Auto-guidance system for tillage tractor

Path tracking algorithms applicable to various agricultural operations, such as tillage, planting, and spraying, are needed to generate steering angles for an auto-guidance tractor to track waypoints that define the desired trajectory. An optimal coverage path planning can enable the tractor to effectively travel an entire field along a path, with parallel paths at a fixed spacing. This paper reports on the development of a computer simulation model to develop an efficient waypoint-based navigation algorithm for a Korean tillage tractor. The computer simulation environment was built based on the kinematic motion of a tractor and the characteristics of tire slippage and side force by soil on a curved path. The validity of the simulation program was confirmed by a driving test using a Tong Yang TX 803 tractor equipped with a RTK-GPS receiver and a steering controller. In the validation test, the developed algorithm for real-time path tracking provided tracking trajectories similar to those obtained from the computer simulation. However, a study on an oscillation in steering angles when the tractor travelled on a straight path was needed. In future work, various parameters related to path tracking, such as waypoints, waypoint intervals, LBO (Limit of Boundary Offset), and traveling velocity will be optimized using the developed computer simulator.