Development of a Laser-Guided, Embedded-Computer-Controlled, Air-Assisted Precision Sprayer

Abstract. An embedded computer-controlled, laser-guided, air-assisted, variable-rate precision sprayer was developed to automatically adjust spray outputs on both sides of the sprayer to match the presence, size, shape, and foliage density of tree crops in real time. The sprayer was the integration of an embedded computer, a touch screen, a 270° radial-range laser sensor, a travel speed sensor, a unique algorithm, a custom-designed automatic flow rate control unit, and 40 pulse-width-modulated (PWM) nozzles. The accuracy of the sprayer to detect different-sized trees and control the spray outputs of individual nozzles based on tree structures was tested in a commercial nursery. Spray deposition qualities between variable-rate and constant-rate operational modes of the sprayer were also compared. Test results demonstrated the capability of the sprayer to measure different trees accurately and then control the spray outputs of nozzles independently to match tree structure. The outline profile similarity of paired images taken with a digital camera and with the laser sensor for three trees ranged from 0.81 to 0.89. To spray trees of different sizes and shapes, the sprayer in variable-rate mode (VRM) consumed 12.1% to 43.3% of the spray volume that was used in constant-rate mode (CRM) with an application rate of 468 L ha-1. Moreover, the sprayer had 30% and 55% greater coverage areas per amount of spray deposits in VRM than in CRM. This innovative sprayer should have significant potential to reduce pesticide waste, provide sustainable crop protection to growers, and safeguard the environment. Keywords: Automation, Nursery, Orchard, Precision agriculture, Variable-rate sprayer.

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Variable-rate Spray Technology Optimizes Pesticide Application by Adjusting for Seasonal Shifts in Deciduous Perennial Crops

HortTechnology ◽

10.21273/horttech04794-21 ◽

2021 ◽

pp. 1-11

Author(s):

Lloyd L. Nackley ◽

Brent Warneke ◽

Lauren Fessler ◽

Jay W. Pscheidt ◽

David Lockwood ◽

...

Keyword(s):

Growing Season ◽

Variable Rate ◽

Pesticide Application ◽

Canopy Density ◽

Perennial Crops ◽

Constant Rate ◽

Canopy Volume ◽

Computer Controlled ◽

Spray Volume ◽

Adequate Coverage

To optimize pesticide applications to the canopies of deciduous perennial crops, spray volume should be adjusted throughout the year to match the changes in canopy volume and density. Machine-vision, computer-controlled, variable-rate sprayers are now commercially available and claim to provide adequate coverage with decreased spray volumes compared with constant-rate sprayers. However, there is little research comparing variable- and constant-rate spray applications as crop characteristics change throughout a growing season. This study evaluated spray volume, spray quality (e.g., coverage and deposit density), and off-target spray losses of variable- and constant-rate sprayers across multiple phenophases in an apple (Malus domestica) orchard and a grape (Vitis vinifera) vineyard. The variable-rate sprayer mode applied 67% to 74% less volume in the orchard and 61% to 80% less volume in the vineyard. Spray coverage (percent), measured by water-sensitive cards (WSC), was consistently greater in the constant-rate mode compared with the variable-rate mode, but in many cases, excessive coverage (i.e., over-spray) was recorded. The variable-rate sprayer reduced off-target losses, measured by WSC coverage, up to 40% in the orchard and up to 33% in the vineyard. Spray application deposit densities (droplets per square centimeter) on target canopies were typically greater in variable-rate mode. However, the deposit densities were confounded in over-spray conditions because droplets coalesced on the WSC resulting in artificially low values (i.e., few, very large droplets). Spray efficiencies were most improved early in the growing season, when canopy density was lowest, demonstrating the importance of tailoring spray volume to plant canopy characteristics.

