UAV environmental perception and autonomous obstacle avoidance: A deep learning and depth camera combined solution

An Internet of Things assisted Unmanned Aerial Vehicle based artificial intelligence model for rice pest detection

We propose a submap-based technique for mapping of underwater structures with complex geometries. Our approach relies on the use of probabilistic volumetric techniques to create submaps from multibeam sonar scans, as these offer increased outlier robustness. Special attention is paid to the problem of denoising/enhancing sonar data. Pairwise submap alignment constraints are used in a factor graph framework to correct for navigation drift and improve map accuracy. We provide experimental results obtained from the inspection of the running gear and bulbous bow of a 600-foot, Wright-class supply ship.

Underwater inspection using sonar-based volumetric submaps

Although drift is not a new issue, it deserves further attention for Unmanned Aerial Spraying Systems (UASS). The use of UASS as a spraying tool for Plant Protection Products is currently explored and applied worldwide. They boast different benefits such as reduced applicator exposure, high operating efficiency and are unconcerned by field-related constraints (ground slope, ground resistance). This review summarizes UASS characteristics, spray drift and the factors affecting UASS drift, and further research that still needs to be developed. The distinctive features of UASS comprise the existence of one or more rotors, relatively higher spraying altitude, faster-flying speed, and limited payload. This study highlights that due to most of these features, the drift of UASS may be inevitable. However, this drift could be effectively reduced by optimizing the structural layout of the rotor and spraying system, adjusting the operating parameters, and establishing a drift buffer zone. Further efforts are still necessary to better assess the drift characteristics of UASS, establish drift models from typical models, crops, and climate environments, and discuss standard methods for measuring UASS drift.

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Characteristics of unmanned aerial spraying systems and related spray drift: A review

UAV-spray application in vineyards: Flight modes and spray system adjustment effects on canopy deposit, coverage, and off-target losses.

Effect of operational parameters of UAV sprayer on spray deposition pattern in target and off-target zones during outer field weed control application

Over the last decade, Unmanned Aerial Vehicles (UAVs), also known as drones, have been broadly utilized in various agricultural fields, such as crop management, crop monitoring, seed sowing, and pesticide spraying. Nonetheless, autonomy is still a crucial limitation faced by the Internet of Things (IoT) UAV systems, especially when used as sprayer UAVs, where data needs to be captured and preprocessed for robust real-time obstacle detection and collision avoidance. Moreover, because of the objective and operational difference between general UAVs and sprayer UAVs, not every obstacle detection and collision avoidance method will be sufficient for sprayer UAVs. In this regard, this article seeks to review the most relevant developments on all correlated branches of the obstacle avoidance scenarios for agricultural sprayer UAVs, including a UAV sprayer’s structural details. Furthermore, the most relevant open challenges for current UAV sprayer solutions are enumerated, thus paving the way for future researchers to define a roadmap for devising new-generation, affordable autonomous sprayer UAV solutions. Agricultural UAV sprayers require data-intensive algorithms for the processing of the images acquired, and expertise in the field of autonomous flight is usually needed. The present study concludes that UAV sprayers are still facing obstacle detection challenges due to their dynamic operating and loading conditions.

https://www.mdpi.com/2073-4395/11/6/1069/pdf

A State-of-the-Art Analysis of Obstacle Avoidance Methods from the Perspective of an Agricultural Sprayer UAV’s Operation Scenario

For granular materials, discrete element modeling is one of the best computer tools to simulate their behavior and interactions. A field experiment was carried out to evaluate the performance of disc furrow openers in paddy soil. Discrete element simulation was done to develop a 3D DEM model for notched, toothed and double disc furrow openers using EDEM software. Hertz Mindlin contact model with bonding was applied for simulation to fulfill the obligations of the soil moisture and bonding between the cohesive particles. Simulated and field experimental data were compared to determine the applicability in the different working conditions. The results of the simulation validated the applicability of the Hertz-Mindlin contact model with bonding to simulate the no till paddy soil using an extremely narrow tillage tool. The calibrated value of normal and shear stiffness was 5×107 N/m, and the calibrated value of bond normal and shear strength was 3×107 Pa. The relative error (–1.7% to 20.6%) for the double disc furrow opener was lower as compared with that notch typed (29.2% to 44.4%) and toothed type (31.5% to 45.9%) furrow openers.
Keywords: soil tillage, discrete element method, discrete element modeling, furrow opener, paddy soil
DOI: 10.25165/j.ijabe.20201304.4800

