scholarly journals Effect of Droplet Size Parameters on Droplet Deposition and Drift of Aerial Spraying by Using Plant Protection UAV

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 195 ◽  
Author(s):  
Shengde Chen ◽  
Yubin Lan ◽  
Zhiyan Zhou ◽  
Fan Ouyang ◽  
Guobin Wang ◽  
...  
Keyword(s):  
Droplet Size ◽  
Drift Rate ◽  
Plant Protection ◽  
Buffer Zone ◽  
Target Area ◽  
Droplet Deposition ◽  
Factors Affecting ◽  
Median Diameter ◽  
Pesticide Drift ◽  
Aerial Spraying

In the field of pesticide spraying, droplet size is one of the most important factors affecting droplet deposition and drift. In order to study the effect of different droplet size parameters on droplet deposition distribution and drift of aerial spraying by using plant protection UAV, an aerial spraying test with the same spraying rate and different size droplets in rice canopy was carried out by using multi-rotor unmanned aerial vehicles (UAV) and four TEEJET nozzles with different orifice sizes (these droplets with a volume median diameter (VMD) of 95.21, 121.43, 147.28, and 185.09 μm, respectively), and the deposition distribution and penetration of droplets in the target area and the drift distribution of droplets in the non-target area were compared and analyzed. The results showed that the deposition distribution and penetration of droplets in the target area and the drift distribution of droplets in the non-target area were influenced by the droplet size. The droplet deposition rate in the upper and lower rice canopies were increased in the target area with the increase of droplet size. The penetration results of droplets also increased with the increase of droplet size, and that of droplets with a VMD of 185.09 μm was the best, reaching 38.13%. The average values of the cumulative drift rate of droplets in the rice canopy in the four tests were 73.87%, 50.26%, 35.91%, and 23.06%, respectively, and the cumulative drift rate and the drift distance of droplets decreased with the increase of droplet size, which indicated that the increase of droplet size can effectively reduce droplet drift. It demonstrated that the droplet size is one of the most important factors affecting droplet deposition and drift for pesticide spraying by plant protection UAV, and for the application of plant protection UAV with extra-low volume spraying, the use of droplets with VMD less than 160 μm should be avoided and a more than 10 m buffer zone should be considered downwind of the spraying field to avoid drug damage caused by pesticide drift. The results have fully revealed the effect of droplet size parameters on droplet deposition and drift of aerial spraying. Moreover, the influence of the wind field below the rotors on the distribution of droplet deposition was surmised and analyzed from the perspective of plant protection UAV. It is important for optimizing the droplet parameters of aerial spraying, increasing the spraying efficiency, and realizing precision agricultural aviation spray.

scholarly journals Influence of the Downwash Wind Field of Plant Protection UAV on Droplet Deposition Distribution Characteristics at Different Flight Heights

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2399
Author(s):  
Yubin Lan ◽  
Shicheng Qian ◽  
Shengde Chen ◽  
Yingjie Zhao ◽  
Xiaoling Deng ◽  
...  
Keyword(s):  
Wind Field ◽  
Plant Protection ◽  
Three Dimensional ◽  
Distribution Characteristics ◽  
Droplet Deposition ◽  
Control Effect ◽  
Flight Height ◽  
Improvement Effect ◽  
Crop Disease ◽  
Aerial Spraying

The aerial spraying of pesticides by plant protection unmanned aerial vehicles (UAV) is a process in which the spray droplet deposition on target sites occurs under the influence of the downwash wind field. The downwash wind field is the most important factor affecting droplet deposition distribution characteristics in an aerial spray. To understand the mechanism of the downwash wind field, spray tests were conducted at different flight heights by using a DJI UAV, and the downwash wind field in the three-dimensional direction (X-directional wind, Y-crosswind, and Z-vertical wind) was measured by using a wind speed measurement system for UAV. Combined with the droplet deposition of aerial spray, the distribution characteristics of the downwash wind field and the influence of the downwash wind field on droplet deposition were studied. The results showed that it had obvious differences in the distribution of the downwash wind field for UAV at different flight heights. As the flight height increases, the downwash wind field in X-direction and Z-direction showed a strong to weak trend, while the downwash wind field in Y-direction showed an opposite trend. In addition, it was found that the downwash wind field in Y-direction and Z-direction both have a significant influence on droplet deposition. With the increase of flight height, the change of the downwash wind field led to a gradual decrease in droplet deposition in the effective spray area, and droplets deposited more uniformly. For the DJI T16 plant protection UAV in this test, the optimal flight height was 2.0 m, and the downwash wind field had a better improvement effect on droplet deposition. Therefore, in order to make full use of the downwash wind field of UAV, the appropriate flight height should be selected to improve droplet deposition of liquid pesticide and achieve a better control effect for crop disease and pests when UAV is used for aerial spray operations in the field. This study revealed the influence mechanism of the downwash wind field on droplet deposition of aerial spray, and proposed appropriate operation parameters from the perspective of practical operation. It was expected to provide data support for improving the operation quality of aerial spraying and the formulation of field operation specifications.

