Guidance of a Forage Harvester with GPS

Precision agriculture requires automatic control of agricultural machinery in order to cope with the large amount of information which has to be applied during site specific field work. The driver is occupied with operating and supervising the controlled and non-controlled implements as well as with vehicle guidance. Steering, in particular, is monotonous and tiring. This can result in reduced operation quality. This was the motivation to develop a concept of a guidance system for agricultural vehicles. A self-propelled forage harvester was the test vehicle for this research. The harvester was equipped with an automatic steering system. Real Time Kinematic Global Positioning System (RTK-GPS) was used as the only positioning sensor due to high absolute accuracy within the field and its high reliability. The system performance was investigated under various test conditions. Additionally a guidance-path-planning for swath harvesting operations was developed. Both the automatically steered forage harvester and the path planner could be examined under real field conditions. The standard deviation of the driving performance was better than 100 mm under all conditions. The swaths could be collected reliably with the automatically steered forage harvester.