Agricultural Tractor Operators Research Articles

Identification of variation in mental strain of an agricultural tractor operator in the field during precise fertilizer spreading

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Effects of the Speed of Mechanical Tillage on the Structure of Ferralitic Soil

The present work consists in evaluating the impacts of the plowing speed of three-body plows/discs hitched to a 60 HP tractor, on the structure of the ferralitic soil, and determining the optimal speed which guarantees good soil and biomass retention capacities, bearing capacity and soil preservation leading to better yield and with a view to using motorized tools wisely in agricultural practices in the Benin plateau, from 2019-2021. All plowing was carried out on the same day on 21 plots, divided into 3 blocks of 7 elementary plots. The treatments are V0, V1, V2, V3, V4, V5, and V6, i.e. 2, 4, 6, 8, 10, and 12 km/h. V0 is a control. The tests are carried out according to the standards: NF EN ISO 17892-4.2018, for the particle size analysis, NF EN ISO 17892.2018, for the Atterberg limits, NF P 94-050.1995, for the water content by weight, NF XP P 94 -047.1998, for the rate of organic matter, NF EN 1097-3.1998, for the apparent density. Soil conductivity is determined by the Muntz method (double rings). The results show that plowing at an average speed (6 km/h) generates a better content of water and organic matter which are respectively 5.04 ± 0.76% and 0.304 ± 0.004% for the ploughshare than (6. 47±0.35%; 0.324± 0.012%) for the disc plow. The higher content of water and organic matter generated by the average speed of 6 km/h would limit the risks of embrittlement while guaranteeing a conservative tendency of fertility. This work will allow agricultural tractor operators to better perform ferralitic tillage operations taking into account the optimal plowing speed without seriously damaging the soil structure, a guarantee of sustainable development in agriculture.

Noise exposure and its impact on psychological health of agricultural tractor operators

Constant exposure of noise to the auditory system of the agricultural tractor opera- tor can cause physical and psychological problems. A field study was conducted in the Faisalabad and Narowal districts of Pakistan to examine the spread of tractor noise and its psychological effects on the safety of tractor operators driving tractors without cabins and other noise reduction measures. Four of the most common imple- ments used in Pakistan, including land scraper, cultivator, disk harrow and seed drill, were used to detect the changes in tractor noise at two speeds of 5.3 km/h and 10.6 km/h in all four directions. Lowest noise was produced during the field operation of the seed drill at a mean noise value of 81.9 dB(A) among all four implements. Disk harrow and cultivator were found to be the most noisy implement, and during oper- ation, the tractor operator was directly exposed to high noise levels of 86.9 dB(A) and 84.9 dB(A), respectively. This noise pollution caused psychological problems in agri- cultural tractor operators, as demonstrated by the highly positive correlations of de- pression, aggression, anxiety and stress. This trend had a negative effect on their social interactions relative to the comparable population of office employees. In or- der to mitigate the adverse health effects, tractor operators must be equipped with sound proof cabins or at least ear plugs because of direct exposure to high noise levels. Furthermore, a safe distance of 48 m or at least a warning distance of 26 m from the tractor must be maintained by farm workers.

Experimental comparison of smooth movement of an agricultural tractor with balancer suspension and torsion bar suspension

One of the reasons for the increased fatigue of tracked agricultural tractor operators is vibration. Reducing overall vibration is possible due to a change in suspension. All agricultural tracked tractors are equipped with an elastic balancing suspension, as a rule. Kharkov Tractor Plant has released an experimental batch of tractors with torsion bar suspension. The aim of this study was to determine the effect of the type of suspension on the smooth movement of the tractor. The experiment considered the real modes of operation of the tractor: plowing the ground in first and fourth gears, as well as the transport mode of movement. As a result of the tests, it was determined that the tractor with torsion suspension provides better ride comfort in transport mode. The torsion bar suspension has an advantage in the frequency range of 0.5–4 Hz, while the balancer suspension has an advantage in the high frequency range of 4–12 Hz when plowing the ground. The level of vibration acceleration of the floor of the tractor cab does not depend on the type of suspension in the frequency range above 12 Hz.

