Aerial Application Research Articles

COMPARATIVE HYGIENIC ASSESSMENT OF THE POTENTIAL DIQUAT HAZARD TO THE POPULATION WHEN CONSUMING AGRICULTURAL CROPS TREATED WITH THE REGLONE AIR 200 SL FORMULATION USING DIFFERENT APPLICATION TECHNOLOGIES (UAV, AERIAL, HIGH-CLEARANCE ROD SPRAYER TREATMENT).

The aim: Assessment of the hazard to the population when consuming treated crops by using different technologies. Materials and methods: Unmanned aerial vehicle XAG XPlanet 2020 equipped with four rotating rotors, which allows to keep in the air a 20-liter tank was used for spraying field; a manned aircraft AN-2 aggregated with a serial sprayer. High-clearance rod treatment of sunflower and rapeseed crops was carried out by using a PLA MAP II 2010 tractor. Results: When the herbicide was applied by aerial application with UAV, the initial content of diquat dibromide in treated rapeseed and sunflower plants on the day of treatment was significantly higher than in the soil under crops (р≤0.05). The analysis of the diquat content dynamics in sunflower also showed a similar behavior of the a.i. in the plant after processing by another application methods: UAV, aerial and high-clearance rod treatment. The integral index of hazard when using pesticide-contaminated products (IIHPCPC) = ADD+С+ DT50 = 4+1+1 = 6 points. That is why, diquat dibromide can be classified according to this index can be classified as compound of 3rd hazard class. Conclusions: As a result of the conducted researches, it was established that the content of diquat in rapeseed and sunflower samples grown with the Reglone Air 200 SL application (after treatment and before harvesting) was below the maximum residue levels in those crops. There are no statistically significant differences in the behavior of diquat dibromide when applying by different methods of application (UAV, aerial, high-clearance rod treatment) in different agro-climatic zones of Ukraine.

Calculation of Swath Width and Swath Displacement for Uncrewed Aerial Spray Systems

Highlights Recent research has focused on the use of Uncrewed Aerial Spray Systems (UASS) for their potential to fill the gap between crewed aircraft and ground application equipment. The spray distribution in swath is highly variable to the point that using the typical metric of uniformity alone to define swath can no longer apply, we present a method that considers dose and uniformity. The swath was rarely found to be directly beneath the flightline, the swath displacement and offsetting can be significant and larger than the assumed swath width. This paper presents the development of an evidence-based, repeatable mathematical solution to the determination of swath width and swath displacement for UASS for calibration and targeting purposes. Abstract. Recent research has focused on the use of Uncrewed Aerial Spray Systems (UASS) for their potential to fill the gap between crewed aircraft and ground application, with UASS being able to be used over less accessible areas than ground equipment, being more appropriate to treat smaller, dispersed targets, and typically available at reduced cost and complexity when compared to crewed aircraft. However, there is limited literature focusing on the proper setup and use of these systems. The objective of this study was to design and conduct a series of large-scale, conceptually linked studies to provide data that is used to guide system optimization and the development of predictive models. An uncrewed system coupled with three nozzle types covering three droplet size classifications was used to conduct swath characterization and drift trials designed to establish effective swath widths, deposition variability, swath displacement, and drift. System and nozzle type, along with nozzle position and wind direction, significantly impacted the spray deposition patterns within and downwind of the effective swath. The spray distribution in a swath is highly variable, to the point that using the typical metric of uniformity alone to define swath can no longer apply. In addition, the swath was rarely found to be directly beneath the flightline, and swath offsetting can be significant and larger than the assumed swath width. An iterative solution has been developed that uses a combination of effective dose and uniformity to define swath width. The offsetting of the swath due to interactions with ambient air has also been defined using the Center of Deposition. The aim is to be able to distinguish between in-swath deposition and drift. The approach to defining swath width and the displacement of the swath is presented. The goal is to develop a real-time onboard navigation system that can reset the flight line in response to wind-driven swath displacement. This allows increased deposition within the target zone and reduces off-target losses. Keywords: Aerial application, Offset, Swath displacement, Swath width, Unmanned aerial spray system.

