This paper presented a novel variable rate fertilization system based on the method of adjusting the active feed-roll length of a fluted roller.The feasibility of this method was discussed using analysis of the fluted...This paper presented a novel variable rate fertilization system based on the method of adjusting the active feed-roll length of a fluted roller.The feasibility of this method was discussed using analysis of the fluted roller model.One seed drill produced by Kuhn Company(France),which could sow and fertilize simultaneously,was used as a test platform to implement the mechanical structure of variable rate fertilization.The design methods for the variable rate fertilization mechanical structure and actuator were introduced in detail.A low-cost and stable embedded support decision subsystem and corresponding software were developed.The support decision subsystem is based on grid management.Each grid field cell contains information about corresponding spatial position and fertilizer application rate.A SpatiaLite database was employed to solve the spatial location search and spatial data query.Experiments were conducted to evaluate the fertilization uniformity and dynamic response time.The average value of coefficient of variation is 8.4%in five different active feed-roll lengths which reflects good uniformity.The dynamic response times for the adjustment of variable rate fertilization system from 204 kg/hm^(2) to 319 kg/hm^(2) and 319 kg/hm^(2) to 204 kg/hm^(2) are about 4.2 s.The results suggest that the variable rate fertilization system performs well in dynamic adjustment and stability.展开更多
Improving pesticide application efficiency is increasingly important in orchard spraying.In this study,a laser-scanning system was designed to acquire gridding volumes of a tree to quantify the geometry characteristic...Improving pesticide application efficiency is increasingly important in orchard spraying.In this study,a laser-scanning system was designed to acquire gridding volumes of a tree to quantify the geometry characteristics of the tree canopy in real-time.A laser-scanning sensor mounted on a linear guide was utilized to measure the structure of a target tree canopy.A computer was used to receive measurement data from the laser scanner and obtain the movement distance of the laser-scanning sensor from a controller.An algorithm written with VC#program was designed to calculate gridding volumes of trees by recognizing valid measurement data from the laser scanner.Laboratory evaluations were conducted on three kinds of regular objects,and the maximum relative errors of section volumes of the cuboid,triangular prism and cylinder objects were 3.3%,7.9%and 9.4%,respectively,which illustrated that the algorithm could calculate the section volumes in different parts of the objects with high accuracy.A conifer tree and an apple tree were chosen to verify detecting accuracy of the laser-scanning system at variable speeds and grid sizes.The variation coefficients of total volumes for each kind of the tree were 0.078 and 0.041,respectively,which indicated that the laser-scanning system could be applied to provide the gridding volumes of different canopy densities in real-time with good reliability for guiding a variable-rate sprayer.展开更多
Remote sensing technology has long been used to detect and map crop diseases.Airborne and satellite imagery acquired during growing seasons can be used not only for early detection and within-season management of some...Remote sensing technology has long been used to detect and map crop diseases.Airborne and satellite imagery acquired during growing seasons can be used not only for early detection and within-season management of some crop diseases,but also for the control of recurring diseases in future seasons.With variable rate technology in precision agriculture,site-specific fungicide application can be made to infested areas if the disease is stable,although traditional uniform application is more appropriate for diseases that can spread rapidly across the field.This article provides a brief overview of remote sensing and precision agriculture technologies that have been used for crop disease detection and management.Specifically,the article illustrates how airborne and satellite imagery and variable rate technology have been used for detecting and mapping cotton root rot,a destructive soilborne fungal disease,in cotton fields and how site-specific fungicide application has been implemented using prescription maps derived from the imagery for effective control of the disease.The overview and methodologies presented in this article should provide researchers,extension personnel,growers,crop consultants,and farm equipment and chemical dealers with practical guidelines for remote sensing detection and effective management of some crop diseases.展开更多
During different growth periods,canopy size and density in orchards are variable,which need application conditions(flow rate and air flow)to be adjusted to match the canopy’s characteristics.In order to improve orcha...During different growth periods,canopy size and density in orchards are variable,which need application conditions(flow rate and air flow)to be adjusted to match the canopy’s characteristics.In order to improve orchard sprayer’s automatic operating performance,an automatic variable-rate orchard sprayer(VARS)fixed with 40 electromagnetic valves and 8 brushless fans was developed based on the canopy’s spatial dimensions.Each solenoid valve and brushless motor can be individually adjusted in real-time through pulse width modulation(PWM)signals emitted by a control system to adjust each nozzle’s spout and fan rotation speed.A high-precision laser scanning sensor(light detecting and ranging,LIDAR)was adopted as the detector to measure the canopy volume using the variable rate algorithm principle.Field experiments were conducted in an apple orchard,and conventional air blast sprayer(CABS)and directed air-jet sprayer(DAJS)were tested as a comparison.Results showed that on average,46%less spraying solution was applied compared to conventional applications,while penetration rate was similar to DAJS.Normalized deposition in the canopy with variable application was higher than that of conventional applications,indicating that electronic sprayers are more efficient than conventional sprayers.It was also observed that VARS could significantly reduce off-target loss.The field experiment showed that the newly developed variable-rate sprayer can greatly reduce pesticide use and protect the environment for the orchard fruit production,and also provide a reference for design and performance optimization for plant protection machinery.展开更多
