Tag Archives: stability of motion

xxx V. Bulgakov, I. Holovach, V. Nadykto, O. Parakhin, H. Kaletnik, L. Shymko and J. Olt
Motion stability estimation for modular traction vehicle-based combined unit
Abstract |

Motion stability estimation for modular traction vehicle-based combined unit

V. Bulgakov¹, I. Holovach¹, V. Nadykto², O. Parakhin², H. Kaletnik³, L. Shymko¹ and J. Olt⁴*

¹National University of Life and Environmental Sciences of Ukraine, Ukraine, 15 Heroyiv Oborony Str., UA 03041 Kyiv, Ukraine
²Dmytro Motornyi Tavria State Agrotechnological University, 18B, Khmelnytsky Ave, UA 72310, Melitopol, Zaporozhye Region, Ukraine
³Vinnytsia National Agrarian University of Ukraine, 3 Soniachna Str., UA 21008 Vinnytsia, Ukraine
⁴Estonian University of Life Sciences, Institute of Technology, 56 Kreutzwaldi Str., EE 51006 Tartu, Estonia
*Correspondence: jyri.olt@emu.ee

Abstract:

One of the promising ways of efficiently applying high power intensity tractors is their design and utilisation in the form of modular traction vehicles comprising two modules: the power module and the process module. In order to provide for the sufficient manoeuvrability of the modular traction vehicle, when its process module passes a turn, the latter is equipped with vertical and horizontal hinge joints. The freedom of the process module’s rotation with respect to the power module in the horizontal plane through the agency of the above-mentioned vertical hinge joint is restrained by a hydraulic cylinder, in which the chambers above and below the piston are connected via a throttle valve with a hydraulic resistance coefficient of about 1.03×106 N m s rad–1. This paper is concerned with the theoretical and experimental research into the stability of motion (on turn spaces as well as in the transport mode) of a modular combined unit, when its velocity changes and/or the slip resistance coefficient of the tyres on the wheels of the process module, in which the hydraulic cylinder is equipped with a throttle valve with the above-mentioned hydraulic resistance coefficient, changes.

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1517-1529 V. Bulgakov, V. Adamchuk, V. Nadykto, O. Kistechok and J. Olt
Theoretical research into the stability of motion of the ploughing tractor-implement unit operating on the ‘push-pull’ principle
Abstract |

Theoretical research into the stability of motion of the ploughing tractor-implement unit operating on the ‘push-pull’ principle

V. Bulgakov¹, V. Adamchuk², V. Nadykto³, O. Kistechok³ and J. Olt⁴*

¹National University of Life and Environmental Sciences of Ukraine, 15, Heroyiv Oborony Str., UA 03041 Kyiv, Ukraine
²National Scientific Centre, Institute for Agricultural Engineering and Electrification, 11, Vokzalna Str., Glevaкha-1, Vasylkiv District, UA 08631 Kiev Region, Ukraine
³Tavria State Agrotechnological University, 18, B. Khmelnytsky Ave., UA 72312 Melitopol, Zaporozhye region, Ukraine
⁴Estonian University of Life Sciences, Institute of Technology, Kreutzwaldi 56, EE51014 Tartu, Estonia
*Correspondence: jyri.olt@emu.ee

Abstract:

The reduction of power consumption in the ploughing operations can be achieved by way of improving the grip properties of the implement-carrying tractors, which is facilitated by setting up ploughing units for operation on the ‘push-pull’ principle. The aim of the current research is to substantiate the set-up and parameters of the ploughing unit with a front-mounted plough basing on the theoretical investigation of the stability of its motion in the horizontal plane. The methods of research include obtaining the amplitude- and phase-frequency response characteristics of the dynamic system in order to analyse the stability of its motion under the action of external statistically random perturbations. Also, the methods of software development and PC-based numerical computation are applied. The results of the study prove that the increase of the ploughing unit’s travel speed results in the considerable rise of the gain of the amplitude of the tractor’s heading angle oscillation in response to the oscillation of the angular displacement of the front-mounted plough in the horizontal plane. The phase-frequency response displays the same behaviour, changing substantially together with the unit’s travel speed. Raising the coefficient of resistance to tyre slip of the tractor’s rear wheels from 100 to 130 kPa and the front wheels from 140 to 175 kPa results in a minor decrease of the amplitude of oscillation of the tractor’s heading angle φ. The ploughing unit has the best response to the input effect, i.e. the oscillation of the front-mounted plough’s angular displacement βp, when it operates using the 1+5 combination. The increase of the number of front-mounted plough bodies from 1 to 3 results in the substantial growth of the tractor’s heading angle oscillation amplitude. Taking into account the way, in which the ploughing unit as a dynamic system responds to the input perturbance, the increase of its travel speed can be restricted not by the condition of its motion stability, but solely by the agrotechnical requirements applied to such a process operation as ploughing. The ploughing unit’s motion stability substantially improves in case of higher air pressure in the tyres on the tractor’s front and rear wheels. This effect is especially pronounced in the perturbance oscillation frequency range (0…1.5 s–1) that covers the main part of its dispersion.

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