The effective swath width(ESW)and the droplet penetration rate(DPR)directly affect the spraying quality,the spraying efficiency and the control effect of pests and diseases during the crop protection unmanned aircraft...The effective swath width(ESW)and the droplet penetration rate(DPR)directly affect the spraying quality,the spraying efficiency and the control effect of pests and diseases during the crop protection unmanned aircraft system(CPUAS)application.However,the ESW and DPR are not constant with the changes of the flight speed(FS)and the flight height(FH).In order to investigate the ESW and DPR of the CPUAS P20,four levels of FS(3 m/s,4 m/s,5 m/s and 6 m/s)and three levels of FH(1.5 m,2.0 m and 2.5 m)experiments were carried out according to the first industry standard of China for the CPUAS in the wheat field.The results demonstrated that the ESWs were negatively correlated with the FS and the FH.Most of the ESWs were over 2 m in the 12 treatments,in which the maximum one was 3.25 m(3 m/s,1.5 m).The DPRs were negatively correlated with the FH under the same FS,the average value of the DPRs was 48.37%,in which the maximum one was 78.34%(4 m/s,1.5 m)and the minimum one was 25.5%(6.0 m/s,2.5 m).The statistical analyses showed that the FS had significant impacts on the ESWs(0.01<p-value<0.05)while there were no significant differences among different FH treatments(p-value>0.05).The impacts of both FS and FH on the DPRs were extremely significant(p-value<0.01),and the interactive impacts were significant(0.01<p-value<0.05).Therefore,it is concluded that reducing the FS could increase the ESWs,and reducing the FH could increase the DRPs at the same FS.In conclusion,the maximum spraying efficiency of P20 was 4.342 hm2/h with 6 m/s FS and 1.5 m FH in case of satisfying the requirement of DPRs.This study provided scientific references for guiding the CPUAS spraying.展开更多
As a new type of crop protection machine,the crop protection unmanned aerial system(CPUAS)is developing rapidly in China.The wind field generated by the rotor has a great influence on the deposition and penetration of...As a new type of crop protection machine,the crop protection unmanned aerial system(CPUAS)is developing rapidly in China.The wind field generated by the rotor has a great influence on the deposition and penetration of spraying droplets.The purpose of this study was to develop a reliable and stable test platform that could be used for wind field test of CPUAS,and to carry out the downwash experiments on the platform to obtain the downwash distribution law of a CPUAS Z-3N(100 kg level,Nanjing Research Institute on Simulation Technique,Nanjing,China).The tests showed that the performances of the developed platform could meet the expected design requirements.The platform operated stably and reliably during the downwash experiments of Z-3N,which indicated it could be applied for CPUASs of 100 kg level and below.The vibration characteristics of the platform with different heights(2.0 m,3.0 m,5.0 m,7.0 m,10.0 m)were obtained through modal analysis,which could effectively guide avoiding the resonance for stable and reliable operation during the experiments with the tested CPUAS Z-3N.A ring-radial method was designed combined with the platform for the downwash measurement.The experimental results showed that the downwash distribution of Z-3N was not symmetrical;the downwash wind speed decreased with the increase of the radial distance while the changing trend was not consistent as the height increased.Moreover,the area with high wind speed was mainly within 3.0 m of the radial distance,and the maximum value was 11.37 m/s.The study provided a new way for wind field test of CPUASs and would provide some references for better utilization of wind field during the CPUAS spraying.展开更多
Electrostatic spraying application is adopted in crop protection to prevent pest infestation,to improve product quality and to maximize yield.It involves a superposition of charges to pesticide spray droplets to attra...Electrostatic spraying application is adopted in crop protection to prevent pest infestation,to improve product quality and to maximize yield.It involves a superposition of charges to pesticide spray droplets to attract substrate ions at obscured surfaces.The droplets wraparound effect reduces off-target deposition,enhances on-target spray and invariably improves spray efficiency.Electrostatic spraying system works effectively at optimum parameters in combination with charging voltages,application pressures,spraying height regimes,flow rate,travel speed,electrode material,and nozzle orientation.Many combinations of the system parameter settings have been systematically used by researchers for the electrostatic application,but there are unknown specific optimum parameters combinations for pesticide spraying.Since droplets chargeability influences the effectiveness of electrostatic spraying system,the parameters that produce ideal charge to mass ratio determine the functionality of the spraying deposition,retention and surface coverage.This article,therefore,analyses electrostatic system parameters that produce suitably charged droplets characteristics for effective impacting behavior of pesticides on substrates.Increasing applied voltages consequently maximizes charge-mass ratio to optimum and starts declining upon further increase in voltages beyond a critical point.This review further proposes the selection of an optimum electrostatic parameters combination that yields optimum droplets chargeability in pesticide application.Also,it is necessary to investigate the charge property of substrates prior to pesticide application in order to superpose the right opposite charge on spray droplets at rupture time during electrostatic spraying system.展开更多