Avaliação do risco ergonômico de um operador agrícola em atividade de trituração de restos culturais

O objetivo do trabalho foi o de avaliar atividade de um operador, quanto a suas posições no posto de trabalho e a sua exposição a níveis de ruído em uma operação de trituração de restos culturais da cultura do milho. Além disso, sugerir possíveis alterações para a melhoria das condições de trabalho do operador. O estudo foi realizado no município de Santa Maria – RS, no qual foi avaliado o posto de trabalho de um operador de um trator agrícola durante a realização de uma atividade de trituração dos restos culturais de uma lavoura de milho, na qual foi utilizado um trator de 75cv e um triturador de restos culturais de 12 martelos. A operação foi registrada por fotos e vídeos, e estas foram avaliadas pelos métodos OWAS, REBA, RULA e QEC com o uso do software Ergolandia 7.0. Ademais, o nível de ruído foi medido com o uso de um decibelímetro. De acordo com os dados medidos foi possível verificar que o nível de ruído de 97,1dB sendo esse valor superior ao estabelecido pela NR 15 e com a análise dos métodos foi constatado a necessidade de realizar intervenções ergonômicas para que a atividade possa ser desempenhada de forma a não ocasionar riscos à saúde do operador.

Ergonomically based design of tractor control tools

Musculoskeletal injuries are well-known disorders among the agricultural tractor operators. Overexertion is a critical factor which can agitate these injuries. Physical body characteristics should be measured for an ergonomically best-fit-optimal design for the operators. In this study, a designed setup was employed to derive the applied forces by tractor operators on the control tools. The different muscle strengths including leg/foot strength, hand push/pull strength, and torque strength applied by both hands were measured. A comparison was made for the obtained values for different strengths by considering the effects of hand dominance. The obtained data were used to estimate the maximum allowed forces in these tools. In contrast to the previous studies, the minimum allowed actuating forces of the pedals were calculated using reasonable assumptions. These values could provide more comfort and less exhaustion for the tractor operators. The obtained ranges were benchmarked against corresponding recommended values in some standards (ISO, ISIRI, and ASABE family). The results revealed the unsuitability of evaluated standards for a proper design and the excessive overestimation of those recommended values (in some cases more than 3 times). In all of the design procedure, a suitable attention was paid to accommodate it with more than 90% of target population. Relevance to industryA prosperous industry which considers ergonomic factors in the design of agricultural machine workplace can overcome the disorders and generate more comfort. Evaluating more exact mechanical forces can result in a suitable design of workplace.

Health risk related to whole-body vibration in agricultural tractor: ballast and displacement speed

Mechanical vibration can lead to health problems in workers during the performance of their professional activi­ties. The objective of this study was to evaluate the vibration incident on the whole body of the agricultural tractor operator in a standard track of vibration tests under different ballast conditions and displacement speeds. A 4x2 AFWD agricultural tractor with 92 kW engine power was tested in four ballast conditions: total ballast (70 kN); solid ballast only (54 kN); liquid ballast only (54 kN); and without any ballast (48 kN), at four working speeds: 1.19 m s -1 ; 1.47 m s -1 ; 1.75 m s -1 and 2.08 m s -1 . The values regarding axle accelerations, the sum of axes for mean accelerations, and the vibration dose value were evaluated by analysis of variance and separation of means (Tukey, p<0.05), in addition to principal components analysis (PCA). Speed was the most influential factor in the vibration generated. The lowest values of mean acceleration and vibration dose value were found in the combina­tion of the lowest speeds with the highest weight of the tractor, while the highest values occurred in the combina­tion of higher speeds with lower weight and liquid ballast. The accelerations obtained on the y axis were more determinant in data behavior than those found in the x and z axes.

