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

2015 ◽  
pp. 39-46
Keyword(s):  
Injection System ◽  
Variable Rate ◽  
Embedded Computer ◽  
Computer Controlled

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

2017 ◽  
Vol 60 (6) ◽  
pp. 1827-1838 ◽  
Author(s):  
Yue Shen ◽  
Heping Zhu ◽  
Hui Liu ◽  
Yu Chen ◽  
Erdal Ozkan
Keyword(s):  
Precision Agriculture ◽  
Spray Deposition ◽  
Crop Protection ◽  
Control Unit ◽  
Laser Sensor ◽  
Variable Rate ◽  
Tree Structures ◽  
Embedded Computer ◽  
Constant Rate ◽  
Computer Controlled

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.

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

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.

scholarly journals Improved premixing in-line injection system for variable-rate orchard sprayers with Arduino platform

2019 ◽  
Vol 162 ◽  
pp. 389-396 ◽  
Author(s):  
Zhihong Zhang ◽  
Heping Zhu ◽  
Huseyin Guler ◽  
Yue Shen
Keyword(s):  
Injection System ◽  
Variable Rate

Development of a real-time chemical injection system for air-assisted variable-rate sprayers

2013 ◽  
Author(s):  
Yue (or initial) Shen ◽  
Heping (or initial) Zhu ◽  
Hui (or initial) Liu ◽  
Yu (or initial) Chen ◽  
Erdal H. Ozkan
Keyword(s):  
Real Time ◽  
Injection System ◽  
Variable Rate

Elimination of membrane compliance in undrained triaxial testing.II. Mitigation by injection compensation

1993 ◽  
Vol 30 (5) ◽  
pp. 739-746 ◽  
Author(s):  
P.G. Nicholson ◽  
R.B. Seed ◽  
H.A. Anwar
Keyword(s):  
Large Scale ◽  
Closed Loop ◽  
Injection System ◽  
Triaxial Testing ◽  
Granular Soils ◽  
Confining Stress ◽  
Controlled System ◽  
Computer Controlled ◽  
Large Scale Tests ◽  
Correction System

A computer-controlled injection-correction system has been developed to continuously and completely mitigate the adverse effects of membrane compliance for undrained testing of granular soils. The system was developed with the explicit idea that it could be quickly and easily adapted to most any up to date triaxial testing apparatus. A relationship between effective confining stress and volumetric compliance can be predetermined, as volumetric-compliance errors have been shown to be a direct and repeatable function of effective confining stresses for a given material. The predetermination of volumetric-compliance errors represents a suitable basis for control of injection–removal compensation for membrane compliance during undrained testing. A closed-loop computer-controlled system continuously monitors changes in sample effective confining stresses such that precalculated volumetric-compliance errors can be continuously offset by injecting or removing volumes of water equal to those errors throughout the duration of each test. The validity of the injection system was verified by comparison of the compensated tests to results of large-scale (300 mm diameter) tests of the same materials, as compliance effects for large-scale tests of this material were negligible. Key words : membrane, penetration, compliance, undrained testing, triaxial, compensation, liquefaction.

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

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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