Unmanned Aerial Vehicle-based Applications in Smart Farming: A Systematic Review

Unmanned Aerial Vehicle-based Applications in Smart Farming: A Systematic Review

A Misalignment Tolerance and Lightweight Wireless Charging System via Reconfigurable Capacitive Coupling for Unmanned Aerial Vehicle Applications

This letter proposes a novel capacitive power transfer system for the unmanned aerial vehicles (UAVs) with lightweight in receivers and robust misalignment tolerance characteristics. The design and analysis of a reconfigurable capacitive coupler are presented at first. The transmitter adopts four rectangular copper plates, which can be reconfigured according to the landing positions and directions. The receiver includes two hollow cylindrical copper-foil sleeves wrapped at the bottom of UAV landing gears, thereby leading to the adaption of the UAV's structure and the tolerance to lateral-, longitudinal-, and angular misalignment. Then, simulation and prototype experiments are carried out to verify the proposal. The results show that the prototype has low leakage electric flux at the UAV fuselage and can deliver 212.1 W with a dc-to-dc efficiency of 82.5%. Especially the proposal allows UAV to be powered within ±0.76 A of output current variation for different landing positions and directions, and the system dc-to-dc efficiency variation is within ±1%.

The Omnirotor Platform: A Versatile, Multi-Modal, Coaxial, All-Terrain Vehicle

Mobile and aerial robots offer many potential applications, including warehouse logistics, surveillance, cinematography, and search and rescue. However, most such robots are task-specific and generally need more versatility to tackle multiple scenarios, terrains, and unstructured, dynamic environments. This paper presents the Omnirotor platform, a versatile, multi-modal, coaxial, tilt-rotor, all-terrain vehicle that combines an Unmanned Aerial Vehicle (UAV) and an Unmanned Ground Vehicle (UGV) into a hybrid, all-terrain vehicle. The Omnirotor has two locomotion modes of operation (aerial and ground vehicle) and five operation configurations, as it can fly both in the normal and inverted configurations, and it can drive on the ground both in the normal and inverted configurations. It can also recover from any non-operational state to its normal, upside-down configuration. Moreover, in addition to the locomotion modes, the continuous omnidirectional thrust vectoring enables the Omnirotor platform to perform complex manipulation of objects. This work introduces the concept and discusses in detail the design, development, and experimental validation of the Omnirotor platform. In particular, it discusses the modeling and control schemes required by the different operation modes and configurations. It experimentally validates the platform’s capabilities with experiments focusing on traversing challenging environments and unstructured, uneven terrains (e.g., a public park). Finally, the platform’s ground, pushing-based manipulation capabilities are demonstrated through the execution of a puzzle-solving experiment where the solved puzzle serves as a landing platform for the all-terrain vehicle. The versatility of Omnirotor offers exciting prospects for use in challenging search-and-rescue scenarios, surveillance, and aerial and ground manipulation applications.

Avian assemblages are maintained after aerial applications of ULV fenitrothion for control of the Australian plague locust (Chortoicetes terminifera (Walker)) in arid and semiarid agroecosystems

Context Risk assessments currently undertaken to approve pesticides for use against locusts in Australia are predominated by laboratory-generated data, often collected from non-endemic species. Very little information exists concerning the potential ecological effects of insecticides used for locust control. Aim To determine the effect of aerial ultra-low volume (ULV) applications of the organophosphorous insecticide, fenitrothion (used for locust control), on avian assemblages in arid and semiarid agro-ecosystems. Methods Avian abundance was surveyed in pesticide-exposed and unexposed locations during standard locust control operations, using fenitrothion, in western New South Wales and Queensland in the spring and summer of 1996, 1997 and 2000, using a transect-point method. Temporal changes in assemblages were analysed using multi-dimensional ordination (MDS) and permutational analysis of variance (PERMANOVA) with PRIMER (V7). Key results Avian assemblages varied over time, independent of pesticide application, reflecting significant redistribution and mobility of birds across a highly disturbed agricultural landscape, irrespective of pesticide exposure. Additionally, pesticide exposure did not affect species abundance or diversity. Conclusions There was no evidence that ultra-low volume (ULV) applications of fenitrothion, currently used in locust control, are impacting avian assemblages, despite previous research indicating that individual birds co-occurring with spray operations suffer suppressions in the enzymatic biomarker for OP exposure, plasma acetylcholinesterase (AChE). Implications Although the risk to avian assemblages associated with the aerial application of locusticides is reduced by the small proportion of the landscape where locust control activities are focused, any change in spray application parameters would necessitate a re-evaluation of the risks associated with insecticide exposure.

