Wide span tractors/vehicles have good prospects as the mechanisation means for controlled traffic farming. The efficiency of the practical application of wide span tractors (vehicles) depends on the availability of the substantiated scientific basis or the theoretical basis for the research into their key properties, including among other factors the smoothness of movement. The aim of the research is to improve the smoothness of movement of wide span tractors (vehicles) by substantiating their configuration, design-and-process and other parameters as well as the properties of the longitudinal profile of the agricultural background irregularities in the ruts of the laid-down process track. The smoothness of movement of the wide span tractor (vehicle) as a dynamic system travelling in the ruts of the permanent process track substantially depends on the structure of the latter's longitudinal profile, the stiffness of tyres on the supporting wheels, while the dynamics of the vertical oscillations of the process section depends on its operating weight.
It is purposeful to increase the efficiency of the 80-100 hp tractors (traction class 1.4) in sowing agricultural crops by increasing the working width of the technological part, using wide-span sowing machineand-tractor aggregates. However, their movement characteristics on the turning strips in many respects determine their technical and economic performance, as a whole. It has been found out by the conducted research that a motivated choice of the parameters of wide-span sowing machine-and-tractor aggregates allows them making manoeuvres of turns on the turning strip in an optimal mode, which promotes reducing the length and time for turns by 4.5-11.2 % and the width of the turning strip by 4.9-12.1 %. In order to improve the turning ability of a two-machine sowing aggregate, it is desirable to apply ballasting (i.e., installation of additional loading) of the front axle wheels of the tractor. Thus, additional loads with a mass of 180 kg, installed on it, can reduce the turning radius of the aggregate. The most noticeable result of ballasting is achieved, when the turning angle of the driven wheels of the tractor is greater than 0.32 rad. At the maximum value of the control action (α = 0.5 rad) the reduction in the turning radius of the aggregate, due to ballasting the front axle of the tractor, is 0.8 m (i.e. 15 %). It has been theoretically established that, in case the speed of the movement is increased from 1.0 to 3.0 m⋅s-1 , the turning radius of the unit tends to decrease. Such a result is because the increase in the drift angle of the rear wheels of the tractor outstrips the increase in the drift angle of the tires of its front wheels.
Abstract. In part, the economic effect gained from the introduction of controlled traffic farming can be directly determined by the area of the field lost under the engineering (or traffic) zone of the vehicles involved. With a wide span tractor, as with other vehicles, the area lost under the traffic zone will depend upon how efficiently operations in the field are organised. The purpose of the present investigation is to substantiate the design and other parameters of the wide span tractor from a position of efficient land use in controlled traffic farming. Theoretical studies, synthesis of the construction diagram and parameters of the wide span tractor were carried out using computer simulation of its operation. These studies indicated that planning of the field for controlled traffic farming with the use of a wide span tractor should take into consideration its track width and its field operational parameters. The use of a contemporary design of wide span tractor with a track width more than 7.5 m results in field traffic zone losses of no more than 5 -6 %, which is quite acceptable. Practical use of a wide span tractor for controlled traffic farming needs automatic steering to reduce field traffic zone area losses by a factor of 1.5 times compared with manual steering.Keywords: controlled traffic farming, wide span tractor, wide span vehicles, bridge (gantry) agriculture, engineering zone, land use, technological track. IntroductionBy using agricultural machinery with different working widths most of the fertile soil (around 75 % of the area) is subject to the unfavourable impact tractor and machinery wheels [1]. Controlled traffic farming (CTF) is a system, which confines all machinery loads to the least possible area of permanent traffic lanes [2].The efficiency of controlled traffic farming is higher, if there are less unproductive parts of the field designed for the engineering zone. The latter, as it is known, is determined by the pass, which depends on the track width and the parameters of the actuators of the undercarriage of the wide span tractor. Naturally, an increase in the track width of the latter has a positive effect on the land use indicators in controlled traffic farming, yet it is becoming more problematic technically to design such machines and to automate the control of their movement. Therefore, it is purposeful to increase the track width of wide span tractors to a definite value, which allows having satisfactory land use indicators in controlled traffic farming.The world science has already accumulated certain experience in the items of studying and practical implementation of controlled traffic farming [2][3][4][5][6][7]. The technological basis of these systems are wide span vehicles or wide span tractors [8][9][10][11]. There is considerably increased interest in wide span tractors recently. Their development is the aim of scientists in the USA, Great Britain, Japan, Poland, the Netherlands, Russia, Ukraine, and many other countries [12].Among the widely known models of wide span ...
: Wide span tractors have a wide transversal bar, on which different implements can be mounted, while the supporting wheels follow the set traffic-lanes. The stability of wide span tractor movement is influenced by unbroken small angular deviations and transversal displacements of the machine due to several factors. These deflections from the set trajectories affect the working implements, especially the peripheral ones, which can cut the plants if wide span tractors are used to manage row crops. In this context, it needs to consider a safeguard zone that allows to reduce the probability of contact between working implements and plants. The aim of this paper was to determine the quantitative effect of transverse displacements of the working implements and the suitable size of the aforesaid safeguard zone. The magnitude of the inner and outer displacements of the working implements depends significantly on their location in relation to the center of the wide span tractor. For working implements located outside the center of the tractor, the outer safeguard zone should be larger than the inner zone. The probability of crop damage by working implements can be reduced by automated control of wide span tractor movement.
Abstract. Practical use of wide span tractors (vehicles) for controlled traffic farming needs further motivation of the principles of their automatic steering, allowing maximum reduction of area losses of the field under the engineering zone at least 1.5 times. The use of contemporary wide span tractors (vehicles) with a track width more than 7.5 m allows reaching a value of the area losses of the field under the engineering zone not more than 5…6 %, which is quite acceptable. The presented brands of such tractors are provided with various technological equipment and means of automation, the technological significance of which can be estimated only by means of objective assessment methods. The developed equation for the estimation of the potential efficiency of the wide span tractors makes it possible to conduct analysis of the degree of impact upon them made by their design parameters and indicators of technical characteristics. Estimation of the degree of potential efficiency, which the contemporary wide span tractors should have, showed that the result exceeds the potential efficiency of the conventional machine and tractor aggregates by 1.5-2 times.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.