Variable Spray Research Articles

Reconfigurability Evaluation of Multifunctional Intelligent Boom Sprayer Based on Fuzzy Comprehensive Evaluation

Multifunctional intelligent boom sprayer is a development direction of boom sprayers, and it could satisfy needs of precision and variable spraying and achieve aims of sustainable development of pesticide spraying, ecological protection, and efficient plant protection by reconfiguring its structures. Therefore, the evaluation of multifunctional intelligent boom sprayer reconfigurability has a role in improving product reconfigurability while reducing product function redundancy and production costs and reducing product function redundancy and production cost. In order to comprehensively evaluate the reconfigurability of a multifunctional intelligent boom sprayer, this paper established an evaluation index system and realized the evaluation process by using fuzzy comprehensive evaluation, analytic hierarchy process, and validity test. The evaluation result would avail to directly and effectively guide product optimization and upgrade process in accordance with quantitatively analyzed evaluation indexes of intelligent boom sprayer reconfigurability by using mathematical methods such as analytic hierarchy process and validity test in evaluation process. The index system was formed from six components, which were key design information, quality, cost, efficiency, intelligence, and operational capability. Index weights were calculated by the analytic hierarchy process. Finally, a multifunctional shiftable boom intelligent sprayer was evaluated for product reconfigurability improvements by using the evaluation method. Reconfigurability evaluation result of the multifunctional shiftable boom intelligent sprayer belonged to "good" evaluation interval by the calculation of formulas. There was further room to improve product reconfigurability, as the membership degree in the “good” evaluation interval was below 0.5. The study could provide a scientific basis for improving the reconfigurability, technical performance, and operation quality of products in intelligent boom sprayer design. In addition, it may be possible to decrease the arbitrary nature of subjective design factors and support economic and ecological goals when businesses upgrade products.

Large eddy simulation of a partially pre-vaporized ethanol reacting spray using the multiphase DTF/flamelet model

Spray reactive flow finds application in various technical devices, and due to the complex nature, their optimization is very challenging, requiring proper modeling of turbulence/chemistry interactions as well as of the contribution from spray evaporation. This work presents a study of sub-grid scale combustion models, where relevant assumptions on multiphase coupling and their effects are analyzed in detail. For this purpose, two different flamelet approaches, i.e. progress variable spray flamelet and multi-regime gas flamelet are examined in an implementation coupled with the dynamic thickened flame model, along with which the impact of inlet inhomogeneities condition and droplet evaporation taking into account internal temperature gradient is also investigated. The numerical evaluation is carried out in large eddy simulations of a benchmark ethanol spray flame with partial pre-vaporization, where an Eulerian-Lagrangian numerical framework is adopted. The analysis demonstrated that the flame dynamics under consideration is governed by a close coupling between spray evaporation, turbulent dispersion and unsteady flame propagation at upstream shear layers. Results show that the spray flamelets built from counterflow partially-premixed spray flames achieved a better agreement with experiments, capturing the flame structure in terms of gas-phase temperature, OH mass fraction as well as spray statistics.

Design of Parallel Injection Online Compound Control System for Liquid and Water Solvent

The variable spraying technology includes premixed drugs and online mixed drugs. The operators need to be in contact with pesticides in the premixed operation.It is harmful to the operators.Meanwhile it has the disadvantages of large amount of pesticides and environmental pollution. In order to solve this problem, an injection-type online mixed drug spray control system for variable spraying and width control was designed.In this paper, a novel injection-type online mixing pesticide control system is designed to solve this problem for variable spray and width control. The mixing ratio of water solvent flow and the pesticide flow is adjusted in real-time spraying by using a sprayer equipped with the proposed online mixing pesticide control system according to the specific prescription map. The concentration of pesticide at the nozzle is controllable consequently. The real-time dynamic response test and the steady state error test were carried out during the pesticide injection. Results show that the steady state error of the proposed system with using DMC strategy is no more than 5%. The uniformity of the mixed pesticide was tested under different mixing ratios of the system, and the calculated spatial variation coefficient is less than 5%. It shows that the injection-type online mixing pesticide control system has better mixing uniformity.