TRIGGER: A Lightweight Universal Jamming Gripper for Aerial Grasping

This work introduces TRIGGER, the first lighTweight univeRsal jammInG Gripper for aErial gRasping. TRIGGER is an omnidirectional, landing-capable aerial grasping system with resilience and robustness to collisions and inherent passive compliance. In particular, this work presents the design, fabrication, and experimental validation of a novel, intelligent, modular, universal jamming gripper specifically designed for aerial applications. Leveraging recent developments in particle jamming and soft granular materials, TRIGGER produces 15N of holding force with only a relatively small activation force of 2.5N. Experiments show the relationship between fill ratio and activation force and reveal that adding an additive to the membrane's silicone mixture improves the holding force by up to 52%. The concept is validated by mounting TRIGGER onto a multicopter performing a pick-and-release task under laboratory conditions. Based on the experimental data, a model for robotic simulators is introduced to facilitate future controller developments.

Critical analysis of the extensive aerial application of pesticides and its implications for human health

Critical analysis of the extensive aerial application of pesticides and its implications for human health

Comparative Study of Real-Time Semantic Segmentation Networks in Aerial Images During Flooding Events

Real-time semantic segmentation of aerial imagery is essential for unmanned ariel vehicle applications, including military surveillance, land characterization, and disaster damage assessments. Recent real-time semantic segmentation neural networks promise low computation and inference time, appropriate for resource-limited platforms, such as edge devices. However, these methods are mainly trained on human-centric view datasets, such as Cityscapes and CamVid, unsuitable for aerial applications. Furthermore, we do not know the feasibility of these models under adversarial settings, such as flooding events. To solve these problems, we train the most recent real-time semantic segmentation architectures on the FloodNet dataset containing annotated aerial images captured after hurricane Harvey. This article comprehensively studies several lightweight architectures, including encoder–decoder and two-pathway architectures, evaluating their performance on aerial imagery datasets. Moreover, we benchmark the efficiency and accuracy of different models on the FloodNet dataset to examine the practicability of these models during emergency response for aerial image segmentation. Some lightweight models attain more than 60% test mIoU on the FloodNet dataset and yield qualitative results on images. This article highlights the strengths and weaknesses of current segmentation models for aerial imagery, requiring low computation and inference time. Our experiment has direct applications during catastrophic events, such as flooding events.

Toughing epoxy nanocomposites with graphene-encapsulated liquid metal framework

Multifunctional epoxy nanocomposites have long been pursued as the crucial component of future aerial vehicles, while their practical implementation is unfortunately restricted by the poor toughness and incapability of chemical activity derived from highly cross-linked networks. Here, inspired by “brittle–ductile” laminated architecture, a stress-induced graphene-encapsulated liquid metal framework was developed to enhance the fracture toughness of multifunctional epoxy nanocomposites and their electromagnetic interference shielding, outdoor deicing and crosslinking behaviors were discussed. The resulting “brittle-ductile” laminated structure enables effective crack deflection and unique fracture surface; the plane strain fracture toughness (KIC) of epoxy nanocomposites is 2.34 times higher than that of pure epoxy resin. Moreover, the reinforced epoxy nanocomposites exhibited high electromagnetic interference shielding effectiveness of 48.24 dB at X-band, about 20 times greater than that of the pure epoxy (∼2.4 dB), and its efficient solar de-icing capability enable spontaneously melting surface ice/frost within 3 min. The dimensionless Cure Index (CI) was used for qualitative analysis of epoxy crosslinking in the presence of graphene-encapsulated liquid metal framework performed by nonisothermal differential scanning calorimetry (DSC). This work shows for the first time to the best of our knowledge graphene encapsulated liquid metal framework as reinforced fillers in epoxy nanocomposite achieve a unification of high toughness, electromagnetic shielding capabilities, and solar deicing properties. Present work thus provides an alternative of constructing high-toughness multifunctional epoxy nanocomposites for aerial vehicles application.

