Automatic control of a modified tractor to work on steep side slopes

Mashadi, Behrooz; Nasrolahi, Hanif

doi:10.1016/j.jterra.2009.08.006

Cited by 33 publications

(26 citation statements)

References 5 publications

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“…A realização de atividades agrícolas mecanizadas em locais de topografia acidentada exige atenção às normas de segurança que, dentre outros, considera-se a inclinação do terreno e a estabilidade lateral das máquinas utilizadas (CHISHOLM, 1979;MASHADI;NASROLAHI, 2009). A declividade é um fator limitante para o uso seguro de tratores agrícolas em terreno íngreme, e tanto o conhecimento do ângulo máximo de estabilidade lateral de tratores quanto do zoneamento agrícola onde as operações são realizadas, são fatores importantes para o gerenciamento do preparo mecanizado de solo.…”

Section: Pereira D P Et Alunclassified

Eficiência da subsolagem na profundidade de preparo do solo em função da declividade do terreno

Pereira

Fiedler

Lima

et al. 2012

CERNE

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RESUMO:Nesta pesquisa objetivou-se avaliar a eficiência da subsolagem por meio da medição das profundidades atingidas em diferentes classes de declividades do local em estudo. Utilizou-se um subsolador-adubador de arraste com haste única lisa parabólica e ponteira não alada, com dimensões de 1 ½ polegadas de espessura e 320 mm de largura tracionado por um trator com motor de potência bruta de aproximadamente 112 kW, com tração dianteira auxiliar ativada e bitola regulada para a máxima largura entre rodas Executou-se essa operação em função de sete classes de declividade. A inclinação lateral máxima para efetuar a subsolagem foi calculada de acordo com o centro de gravidade e a bitola do trator. Determinou-se o número e a amplitude das classes pela fórmula de Sturges. Os dados foram avaliados segundo a análise de regressão para o caso de dados com repetição a 5% de significância. O modelo de regressão proposto foi adequado para descrever os valores uma vez que teve resultado significativo para o teste F. Para o ajuste da equação de regressão, o coeficiente de determinação apresentou como resultado 78,95%, indicando que esse valor representa a quantidade de valores de profundidade que são explicados pela declividade. Assim, pode-se afirmar que existe tendência para a profundidade da subsolagem diminuir com o aumento da declividade do terreno, sendo um limitador para a qualidade da operação de preparo mecanizado do solo. Demonstrou que as declividades até 40% permitiram atingir a profundidade mínima de 0,50 m para a subsolagem.Palavras-chave: Manejo florestal, compactação do solo, profundidade de trabalho. EFFICIENCY OF SUBSOILING DEPTH ACCORDING TO THE SLOPE OF THE LAND ABSTRACT: The effectiveness of subsoiling by measuring the depths achieved in different classes of slope of a forest plantation was evaluated. This operation was made with a fertilizer trawling subsoiler with a single smooth parabolic rod depending on seven groups of slope and the maximum lateral inclination of the tractor to perform the subsoiling. It was determined the number and breadth of slope classes by

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Section: Pereira D P Et Alunclassified

Eficiência da subsolagem na profundidade de preparo do solo em função da declividade do terreno

Pereira

Fiedler

Lima

et al. 2012

CERNE

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“…The attitude of the tractor to be stable is quantified by a single number, called Roll Stability Index (RSI), in a way similar to [23] and [24]. The more this index is close to zero, the more the vehicle is next to reach a possible overturn condition; so, this index could be very useful as input signal for activating many real-time active safety devices, acting for example on: the braking system, the limited-slip differentials [25], the variable-geometry roll-over structures [26], the self-levelling cab system [27]. As proposed in this study, the same index can be calculated also for a tractor having a mounted implement and then it can be used: (1) to inquiry several configurations of "tractor + implement" and compile a series of tables, (2) to calculate some regression equations giving the minimum RSI starting from the values reported in these tables and, then, (3) to generate also a set of "stability maps", i.e.…”

Section: Introductionmentioning

confidence: 99%

A parametric approach for evaluating the stability of agricultural tractors using implements during side-slope activities

