A plant protection unmanned aerial vehicle(UAV)applied for spraying pesticide has the advantages of low cost,high efficiency and environmental protection.However,the complex and changeable farmland environment is not ...A plant protection unmanned aerial vehicle(UAV)applied for spraying pesticide has the advantages of low cost,high efficiency and environmental protection.However,the complex and changeable farmland environment is not conductive to perform spray test effectively.It is therefore necessary to carry out spray test under controlled conditions.The current study aimed to illuminate the variation law of droplet deposition characteristics under different UAV flight speeds,and to verify the feasibility for applying infrared thermal imaging in detection of droplet deposition effects.A UAV simulation platform with an airborne spray system was established and an analysis program Droplet Analysis for dealing with water-sensitive paper was developed.The results showed that,when the flight speed was set at 0.3 m/s,0.5 m/s,0.7 m/s,0.9 m/s and 1 m/s,respectively,the droplet deposition density,droplet deposition coverage and arithmetic mean of droplet size D0 decreased as the UAV flight speed increased.On the contrary,the droplet diameter variation coefficient CV increased with the increase of UAV flight speed,resulting in the worse uniformity of sprayed droplet distribution as well.The results can provide a theoretical support for optimizing the spraying parameters of plant protection UAV,and demonstrate the practicability of infrared thermal imaging in evaluating the droplet deposition in the field of aerial spraying.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This research was financially support by Major Science and Technology Projects of Zhejiang Province(2015C02007).
文摘A plant protection unmanned aerial vehicle(UAV)applied for spraying pesticide has the advantages of low cost,high efficiency and environmental protection.However,the complex and changeable farmland environment is not conductive to perform spray test effectively.It is therefore necessary to carry out spray test under controlled conditions.The current study aimed to illuminate the variation law of droplet deposition characteristics under different UAV flight speeds,and to verify the feasibility for applying infrared thermal imaging in detection of droplet deposition effects.A UAV simulation platform with an airborne spray system was established and an analysis program Droplet Analysis for dealing with water-sensitive paper was developed.The results showed that,when the flight speed was set at 0.3 m/s,0.5 m/s,0.7 m/s,0.9 m/s and 1 m/s,respectively,the droplet deposition density,droplet deposition coverage and arithmetic mean of droplet size D0 decreased as the UAV flight speed increased.On the contrary,the droplet diameter variation coefficient CV increased with the increase of UAV flight speed,resulting in the worse uniformity of sprayed droplet distribution as well.The results can provide a theoretical support for optimizing the spraying parameters of plant protection UAV,and demonstrate the practicability of infrared thermal imaging in evaluating the droplet deposition in the field of aerial spraying.
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.