SRODNet: Object Detection Network Based on Super Resolution for Autonomous Vehicles

Object detection methods have been applied in several aerial and traffic surveillance applications. However, object detection accuracy decreases in low-resolution (LR) images owing to feature loss. To address this problem, we propose a single network, SRODNet, that incorporates both super-resolution (SR) and object detection (OD). First, a modified residual block (MRB) is proposed in the SR to recover the feature information of LR images, and this network was jointly optimized with YOLOv5 to benefit from hierarchical features for small object detection. Moreover, the proposed model focuses on minimizing the computational cost of network optimization. We evaluated the proposed model using standard datasets such as VEDAI-VISIBLE, VEDAI-IR, DOTA, and Korean highway traffic (KoHT), both quantitatively and qualitatively. The experimental results show that the proposed method improves the accuracy of vehicular detection better than other conventional methods.

A mechanism-based fate model of pesticide solutions on the plant surface under aerial application

ABSTRACT Pesticide residues on plant surfaces are a primary source of pesticide bioaccumulation in crops. In this context, we propose a mechanism-based model for understanding the pesticide fate on the plant surface following aerial application, taking into account fate modelling of the pesticide spray solution on the plant surface. Using chlorothalonil as an example, the simulation results revealed that the spray solution dissipated rapidly after aerial application, resulting in the formation of a saturated pesticide solution, which facilitated the diffusion process of the pesticide residue from the plant surface into the peel tissue. The proposed model generated higher simulated residue concentrations in the peel or pulp than the current model, owing to the proposed model’s assumption of rapid dissipation of the spray solution. This indicated that the proposed model specified the influence of the spray solution on the plant’s exposure to residues via the surface deposition pathway, whereas the current modelling approach presented a generic estimate of the residue dissipation on the plant surface that linked to the residue’s fate in the soil.

Ansys-Based Evaluation of Natural Fiber and Hybrid Fiber-Reinforced Composites

In this research, we analyzed natural composite structures that optimize the material and weight of the structure. Green composites are made of natural fibers and epoxy resin that are biodegradable, recyclable, and eco-friendly. Core material failures include wrinkling, failure in compression, and buckling. To address these issues, this work attempted to create CAD models using jute fiber, glass fiber, and epoxy resin with various ply sequences using angle orientations of 0°, 30°, and 45°, and 2–4 mm thick laminates were produced. After creating CAD models, the material strength, stiffness, deformation of samples, shear strength, strain, and other mechanical properties of the natural-fiber-reinforced composite laminates were analyzed. The samples were based on two layers of glass fiber as a core with natural fiber plies below and above this core. The natural fiber with epoxy resin, the hybrid composite with jute fiber, and the glass fiber with epoxy resin were prepared and mechanical properties of the samples were evaluated with Ansys. The results indicated that the 0° ply orientation of 3 mm thickness had a low deformation (0.237 mm) and was the best material. The tensile test was performed for natural-fiber-reinforced composite and hybrid natural reinforced composite laminates at various thicknesses and at various ply orientations using a tensile load of 2500 N. In this investigation, the best material was the one with the thickness of 3 mm with the Young modulus 35.59 GPa at 0.149 strain with 5303 Pa stress conditions. Further, the above conditions were noted with low deformation (0.237 mm) at 0° ply orientation and tensile strength was noted as 1188 GPa at 3 mm with 45° ply orientation. This hybrid composite material can be considered for unmanned aerial vehicle applications.

Potential risk to aquatic biota from aerial application of firefighting water additives

The frequency and severity of forest fires is increasing due to climate change. Consequently, there will be an increased use of forest firefighting additives, which increase the ability of water to extinguish fires and prevent reignition. Increased use will potentially result in increased exposure to aquatic ecosystems within forests. This study examined the toxicity of nine firefighting water additives that are currently on the market to three species of freshwater invertebrates that occupy different niches within freshwater ecosystems. The toxicity of the water additives varied up to three orders of magnitude. Pelagic and epibenthic invertebrates are affected at lower rates of application than endobenthic invertebrates. A field relevant application rate of three of the nine water additives tested represent a hazard to freshwater ecosystems under varies exposure scenarios represented by the depth of a theoretical water body (15–200 cm). This study highlights the importance of application buffers around water bodies and the selection of water additives that pose the lowest hazard to freshwater ecosystem, assuming that the efficacy of the additives in extinguishing fires is similar.

