Automatic Navigation of the Agricultural Vehicle by the Geomagnetic Direction Sensor and Gyroscope

Abstract

The objective of this research is to develop an automatic guidance system composed of relatively low cost sensors. As a navigation sensor, we used a geomagnetic direction sensor (GDS) and a gyroscope. To increase the accuracy of these sensors outputs and navigation performance, these sensor output were integrated based on sensor fusion technique. In this paper, the precise estimation method of the vehicle orientation was proposed. First, the noise of the GDS and inclinometer were eliminated by the adaptive line enhancer(ALE). As the result of inclination correction of the GDS by ALE, the corrected GDS was consistent with the actual orientation. Second, the drift error of the gyroscope was estimated by least square method(LSM). Third, these sensors output were integrated to obtain the accurate vehicle orientation. Finally, to evaluate the accuracy of the proposed estimation method of orientation, the automatic navigation test was carried out in the actually used field. As a result of the automatic navigation test, it was confirmed that proposed estimation method had the ability to navigate the mobile vehicle with high accuracy.