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 ...