Operational characteristics of four metering systems for agricultural fertilizers and amendments

Camacho-Tamayo, Jesús Hernán; Barbosa, Angela M.; Pérez, Nancy M.; Leiva, Fabio R.; Rodriguez, G.

doi:10.1590/s0100-69162009000400010

Cited by 12 publications

(13 citation statements)

References 11 publications

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“…As noted from the results obtained by UMEZU & CAPPELLI (2006) and CAMACHO-TAMAYO et al (2009), the mass flow rate as a function of average angular speed of the shaft of the applicator can be approximated by a linear curve. This corroborates that the angular speed of the drive shaft does not affect the transport efficiency of the applicator; otherwise it would be a noticeable non-linearity factor in the simulation results obtained.…”

Section: Resultsmentioning

confidence: 95%

“…These speeds were defined from the maximum and minimum angular speed applied to the shaft and their multiple dosing. CAMACHO-TAMAYO et al (2009) presented a mathematical model of the average application rate provided by an auger-type applicator that correlates the angular speed and does not take time as a relevant factor in the expected application rate. This model showed a linear relationship between the application rate and the angular speed of the auger of the applicator.…”

Section: F (η; A; P; θ(T); ρ) θ(T)mentioning

confidence: 99%

“…It should be noted also that the lower the transport efficiency, the more inconsistent the fertilizer application will be. Typically, for auger-type applicators, the efficiency of transport does not depend on the angular speed of the auger axis, because, as noted by CAMACHO-TAMAYO et al (2009), the application rate behaves linearly as a function of the angular speed of the drive shaft. In the same study, the authors noted that factors that affect the transport efficiency are associated with the physical characteristics of the fertilizer, such as density and embankment slope, as well as the design characteristics of the applicator mechanism.…”

mentioning

confidence: 99%

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Auger-type granular fertylizer distributor: matemathical model and dynamic simulation

García¹,

Cappelli

Umezu³

2012

Eng. Agríc.

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ABSTRACT:The objective of this study was to model mathematically and to simulate the dynamic behavior of an auger-type fertilizer applicator (AFA) in order to use the variable-rate application (VRA) and reduce the coefficient of variation (CV) of the application, proposing an angular speed controller ( ) for the motor drive shaft. The input model was and the response was the fertilizer mass flow, due to the construction, density of fertilizer, fill factor and the end position of the auger. The model was used to simulate a control system in open loop, with an electric drive for AFA using an armature voltage (V A ) controller. By introducing a sinusoidal excitation signal in V A with amplitude and delay phase optimized and varying during an operation cycle, it is obtained a reduction of 29.8% in the CV (constant V A ) to 11.4%. The development of the mathematical model was a first step towards the introduction of electric drive systems and closed loop control for the implementation of AFA with low CV in VRA.KEYWORDS: seeder fertilizer drill, modeling, precision agriculture. DOSADOR HELICOIDAL DE FERTILIZANTE GRANULAR: MODELO MATEMÁTICO E SIMULAÇÃO DA DINÂMICARESUMO: O objetivo deste trabalho foi modelar matematicamente e simular o comportamento dinâmico de um dosador helicoidal de fertilizantes (DHF) a fim de utilizá-lo em aplicação a taxas variáveis (ATV)e reduzir o coeficiente de variação (CV) da aplicação, propondo uma forma de atuação na velocidade angular de acionamento ( ) do seu eixo. A entrada do modelo foi e a resposta foi a vazão mássica de fertilizante em função de suas características construtivas, densidade do fertilizante, fator de enchimento e posição do fim do helicoide. O modelo foi usado na simulação de um sistema de controle em malha aberta, com o acionamento do DHF feito por meio de um motor elétrico com atuação na tensão de armadura (V A ). Introduzindo-se um sinal de excitação senoidal em V A com amplitude e defasagem otimizada, consequentemente variando-se durante um ciclo de operação, obteve-se redução no CV de 29,8 % (V A constante) para 11,4 %. O desenvolvimento do modelo matemático foi um primeiro passo no sentido da introdução de acionamento elétrico e de sistemas de controle em malha fechada, visando à aplicação de DHF com baixos índices de CV em ATV.

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Section: Resultsmentioning

confidence: 95%

Section: F (η; A; P; θ(T); ρ) θ(T)mentioning

confidence: 99%

mentioning

confidence: 99%

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Auger-type granular fertylizer distributor: matemathical model and dynamic simulation

García¹,

Cappelli

Umezu³

2012

Eng. Agríc.