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Embedded Computer-Controlled Premixing Inline Injection System for Air-Assisted Variable-Rate Sprayers

Transactions of the ASABE ◽

10.13031/trans.58.11037 ◽

2015 ◽

pp. 39-46

Keyword(s):

Injection System ◽

Variable Rate ◽

Embedded Computer ◽

Computer Controlled

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Embedded computer-controlled laser sensor-guided air-assisted precision sprayer development

10.13031/aim.20152188550 ◽

2015 ◽

Keyword(s):

Laser Sensor ◽

Embedded Computer ◽

Computer Controlled

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A Path Model of the Intention to Adopt Variable Rate Irrigation in Northeast Italy

Sustainability ◽

10.3390/su13041879 ◽

2021 ◽

Vol 13 (4) ◽

pp. 1879

Author(s):

Maurizio Canavari ◽

Marco Medici ◽

Rungsaran Wongprawmas ◽

Vilma Xhakollari ◽

Silvia Russo

Keyword(s):

Technology Acceptance ◽

Precision Agriculture ◽

Ease Of Use ◽

Perceived Usefulness ◽

Path Model ◽

Irrigated Agriculture ◽

Variable Rate ◽

Intention To Adopt ◽

Factors Influencing ◽

Variable Rate Irrigation

Irrigated agriculture determines large blue water withdrawals, and it is considered a key intervention area to reach sustainable development objectives. Precision agriculture technologies have the potential to mitigate water resource depletion that often characterises conventional agricultural approaches. This study investigates the factors influencing farmers’ intentions to adopt variable rate irrigation (VRI) technology. The Technology Acceptance Model 3 (TAM-3) was employed as a theoretical framework to design a survey to identify the factors influencing farmers’ decision-making process when adopting VRI. Data were gathered through quantitative face-to-face interviews with a sample of 138 fruit and grapevine producers from the Northeast of Italy (Veneto, Emilia-Romagna, Trentino-Alto Adige, Friuli-Venezia Giulia). Data were analysed using partial least squares path modelling (PLS-PM). The results highlight that personal attitudes, such as perceived usefulness and subjective norm, positively influence the intention to adopt VRI. Additionally, the perceived ease of use positively affects intention, but it is moderated by subject experience.

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Using laser sensor for measuring crop conditions in precision agriculture

10.13031/aim.20131596640 ◽

2013 ◽

Author(s):

Yongjun Zheng ◽

Yubin Lan ◽

Feng Kang ◽

Chao Ma ◽

He Chen ◽

...

Keyword(s):

Precision Agriculture ◽

Laser Sensor

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SPECIFICATIONS OF A PROTOTYPE SOFTWARE SYSTEM FOR DEVELOPING VARIABLE-RATE TREATMENT PRESCRIPTIONS FOR USE IN PRECISION AGRICULTURE

Conference on Applied Statistics in Agriculture ◽

10.4148/2475-7772.1108 ◽

2007 ◽

Cited By ~ 2

Author(s):

Kevin S. McCarter ◽

Eugene Burris ◽

George A. Milliken ◽

Ernest L. Clawson ◽

Hoi Yee Wong ◽

...

Keyword(s):

Precision Agriculture ◽

Software System ◽

Variable Rate ◽

Prototype Software

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Spray deposition inside multiple-row nursery trees with a laser-guided sprayer1

Journal of Environmental Horticulture ◽

10.24266/0738-2898-35.1.13 ◽

2017 ◽

Vol 35 (1) ◽

pp. 13-23 ◽

Cited By ~ 1

Author(s):

H. Zhu ◽

H. Liu ◽

Y. Shen ◽

Hengyu Liu ◽

R. H. Zondag

Keyword(s):

