An Independent Steering Driving Wheel Design of Automatic Tractor for Headland Turn Realization

Turning around at the headland is one of the factors that affects the working efficiency of the automatic tractor. In most cases, the tractor turns at the headland following a curved path planned based on the minimum turning radius and drives into the next path between crop rows. However, the efficiency of the tractor with this turning method is limited by the steering angle range of the front wheels. In this paper, an auxiliary wheel system is designed to achieve efficient turning by equipping a 360° steering auxiliary wheel at the front of the tractor, which includes auxiliary wheel system structure, hydraulic drive system and electro-hydraulic servo controller. The designed electro-hydraulic system can realize automatic steering, lifting and driving of the auxiliary wheel system. Finally, field experiments are conducted to verify the superiority of the proposed auxiliary wheel turning method compared to the existing turning methods. The results show that the auxiliary wheel steering method improved the efficiency of the automatic tractor at the headland by 50%, 80% and 50% in terms of time efficiency, travel distance and ground space occupation, respectively, compared with the conventional steering method