System Model for Smart Precision Farming for High Crop Yielding

The meticulous application of Sensing and Machine Learning technology in precision farming has optimized the irrigation resources, improved the quality of crops, minimizes the risk of diseases in fields and reduces the energy consumption. The proper crop management and proper placement of seeds also controls the crop diseases as well as reduces the expenses of irrigation and pesticides etc. The diseases that can be caused in various stages are monitored by proper visual identification of the disease and the precise amount and position of spraying medicine for that plant is calculated. There is a need to build the perfect plans for the water irrigation in order to save the water (around 60% to 70%). The goal is to build solution which would reduce the cost per hectare and could also increase the yields to make farming more profitable. The proposed Smart system optimizes the crop yield by providing, yield mapping, yield monitoring, weed mapping, variable rate fertilizer, variable spraying etc. The System uses drones to gather the information for calculating the crop patterns and analyzing the field so that more area can be captured for the crop plantation in later model.

Design of Plant Protection UAV Variable Spray System Based on Neural Networks.

Recently, unmanned aerial vehicles (UAVs) have rapidly emerged as a new technology in the fields of plant protection and pest control in China. Based on existing variable spray research, a plant protection UAV variable spray system integrating neural network based decision making is designed. Using the existing data on plant protection UAV operations, combined with artificial neural network (ANN) technology, an error back propagation (BP) neural network model between the factors affecting droplet deposition is trained. The factors affecting droplet deposition include ambient temperature, ambient humidity, wind speed, flight speed, flight altitude, propeller pitch, nozzles pitch and prescription value. Subsequently, the BP neural network model is combined with variable rate spray control for plant protection UAVs, and real-time information is collected by multi-sensor. The deposition rate is determined by the neural network model, and the flow rate of the spray system is regulated according to the predicted deposition amount. The amount of droplet deposition can meet the prescription requirement. The results show that the training variance of the ANN is 0.003, and thus, the model is stable and reliable. The outdoor tests show that the error between the predicted droplet deposition and actual droplet deposition is less than 20%. The ratio of droplet deposition to prescription value in each unit is approximately equal, and a variable spray operation under different conditions is realized.

TRIBOLOGICAL PROPERTIES OF Al2O3 + TiO2 COATINGS MANUFACTURED BY PLASMA SPRAYING

In the paper the results of tribological, microscopic, and mechanical research of Al2O3 + TiO2 coatings manufactured by plasma spraying are presented. The feeding material was a powder Al2O3 + 13 wt.% TiO2 (Metco 6221, OerlikonMetco) with grain size – 45 ± 15 μm. The cylinder substrates made from stainless steel (X5CrNi18-10) had a diameter equal to 25 mm and 2 mm of thickness. The variable spray parameters were plasma torch velocity in terms of substrate and spray distance. The morphology of obtained coatings was tested by scanning electron microscope (SEM), and the microstructure was investigated by light optical microscopy (LOM) and SEM. The results of mechanical properties examinations revealed the dependence of the microhardness and fracture toughness on the spray parameters. Tribological examinations were made in the ball-on-disc mode in technical dry friction conditions. Two loads were used, 5 N and 10 N. Based on the carried out tests, it could be concluded that a shorter spray distance and a reduction of the torch velocity allows one to achieve a more compact structure, which is characterized by good adhesion at the coating-substrate interface (in range from 11 to 14 MPa) and good wear resistance.