In order to reduce the use of chemical pesticides in crop plant protection and improve the utilization efficiency of pesticides,it is necessary to study advanced application machinery and application techniques.The us...In order to reduce the use of chemical pesticides in crop plant protection and improve the utilization efficiency of pesticides,it is necessary to study advanced application machinery and application techniques.The use of unmanned aerial vehicle(UAV)for pesticide spraying has the characteristics of less application,strong penetrability,wide applicability and flexible operation scheduling,and has gradually become one of the important development directions in the field of aviation plant protection.However,the operation process of the UAV is often affected by meteorological factors and human manipulation,resulting in poor actual operation with inaccurate spray volume and uneven application.Therefore,to improve the stability and uniformity of the application of the plant protection UAV under variable operating conditions,in this paper a real-time control method was proposed for the application flow rate,and a precision variable-rate spray system was designed based on single-chip microcomputer and micro diaphragm pump that can controls the flow rate of the pump in real time with the changes of the operating state.The response s-peed of the variable-rate spray system was tested.The average control response time of the system was 0.18 s,and the average stability time of the pump flow change was 0.75 s.The test results showed that the system has a quick response to the working state and the adjustment of the target flow of the pump can be quickly completed to realize the variable-rate spray function.The research results can provide a reference for the practical application of plant protection UAV variable-rate spray system.展开更多
Herbicide use is rising globally to enhance food production,causing harm to environment and the ecosystem.Precision agriculture suggests variable-rate herbicide application based on weed densities to mitigate adverse ...Herbicide use is rising globally to enhance food production,causing harm to environment and the ecosystem.Precision agriculture suggests variable-rate herbicide application based on weed densities to mitigate adverse effects of herbicides.Accurate weed density estimation using advanced computer vision techniques like deep learning requires large labelled agriculture data.Labelling large agriculture data at pixel level is a time-consuming and tedious job.In this paper,a methodology is developed to accelerate manual labelling of pixels using a two-step procedure.In the first step,the background and foreground are segmented using maximum likelihood classification,and in the second step,the weed pixels are manually labelled.Such labelled data is used to train semantic segmentation models,which classify crop and background pixels as one class,and all other vegetation as the second class.This paper evaluates the proposed methodology on high-resolution colour images of canola fields and makes performance comparison of deep learning meta-architectures like SegNet and UNET and encoder blocks like VGG16 and ResNet-50.ResNet-50 based SegNet model has shown the best results with mean intersection over union value of 0.8288 and frequency weighted intersection over union value of 0.9869.展开更多
The variable-rate application is an important aspect of precision agriculture.In order to determine the regular patterns of droplet deposition and compare the actual variable-rate spraying effect of the AS350B3e helic...The variable-rate application is an important aspect of precision agriculture.In order to determine the regular patterns of droplet deposition and compare the actual variable-rate spraying effect of the AS350B3e helicopter with the AG-NAV Guía system,spray tests were conducted with different operating parameters and operating methods.In this study,the deposition distribution of droplets in the effective swath area was evaluated for six single-pass applications at four different flight velocities.The effects of adding adjuvant on droplet deposition,drift and droplet size were compared,and the actual variable effect of the forth-back application was verified.The analysis results showed that the position of the effective swath area was affected by natural wind velocity and wind direction,and would shift to the downwind direction area from the helicopter route of a different degree.The effective swath width increased slowly and then decreased sharply with the increase of flight velocity.It was found that flight velocity of 100 km/h was the peak inflection point of effective spray width variation.Moreover,the effect of flight velocity on the distribution uniformity of droplet deposition in the effective swath area was not significant.In the single-pass application of 90 km/h,adding adjuvant could increase droplet size in the effective swath area.The deposition increased by 8.98%,and the total drift decreased by 28.65%,of which the upwind drift decreased by 28.31%and the downwind drift decreased by 29.06%.In the forth-back application of 90 km/h,the error between actual application volume and system setting dose was 12%.The results of this study can provide valuable references for future research and practices on variable-rate aerial applications by manned helicopters.展开更多
基金We acknowledge that the research is supported by the National Key Technology Research and Development Program(No.2012BAK17B15).
