Development of a Low-Volume Sprayer for an Unmanned Helicopter

Huang, Yanbo; Hoffman, William C.; Lan, Yubin; Fritz, Bradley K.; Thomson, Steven J.

doi:10.5539/jas.v7n1p148

Cited by 17 publications

(14 citation statements)

References 3 publications

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“…There is a wider variety of flat fan nozzles which are lighter and use less power than the rotary atomizers. Huang et al [ 9 ] recovered material up to 42 m downwind of the release point with their system while our tests yielded a swath of 14 m. This discrepancy is likely due to the more sensitive collection method used and the fact that the spray system was run from a pole mounted on a truck, not from a running helicopter. The vortices created by the helicopter will push material down, reducing the total swath [ 19 ].…”

Section: Resultsmentioning

confidence: 77%

“…Those factors, combined with prohibitive regulations and technical difficulties, caused the military to transfer the project to the US Department of Agriculture in 2004 [ 8 ]. Researchers made significant improvements to the application technologies [ 9 , 10 ] but unmanned aircraft systems (UAS) remained too expensive and difficult to fly to be practical for mosquito management.…”

Section: Introductionmentioning

confidence: 99%

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The development of autonomous unmanned aircraft systems for mosquito control

et al. 2020

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We constructed an electric multi-rotor autonomous unmanned aerial system (UAS) to perform mosquito control activities. The UAS can be equipped with any of four modules for spraying larvicides, dropping larvicide tablets, spreading larvicide granules, and ultra-low volume spraying of adulticides. The larvicide module sprayed 124 μm drops at 591 mL/min over a 14 m swath for a total application rate of 1.6 L/ha. The tablet module was able to repeatedly deliver 40-gram larvicide tablets within 1.1 m of the target site. The granular spreader covered a 6 m swath and treated 0.76 ha in 13 min at an average rate of 1.8 kg/ha. The adulticide module produced 16 μm drops with an average deposition of 2.6 drops/mm 2. UAS pesticide applications were made at rates prescribed for conventional aircraft, limited only by the payload capacity and flight time. Despite those limitations, this system can deliver pesticides with much greater precision than conventional aircraft, potentially reducing pesticide use. In smaller, congested environments or in programs with limited resources, UAS may be a preferable alternative to conventional aircraft.

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Section: Resultsmentioning

confidence: 77%

Section: Introductionmentioning

confidence: 99%

The development of autonomous unmanned aircraft systems for mosquito control

et al. 2020

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“…Multicopters are well-suited to a wide range of mission scenarios, such as search and rescue [2], [3], package delivery [4], border patrol [5], military surveillance [6] and agricultural production [7]. In either pre-flight process or in-flight process, multicopter failures cannot be absolutely avoided.…”

Section: Introductionmentioning

confidence: 99%

Failsafe mechanism design of multicopters based on supervisory control theory

Quan

Zhao

Lin

et al. 2020

IET cyber-systems robotics

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In order to handle undesirable failures of a multicopter which occur in either the pre-flight process or the in-flight process, a failsafe mechanism design method based on supervisory control theory is proposed for the semi-autonomous control mode 1 . Failsafe mechanism is a control logic that guides what subsequent actions the multicopter should take, by taking account of real-time information from guidance, attitude control, diagnosis, and other low-level subsystems. In order to design a failsafe mechanism for multicopters, safety issues of multicopters are introduced.Then, user requirements including functional requirements and safety requirements are textually described, where function requirements determine a general multicopter plant, and safety requirements cover the failsafe measures dealing with the presented safety issues. In order to model the user requirements by discrete-event systems, several multicopter modes and events are defined.On this basis, the multicopter plant and control specifications are modeled by automata. Then, a supervisor is synthesized by monolithic supervisory control theory. In addition, we present three examples to demonstrate the potential blocking phenomenon due to inappropriate design of control specifications. Also, we discuss the meaning of correctness and the properties of the obtained supervisor. This makes the failsafe mechanism convincingly correct and effective. Finally, based on

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“…In recent years, unmanned aerial vehicles (UAV) have been introduced as carriers to apply chemicals for the prevention and control of pests and diseases of cotton [5][6][7] , due to their high efficiency, strong capability, low damage to crops and low cost. The spraying of pesticides by UAV usually involves low volumes and high concentrations with small droplet size because of the UAV weight and tank limits [8,9] . Consequently, the volume of spray per unit area is much lower than for spraying with ground-based machinery [10] .…”

Section: Introductionmentioning

confidence: 99%

Effect of UAV prewetting application during the flowering period of cotton on pesticide droplet deposition

Yao¹,

Wang²,

Lan³

et al. 2018

Front. Agr. Sci. Eng.

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Prewetting process can reduce the contact angle between the droplet and the leaf blade, so that the droplet can more easily wet and spread, thereby increasing the quantity of deposition. To improve the effectiveness of pesticides on cotton leaves, prewetting by single-rotor electric unmanned aerial vehicles (UAV) was studied, focusing on the effects of pesticide deposition on cotton leaves during the flowering period. Cotton leaves in 0°-30°, 30°-60°, 60°-90°leaf blade angle ranges (angle between the leaf blade and the horizontal plane) were examined. In the first experiment, four different prewetting volumes (0, 1.6, 3.2 and 4.8 L) were sprayed by a singlerotor electric UAV on four cotton plots (plots A-D) each with an area of 120 m 2 , and then each area was sprayed with a 0.8% (w/v) ponceau 2R solution by another singlerotor electric UAV. The results revealed that with no prewetting, droplet deposition quantity decreased with increasing leaf blade inclination. After prewetting, the mean droplet deposition quantity on plots B, C and D increased by 39.8%, 9.7% and 24.9%, respectively. The prewetting rate of 1.6 L per 120 m 2 had the most significant effect on improving the deposition of droplets. It was also found that the mean droplet deposition quantity in each leaf blade angle range increased after prewetting. For the leaf blade angle range 60°-90°, this increase was the most pronounced, with 0.043, 0.062, 0.057 and 0.048 mL$cm -2 in plots A-D, respectively. Also, droplet deposition uniformity in the leaf blade angle range 60°-90°was better after prewetting. These results should provide a valuable reference for future research and practice to improve the effectiveness of pesticides applied to cotton by aerial applications.

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Development of a Low-Volume Sprayer for an Unmanned Helicopter

Cited by 17 publications

References 3 publications

The development of autonomous unmanned aircraft systems for mosquito control

The development of autonomous unmanned aircraft systems for mosquito control

Failsafe mechanism design of multicopters based on supervisory control theory

Effect of UAV prewetting application during the flowering period of cotton on pesticide droplet deposition

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