Citation: Ahmad F, Qiu B J, Ding Q S, Ding W M, Khan Z M, Shoaib M, et al. Discrete element method simulation of disc type furrow openers in paddy soil. Int J Agric & Biol Eng, 2020; 13(4): 103–110.

http://www.abepublishing.org/journals/index.php/ijabe/article/download/4800/pdf

Discrete element method simulation of disc type furrow openers in paddy soil

As a new type of crop protection machinery, the Crop Protection Unmanned Aerial System (CPUAS) has developed rapidly and been widely used in China; currently, how to use the CPUAS scientifically has become a top priority. However, the relationships between the operating parameters of the CPUAS and the effective spraying width (ESW), droplet distribution characteristics, and control effects of insect pests and diseases are not clear yet. Therefore, three levels of flight speed (FS) as 3, 4, and 5 m/s, three levels of flight height (FH) as 1.5, 2.0, and 2.5 m, and spraying volume 2.0 L/min experiments were carried out to investigate the effects of FS and FH on the ESW, droplet deposition uniformity (DDU), and droplet penetration rate (DPR) by using an electric single-rotor CPUAS CE20. Based on the obtained results, combined with the insect pests and diseases occurrence agronomic laws, the optimal operation parameters of the CPUAS were selected to control the wheat aphids, powdery mildew, and head blight. The results showed that the ESW of CE20 was not consistent, the maximum value was 5.78 m, and the minimum one was 2.51 m. The FS had a highly significant impact on ESW (p = 0.0033 < 0.01), while the FH and the interaction between FS and FH had no significant impact on ESW. The coefficients of variation (CV) of the droplet deposition were between 23.3% and 34.4%, which meant good deposition uniformity. The FH (p = 0.0019) and the interaction between FS and FH (p = 0.02) had significant impacts on the DDU. The control effects on aphids were 78.71% (1 day), 84.88% (3 days), and 90.42% (7 days), the control effects on powdery mildew were 77.17% (7 days) and 82.83% (14 days), and the control effect on head blight was 88.32% (20 days). This study proved that by the optimization of parameters and the combination of agronomy, good control effects for insect pests and diseases could be achieved by the CPUAS. The research results would provide some technical supports for CPUAS application.

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Effects of Crop Protection Unmanned Aerial System Flight Speed, Height on Effective Spraying Width, Droplet Deposition and Penetration Rate, and Control Effect Analysis on Wheat Aphids, Powdery Mildew, and Head Blight

The invention relates to a railed self-propelled multimode automatic atomizing machine for a greenhouse. A rail is erected below a ceiling arch pipe of the greenhouse through hanging rods along the length direction of the greenhouse, and a self-propelled platform is mounted on the rail to move along the rail. A lifting module, an atomizing module, an air supply module, a control system and the like are mounted on a frame of the self-propelled platform to move on the rail along with the self-propelled platform. Nozzles and an air supply spray pipe are mounted on a T-shaped supporting frame which is fixed to a slider of the lifting module, and immersing into a tall crop canopy to implement atomization is realized. A remote control module, a position sensor and a stroke sensor are mounted onthe self-propelled platform, corresponding triggers are mounted on the rail, and a liquid level sensor is mounted on a pesticide tank. Sensor signals are all transmitted to a PLC controller, and the controller outputs control instructions to drive module executing terminals. The atomizing machine executes start-stop motion of the self-propelled platform according to a selected operating mode, enables on and off of the atomizing module, the air supply module and the lifting module and executes operation action to cooperatively complete atomization.

Baijing Qiu

Papers

Effect of operational parameters of UAV sprayer on spray deposition pattern in target and off-target zones during outer field weed control application

A State-of-the-Art Analysis of Obstacle Avoidance Methods from the Perspective of an Agricultural Sprayer UAV’s Operation Scenario

Discrete element method simulation of disc type furrow openers in paddy soil

Effects of Crop Protection Unmanned Aerial System Flight Speed, Height on Effective Spraying Width, Droplet Deposition and Penetration Rate, and Control Effect Analysis on Wheat Aphids, Powdery Mildew, and Head Blight

Railed self-propelled multimode automatic atomizing machine for greenhouses