Uniformity Analysis of Unmanned Aerial Application with Variable Rate Spray System

Uniformity Analysis of Unmanned Aerial Application with Variable Rate Spray System

Design and Experiment of a Variable Spray System for Unmanned Aerial Vehicles Based on PID and PWM Control

Unmanned aerial vehicle (UAV) variable-rate spraying technology, as the development direction of aviation for plant protection in the future, has been developed rapidly in recent years. In the actual agricultural production, the severity of plant diseases and insect pests varies in different locations. In order to reduce the waste of pesticides, pesticides should be applied according to the severity of pests, insects and weeds. On the basis of explaining the plant diseases and insect pests map in the target area, a pulse width modulation variable spray system is designed. Moreover, the STMicroelectronics-32 (STM32) chip is invoked as the core of the control system. The system combines with sensor technology to get the prescription value through real-time interpretation of prescription diagram in operation. Then, a pulse square wave with variable duty cycles is generated to adjust the flow rate. A closed-loop Proportional-Integral-Derivative (PID) control algorithm is used to shorten the time of system reaching steady state. The results indicate that the deviation between volume and target traffic is stable, which is within 2.16%. When the duty cycle of the square wave is within the range of 40% to 100%, the flow range of the single nozzle varies from 0.16 L/min to 0.54 L/min. Variable spray operation under different spray requirements is achieved. The outdoor tests of variable spray system show that the variable spray system can adjust the flow rapidly according to the prescription value set in the prescription map. The proportion of actual droplet deposition and deposition density in the operation unit is consistent with the prescription value, which proves the effectiveness of the designed variable spray system.

Removal of acetone from air emissions by biotrickling filters: providing solutions from laboratory to full-scale

A full-scale biotrickling filter (BTF) treating acetone air emissions of wood-coating activities showed difficulties to achieve outlet concentrations lower than 125 mg C m−3, especially for high inlet concentrations and oscillating emissions. To solve this problem, a laboratory investigation on acetone removal was carried out simulating typical industrial conditions: discontinuous and variable inlet concentrations and intermittent spraying. The results were evaluated in terms of removal efficiency and outlet gas emission pattern. Industrial emissions and operational protocols were simulated: inlet load up to 70 g C m−3 h−1 during 2 cycles of 4 h per day and intermittent trickling of 15 min per hour. The outlet gas stream of the pollutant was affected by intermittent spraying, causing a fugitive emission of pollutant. Complete removal efficiency was obtained during non-spraying. Average removal efficiencies higher than 85% were obtained, showing the feasibility of BTF to treat acetone. The outlet gas stream showed a clear dependence on the pH of the trickling liquid, decreasing the removal at pH < 5.5. Thus, a proper control of alkalinity, with regular NaHCO3 addition, was required for successful operation. The laboratory findings were fruitfully transferred to the industry, and the removal of acetone by full-scale BTF was improved.

Application of variable spray technology in agriculture

As one of the representatives of precision agriculture, variable spray technology has made great progress in the development and application of technology in recent years. This paper describes the principle and characteristics of variable spray technology, and outlines the development results of variable spray technology in target detection, automatic control, and spray application. In terms of target detection technology, automatic target spray technology based on real-time sensors and automatic target spray technology based on geographic information technology are introduced; In control technology, pressure control flow regulation technology, PWM control flow regulation technology and liquid chemical concentration mixed regulation system are described. In the field of spray technology, it mainly describes the research and application of variable nozzles and forecasts the application prospect and development direction of variable spray technology.

The effect of coarse-droplet spraying with double flat fan air induction nozzle and spray volume adjustment model on the efficiency of fungicides and residues in processing tomato

The study was conducted for the purpose of improving the application of fungicides against potato late blight (Phytophthora infestans (Mont.) de Bary) (PLB) in processing tomato. The usability of coarse spray quality with double flat fan air induction IDKT12003 nozzle and the impact of fixed and variable spray volume and adjuvants during alternate application of azoxystrobin and chlorothalonil were analysed on the basis of plant infestation and fungicide residues. The variable spray volume was calculated based on the number of leaves on a plant. The study was conducted during three vegetation seasons. Spraying of plants with significantly flattened canopies during the peak of the fructification season using an IDKT12003 nozzle was as effective as in the case of fine spraying performed with an XR11003 nozzle and facilitated the increase of fungicides residue. In the case of plants with high-spreading canopy at the beginning of fructification, XR11003 nozzle favoured the reduction of PLB infestation. Both spray volume adjustment systems enabled the same level of protection of tomato against PLB, which could result from alternate application of systemic and contact fungicides. Polyalkyleneoxide modified heptamethyltrisiloxane adjuvant, which causes siginificant increase in wetting and droplet spreading, facilitated the reduction of tomato PLB infestation during the application of fungicides using an IDKT12003 nozzle.