Attentional Control in Accidents Involving Agricultural Tractor Operators

Feature at a glance: Although a lack of safety features is often reported as the most important factor in tractor accidents, an accident per se is the outcome of many elements, including the amount of attentional control operators exert over the driving task. The lack of active attentional control is sometimes referred as “absentmindedness,” and many studies have investigated this phenomenon as the expression of individual differences. The present retrospective study represents a first attempt at investigating the relation between lack of attention and tractor accidents in a large sample of operators. The results show that attentional control is involved in tractor accidents, which can be taken as evidence of habit effects in operating agricultural machinery: Lower attentional control is required in routine actions, which makes expert operators more exposed to the possibility of making (skill-based) errors. This finding leads to suggestions for the design of future systems.

Measurement and evaluation of whole body vibration of agricultural tractor operator

Exposure of whole body vibration (WBV) influences performance, comfort, and long term health risks of tractor operator. Therefore, measurement and evaluation of WBV parameters should be carried out to find probable effects on the health of tractor operators. In this study, a system was designed to measure the WBV of agricultural tractor operators and evaluated the hazard risks on operator’s body according to the ISO standards, and implementation of the WBV test in the official testing station was also suggested. A tri-axial accelerometer was employed to measure vibrations transmitted to the seated operator body as a whole through the supporting surface of the buttock on four typical farm roads under different speeds. The vector sum A(8) exposures on the rough tracks (earthen and grassland roads) exceeded the action limits of 0.5 m/s2 at a 10.9 km/h forward speed and reached to the action limit value at a 16.0 km/h forward speed on the concrete road. The vector sum of VDV(8) exposures did not exceed the action limits of 9.1 m/s1.75 and was greater on the grassland road. The vector sum Sed(8) exposures values exceeded the moderate probability of an adverse health limit of 0.5 MPa on all farm roads at high forward speeds and exceeded the high probability of an adverse health limit of 0.8 MPa on asphalt, concrete, and grassland roads which should be lower than the exposure limit values as suggested by the ISO and EC standards. The WBV evaluation procedure should be considered for implementation at the official tractor test station, which would response to domestic and international tractor test regulations and improve the market competitiveness. Keywords: agricultural tractor, whole body vibration, tractor operator, driving safety, ride comfort, test standard, health risk DOI: 10.3965/j.ijabe.20171001.2113 Citation: Kabir Md S N, Chung S-O, Kim Y-J, Sung N-S, Hong S-J. Measurement and evaluation of whole body vibration of agricultural tractor operator. Int J Agric & Biol Eng, 2017; 10(1): 248–255.

УСЛОВИЯ ФОРМИРОВАНИЯ И ВАРИАНТЫ ТЕЧЕНИЯ ОСНОВНЫХ КЛИНИЧЕСКИХ СИНДРОМОВ ПРОФЕССИОНАЛЬНОЙ ВЕРТЕБРОГЕННОЙ ПОЯСНИЧНО-КРЕСТЦОВОЙ ПАТОЛОГИИ У ТРАКТОРИСТОВ

This paper focuses on the impact of working conditions of tractor operators on the development of occupational vertebral lumbar-sacral pathology. Clinical and progression specificities of occupational vertebral lumbar-sacral pathology in agricultural tractor operators are presented in there paper. The development of the pathology is related to hazardous occupational factors including general and local vibration, dynamic and static physical loads, incorrect body posture at work, cooling microclimate.

English

Due to the agricultural modernization, some crops already have their production process fully realized by farm machinery. In order to enhance operational performance and reduce both fatigue and accident risk, it is fundamental to provide a safe and adequate working environment. Therefore, the working station must be adapted to the operator’s anthropometric and mechanical characteristics. The present study aimed to evaluate the anthropometric profile of agricultural tractor operators in the macro-region of Ceara state’s west coast, and check whether the tractors are up to ISO and NBR ISO standards as well as to assess the risks of heart disease to which these drivers are exposed from epidemiological studies. The experiment was conducted in nine farms located along the macro-region of the Ceara state’s west coast, in the following cities, Itapipoca, Itarema, Acarau and Camocim with 39 agricultural tractor operators. For the samples, statistical analysis calculated were the minimum and maximum found values, mean, standard deviation, coefficient of variation, the amplitude and the percentiles of 5, 50 and 95%. The operators of the macro-region of the Ceara west coast had a lower height average than both the national average of 1.73 m and the Ceara state mean of 1.69 m. From the ISO and NBR ISO standards specifications evaluated, it is possible to say that the standards are either inadequate or partially unsuitable for the operators evaluated. Key words: Ergonomics, safety in agriculture, agricultural tractor, anthropometry.

