Study of the steering of a wide span vehicle controlled by a local positioning system

Abstract

Controlled traffic farming allows to minimize traffic-induced soil compaction by a permanent separation of the crop zone from the traffic lanes used by wide span tractors. The Authors developed an agricultural wide span vehicle equipped with a skid equipment for turning and an automatic driving system prototype based on a laser beam. The aim of this work was to study the kinematic conditions that control the steering of this machine. Furthermore, the accuracy and the maximum delay time of the signal transmission by the automatic driving system of the set-up was also assessed. In comparison with crawler tractors, the turning of the agricultural wide span vehicle needs a smaller difference in the moments applied to its right- and left-side wheels. For the predetermined accuracy of the beam position relative to the plant rows, ±ds = ±0.025 m, the accuracy of the direction of the laser beam at a distance S=200 m should not be more than ±0.07° and ±0.0014°, considering a run length of 1000 m. Furthermore, at a speed V=2.5 m s–1 a trajectory deviation φ≤5° requires a topmost delay time of the control signal of Δtmax=0.11 s is required.

Effects of Tractor and Soil Parameters on the Depth of the Permanent Traffic Lanes in Controlled Traffic Farming Systems

“…The left track depth made by the MTZ-1221.2 tractor was measured in duplicate with a ruler-depth meter with an error of ±0.005 m. Measurements were carried out at the center of the wheel track, as shown by the white points along the red line in Figure 2. The measurement points were 100, with a measurement step of 0.1 m [35].…”

“…However, the CTF method is still implemented without using satellite navigation systems in many countries, including Ukraine [35,36]. In these contexts, the PTL tracks are arranged earlier so that they will be detectable during the full crop growing cycle and then be used by the wheels or tracks of all implements and tractors for cultivation works.…”