This study aimed to resolve the problems of full wheat straw returning to the field,which might readily cause stalk obstruction,poor sowing quality,and serious weeds at the seedling stage,affecting the growth of maize...This study aimed to resolve the problems of full wheat straw returning to the field,which might readily cause stalk obstruction,poor sowing quality,and serious weeds at the seedling stage,affecting the growth of maize.Based on the idea of“simultaneous seeding and spraying,closed weeding”,this paper presented a design method for designing a corn seed-fertilizer-herbicide simultaneous operation machine,which focuses on the design of vertical active straw-removing anti-blocking device mechanism,design of nozzle key parameters,nozzle selection,seeding monomer analysis and spatial layout design of seed-fertilizer-herbicide mechanism.In addition,the interrelated formulas were deduced and machine design and field experiment were conducted.The experiment results showed that the average variation coefficient of spray uniformity of machines was 17.70%.The post-experiment weed amount was 8.9%,which was lower than that before sowing,8.5%lower than that before artificially closed weeding,and 14.3%lower than that in unenclosed weeding area.Moreover,the weeds were less in the working area of the machine,and the growth of corn was better.Compared with manual closed weeding,the average plant height uniformity and average stem diameter uniformity increased by 4.4%and 5.1%,respectively.Compared with unclosed weeding,the average plant height uniformity and average stem diameter uniformity increased by 18.3%and 10.8%,respectively.Overall,the rationality of the design method proposed in this paper was validated,and these can lay a foundation for the research and development of the same type of machine.展开更多
基金This research was supported by the National Key Research and Development Program of China(Grant No.2017YFD0701000)the National Natural Science Foundation of China(No.31701327)+1 种基金Jiangsu Agriculture Science and Technology Innovation Fund(CX(17)1002)Collaborative Innovation Plan of Scientific and Technological Innovation Project(Grant No.CAAS-XTCX2016006).
文摘The effective swath width(ESW)and the droplet penetration rate(DPR)directly affect the spraying quality,the spraying efficiency and the control effect of pests and diseases during the crop protection unmanned aircraft system(CPUAS)application.However,the ESW and DPR are not constant with the changes of the flight speed(FS)and the flight height(FH).In order to investigate the ESW and DPR of the CPUAS P20,four levels of FS(3 m/s,4 m/s,5 m/s and 6 m/s)and three levels of FH(1.5 m,2.0 m and 2.5 m)experiments were carried out according to the first industry standard of China for the CPUAS in the wheat field.The results demonstrated that the ESWs were negatively correlated with the FS and the FH.Most of the ESWs were over 2 m in the 12 treatments,in which the maximum one was 3.25 m(3 m/s,1.5 m).The DPRs were negatively correlated with the FH under the same FS,the average value of the DPRs was 48.37%,in which the maximum one was 78.34%(4 m/s,1.5 m)and the minimum one was 25.5%(6.0 m/s,2.5 m).The statistical analyses showed that the FS had significant impacts on the ESWs(0.01<p-value<0.05)while there were no significant differences among different FH treatments(p-value>0.05).The impacts of both FS and FH on the DPRs were extremely significant(p-value<0.01),and the interactive impacts were significant(0.01<p-value<0.05).Therefore,it is concluded that reducing the FS could increase the ESWs,and reducing the FH could increase the DRPs at the same FS.In conclusion,the maximum spraying efficiency of P20 was 4.342 hm2/h with 6 m/s FS and 1.5 m FH in case of satisfying the requirement of DPRs.This study provided scientific references for guiding the CPUAS spraying.
基金This research was financially supported by the National Key Research and Development Program of China(Grant No.2017YFD0701000)the National Natural Science Foundation of China(Grant No.31701327)+3 种基金the China Agriculture Research System of MOF and MARA(Grant No.CARS-12)the Agricultural Science and Technology Innovation Project of the Chinese Academy of Agricultural Sciences,Crop Protection Machinery Team(Grant No.CAAS-ASTIP-CPMT)the Jiangsu Science and Technology Development Plan(Grant No.BE2019305)the Science and Technology Development Plan of Suzhou,Jiangsu Province(Grant No.SNG2020042).
