ABSTRACT Statistical process control has been widely used in agricultural operations for monitoring and improving process quality. This study aims to evaluate the Shewhart and exponentially weighted moving average (EWMA) control charts to monitor the performance of an agricultural tractor–planter set. The design is completely randomized based on the assumptions of statistical process control and comprises two treatments: day and night shift treatments. The data to assess the performance of the tractor–planter set are collected during the day and night shifts and used to evaluate the operating speed, motor rotation, engine oil pressure and water temperature, and hourly fuel consumption. The dataset comprised 40 samples compiled from the frontal monitor column inside a tractor cab. It is concluded that both Shewhart and MMEP/EWMA control charts can be used to evaluate engine performance based on the quality indicator parameters investigated, regardless of the normality assumption of the datasets.

ABSTRACT Sugarcane mechanized harvesting can lead to serious risks to the longevity of plantations when improperly operated, and may cause damages and disturbances in the remaining ratoons in the field. In this sense, this study aimed to evaluate the damage and disturbance to the sugarcane ratoons by the base cutting quality of two-blade models through statistical process control. The experiment was carried out during the 2015/16 growing season in an agricultural area of the Moreno Mill, located in Cravinhos, São Paulo, Brazil. The sugarcane harvester models A8800 (Machine 1) and BE1035 (Machine 2). The sugarcane variety cultivated in both treatments was SP80-1816. Thirty points were sampled per harvester, with 10-minute intervals between them. Equations were used to calculate the indices, which were then evaluated through descriptive analysis and statistical process control. Machine 2 presented process instability for the index of damages, with lower data variability. On the other hand, Machine 1 presented instability during the process due to the quality indicator and index of disturbance, but with a lower operation variability.

ABSTRACT The mechanized sugarcane harvesting process is considered one of the major economic bottlenecks, with low operational efficiency and, mainly, high losses of stalks left in the field. In order to minimize these problems and assist in the improvement of processes, this study aimed to evaluate the losses in the mechanized sugarcane harvesting using statistical process control. The experimental design was completely randomized, based on the methodology of statistical process control with samples collected on five work fronts during the daytime and nighttime operation. The experiment was carried out in an agricultural area of a sugarcane mill in the municipality of Ribeirão Preto, SP, Brazil, on five sugarcane harvest fronts. Losses were measured using a 3.0 × 3.33-m frame, being divided into stump, loose piece + fixed piece, whole sugarcane, fragment, and total losses for each harvest front. The data were grouped into 50 weeks over the sugarcane-growing season, and statistical analyses were performed using the Minitab 16® software. Losses of loose piece + fixed piece were higher than the losses of stump, whole sugarcane, and fragment. The total losses showed higher and lower losses for the fronts F5 and F4, respectively, compared to the others.

ABSTRACT The mechanized harvesting of sugarcane has increased exponentially in recent years because of the gradual prohibition of burning on the cane fields in mechanizable and non-mechanizable areas. This study aimed to evaluate the wear of the basal cutting knives in two different mechanized sugarcane harvesters, through statistical process control. The experiment was conducted in Cravinhos, São Paulo, in an agricultural area, on July 25, 26, and 27, 2016. Two harvesters with different basal cutting mechanisms were evaluated: harvester A—Model BE1035e (conventional type knife), and harvester B—Model A8800 (racket type knife). The experimental design was completely randomized with two treatments. The wear was quantified by measuring the thickness increase and width losses of each knife, and it was evaluated for each harvester every 2 hours, during 3 days of operation. Data were evaluated using descriptive statistics and statistical process control. The harvester B model (racket knife) presented lower variability in the cutting width and stability in the cutting width of the knives. The harvester A model (conventional knife) presented greater wear in the width, but less variability in the thickness of the cutting wire.

