Computer simulation of stability and control of tractor-trailed implement combinations under different operating conditions

Abstract

The mechanics of a tractor-trailer system moving up and down sloping ground under different operating conditions was theoretically simulated. A computer program was developed to analyze the system to predict the effect of both the trailer loading weight and the slope angle on the tractor stability, traction ability, and drawbar loading. The program was used to analyze a tractor-trailer system moving at uniform motion up and downhill. The results of this analysis showed that the tractor becomes unstable when towing a 3750 kg trailer uphill at 28° slope angle. Insufficient traction occurred at slope angles ranging from 15° to 18° corresponding to trailer weight of 3750 to 750 kg. The parallel component of drawbar pull reached a maximum value of 17318 N when the trailer was pushing the tractor downhill at 30° slope angle. The normal component (normal to the tractive surface) showed similar maximum values for both uphill and downhill motions of the system. The use of computer analysis in this study provided a significant improvement in predicting the effect of different parameters on stability and control of tractor-trailer combination on sloping ground. Key words:Tractor-trailer, Stability, Traction, Sloping ground, Drawbar. RESUMO SIMULAÇÃO COMPUTACIONAL DA ESTABILIDADE E CONTROLE DE COMBINAÇÕES TRATOR-CARRETA SOB DIFERENTES CONDIÇÕES DE OPERAÇÃOA mecânica do sistema trator-carreta movendo-se encosta acima e abaixo, sob diferentes condições de operação, foi simulada teoricamente. Foi desenvolvido um programa de computador para analisar o sistema visando prever o efeito do peso da carga da carreta e do ângulo da pendente na estabilidade do trator, na capacidade de tração e no carregamento da barra de tração. O programa computacional foi usado para analisar o sistema trator-carreta em deslocamento uniforme encosta acima e abaixo. Os resultados dessa análise mostraram que o trator se torna instável quando traciona uma carreta de 3.750 kg subindo uma encosta com 28º de declividade. Tração insuficiente ocorre quando os ângulos de inclinação variam de 15º a 18º, com pesos na carreta, respectivamente, de 3.750 a 750 kg. A componente paralela da força na barra de tração atingiu valor máximo de 17.318 N quando a carreta estava empurrando um trator encosta abaixo em uma ladeira com 30º de inclinação. A componente normal (normal à superfície de tração) apresentou valores máximos semelhantes, tanto nos deslocamentos do sistema encosta acima como encosta abaixo. O uso da análise computacional neste estudo trouxe melhoria significativa na previsão do efeito de diferentes parâmetros na estabilidade e no controle da combinação trator-carreta em terrenos inclinados.Palavras-chave: trator-carreta, estabilidade, tração, terrenos inclinados, barra de tração.

Definition of the Layout for a New Facility to Test the Static and Dynamic Stability of Agricultural Vehicles Operating on Sloping Grounds

“…The key point to ensure the operators' safety as well as the operability of a machine is the full knowledge of the stability performance of agricultural machines. The critical parameter is the CoG position as a function of other constructive parameters, also in vehicle operating configurations that foresee the presence of payloads or mounted/trailed implements [23][24][25][26], or of a battery pack as a consequence of the electric hybridization of a conventional vehicle [27]. As acknowledged in literature, the CoG position affects the operation of any active-safety device acting on several on-board technical systems [16,[28][29][30][31].…”

“…• Theoretical-numerical [4,[35][36][37][38][39]: By modeling a vehicle in terms of masses, constraints and supports, and developing equations in more or less complex simulators, as done by Abu-Hamdeh and Al-Jalil [25], suitable to calculate the position of the CoG of the machine possibly with some mounted implements and trailers [23,24], thus predicting the static conditions and the security level for many inclinations of the supporting plane. For example, several scholars [1,5,36,37] use an analytical-Newtonian approach combined with a kineto-static approach based on rigid bodies.…”

Factorial significance on tractor stability under variation of terrain roughness employing the Taguchi method

“…Pioneering investigations on the mechanism of tractor rollover have established fundamental theories explaining how a tractor behaves under certain ground conditions. The mathematical models thus generated further provide the basic concepts of consideration for tractors in dynamic, static, and quasi-static states [2][3][4][5][6][7][8][9][10][11][12][13][14][15] . Indicators of tractor stability obtained from mathematical models provide a simple way of describing vehicle stability.…”

<b>Simtrac – an application for simulation of traction efficiency of agricultural tractors with front wheel assist

“…The computational simulation of the traction performance favors the factors that interfere in the operational efficiency of agricultural tractors without field trials (Al-Hamed & Al-Janobi, 2001). Several researches have been carried out to develop models to predict traction efficiency and stability of tractor-implement set and for the development of computational simulation tools (Abu-Hamdeh & Al-Jalil, 2004;Catalán, Lineares, & Méndez, 2008;Sahu & Raheman, 2008;Tiwari et al, 2010).…”