scholarly journals Quantitative Analysis of Droplet Size Distribution in Plant Protection Spray Based on Machine Learning Method

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 175
Author(s):  
Yong He ◽  
Jianjian Wu ◽  
Haoluan Fu ◽  
Zeyu Sun ◽  
Hui Fang ◽  
...  
Keyword(s):  
Machine Learning ◽  
Size Distribution ◽  
Droplet Size ◽  
Evaluation Method ◽  
Plant Protection ◽  
Droplet Size Distribution ◽  
Support Vector ◽  
Median Diameter ◽  
Deposition Uniformity ◽  
Main Factor

Spray droplet size is the main factor affecting the deposition uniformity on a target crop. Studying the influence of multiple factors on the droplet size distribution as well as the evaluation method is of great significance for improving the utilization of pesticides. In this paper, volume median diameter (VMD) and relative span (RS) were selected to evaluate the droplet size distribution under different hollow cone nozzles, flow rates and spatial positions, and the quantitative models of VMD and RS were established based on machine learning methods. The results showed that support vector regression (SVR) had excellent results for VMD (Rc = 0.9974, Rp = 0.9929), while multi-layer perceptron (MLP) had the best effect for RS (Rc = 0.9504, Rp = 0.9537). The correlation coefficient of the prediction set is higher than 0.95, showing the excellent ability of machine learning on predicting the droplet size distribution. In addition, the visualization images of the droplet size distribution were obtained based on the optimal models, which provided intuitive guidance for realizing the uniform distribution of pesticide deposition. In conclusion, this study provides a novel and feasible method for quantitative evaluation of droplet size distribution and offers a theoretical basis for further determining appropriate operation parameters according to the optimal droplet size.

Developed jet-centrifugal spray devices: experimental testing to establish the possibility of their application in plants spraying technologies

2020 ◽  
Vol 1 (102) ◽  
pp. 30-41
Author(s):  
S. Vambol ◽  
N.A. Khan ◽  
A.H. Khan ◽  
M. Kiriyenko ◽  
L. Borysova ◽  
...  
Keyword(s):  
Droplet Size ◽  
Plant Protection ◽  
Experimental Testing ◽  
Maximum Efficiency ◽  
Design Parameters ◽  
Droplet Deposition ◽  
Deposition Area ◽  
Protection Agent ◽  
Different Diameters

Purpose: Experimentally substantiate the possibility of using the developed jet-centrifugal spraying device in plants spraying technologies. Design/methodology/approach: Many years of experience in creating spraying devices for solving practical problems in various industries made it possible to propose a design diagram of a single-phase jet-centrifugal spraying device. The tests were aimed at achieving device characteristics that are acceptable for use in plants spraying technologies such as jet coverage distance, droplet size and droplet deposition area (spray diameter). For this a several tests series with different design parameters was done. Before testing, the tightness of the device body was checked (the holding time under a pressure of 1 MPa is not less than 2 minutes). Findings: Based on the obtained jet coverage distance, droplet size and droplet deposition area, the developed spray device of some modifications can be used in plants spraying technologies. However, it is necessary to determine the quality of the spray device according to the BCPC classification; the device should be tested with some insecticides, fungicides and in plants spraying technologies to develop recommendations for their use. Research limitations/implications: The influence of design features of developed jetcentrifugal spray device on the jet coverage distance, droplet size and droplet deposition area was studied. Practical implications: The results obtained are useful in the field of improving national plants spraying technologies in order to improve the quality of the plant protection agent application and reduce the loss of the drug into the environment. Originality/value: To ensure maximum efficiency the proposed design of the jetcentrifugal spray device can be upgraded directly by the farmer by installing interchangeable nozzles that are attached with a union nut. Replaceable nozzles have different diameters and modifications and can be selected depending on the required jet coverage distance and spraying dispersion according to the current environmental conditions.