RESUMO O direcionamento automático de máquinas agrícolas via sinal GNSS (Global Navigation Satellite System) tem sido adotado cada vez mais pela comunidade agrícola na última década. Produtores de amendoim estão adotando tal tecnologia a fim de melhorar o paralelismo das operações face às dificuldades principalmente encontradas no arranquio mecanizado, onde as perdas são, todavia, um grande problema. Objetivou-se avaliar as operações mecanizadas de semeadura e de arranquio de amendoim controlados manualmente e com piloto automático, juntamente com a qualidade das operações. Os tratamentos consistiram de duas operações de escavação, com e sem piloto automático, e duas velocidades de deslocamento (4,5 e 6,0 km h-1). O experimento foi realizado em solo de textura média, sob delineamento inteiramente casualizado disposto em faixas, utilizando-se das variáveis analisadas como indicadores de qualidade. Na semeadura foi avaliado o paralelismo entre as passadas do conjunto trator-semeadora em 120 pontos de cada sistema (direcionamento manual e automático). Foram avaliadas as perdas de arranquio nos dois sistemas de direcionamento sob duas velocidades de deslocamento (4,5 e 6,0 km h-1), em 15 pontos de cada tratamento. Verificou-se que o paralelismo entre as passadas do conjunto trator-semeadora foi melhor quando se utilizou do piloto automático, além da maior qualidade da operação. A velocidade de deslocamento não influenciou as perdas de arranquio. Não houve diferenças nas perdas visíveis de arranquio, porém quando o arranquio foi realizado com o piloto automático obteve-se maior qualidade. Menores perdas invisíveis e totais de arranquio foram obtidas quando o arranquio foi realizado com o direcionamento automático, e qualidade superior foi obtida na velocidade de 4,5 km h-1; porém, a qualidade foi afetada negativamente sob operação manual. Portanto, o uso do piloto automático se mostrou eficaz na melhoria da precisão e da qualidade das operações.

ABSTRACT Over the past decade, automatic guidance of agricultural machinery via Global Navigation Satellite System (GNSS) signals has been increasingly adopted by the farming community. Peanut farmers are adopting such technology in order to improve the parallelism of operations to address difficulties that occur in mechanical digging, where losses are a big problem. This study aimed to evaluate mechanized operations of peanut sowing and digging controlled manually and by autopilot, along with their quality. The treatments consisted of two digging operations, with and without autopilot, and two displacement speeds (4.5 and 6.0 km h-1). The experiment was conducted in a medium-textured soil in a completely randomized design arranged in bands, using the analyzed variables as quality indicators. At sowing, parallelism between passes of the tractor-sower set, was evaluated at 120 points of each system (manual and automatic routing). The digging losses were evaluated in the two guidance systems, under two displacement speeds (4.5 to 6.0 km h-1) at 15 points per treatment. It was verified that the parallelism between the passes of the tractor-sower set was better when using the autopilot, which improved the operation quality. Displacement speed did not influence the digging loss. There were no differences in the visible digging loss, but higher quality was obtained when the operation was performed using autopilot. Minor invisible and total digging losses were obtained when the digging was performed with automatic routing, and superior quality was found at a speed of 4.5 km h-1; however, quality was adversely affected under manual operation. Thus, the use of autopilot is effective for improving the accuracy and the quality of the operations.

ABSTRACT Work in the field is characterized as unstructured because it is performed in inconvenient postures, without a fixed workstation, exposing the worker directly to the sun and other inclement weather. This may interfere in the health and the performance of the activity. The objective of this work was to characterize the environment of the agricultural microtractor operator, evaluating the thermal comfort during the activity in the municipality of Quixadá, CE. A model TC14 Super Yanmar Agritech microtractor, coupled to a rotary spindle, was used. For the measurements of the environmental variables, sensors and devices were installed on the operator and in the microtractor. The experimental design adopted the assumptions of statistical quality control. Fifteen collections were done daily at different times for three consecutive days. The data obtained were indices of thermal discomfort and thermography, both of which were analyzed by sequential graphs (run charts), control graph (Xbar-R chart), and scatter plot. At all rates, the work performed proved to be inadequate, exceeding the operator's capabilities and limitations. It was concluded that the activity performed by the microtractor operator is stressful. Measures should be taken to improve working conditions without affecting the operator's health.

RESUMO O sucesso da lavoura de soja depende de diversos fatores, entre eles cita-se a utilização de sementes de elevada qualidade fisiológica a fim de garantir a obtenção da população de plantas desejada na lavoura. Dessa forma, objetivou-se, por meio das ferramentas do Controle Estatístico de Processo (CEP), monitorar possíveis falhas no processo de produção das sementes e buscar relação entre os testes de germinação e tetrazólio. O delineamento experimental foi baseado nas premissas do CEP, utilizando como indicadores de qualidade a porcentagem de germinação, viabilidade das sementes, danos mecânicos, por percevejo e por umidade. Foi possível detectar falhas no processo de produção de sementes de soja por meio das cartas de controle, dos testes de germinação e tetrazólio, sendo principalmente estas causas relacionadas a danos mecânicos e ataque de percevejos.

ABSTRACT The success of soybean cultivation depends on several factors, one which is the use of high-quality seeds, which can guarantee growth of the desired plant population. The objective of this study was to monitor possible failures during the seed production process, and to determine the association between germination and tetrazolium tests through tools of Statistical Process Control (CEP). The experimental design was based on premises of the CEP, using percentage of germination, seed viability, mechanical damage, bed bug, and moisture as indicators of quality. It is possible to detect flaws in the soybean production process through control charts, as well as through germination and tetrazolium tests; results indicated that germination failures are largely caused by mechanical damage and bed bug attacks.