文摘This paper presented a novel variable rate fertilization system based on the method of adjusting the active feed-roll length of a fluted roller.The feasibility of this method was discussed using analysis of the fluted roller model.One seed drill produced by Kuhn Company(France),which could sow and fertilize simultaneously,was used as a test platform to implement the mechanical structure of variable rate fertilization.The design methods for the variable rate fertilization mechanical structure and actuator were introduced in detail.A low-cost and stable embedded support decision subsystem and corresponding software were developed.The support decision subsystem is based on grid management.Each grid field cell contains information about corresponding spatial position and fertilizer application rate.A SpatiaLite database was employed to solve the spatial location search and spatial data query.Experiments were conducted to evaluate the fertilization uniformity and dynamic response time.The average value of coefficient of variation is 8.4%in five different active feed-roll lengths which reflects good uniformity.The dynamic response times for the adjustment of variable rate fertilization system from 204 kg/hm^(2) to 319 kg/hm^(2) and 319 kg/hm^(2) to 204 kg/hm^(2) are about 4.2 s.The results suggest that the variable rate fertilization system performs well in dynamic adjustment and stability.
基金This study was financially supported by the National Key Research and Development Program(No.2016YFD0200700).
文摘Improving pesticide application efficiency is increasingly important in orchard spraying.In this study,a laser-scanning system was designed to acquire gridding volumes of a tree to quantify the geometry characteristics of the tree canopy in real-time.A laser-scanning sensor mounted on a linear guide was utilized to measure the structure of a target tree canopy.A computer was used to receive measurement data from the laser scanner and obtain the movement distance of the laser-scanning sensor from a controller.An algorithm written with VC#program was designed to calculate gridding volumes of trees by recognizing valid measurement data from the laser scanner.Laboratory evaluations were conducted on three kinds of regular objects,and the maximum relative errors of section volumes of the cuboid,triangular prism and cylinder objects were 3.3%,7.9%and 9.4%,respectively,which illustrated that the algorithm could calculate the section volumes in different parts of the objects with high accuracy.A conifer tree and an apple tree were chosen to verify detecting accuracy of the laser-scanning system at variable speeds and grid sizes.The variation coefficients of total volumes for each kind of the tree were 0.078 and 0.041,respectively,which indicated that the laser-scanning system could be applied to provide the gridding volumes of different canopy densities in real-time with good reliability for guiding a variable-rate sprayer.
文摘Remote sensing technology has long been used to detect and map crop diseases.Airborne and satellite imagery acquired during growing seasons can be used not only for early detection and within-season management of some crop diseases,but also for the control of recurring diseases in future seasons.With variable rate technology in precision agriculture,site-specific fungicide application can be made to infested areas if the disease is stable,although traditional uniform application is more appropriate for diseases that can spread rapidly across the field.This article provides a brief overview of remote sensing and precision agriculture technologies that have been used for crop disease detection and management.Specifically,the article illustrates how airborne and satellite imagery and variable rate technology have been used for detecting and mapping cotton root rot,a destructive soilborne fungal disease,in cotton fields and how site-specific fungicide application has been implemented using prescription maps derived from the imagery for effective control of the disease.The overview and methodologies presented in this article should provide researchers,extension personnel,growers,crop consultants,and farm equipment and chemical dealers with practical guidelines for remote sensing detection and effective management of some crop diseases.
基金The authors acknowledge that this work was financially supported by Special Fund for Agro-scientific Research in Public Interest(No.201503130)Beijing Science and technology plan projects(No.D171100002317003)National Natural Science Foundation of China(31470099).
文摘During different growth periods,canopy size and density in orchards are variable,which need application conditions(flow rate and air flow)to be adjusted to match the canopy’s characteristics.In order to improve orchard sprayer’s automatic operating performance,an automatic variable-rate orchard sprayer(VARS)fixed with 40 electromagnetic valves and 8 brushless fans was developed based on the canopy’s spatial dimensions.Each solenoid valve and brushless motor can be individually adjusted in real-time through pulse width modulation(PWM)signals emitted by a control system to adjust each nozzle’s spout and fan rotation speed.A high-precision laser scanning sensor(light detecting and ranging,LIDAR)was adopted as the detector to measure the canopy volume using the variable rate algorithm principle.Field experiments were conducted in an apple orchard,and conventional air blast sprayer(CABS)and directed air-jet sprayer(DAJS)were tested as a comparison.Results showed that on average,46%less spraying solution was applied compared to conventional applications,while penetration rate was similar to DAJS.Normalized deposition in the canopy with variable application was higher than that of conventional applications,indicating that electronic sprayers are more efficient than conventional sprayers.It was also observed that VARS could significantly reduce off-target loss.The field experiment showed that the newly developed variable-rate sprayer can greatly reduce pesticide use and protect the environment for the orchard fruit production,and also provide a reference for design and performance optimization for plant protection machinery.
