Abstract
We developed an autonomous crawler forwarder for the purpose of the improvement of the working efficiency and also safety of logging operations. The developed forwarder can travel with no driver by comparing self-position with the planning route that is input beforehand. The internal sensors that detect the azimuth and also the traveled distance recognize the self-position. Azimuth is detected by optical fiber gyro, using a geo-magnetic sensor to eliminate the influence of drift. Also, traveled distance is measured by integrating the axle speed. So, an error becomes big as it measures long distance by the influence of the slip. Because of this, we made the method that revises the control error by the external sensor, because it is difficult to extend the traveled distance using only the internal sensors. Permanent magnets and magnetic field sensor are used as the external sensor. Although there needs the labor that must lay down permanent magnets in strip road beforehand, it is possible to last autonomous traveling, by detecting the permanent magnets that are laid down separately.