Reflectance Measurement Method Based on Sensor Fusion of Frame-Based Hyperspectral Imager and Time-of-Flight Depth Camera.

Hyperspectral imaging and distance data have previously been used in aerial, forestry, agricultural, and medical imaging applications. Extracting meaningful information from a combination of different imaging modalities is difficult, as the image sensor fusion requires knowing the optical properties of the sensors, selecting the right optics and finding the sensors' mutual reference frame through calibration. In this research we demonstrate a method for fusing data from Fabry-Perot interferometer hyperspectral camera and a Kinect V2 time-of-flight depth sensing camera. We created an experimental application to demonstrate utilizing the depth augmented hyperspectral data to measure emission angle dependent reflectance from a multi-view inferred point cloud. We determined the intrinsic and extrinsic camera parameters through calibration, used global and local registration algorithms to combine point clouds from different viewpoints, created a dense point cloud and determined the angle dependent reflectances from it. The method could successfully combine the 3D point cloud data and hyperspectral data from different viewpoints of a reference colorchecker board. The point cloud registrations gained 0.29-0.36 fitness for inlier point correspondences and RMSE was approx. 2, which refers a quite reliable registration result. The RMSE of the measured reflectances between the front view and side views of the targets varied between 0.01 and 0.05 on average and the spectral angle between 1.5 and 3.2 degrees. The results suggest that changing emission angle has very small effect on the surface reflectance intensity and spectrum shapes, which was expected with the used colorchecker.

Herbicide spray drift from ground and aerial applications: Implications for potential pollinator foraging sources

A field spray drift experiment using florpyrauxifen-benzyl was conducted to measure drift from commercial ground and aerial applications, evaluate soybean [Glycine max (L.) Merr.] impacts, and compare to United States Environmental Protection Agency (US EPA) drift models. Collected field data were consistent with US EPA model predictions. Generally, with both systems applying a Coarse spray in a 13-kph average wind speed, the aerial application had a 5.0- to 8.6-fold increase in drift compared to the ground application, and subsequently, a 1.7- to 3.6-fold increase in downwind soybean injury. Soybean reproductive structures were severely reduced following herbicide exposure, potentially negatively impacting pollinator foraging sources. Approximately a 25% reduction of reproductive structures up to 30.5-m downwind and nearly a 100% reduction at 61-m downwind were observed for ground and aerial applications, respectively. Aerial applications would require three to five swath width adjustments upwind to reduce drift potential similar to ground applications.

Observations on populations of a small insectivorous bird,

The use of chemical pesticides to manage locust populations in natural ecosystems is likely to impact non-target arthropods and their predators. However, the relative effects of different locust control applications on Australian birds are unknown. Aerial applications of fipronil and fenitrothion are examples of two pesticides used in locust control in semiarid Australia. To test the relative impacts of pesticides on non-target fauna, pesticides were applied to replicate sites using aerial ultra-low-volume application methods. The body condition and biomarkers of pesticide exposure in resident white-winged fairy wrens (Malurus leucopterus leuconotus) at treatment and control sites were measured for two weeks before and after treatments. No measures suggested negative impacts of pesticide applications. However, birds monitored at treatment sites gained mass, possibly due to indirect impacts of pesticides on bird feeding patterns or the availability or behaviour of insect prey. Bird mass measures remained high at fipronil sites, whereas the mass of birds at fenitrothion sites returned to baseline levels within one week. As this study was conducted during dry conditions, when locust plagues are less likely, future insecticide research should also consider the availability of insect prey, its effect on insectivore feeding behaviour and the interaction of rainfall events.