CARACTERIZAÇÃO DAS VIBRAÇÕES MECÂNICAS NO E RUÍDO NO POSTO DE OPERAÇAO NO TRATOR AGRÍCOLA MODIFICADO “TRANSFORMAX”

Os estudos ergonômicos visam adaptar o trabalho ao homem por meio da análise da tarefa, da postura e dos movimentos do trabalhador, assim como de suas exigências físicas e psicológicas, no intuito de reduzir a fadiga e o estresse, proporcionando um posto de trabalho confortável e seguro. Um dos fatores indesejáveis que ocorre em tratores agrícolas é a vibração, não só por causa do desconforto produzido e possível degradação da saúde do operador, mas também por causa do aumento das tensões dinâmicas que podem levar à fadiga e insuficiência dos elementos do trator. Já o ruído excessivo pode causar diminuição ou perda da capacidade auditiva do operador quando o tempo de exposição for muito longo. Dessa forma, objetivou-se, avaliar os níveis de ruído e vibração no posto de operação do trator agrícola modificado Transformax®, em função da força de tração e rotação do eixo motriz, com tipos de rodados, com largura de 13.6 e 18.4. Para esse experimento, foi realizada uma análise de espectro de frequências para todos os tratamentos com intuito de verificar o comportamento das vibrações verticais e longitudinais na base do posto de operação, de acordo com cada faixa de frequência e os níveis de ruído foram determinados com auxílio de um decibelímetro digital, posicionado próximo ao ouvido do operador. As variáveis, força de tração e rotação do eixo motriz, não apresentaram efeito significativo nos níveis de ruído no posto de operação do trator, entretanto, os níveis médio de ruído foram mais elevados no trator quando equipado com pneu 18.4.

Development of a simplified method for evaluating agricultural tractor’s operator whole body vibration

Whole body vibrations (WBV) are one of the risk factors causing the onset of professional diseases in agricultural tractors operators: a method for assessing vehicle’s properties in terms of vibrations turns out to be fundamental for comfort and safety improvement. Studying agricultural tractor operator exposure to vibrations has always been difficult for the several topics to the tractor is used. Studies have pointed out that the combination of vehicle speed and surface roughness induces a transformation of part of vehicle forwarding speed in vertical accelerations acting as a series of impulses exciting the elastic parts of the tractor to have similar shapes in the frequency domain. Following this consideration the CREA-ING has developed three simplified test track, one for each axis of solicitation, for investigating the possibility of defining tractor’s comfort level with a simplified test.

Visibility Evaluation for Agricultural Tractor Operators According to ISO 5006 and 5721-1 Standards

Purpose: A system to measure the visibility of agricultural tractor operators was designed and evaluated according to ISO standards, and a blind area diagram around the tested tractor was created based on the manual method recommended by the National Institute for Occupational Safety and Health (NIOSH). Methods: A visibility measurement system was designed and evaluated based on the ISO 5006 and ISO 5721-1 standards. T wo bulbs used to simulate the operator's eyes were mounted on a bar with a supporting frame. A wooden frame was used to determine the seat index point position. The 12-m visibility test circle was divided into six sectors of vision, and the test tractor was placed at the center of the circle. Artificial light was supplied in the darkened environment, and shadow or masking effects were measured manually around the 12-m circle. Results: When the bulbs were placed at the operator’s eye level, front visibility was good; no masking was found in the “A” vision sector, but larger masking widths were found in the “B” and “C” vision sectors. Since the masking width exceeded 700 mm, additional tests, such as movement of the light sources to both sides of the operator’s eye level, were performed. Less than six masking effects were found in the semi-circle of vision to the front, and more than one masking was found in the “B” and “C” visual fields. The minimum distance between the centers of two masking effects exceeded 2500 mm when measured as a chord on the semi-circle of vision. A blind area diagram was created to define the exact nature of the blind spots and mirror visibility. Conclusions: Visibility evaluation is an effective way to enable proper and safe operation for agricultural tractor operators. Inclusion of this visibility evaluation test in the general testing process might aid tractor manufacturers.

