Development of working cycle for an agricultural tractor during plow tillage

Abstract. Field tests according to various field operations are needed to improve performance of an agricultural tractor. However, field test is hard to acquire reliable data because field tests depend on environmental conditions. In addition, field test require high costs for constructing an experiment system and time for conducting the repetition tests. For these reasons, reliable indoor tests in the automotive industry are conducted using a dynamometer with standardized driving cycles. Therefore, the purpose of this study was to develop standardized working cycle during plow tillage for agricultural tractors. Field data of plow tillage were measured by installing a load measurement system on four driving axles and the hydraulic pumps. Plow tillage was conducted on total ten farmlands with similar sizes. The plow tillage cycles were developed using the driving cycle construction method for conventional vehicles with the measured load data. The arbitrary working cycles were generated by combining micro-trips, and some of them achieved less than 5% absolute percentage error between the entire dataset and the generated arbitrary working cycle. The plow tillage cycle was determined considering the sum square difference (SSD) with a torque-torque variation probability distribution. The working cycle with the lowest SSD was determined as the plow tillage cycle. The performance of the plow tillage cycle was evaluated by comparing the performance values (PVs) and the international standard driving cycles. The plow tillage cycle could possibly be representative of the actual plow tillage because the absolute percentage error between the plow tillage cycle and the entire measured dataset was less than 5%. The results of this study showed that developing the plow tillage cycle using the driving cycle development method is feasible.