Application of infield path planner with optimal track sequence for land preparation autonomous tractor in rectangular paddy field

The agricultural sector including industry and academia is facing an increasing number of challenges regarding farm management related to an increase in agricultural production with fewer resource usages. To seek measures for optimizing resource utilization and time needed to manage farm logistics, an agricultural routing planning technology is one of the integral tasks in farm management. In this study, an infield path planner with an optimal track sequence for autonomous land preparation in the paddy field, i.e. tillage and puddling, was evaluated in the rectangular paddy field. The test platform was a 60-kW auto-guided tractor equipped with a GNSS/INS and a navigation controller running a slip estimation-based path tracking algorithm. Field tests were conducted in rectangular paddy fields of 97x37 m2 and 97x36 m2 for tillage and puddling operation, respectively to validate the autonomous land preparation tractor. The evaluation parameters focused on the reduction of non-working distance and increase of field coverage rate, comparing the previously developed system. As a result of automatic tillage work, the proposed path planner showed superior performance in guiding the tractor along a headland turn with a 16% reduction in travel distance and covering the entire field, especially in the border corner area, from 91.5% to 99.1%. In the field test of the puddling task, the autonomous tractor successfully followed the path with RMSEs of lateral deviation < 9 cm and heading error < 1.1 deg in the presence of slippery condition with 98.4% coverage rate.