Development of Driving Simulator for Safety Training of Agricultural Tractor Operators

Purpose: This study was aimed at developing a tractor-driving simulator for the safety training of agricultural tractor operators. Methods: The developed simulator consists of five principal components: mock operator control devices, a data acquisition and processing device, a motion platform, a visual system that displays a computer model of the tractor, a motion platform, and a virtual environment. The control devices of a real tractor cabin were successfully converted into mock operator control devices in which sensors were used for relevant measurements. A 3D computer model of the tractor was also implemented using 3ds Max, tractor dynamics, and the physics of Unity 3D. The visual system consisted of two graphic cards and four monitors for the simultaneous display of the four different sides of a 3D object to the operator. The motion platform was designed with two rotational degrees of freedom to reduce cost, and inverse kinematics was used to calculate the required motor positions and to rotate the platform. The generated virtual environment consisted of roads, traffic signals, buildings, rice paddies, and fields. Results: The effectiveness of the simulator was evaluated by a performance test survey administered to 128 agricultural machinery instructors, 116 of whom considered the simulator as having potential for improving safety training. Conclusions: From the study results, it is concluded that the developed simulator can be effectively used for the safety training of agricultural tractor operators.

Anthropometric model and obesity index of agricultural tractor operators

This work evaluates the anthropometric model of agricultural tractor operators, presenting a diagnosis of the control instruments’ position and the nutritional state of the operators. One hundred and twenty-seven agricultural tractors operators were interviewed, of which 23 were selected for the anthropometric evaluation. A rural company, a farm, a farmers’ meeting and a tractor dealership were selected for the data collection. Twenty-three anthropometric measurements of each operator were collected and arranged in a table with the dimensions of all operators, presenting statistical results in a 90% confidence interval. Two types of tractors of medium mass and similar power, representing the largest portion of the market, were used. The positioning of the tractors’ controls and their interactions with the operators’ area of reach, as well as their accessibility in the command position, were evaluated. The nutritional state of the tractor operators was studied, as well as the relationship of their body mass index with their age. The results show that there was no difference between the general operator types in South Brazil in regard to the measures of their height when standing erect. Seven of the operators who presented BMIs with characteristics of obesity within the normal range were less than 38 years old, and those with characteristics of pre-obesity and obesity were more than 38 years old. Key words: Ergonomics, control instruments, command position, body mass index.

NOTA TÉCNICA: ACIDENTES COM TRATORES AGRÍCOLAS: NATUREZA, CAUSAS E CONSEQUÊNCIAS - DOI: 10.13083/1414-3984.v22n04a08

Objetivou-se com o presente trabalho a caracterização dos acidentes com tratores agrícolas em algumas regiões do estado de Minas Gerais, permitindo definir as principais causas e suas consequências. O trabalho abrangeu 389 operadores de tratores agrícolas das regiões nordeste, central e leste de Minas Gerais. Os dados foram obtidos por meio da aplicação de questionário estruturado com questões fechadas aos operadores que já tenham sofrido acidentes com máquinas agrícolas. A frequência dos acidentes com tratores agrícolas nas regiões estudadas é alta, acidente de maior ocorrência foi o contato com as partes ativas do trator, seguido do capotamento. Verificou-se que a falta de treinamento e desconhecimento dos operadores são as principais causas de acidentes com tratores agrícolas.