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

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1112 ◽  
Author(s):  
Sheng Wen ◽  
Quanyong Zhang ◽  
Xuanchun Yin ◽  
Yubin Lan ◽  
Jiantao Zhang ◽  
...  
Keyword(s):  
Neural Network ◽  
Network Model ◽  
Neural Network Model ◽  
Bp Neural Network ◽  
Plant Protection ◽  
Back Propagation ◽  
Droplet Deposition ◽  
Factors Affecting ◽  
Spray System ◽  
Bp Neural Network Model

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.

scholarly journals WSN-Assisted UAV Trajectory Adjustment for Pesticide Drift Control

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5473 ◽  
Author(s):  
Jie Hu ◽  
Tuan Wang ◽  
Jiacheng Yang ◽  
Yubin Lan ◽  
Shilei Lv ◽  
...  
Keyword(s):  
Wind Speed ◽  
Prediction Model ◽  
Wind Direction ◽  
Raspberry Pi ◽  
Target Area ◽  
Droplet Deposition ◽  
Communication Latency ◽  
Pesticide Drift ◽  
Adjustment System ◽  
Drift Control

Unmanned Aerial Vehicles (UAVs) have been widely applied for pesticide spraying as they have high efficiency and operational flexibility. However, the pesticide droplet drift caused by wind may decrease the pesticide spraying efficiency and pollute the environment. A precision spraying system based on an airborne meteorological monitoring platform on manned agricultural aircrafts is not adaptable for. So far, there is no better solution for controlling droplet drift outside the target area caused by wind, especially by wind gusts. In this regard, a UAV trajectory adjustment system based on Wireless Sensor Network (WSN) for pesticide drift control was proposed in this research. By collecting data from ground WSN, the UAV utilizes the wind speed and wind direction as inputs to autonomously adjust its trajectory for keeping droplet deposition in the target spraying area. Two optimized algorithms, namely deep reinforcement learning and particle swarm optimization, were applied to generate the newly modified flight route. At the same time, a simplified pesticide droplet drift model that includes wind speed and wind direction as parameters was developed and adopted to simulate and compute the drift distance of pesticide droplets. Moreover, an LSTM-based wind speed prediction model and a RNN-based wind direction prediction model were established, so as to address the problem of missing the latest wind data caused by communication latency or a lack of connection with the ground nodes. Finally, experiments were carried out to test the communication latency between UAV and ground WSN, and to evaluate the proposed scheme with embedded Raspberry Pi boards in UAV for feasibility verification. Results show that the WSN-assisted UAV trajectory adjustment system is capable of providing a better performance of on-target droplet deposition for real time pesticide spraying with UAV.

scholarly journals Opportunities and Possibilities of Developing an Advanced Precision Spraying System for Tree Fruits

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3262
Author(s):  
Md Sultan Mahmud ◽  
Azlan Zahid ◽  
Long He ◽  
Phillip Martin
Keyword(s):  
Travel Speed ◽  
Crop Productivity ◽  
Target Area ◽  
Factors Affecting ◽  
Air Jet ◽  
Spraying Parameters ◽  
World Food Supply ◽  
Significant Damage ◽  
Tree Fruits ◽  
Precision Spraying

Reducing risk from pesticide applications has been gaining serious attention in the last few decades due to the significant damage to human health, environment, and ecosystems. Pesticide applications are an essential part of current agriculture, enhancing cultivated crop productivity and quality and preventing losses of up to 45% of the world food supply. However, inappropriate and excessive use of pesticides is a major rising concern. Precision spraying addresses these concerns by precisely and efficiently applying pesticides to the target area and substantially reducing pesticide usage while maintaining efficacy at preventing crop losses. This review provides a systematic summary of current technologies used for precision spraying in tree fruits and highlights their potential, briefly discusses factors affecting spraying parameters, and concludes with possible solutions to reduce excessive agrochemical uses. We conclude there is a critical need for appropriate sensing techniques that can accurately detect the target. In addition, air jet velocity, travel speed, wind speed and direction, droplet size, and canopy characteristics need to be considered for successful droplet deposition by the spraying system. Assessment of terrain is important when field elevation has significant variability. Control of airflow during spraying is another important parameter that needs to be considered. Incorporation of these variables in precision spraying systems will optimize spray decisions and help reduce excessive agrochemical applications.