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“…GARCIA et al (2012) verified in experimental tests applying fertilizer with a helical injector driven by a fixed angular speed, CV of approximately 20%. On the other hand, CAMACHO TAMAYO et al (2009), under similar conditions, obtained CV around 32%.…”

Section: Resultsmentioning

confidence: 68%

Electrically driven fertilizer applicator controlled by fuzzy logic

2014

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The present study shows the development, simulation and actual implementation of a closed-loop controller based on fuzzy logic that is able to regulate and standardize the mass flow of a helical fertilizer applicator. The control algorithm was developed using MATLAB's Fuzzy Logic Toolbox. Both open and closed-loop simulations of the controller were performed in MATLAB's Simulink environment. The instantaneous deviation of the mass flow from the set point (SP), its derivative, the equipment´s translation velocity and acceleration were all used as input signals for the controller, whereas the voltage of the applicator's DC electric motor (DCEM) was driven by the controller as output signal. Calibration and validation of the rules and membership functions of the fuzzy logic were accomplished in the computer simulation phase, taking into account the system's response to SP changes. The mass flow variation coefficient, measured in experimental tests, ranged from 6.32 to 13.18%. The steady state error fell between -0.72 and 0.13g s -1 and the recorded average rise time of the system was 0.38 s. The implemented controller was able to both damp the oscillations in mass flow that are characteristic of helical fertilizer applicators, and to effectively respond to SP variations.KEYWORDS: fertilizer applicator, agricultural machinery, closed-loop control. DOSADOR DE FERTILIZANTE ACIONADO ELETRICAMENTE E CONTROLADOPOR LÓGICA FUZZY RESUMO: Este trabalho apresenta o desenvolvimento, a simulação e a implementação de um sistema de controle, em malha fechada, baseado em lógica fuzzy, para regular e uniformizar a vazão mássica aplicada por um dosador de fertilizante do tipo helicoidal. A estratégia de controle foi desenvolvida, utilizando-se da ferramenta "Fuzzy Logic Toolbox", do programa MATLAB. Foi simulado, em linguagem Simulink -MATLAB, o sistema operando em malha aberta e em malha fechada. A variável manipulada pelo controlador foi a tensão do motor elétrico de corrente contínua (MECC), e as suas variáveis de entrada foram: o erro e a variação do erro entre a vazão mássica atual aplicada e o valor de referência (VR), além da velocidade de deslocamento e a variação da velocidade de deslocamento do equipamento. A sintonia e o projeto das regras das funções de pertinência da lógica fuzzy foram realizados por meio de simulações, além de verificação de que o sistema foi capaz de responder às mudanças no VR. Nos testes experimentais, o coeficiente de variação da vazão mássica ficou entre 6,32 e 13,18%, o erro em regime estacionário variou de -0,72 a 0,13 g s -1 e o tempo de resposta médio foi de 0,38 s. O sistema de controle foi capaz de reduzir a característica oscilatória da vazão mássica aplicada pelo mecanismo dosador e foi eficiente em acompanhar as mudanças do VR.PALAVRAS CHAVE: adubadora, máquinas agrícolas, controle em malha-fechada.

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“…This behavior was also observed in earlier studies. [13][14] The effect was described as ''fullness effect.'' [13] Finally, the VRTDATA_Host.vi acquired the data published as network variables by VRTCTRL_RT.vi via the network.…”

Section: Labview Programmentioning

confidence: 99%

A Novel Variable Rate Pneumatic Fertilizer Applicator

Ishola

Yahya

Shariff

et al. 2014

Instrumentation Science & Technology

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& The canopy prevents the use of global positioning system based fertilizer applicators in oil palm plantations. Hence, a radio frequency identification triggered variable rate pneumatic fertilizer system was developed for this application. A real-time embedded system was used as the core controller, Lab-VIEW software was used to program and coordinate the operations of the embedded system and the host computer. A speed measuring unit was used to provide feedback to the system. A field test was conducted to examine the response time. The sensors were calibrated in the laboratory and the measurement linearity had regression coefficients close to 1. Two to three seconds were required for the device to respond to changes in application rate. It is expected that this approach will become an alternative in plantations where the canopy hinders proper application of global positioning systems.

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Operational characteristics of four metering systems for agricultural fertilizers and amendments

Cited by 12 publications

References 11 publications

Auger-type granular fertylizer distributor: matemathical model and dynamic simulation

Auger-type granular fertylizer distributor: matemathical model and dynamic simulation

Electrically driven fertilizer applicator controlled by fuzzy logic

A Novel Variable Rate Pneumatic Fertilizer Applicator

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