Personal noise exposures of operators of agricultural tractors

Approximately one million agricultural tractors are used in Turkey for crop production and about one-third of the population lives in rural areas. The objectives of this study were to determine sound pressure levels, A-weighted sound pressure levels, and the permissible exposure time for tractors without cabins, field-installed cabins, and original cabins at ear level of agricultural tractor operators for following machines: plows, cultivators, top soil cultivators, rotary tillers, tool combinations (harrow + roller), mechanical drills, pneumatic drills, chemical applicators, fertilizer applicators, drum mowers, balers, and forage harvesters. Variance analyses showed that type of operation, type of cabins, and operation × cabin interactions were statistically significant ( P < 0.01) both for sound pressure levels and equivalent (A-weighted) sound pressure levels. The use of original cabins had a greater effect in decreasing average sound pressures and resulted in more efficient noise insulation, especially at higher center frequencies compared to field-installed cabins whereas field-installed cabins proved to be more favorable compared to tractors without cabins. Sound pressure levels at 4000 Hz center frequency was reduced 2–13 dB and 4–18 dB by using a field-installed cabin and an original cabin, respectively. The measured A-weighted equivalent sound pressure levels were compared to the threshold limit level, and was concluded that depending on the cabin types used, the operators could usually work from 4 to 6 h a day without suffering from noise induced inconveniences while 2–3 h is permissible for plowing and forage harvesting on tractors without cabins. Due to timeliness considerations in agricultural machine operations, a farmer would not be willing to interrupt the operation based on permissible exposure time set by the standards. Based on the findings of this study, particularly an original cabin is recommended to reduce machine-induced noise below the danger limit during agricultural machine operations. Personal protection devices should be used when tractors are operated without cabins, which could reduce A-weighted equivalent sound pressure levels by 10–45 dB(A).

A Mathematical Equation for Quantifying Control Functionality in Agricultural Tractors

The overall accessibility of controls is one of the most important issues to consider when designing a control layout. Well-arranged controls, whose operational characteristics are based on both design guidelines and on human factors considerations, allow the operator to efficiently interact with the system in question. The objective of this article is to introduce a numerical index, referred to as the "index of functionality", capable of comparing, on a mathematical basis, different control arrangements in agricultural tractors. The model is based on information that has been gleaned from the published literature, with input from both professional ergonomists and experienced agricultural tractor operators. The numerical index may take any value between 0 and +1, with +1 being defined as an optimum value in terms of the functionality of a workstation. Data were collected from six old (pre-1982) and six modern (post-2003) tractor workstations to determine whether the model would recognize improvements that have occurred in the ergonomic design of tractor control layouts over the past 20 years. An average score of 0.19 +/- 0.07 was calculated for the pre-1982 tractor workstations. By contrast, an average score of 0.63 +/- 0.10 was calculated for the post-2003 tractor workstations. A number of limitations have been identified with the current model; despite these limitations, the index of functionality clearly recognized the ergonomic improvements in tractor workstations that have occurred over the past 20 years.

Caracterização dos acidentes com tratores agrícolas

Em despeito à sua importância, poucas pesquisas vêm sendo executadas com o intuito de caracterizar os acidentes de trabalho com tratores agrícolas, identificando sua natureza (tipo) bem como suas causas. O objetivo deste trabalho foi caracterizar os acidentes envolvendo tratores agrícolas ocorridos na região da Depressão Central do Rio Grande do Sul e, a partir disto, delinear estratégias eficientes na sua prevenção. Para o levantamento dos dados, foi aplicado um questionário aos operadores de tratores agrícolas da região da Depressão Central do Rio Grande do Sul. Os dados demonstraram que 39% dos trabalhadores rurais entrevistados já sofreram algum tipo de acidente de trabalho com tratores agrícolas. Dentre os tipos de acidentes com tratores agrícolas detectados na pesquisa, destacam-se o capotamento, que correspondeu a 51,71% do total de acidentes graves, e os escorregões, que corresponderam a 40,82% dos acidentes leves. As principais causas dos acidentes relatados foram a falta de conhecimento a respeito das medidas de segurança na operação de tratores (32,77%), a falta de atenção (32,22%) para a tarefa executada e o equipamento inadequado (22,22%). Os acidentes graves tiveram causas diferentes comparativamente aos leves. Operadores sem treinamento adequado, a não observação de regras básicas de segurança e a longa jornada de trabalho são tendências observadas neste trabalho que ampliam os riscos de ocorrência de acidentes. A inclusão de dispositivos que tornem a máquina mais segura e confortável, bem como o treinamento dos operadores de tratores agrícolas são práticas de importância fundamental para a prevenção dos acidentes com tratores agrícolas.