​Factors Affecting Production of Important Pulse Crops in Rajasthan: A Cobb Douglas Analysis

2021 ◽  
Author(s):  
Devendra Kumar Verma ◽  
Hari Singh ◽  
Girdhari lal Meena ◽  
Jitendra Suman ◽  
Sharad Sachan
Keyword(s):  
Production Function ◽  
Irrigation Water ◽  
Agricultural Sector ◽  
Plant Protection ◽  
Secondary Data ◽  
Protection Measures ◽  
Factors Affecting ◽  
Pulse Crops ◽  
Human Labour ◽  
Negative Effect

Background: Pulses are one of the most important food crops grown globally owed to their higher protein content. It also accounts for larger financial gains of the agricultural sector by amounting for a large part of the exports. The present study was carried out to determine the factors affecting production of pulse crops in Rajasthan. Methods: This paper based on secondary data collected over the years i.e. from 2000-01 to 2017-18. The Cobb-douglas production function was used to the observation for the estimation of elasticity of selected variables contributing to the production of pulses in Rajasthan state, Cobb douglas type production function was employed to assess the effects of seed, fertilizer, manure, human labour, irrigation, bullock labour and plant protection measures on pulses production. Result: The results from the study have shown that fertilizer and plant protection measures were positively significant while the variable corresponding to irrigation water was negatively significantly affecting the gram production. The variables such as seed and irrigation water were found positive and significant, while plant protection measures had significant negative effect on black gram production. Only two variables namely, fertilizer and irrigation water were found positively significant out of estimating production function of green gram.

Factors affecting agricultural students’ loyalty: a study at Nong Lam University Ho Chi Minh City

2021 ◽  
Vol 66 (1) ◽  
pp. 78-87
Author(s):  
Viet Vo Van ◽  
Thu Le Anh
Keyword(s):  
Service Quality ◽  
Student Satisfaction ◽  
Quantitative Research ◽  
Plant Protection ◽  
Animal Husbandry ◽  
Ho Chi Minh City ◽  
Research Approach ◽  
Factors Affecting ◽  
Agricultural Students ◽  
Students Satisfaction

This study was conducted with the objective of identifying the influence of service quality, university image on agricultural students’ satisfaction and loyalty. The quantitative research approach was applied. Data were collected using questionnaires with a sample size of 313 students who majored in Veterinary Medicine, Animal Husbandry, Agronomy and Plant Protection at Nong Lam University Ho Chi Minh City. The sample has been selected by convenient method. The research results show that agricultural students’ satisfactions and loyalty are affected by service quality and school image. In which, the school image has the stronger impact on student satisfaction and loyalty. From the findings, the researcher has made conclusions and some suggestions to contribute to improving student loyalty.

scholarly journals Numerical Simulation and Analysis on Spray Drift Movement of Multirotor Plant Protection Unmanned Aerial Vehicle

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2399 ◽  
Author(s):  
Fengbo Yang ◽  
Xinyu Xue ◽  
Chen Cai ◽  
Zhu Sun ◽  
Qingqing Zhou
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Droplet Size ◽  
Wind Field ◽  
Flow Model ◽  
Two Phase Flow ◽  
Plant Protection ◽  
Three Dimensional ◽  
Phase Flow ◽  
Two Phase

In recent years, multirotor unmanned aerial vehicles (UAVs) have become more and more important in the field of plant protection in China. Multirotor unmanned plant protection UAVs have been widely used in vast plains, hills, mountains, and other regions, and become an integral part of China’s agricultural mechanization and modernization. The easy takeoff and landing performances of UAVs are urgently required for timely and effective spraying, especially in dispersed plots and hilly mountains. However, the unclearness of wind field distribution leads to more serious droplet drift problems. The drift and distribution of droplets, which depend on airflow distribution characteristics of UAVs and the droplet size of the nozzle, are directly related to the control effect of pesticide and crop growth in different growth periods. This paper proposes an approach to research the influence of the downwash and windward airflow on the motion distribution of droplet group for the SLK-5 six-rotor plant protection UAV. At first, based on the Navier-Stokes (N-S) equation and SST k–ε turbulence model, the three-dimensional wind field numerical model is established for a six-rotor plant protection UAV under 3 kg load condition. Droplet discrete phase is added to N-S equation, the momentum and energy equations are also corrected for continuous phase to establish a two-phase flow model, and a three-dimensional two-phase flow model is finally established for the six-rotor plant protection UAV. By comparing with the experiment, this paper verifies the feasibility and accuracy of a computational fluid dynamics (CFD) method in the calculation of wind field and spraying two-phase flow field. Analyses are carried out through the combination of computational fluid dynamics and radial basis neural network, and this paper, finally, discusses the influence of windward airflow and droplet size on the movement of droplet groups.

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