Performance releaser with smart anchor learning for arbitrary‐oriented object detection

AbstractArbitrary‐oriented object detection is widely used in aerial image applications because of its efficient object representation. However, the use of oriented bounding box aggravates the imbalance between positive and negative samples when using one‐stage object detectors, which seriously decreases the detection accuracy. We believe that it is the anchor learning strategy (ALS) used by such detectors that needs to take the responsibility. In this study, three perspectives on ALS design were summarised and ALS—Performance Releaser with Smart Anchor Learning (PRSAL) was proposed. Performance Releaser with Smart Anchor Learning is a dynamic ALS that utilises anchor classification ability as an equivalent indicator to anchor box regression ability, this allows anchors with high detection potential to be filtered out in a more reasonable way. At the same time, PRSAL focuses more on anchor potential and it is able to automatically select a number of positive samples that far exceed that of other methods by activating anchors that previously had a low spatial overlap, thereby releasing the detection performance. We validate the PRSAL using three remote sensing datasets—HRSC2016, DOTA and UCAS‐AOD as well as one scene text dataset—ICDAR 2013. The experimental results show that the proposed method gives substantially better results than existing models.

Efficacy of cuprous oxide for control of dothistroma needle blight in Pinus radiata plantations in Australia

ABSTRACT Dothistroma needle blight (DNB, Dothistroma septosporum) is a significant disease in Pinus radiata plantations on the Northern Tablelands of New South Wales and in the Murray Valley region of Victoria/New South Wales, Australia. Aerial application of copper oxychloride has been used to control DNB in these regions since soon after it was established. Research in New Zealand, however, has identified cuprous oxide as a more efficient and cheaper fungicide for controlling DNB. In this study, we test the efficacy of a single (applied in late October–early November) and double (October and February) application of cuprous oxide for controlling severe (50%) DNB in P. radiata plantations on the Northern Tablelands. We established replicated blocks 5–10 ha in size to ensure the results were operationally valid. Disease severity and defoliation were assessed on individual trees pre- and post-treatment, and aerial surveys were conducted to gauge the effect of treatments on the subsequent operational fungicide spray program. Cuprous oxide application significantly (P 0.01) reduced disease severity compared with no application, with a second application reducing severity even further. Ten months post-treatment, tree-level disease severity was 39% in unsprayed plots, 31% in single-sprayed plots and 8.5% in double-sprayed plots. The double application effectively reduced disease to negligible levels, while the single application provided adequate control for up to three months. At an operational level, even the single fungicide application reduced disease severity at the block scale when mapped during aerial surveys. Based on aerial assessments that trigger control action, all unsprayed plots required fungicide application in the season after the study (2013), while only two of seven single-sprayed blocks and none of the double-sprayed blocks required additional control. Extrapolating from this, a single fungicide application meant that 70% of the area did not require a fungicide application in the subsequent year. Based on these results and evidence from New Zealand, we recommend that cuprous oxide replace copper oxychloride for DNB control in Australia and that a double application is used in areas with severe (50%) levels of the disease.

Understanding Spray Attributes of Commercial UAAS as Impacted by Operational and Design Parameters

Unmanned aerial application systems (UAAS) have recently gained momentum for the application of crop protection (CP) products. Due to their high operational efficiency, mobility, and low cost, UAAS may be perceived as a more viable option for spray application when compared to conventional application techniques, especially backpack/knapsack sprayers. However, being a relatively new technology and not a common practice in the USA, there are no best management practices or guidelines for testing UAAS spray performance. Therefore, this study was undertaken to assess the impact of different attributes pertinent to UAAS flight (e.g., altitude, speed, etc.), application (e.g., droplet size, tank additive, etc.), and UAAS design (e.g., nozzle placement relative to a the rotor) on spray performance. The spray performance was evaluated in terms of swath and spray drift (ground and airborne) using water-sensitive papers (WSP) and mylar card/string samplers, respectively. The samplers were respectively analyzed using image processing and fluorometry techniques. The different treatments under study were UAAS type (MG-1P and AG V6A+), flight altitude (1.5, 2.5, and 4.0 m) and speed (2 and 3 ms−1), and nozzle type (XR11001 and XR8002 flat fan nozzles) with different droplet volume median diameter (VMD) at ~207 kPa (very fine [140 µm] and fine [196 µm], respectively). The results indicated a highly variable swath for both platform types. While nozzles under each rotor may be a common design in commercial UAAS, the results indicated that placement of nozzles out on a boom might have a less variable swath and a lower drift potential. In addition, flying slower, using a relatively larger droplet VMD (i.e., 196 µm at ~207 kPa) may reduce both ground and airborne drift. This study may serve as a guideline for growers/operators to evaluate their UAAS platforms and optimize key attributes pertinent to UAAS operation for effective spraying.