0.05m。 An orchard tracked mobile robot was developed in order to raise automation level of orchard management, improve operation efficiency, and reduce the intensity of operation. A navigation method based on the slider-crank mechanism was developed, and a fuzzy PID controller was designed, which used the attitude angle and position angle of the robot guiding mechanism as the input parameters. The experiments showed that the robot could travel in a straight line with a maximum lateral error of 0.02m when the robot moved at the speed of 0.15m/s, and the maximum lateral error of 0.05m when the turning radius was 2m.