Performance test and parameter optimization of variable spraying liquid fertilizer machine

The performance test and parameter optimization of variable spraying liquid fertilizer machine was conducted in this research for the uniform spraying of foliar fertilizer. A crop protection of high-clearance tractor with a variable sprayer was used in the experiment. According to the parameter design, three factors and three levels of test were performed based on the Box-Behnken center-united experimental design principles. The performance tests were combined with response surface methodology to analyze spray parameters such as machine walking speed, spray flow rate and plot distance test which would influence Droplet distribution uniformity. A mathematical model was established by using Design-Expert 8.0 software, and the model was analyzed to obtain the optimal combination of spray parameters. The optimized spray parameter combination is: machine walking speed is 4.5km/h, the spray flow rate is 375L/hm2, and the distance between the plots is 3m. Under this condition, the minimum variation coefficient of droplet distribution is 10.759%, and the relative error is 9.1% compared with the model prediction value of 9.78%. The results of the study can provide operators with reasonable operating conditions when fertilizing.

Attenuation of thermal radiation through water mist

This article focuses on the interaction of thermal radiation with water droplets and the creation of water mist for the purpose of evaluating the decrease of heat flux when positioning a water curtain of various parameters between a radiation source and a radiometer. The change of water curtain parameters, affecting the passing through of thermal radiation, was performed using five nozzles with a variable spray characteristics. For the respective nozzles the attenuation of thermal radiation was determined and the thermal radiation transmittance was calculated. Water mist was created using a high‐pressure pump and nozzles with a different size of the orifice. The measurement of droplet size was performed using the time‐shift technique. The Omegalux radiant panel was used as the radiation source and the Hukseflux SBG01 radiometer with a working range of 0–5 kW.m−2 was used as the detector. © 2017 American Institute of Chemical Engineers Process Process Saf Prog 37:18–24, 2018

Plausibility of variable coverage high range spraying: Experimental studies of an externally air-assisted electrostatic nozzle

A system for spraying liquid pesticides to crops and orchards combines an induction based electrostatic nozzle and externally air-assisted manually controlled mechanical device. In this paper, an innovative concept has been executed for variable coverage high range spraying through an external air-assistance system, which supplies compressed air to assist the finely divided charged liquid droplets by farming a virtual covering around the fine mist of liquid spray. External air-assistive device consists of movable support for air supplies whose variation of cone angle is from parallel spray center line (0°) to maximum spray cone angle (25°). This provides a means to transport electrostatically charged fine mist of liquid droplets to intended target with variable spray coverage angle of target, applicable in high wind and transient conditions with enhanced performance without degradation of charge-to-mass ratio. The results of applied induction electrification process were characterized by a charge-to-mass ratio as a function of applied voltage, target distance, and wind current. It has been shown that the wind current has an insignificant (p value=0.021615) and significant (p value=0.000325) effects on the performance of the electrostatic nozzle at 99% confidence level with and without external air-assistive mechanical device respectively. The experimental results are in good agreements with proposed concept.

Multi-type Feature Fusion Technique for Weed Identification in Cotton Fields

Weed identification is core of precision variable spray technology and weed information management system. Single type features are difficult to identify multi-class weeds in cotton fields. In this paper, multi-type feature fusion technique for weed identification is proposed. Firstly, multi-type features are extracted. In color feature extraction, FMS, SMS and TMS in HSI are extracted by color moment. In shape feature extraction, REC, RWL, CIR and SPH are extracted by geometric parameter method. In texture feature extraction, ASM, CON and COR are extracted by GLCM. Secondly, because feature dimension is too large, principle component analysis is used to reduce dimension to extract new features including COR, ASM, REC and two components. Finally, three comparative experiments including identification of five kinds of weeds, three kinds of weeds and two kinds of weeds are carried out. Experimental results show that method proposed in this paper is superior to state of the art and is suitable for identification of multi-class weeds. This method can also be applied in identifying weeds in other fields.