基金The authors acknowledge that the research was financially supported by the graduate student innovation project of Heilongjiang Bayi Agriculture University(YJSCX2017-Z03)the Youth Innovative Talent Program of Heilongjiang Bayi Agriculture University(ZRCQC201802).
文摘In order to reduce the use of chemical pesticides in crop plant protection and improve the utilization efficiency of pesticides,it is necessary to study advanced application machinery and application techniques.The use of unmanned aerial vehicle(UAV)for pesticide spraying has the characteristics of less application,strong penetrability,wide applicability and flexible operation scheduling,and has gradually become one of the important development directions in the field of aviation plant protection.However,the operation process of the UAV is often affected by meteorological factors and human manipulation,resulting in poor actual operation with inaccurate spray volume and uneven application.Therefore,to improve the stability and uniformity of the application of the plant protection UAV under variable operating conditions,in this paper a real-time control method was proposed for the application flow rate,and a precision variable-rate spray system was designed based on single-chip microcomputer and micro diaphragm pump that can controls the flow rate of the pump in real time with the changes of the operating state.The response s-peed of the variable-rate spray system was tested.The average control response time of the system was 0.18 s,and the average stability time of the pump flow change was 0.75 s.The test results showed that the system has a quick response to the working state and the adjustment of the target flow of the pump can be quickly completed to realize the variable-rate spray function.The research results can provide a reference for the practical application of plant protection UAV variable-rate spray system.
文摘Herbicide use is rising globally to enhance food production,causing harm to environment and the ecosystem.Precision agriculture suggests variable-rate herbicide application based on weed densities to mitigate adverse effects of herbicides.Accurate weed density estimation using advanced computer vision techniques like deep learning requires large labelled agriculture data.Labelling large agriculture data at pixel level is a time-consuming and tedious job.In this paper,a methodology is developed to accelerate manual labelling of pixels using a two-step procedure.In the first step,the background and foreground are segmented using maximum likelihood classification,and in the second step,the weed pixels are manually labelled.Such labelled data is used to train semantic segmentation models,which classify crop and background pixels as one class,and all other vegetation as the second class.This paper evaluates the proposed methodology on high-resolution colour images of canola fields and makes performance comparison of deep learning meta-architectures like SegNet and UNET and encoder blocks like VGG16 and ResNet-50.ResNet-50 based SegNet model has shown the best results with mean intersection over union value of 0.8288 and frequency weighted intersection over union value of 0.9869.
基金We deeply thank for the financial support given by the Guangdong Leading Talent Project(2016LJ06G689)National Key Technologies Research and Development Program(2016YFD0200700)+3 种基金111 Project(D18019)Guangdong Leading Talent Project(2016LJ06G689)Educational Commission of Guangdong Province of China for Platform Construction and(2015KGJHZ007)Science and Technology Planning Project of Guangdong(2017B010117010).
文摘The variable-rate application is an important aspect of precision agriculture.In order to determine the regular patterns of droplet deposition and compare the actual variable-rate spraying effect of the AS350B3e helicopter with the AG-NAV Guía system,spray tests were conducted with different operating parameters and operating methods.In this study,the deposition distribution of droplets in the effective swath area was evaluated for six single-pass applications at four different flight velocities.The effects of adding adjuvant on droplet deposition,drift and droplet size were compared,and the actual variable effect of the forth-back application was verified.The analysis results showed that the position of the effective swath area was affected by natural wind velocity and wind direction,and would shift to the downwind direction area from the helicopter route of a different degree.The effective swath width increased slowly and then decreased sharply with the increase of flight velocity.It was found that flight velocity of 100 km/h was the peak inflection point of effective spray width variation.Moreover,the effect of flight velocity on the distribution uniformity of droplet deposition in the effective swath area was not significant.In the single-pass application of 90 km/h,adding adjuvant could increase droplet size in the effective swath area.The deposition increased by 8.98%,and the total drift decreased by 28.65%,of which the upwind drift decreased by 28.31%and the downwind drift decreased by 29.06%.In the forth-back application of 90 km/h,the error between actual application volume and system setting dose was 12%.The results of this study can provide valuable references for future research and practices on variable-rate aerial applications by manned helicopters.