RESUMO A qualidade da colheita mecanizada de soja é essencial para garantir que todo investimento realizado nas demais etapas do processo produtivo da cultura seja convertido em lucro para o produtor. Considerando que a qualidade dessa operação está relacionada com menores perdas e que a plataforma de corte utilizada e a velocidade de colheita podem influenciar nisso, objetivou-se avaliar a qualidade da colheita mecanizada da soja, no Cone Sul de Rondônia, em colhedoras com diferentes plataformas de corte e velocidades de deslocamento por meio do controle estatístico de processo. O experimento foi realizado na safra 2015/16 em uma área agrícola no município de Cabixi, RO, localizada nas coordenadas geográficas 13º 27’ S e 60º 41’ W. O delineamento experimental foi estabelecido de acordo com as premissas do controle estatístico de processo, sendo amostrados 80 pontos distanciados a cada 100 m. Avaliaram-se as perdas na plataforma, nos mecanismos internos e totais e a altura de corte. A melhor qualidade do processo de colheita foi obtida na plataforma de esteira, com pouca influência da velocidade de deslocamento. O nível de perdas na colheita foi acima do limite aceitável, indicando necessidade de melhorias do processo.

ABSTRACT Assuring the quality of mechanical soybean harvesting is crucial to ensure that investment in other stages of crop production is converted into profit for the farmer. Because the quality of this operation is related to decreased losses, which may be affected by the combine header used and by the harvesting speed, the aim of the present study was to assess the quality of mechanical soybean harvesting in the Southern Cone of Rondônia, using harvesters with different combine headers and travel speeds via statistical process control. The experiment was performed during the 2015/16 harvest in an agricultural area of the municipality of Cabixi, RO, located at the geographical coordinates 13° 27’ S and 60° 41’ W. The study was designed based on the premises of the statistical process control, sampling 80 points 100 m apart. Combine header, internal, total, and cutting height losses were assessed. Quality of the harvesting process was assessed using the draper header. Travel speed had little effect on process quality. Crop losses were higher than the acceptable limit, indicating the need to improve the process.

ABSTRACT Studies conducted by the international labor organization have shown that operations involving agricultural machinery are among the three activities with the highest risk of accidents to workers. Among the possible causes, rollover is the most common, accounting for 33% of fatal accidents. Despite this, there are standards that provide for the use of safety devices to ensure the physical integrity of the operator, among these equipment stand out rollover protection structures, which can be foldable or not. In this sense, the objective of this study was to perform an ergonomic study in order to analyze the torque required for lowering and lifting a foldable rollover protection structure attached to an agricultural tractor, developing instrumentation for validation of the efforts required to operate the structure and comparing the results obtained with the values recommended by the Standard (CODE 6 - OECD). When torque values were above those recommended by the standard, a set of torsion springs was used as solution to torque reduction. After further testing, the effectiveness of the solution was verified. Furthermore, it was observed that the angular speed of the bar does not have a significant influence on the torque required to lift the bar.

ABSTRACT The quality control is used for the evaluation of processes and products, and it is important to detect and reduce variability and in operations management can be applied in mechanized harvesting of sugarcane billets. In this sense, this study aimed to identify critical quality indicators and, if necessary, to develop a continuous improvement plan for harvest of sugarcane billets. For the survey and definition of critical quality indicators the FMEA (Failure Mode and Effect Analysis) was applied, after the formation of the quality technical team. Evaluations of the collected variables were through control charts of individual values and the process capability indexes. There are 8 critical quality indicators in the billets harvesting process; the cutting height, the damage index, the percentage of non-viable buds and operating speed have greater importance for analysis due to the risk priority index and the easiness of obtaining data for analysis. The development of the improvement plan aims to reduce the variability due to crop billets, thus, making it able to perform the operation within the required quality standards.

ABSTRACT: The intensive mechanization during the harvest operation and success of this operation depends on several factors, one of which is the length and format of the plots. The aim of this study was to evaluate the operating performance of a soybean harvester in different geometric plots shape, using as quality indicators performance parameters by means of statistical control tools of process. The experiment was conducted in March 2014 in the city of Uberaba - MG. Operational capacity was evaluated in the mechanical harvesting of soybeans in three plots: irregular, rectangular and trapezoidal. Performance evaluations of soybean harvester were made from the following parameters: displacement speed, engine rotation, cylinder rotation and concave opening. The grain water contents affect the quality indicators of the soybean harvester performance in all plots shapes. The harvester performance is considered able to maintain between the specification limits and close to the target, to speed quality indicators the irregular and the trapezoidal plots and for cylinder rotation the trapezoidal plot.