文摘As a new type of crop protection machine,the crop protection unmanned aerial system(CPUAS)is developing rapidly in China.The wind field generated by the rotor has a great influence on the deposition and penetration of spraying droplets.The purpose of this study was to develop a reliable and stable test platform that could be used for wind field test of CPUAS,and to carry out the downwash experiments on the platform to obtain the downwash distribution law of a CPUAS Z-3N(100 kg level,Nanjing Research Institute on Simulation Technique,Nanjing,China).The tests showed that the performances of the developed platform could meet the expected design requirements.The platform operated stably and reliably during the downwash experiments of Z-3N,which indicated it could be applied for CPUASs of 100 kg level and below.The vibration characteristics of the platform with different heights(2.0 m,3.0 m,5.0 m,7.0 m,10.0 m)were obtained through modal analysis,which could effectively guide avoiding the resonance for stable and reliable operation during the experiments with the tested CPUAS Z-3N.A ring-radial method was designed combined with the platform for the downwash measurement.The experimental results showed that the downwash distribution of Z-3N was not symmetrical;the downwash wind speed decreased with the increase of the radial distance while the changing trend was not consistent as the height increased.Moreover,the area with high wind speed was mainly within 3.0 m of the radial distance,and the maximum value was 11.37 m/s.The study provided a new way for wind field test of CPUASs and would provide some references for better utilization of wind field during the CPUAS spraying.
基金The authors would like to appreciate the financial support from the funds of the National Key Research and Development Plan of China(grant number 2016YFD0200700)the National Natural Science Foundation of China(grant number 51475215,31601676)the Advanced Talent Research Funding of Jiangsu University(grant number 5501200004).
文摘Electrostatic spraying application is adopted in crop protection to prevent pest infestation,to improve product quality and to maximize yield.It involves a superposition of charges to pesticide spray droplets to attract substrate ions at obscured surfaces.The droplets wraparound effect reduces off-target deposition,enhances on-target spray and invariably improves spray efficiency.Electrostatic spraying system works effectively at optimum parameters in combination with charging voltages,application pressures,spraying height regimes,flow rate,travel speed,electrode material,and nozzle orientation.Many combinations of the system parameter settings have been systematically used by researchers for the electrostatic application,but there are unknown specific optimum parameters combinations for pesticide spraying.Since droplets chargeability influences the effectiveness of electrostatic spraying system,the parameters that produce ideal charge to mass ratio determine the functionality of the spraying deposition,retention and surface coverage.This article,therefore,analyses electrostatic system parameters that produce suitably charged droplets characteristics for effective impacting behavior of pesticides on substrates.Increasing applied voltages consequently maximizes charge-mass ratio to optimum and starts declining upon further increase in voltages beyond a critical point.This review further proposes the selection of an optimum electrostatic parameters combination that yields optimum droplets chargeability in pesticide application.Also,it is necessary to investigate the charge property of substrates prior to pesticide application in order to superpose the right opposite charge on spray droplets at rupture time during electrostatic spraying system.
基金This research was financially supported by the Special Fund of Ministry of Agriculture of China for Public Welfare Projects(No.201503136)Science and Technology Project in Anhui Province(NO:1604a0702035).
文摘This study aimed to resolve the problems of full wheat straw returning to the field,which might readily cause stalk obstruction,poor sowing quality,and serious weeds at the seedling stage,affecting the growth of maize.Based on the idea of“simultaneous seeding and spraying,closed weeding”,this paper presented a design method for designing a corn seed-fertilizer-herbicide simultaneous operation machine,which focuses on the design of vertical active straw-removing anti-blocking device mechanism,design of nozzle key parameters,nozzle selection,seeding monomer analysis and spatial layout design of seed-fertilizer-herbicide mechanism.In addition,the interrelated formulas were deduced and machine design and field experiment were conducted.The experiment results showed that the average variation coefficient of spray uniformity of machines was 17.70%.The post-experiment weed amount was 8.9%,which was lower than that before sowing,8.5%lower than that before artificially closed weeding,and 14.3%lower than that in unenclosed weeding area.Moreover,the weeds were less in the working area of the machine,and the growth of corn was better.Compared with manual closed weeding,the average plant height uniformity and average stem diameter uniformity increased by 4.4%and 5.1%,respectively.Compared with unclosed weeding,the average plant height uniformity and average stem diameter uniformity increased by 18.3%and 10.8%,respectively.Overall,the rationality of the design method proposed in this paper was validated,and these can lay a foundation for the research and development of the same type of machine.
