the introduction of core technical features of sensing, data processing and interpretation technologies, crop modeling and production control theory, intelligent machinery and field robots for precision agriculture production

    Data Acquisition Applications

    Get PDF
    Data acquisition systems have numerous applications. This book has a total of 13 chapters and is divided into three sections: Industrial applications, Medical applications and Scientific experiments. The chapters are written by experts from around the world, while the targeted audience for this book includes professionals who are designers or researchers in the field of data acquisition systems. Faculty members and graduate students could also benefit from the book
    corecore