High Speed ◽

Laser Scanning ◽

Quercus Rubra ◽

Spray Deposition ◽

Field Tests ◽

Red Oak ◽

Northern Red Oak ◽

Tree Structures ◽

Speed Sensor ◽

Tilia Tomentosa

Abstract Multiple-row container-grown trees require specially designed sprayers to achieve efficient spray delivery. A five-port air-assisted sprayer with both automatic and manual control modes was developed to discharge adequate spray deposition inside multiple-row trees. The sprayer resulted from integration of a high-speed laser-scanning sensor with a sophisticated nozzle flow control system, an embedded computer with a touch screen, a Doppler speed sensor, a specially-designed algorithm and an air-assisted sprayer base. It was able to detect target tree presence and measure target tree size, shape and leaf density. The sprayer then controlled the spray output of each nozzle to match tree structures. The sprayer was tested for its sprayer deposition quality inside canopies in a four-row sterling silver linden (Tilia tomentosa 'Sterling Silver' Moench) field and another six-row northern red oak (Quercus rubra L.) field. Tests were conducted with the sprayer in variable-rate application (VRA) and constant-rate application (CRA) modes. The average spray deposit on foliage of trees was 1.37±0.47 μL cm−2 from VRA and 1.29±0.42 μL cm−2 from CRA in linden, and was 2.15±0.57 μL cm−2 from VRA and 2.72±0.94 μL cm−2 from CRA in red oak, respectively. In comparison, spray coverage on foliage of trees was 19.8±3.0% from VRA and 20.9±4.3% from CRA in the linden trial, and was 27.9±3.7% from VRA and 30.5±5.4% from CRA, respectively, in the red oak trial. The newly developed air-assisted sprayer in both VRA and CRA modes would be able to discharge adequate spray deposition inside multiple-row tree plants while conserving pesticide. Index words: environmental protection, pest control, pesticide, precision sprayer, spray coverage. Species used in this study: sterling silver linden (Tilia tomentosa 'Sterling Silver' Moench), northern red oak (Quercus rubra L.).

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Chemical Concentration and Spatial Uniformity of a Premixing In-Line Injection System Attached to a Variable-Rate Orchard Sprayer

Transactions of the ASABE ◽

10.13031/trans.14113 ◽

2021 ◽

Vol 64 (6) ◽

pp. 1977-1987

Author(s):

Zhihong Zhang ◽

Heping Zhu ◽

Zhiming Wei ◽

Ramon Salcedo

Keyword(s):

Spatial Distribution ◽

Duty Cycle ◽

Spray Deposition ◽

Injection System ◽

List Type ◽

Variable Rate ◽

Chemical Concentration ◽

Fluorescent Tracer ◽

Distribution Uniformity ◽

The Mean

HighlightsA newly developed premixing in-line injection system attached to a variable-rate orchard sprayer was evaluated.Tests were conducted to verify the in-line injection system performance using a vertical spray patternator.Concentration accuracy and spatial distribution uniformity were determined with a fluorescent tracer.Uniform spray mixtures were obtained for different spray viscosities and duty cycle combinations.Abstract. Pesticide spray application efficiency is highly dependent on the chemical concentration accuracy and spatial distribution uniformity. In this study, the performance of a newly developed premixing in-line injection system was evaluated when it was attached to a laser-guided, pulse width modulated (PWM), variable-rate orchard sprayer. The chemical concentration accuracy was determined with respect to spray deposition with a fluorescent tracer, and the spatial distribution uniformity was determined with spray deposits at different heights on a vertical spray patternator. Outdoor tests were conducted with 27 combinations of target chemical concentration (1.0%, 1.5%, and 2.0%), viscosity of the simulated pesticide (1.0, 12.0, and 24.0 mPa·s), and various spray outputs manipulated with PWM duty cycles. For each injection loop, the amounts of the chemical concentrate and water discharged into the mixing line were measured separately in response to preset target concentrations. The results showed that the measured concentrations were consistent across the patternator heights, spray viscosities, and duty cycle combinations. For all treatments, the mean absolute percentage error (MAPE) of the measured concentration was 6.96%, indicating that the concentration accuracy of the system was acceptable. The mean coefficient of variation was 3.35%, indicating that the spatial distribution uniformity of the system was in the desirable range. In addition, there was little variation in chemical concentration for spray mixtures collected at different heights on the patternator. Thus, the premixing in-line injection system could adequately dispense chemical concentrate and water to produce accurate concentrations and uniform spray mixtures for variable-rate nozzles to discharge to targets. Keywords: Environment protection, Precision pesticide application, Laser-guided sprayer, Tank mixture disposal, Specialty crop.

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