ABSTRACT: Information on harvester performance is important in the management and optimization of mechanized agricultural systems. In this sense, the aim of this study was to monitor the operation quality of soybean mechanical harvesting in different plot shapes by means of statistical process control. The harvest was carried out in an agricultural area of a farm located in Uberaba, MG, Brazil, with an experimental design based on the assumptions of statistical quality control and 18, 28, and 24 replications for irregular, rectangular, and trapezoidal plots, respectively. The variables and/or quality indicators of harvester performance were forward speed, engine speed, cylinder speed, and concave opening. The lowest variation occurred in the irregular plot for the quality indicators forward speed and engine speed of harvester. Engine speed and the concave opening of harvester were unstable for all plot shapes. Only the cylinder speed of the soybean harvester presented process stability during operation for the three plot shapes.

ABSTRACT: The mechanized gathering process of sweeping coffee is extremely important to reduce the losses of fruit not used in the harvesting operation. But this operation usually has a low operational performance and a high cost per unit collected in this way any measures that can effectively reduce costs increase the viability of the operation. In this sense, studies on adequacy tractor mass for each operation show improvement in energy use, reducing fuel consumption. So, this study aimed to quantify the fuel consumption and effective power along the process of a tractor 4x2 FWD pulling the coffee harvester. I was used as treatments three ballasting settings, these being equivalent the relations power to weight of 36, 39 and 42 kg hp-1 working with and without activated FWD, randomized statistically, with 10 repetitions each configuration. It was conclude that, at low power-weight ratio, the front wheel drive assist had no significant influence on the hour fuel consumption. Already in the configuration with higher ratio, the use of front wheel drive favored in reducing fuel consumption and better energy use.

ABSTRACT The digging of peanut, which has the pod production in the subsurface, is directly affected by soil conditions, physical or environmental characteristics, at the time of operation and may be the cause of unwanted losses. Therefore, the quality of the operation is very important for minimizing these losses. Thus, this study aimed to evaluate the quality of mechanized digging operation of peanut according to three soil textural classes (Sandy, Medium and Loamy) and their water content conditions at operation through statistical process control. The experiment was conducted at three locations in the state of São Paulo, Brazil, under sampling scheme arranged in tracks and 40 sampling points for each textural class of soil, using the mechanical digging variables as indicators of quality. We found that the mechanized digging operation in Sandy soil was the most critical, just meeting the specifications of quality indicators, reflecting higher losses and lower quality of the operation. Medium soil showed at the digging good and homogeneous conditions in relation to water content in soil and pods, and because it has favorable characteristics it obtained the lower total losses and higher quality of operation. Loamy soil showed satisfactory quality, meeting the specifications as well, but with poorer quality than the Medium Soil.

RESUMO A colheita mecanizada de soja é fundamental no processo produtivo desta cultura e, caso não seja realizada adequadamente, poderá resultar em danos mecânicos severos às sementes, acarretando prejuízos significativos na colheita, particularmente devido à redução da qualidade. Neste sentido se objetivou, neste trabalho, avaliar a qualidade física e fisiológica das sementes de soja em três velocidades da colhedora, por meio do controle estatístico de processo. O experimento foi realizado em área agrícola, no município de Conceição das Alagoas, MG, com três velocidades de deslocamento da colhedora (4,5; 5,0 e 5,5 km h-1). As amostras de sementes foram coletadas em intervalos de 20 min durante 3 h de operação, totalizando nove amostras para cada velocidade. As avaliações foram realizadas a partir dos seguintes parâmetros: temperatura das sementes, teor de água, abertura do côncavo, rotação do cilindro, danos mecânicos e condutividade elétrica. A qualidade física e fisiológica das sementes foi influenciada pela velocidade de deslocamento da máquina. A maior velocidade apresentou menor valor de dano mecânico e maior vigor das sementes de soja.

ABSTRACT The mechanized harvesting of soybean is a fundamental tool in the production process of this crop and, if not performed properly, it can result in severe mechanical damage to the seeds, causing significant losses at harvest, particularly due to reduced quality. Thus, this study aimed to evaluate the physical and physiological quality of soybean seeds at three speeds of the harvester, using statistical process control. The experiment was carried out in the municipality of Conceição das Alagoas, MG, Brazil, with three travel speeds: 4.5, 5.0 and 5.5 km h-1. The seed samples were collected at 20 min intervals for 3 h of operation, with a total of 9 samples for each speed. The evaluations were performed based on the following parameters: grain temperature, water content, concave opening, cylinder rotation, mechanical damage and electrical conductivity. The physical and physiological quality of the seeds was dependent on the displacement speed of machine. The highest speed led to lower mechanical damage and higher vigor of soybean seeds.