Bietresato¹,

Carabin²,

Vidoni³

et al. 2015

ces

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A parametric approach for evaluating the stability of agricultural tractors using implements during side-slope activities / Bietresato, M.; Carabin, G.; Vidoni, R.; Mazzetto, F.; Gasparetto, A.. -In: CONTEMPORARY ENGINEERING SCIENCES. -ISSN 1313-ISSN -6569. -8:28(2015, pp. 1289-1309. OriginalA parametric approach for evaluating the stability of agricultural tractors using implements during side-slope activities 1290Marco Bietresato et al. AbstractA methodological approach for evaluating a priori the stability of agricultural vehicles equipped with different mounted implements and operating on sloping hillsides is shown here. It uses a Matlab simulator in its first phase and, subsequently, the Response Surface Modelling (RSM) to evaluate the coefficients of a set of regression equations able to account for the Type-I and Type-II stability of the whole vehicle (tractor + implement with known dimensions and mass). The regression equations can give reliable punctual numeric estimations of the minimum value of the Roll Stability Index (RSI) and can verify the existence of a Type-I equilibrium without the need of using the simulator or knowing any detail about the model implemented in it. The same equations can also be used to generate many intuitive graphs ("equilibrium maps") useful to verify quickly the possible overturning of the vehicle. A case-study concerning a 4-wheel drive articulated tractor is then presented to show the potential of the approach and how using its tools. The tractor has been studied in three scenarios, differing on where the implement has to be connected to the tractor (1: frontally; 2: frontally-laterally; 3: in the back). After performing a series of simulations, a set of polynomial models (with 6 independent variables) has been created and verified. Then, these models were used, together with the related equilibrium maps, to predict the stability of 8 implements for scenario 1, 7 implements for scenario 2, and 3 implements for scenario 3, evidencing in particular the danger of using a lateral shredder with a mass greater than 245 kg. The proposed approach and its main outcomes (i.e., the regression equations and the equilibrium maps) can give an effective contribution to the preventive safety of the tractor driver, so it could be useful to integrate it in the homologation procedures for every agricultural vehicle and to include the resulting documentation within the tractor logbook.

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“…This index synthetizes possible overturn conditions (e.g., roll and pitch angles) in a single number and it could be very useful if used as input signal for many real-time active safety devices acting on several systems, e.g. : braking systems, limited-slip differentials (Huang, Zhan, & Wu, 2012), variable-geometry roll-over structures (Silleli et al, 2007), self-levelling cab system (Mashadi & Nasrolahi, 2009). …”

Section: Journal Of Agricultural Engineering 2013; Volume Xliv(s2):e133mentioning

confidence: 99%

Simulated stability tests of a small articulated tractor designed for extreme-sloped vineyards

Mazzetto¹,

Bietresato²,

Gasparetto³

et al. 2013

J Agricult Engineer

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A new reversible wheeled articulated tractor, designed to work in terraced vineyards trained with "pergola" system, common in mountain areas, is here described in its latest version and analysed through numerical simulations.This tractor has small dimensions, necessary to operate in that environment, and its central articulation has two rotational degrees-offreedom. The described features are surely strong design points but could be critical for vehicle's stability, as affecting the supporting base's dimensions and shape. Therefore, the tractor was equipped with a new automatic safety system: a self-locking articulation activated by contact sensors on the wheels. This device makes the vehicle partially-rigid in case of lateral unbalancing, so that rollover can happen only by overcoming the whole vehicle mass.A mathematical description of vehicle-ground interactions was implemented to deeply inquiry the tractor behaviour in different configurations (straight, angled) at increasing values of ground slope; roll and pitch stability indexes were then computed and used for comparisons with conventional tractors.Thanks to the low centre-of-gravity, the resulting rollover angle with the vehicle in straight configuration is promising (43.8°→96%): it is greater than the maximum lateral (20°→36%) and frontal (38°→78%) slope angle ever recorded on terraced vineyards. The same rollover angle is lower when the tractor turns.

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Automatic control of a modified tractor to work on steep side slopes

Cited by 33 publications

References 5 publications

Eficiência da subsolagem na profundidade de preparo do solo em função da declividade do terreno

Eficiência da subsolagem na profundidade de preparo do solo em função da declividade do terreno

A parametric approach for evaluating the stability of agricultural tractors using implements during side-slope activities

Simulated stability tests of a small articulated tractor designed for extreme-sloped vineyards

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