Abstract: With the rise of big data and technological support, more and more robots have been applied in agriculture. In order to cope with the positioning error and trajectory deviation in the navigation process, a navigation correction method based on ultrasonic sensor was studied. By means of the extended Kalman filter of the position of the inspection robot, the fused position was used for its navigation and positioning, and the metrical data of the ultrasonic sensor was combined with the fused position. According to the relative position between the inspection robot and the walls, the deviation was judged to correct the navigation trajectory. The experiment showed that the average error of the navigation correction based on the ultrasonic sensor was 0.011 3 rad without turning, and the average error of the correction was 0.023 9 rad in the case of one turn. In this case, the chance that the inspection robot collided with the walls was lowered, and the working performance in the navigation process was enhanced.

Key words: extended Kalman filter, navigation correction, inspection robot, positioning accuracy