A Tool for Predicting the Dynamic Response of Biotrickling Filters for VOC Removal

This article presents the development of a MATLAB® computer program to simulate the performance of biotrickling filters. Since these filters behave differently during spraying and nonspraying cycles, the presented simulation tool is built on top of a mathematical description of each situation. The resulting variable-structure model is then used as the basis for simulation experiments. The model presented herein represents the first attempt to take into account the variable spraying pattern usually found in industrial installations. Overall, the software is flexible and easy to use, allowing the user to specify the emission concentration pattern, the gas concentration pattern, as well as the spraying cycle periods for up to two different emission patterns per day. The model is able to predict experimental data from a biotrickling filter treating isopropanol under intermittent conditions of loading and spraying. Simulation examples are then provided to study the effect of variable inlet concentrations and gas flow rates.

Effects of Operating Parameters for Dynamic PWM Variable Spray System on Spray Distribution Uniformity

Abstract: A dynamic PWM (Pulse Width Modulation) variable spray experiment platform was built up to study the spray distribution characteristics of PWM spray progress. The homogeneity of single nozzle dynamic spraying was evaluated based on this platform under different experiment condition. Carmine solution concentration-absorbance technology was adopted to get the CV (Coefficient of Variation) value of percent area spray coverage. RSM (Response Surface Methodology) with three variables including frequency, duty cycle of PWM control signal and forward velocity of spray was employed to study the effects of these three factors on dynamic spray distribution uniformity. Compared with previous common study of static spraying, the research on this paper can evaluate the actual spray distribution uniformity of dynamic spraying more accurately. Moreover, the platform and the research method can provide references for the settings of PWM variable-rate spray operation parameters in practical plant protection work.

Development of a Variable Rate Spray Controller for an Unmanned Aerial Application

Development of a Variable Rate Spray Controller for an Unmanned Aerial Application

Study of Pressure Characteristics in PWM Controlled Variable Rate Spraying System

In PWM controlled variable rate spraying system, spraying quantities were regulated by fast switching solenoid valves. However, hydraulic impacts were generated by these fast switching solenoid valves in pipe system, which affected stabilities of spraying quantities and atomization characteristics. In order to study pressure changing regularities when solenoid valves operated, then to design a pressure controller to improve spraying qualities in PWM controlled variable rate spraying system, Fluent was used to simulate pressure characteristics in the pipe system and pressure curves were drawn under the following 3 working conditions, solenoid valve opening, closing, and switching continuously with 5 Hz frequency and 50% duty ratio. Related experiments were carried out to test real pressure signals in the pipe based on a PWM controlled variable rate spraying system. Relative errors between simulation results and experiment results were below 10%. Thus, this simulation model of PWM controlled variable rate spraying system in Fluent was reliable to simulate pressure characteristics in the pipe in other common working conditions, and which contributed to design pressure controller and to optimize the whole PWM controlled variable rate spraying system.

Use of a Variable Rate Spray Bar to Minimize Wheel Path Bleeding for Asphalt-Rubber Chip Seal Applications

Chip seals constructed in areas with a combination of high truck traffic volume and high climatic temperatures are susceptible bleeding in the wheel paths and raveling in nonwheel path areas. These failures arise from inherent differences in traffic loading in the two areas. Addressing this problem calls for the binder application rate for the two regions to be varied and using asphalt binders with a high stiffness at high temperatures to prevent bleeding. No well-established design methods that yield a different binder application rate exists. Although equipment for applying variable binder rates exists, there is limited performance data, and no guidelines for calibrating the equipment in the field exist. This paper presents the findings of field studies in which both uniform and variable application rates were used to construct asphalt-rubber chip seals in California. The results show that using different binder application rates in and out of wheel paths can mitigate bleeding and raveling. The paper also presents a new field calibration test method for both conventional and variable rate distributor spray bars.