Accuracy and performance experiences of four wheel steered autonomous agricultural tractor in sowing operation

Abstract

In agriculture, a typical task is to do a coverage operation for a field. Coverage path planning algorithms can be used to create the path for a vehicle. In case of an autonomous agricultural vehicle, the path is provided to the guidance or navigation system that steers the vehicle. In this paper, a four wheel steered tractor is used in autonomous sowing operation. The full size tractor is equipped with 2.5 m hitch mounted seed drill and the developed guidance system is used to sow about six hectares spring wheat. In this paper is presented the results of the guidance accuracy in the field tests, in four field plots. The guidance accuracy in terms of lateral and angular error to the path is typically less than 10 cm and one degree, respectively. The paper also presents real life problems happened in the field tests, including losing GPS positioning signal and tractor safety related wireless communication problems.