抄録
This paper describes an applied research established in response to farmer's request for improvement of performance of tractor-implement in tillage operations. An effort for decrement of variations in plowing depth as well as increment of tractive efficiency of a moderate power tractor in tillage operations with mounted implements led to development of a fuzzy depth and draft control system for tractor-implement. The fuzzy control system consisted of an electrical sensing, control, and electro-hydraulic actuator unit. A command set including four fuzzy rules were programmed for the control unit. To determine merits of the fuzzy control system, the field experiments were carried out at three levels of plowing depth (10, 20 and 30 cm), forward speed (2, 4 and 6 km/h), and implement types (moldboard, disk, and chisel plow) utilizing the system mounted on a tractor (MF-399). Some performance parameters of tractor-implement were then determined in the field experiments. The results indicated application of the fuzzy control system rather than available draft control system of the tractor resulted in increment of tractive efficiency and overall energy efficiency up to 20 and 73%, respectively. Meanwhile, plowing depth error, driving wheel slip, and fuel consumption decreased up to 53, 34 and 34%, respectively. The performance of the fuzzy control system was not sensitive to implement type and plowing depth, while it was influenced by forward speed (P ≤ 0.01). The fuzzy control system adequately improved performance of tractor-implement in tillage operations and satisfied farmer's requirements. Hence, it is recommended to industrialize and commercialize the fuzzy control system in order to mount it on any moderate power tractor.
