Automated Rice Transplanter with GPS and FOG

The authors developed an automated 6-row rice transplanter. It has RTKGPS to locate precise position, FOG sensors to measures direction and actuators to control steering, engine throttle, clutch, brake and so on. RTKGPS has 3cm precision at 10Hz data output rate and FOG sensors are issued to restore the inclination of the vehicle. Main computer synchronizes RTKGPS position data with FOG data then it corrects the position error caused by the vehicle inclination. All actuators are controlled by a programmable logic controller (PLC). All control data is sent form main computer to PLC through RS232C. The drift of the FOG sensor was corrected by the using position data. To eliminate the influence of the drift, first, the deviation from the desired path calculated by the yaw angle and vehicle speed was compared with the deviation calculated by GPS data. Then the drift of the heading angle was calculated. The influence of the FOG drift can be eliminated, the authors can correct the FOG drift and the initial error of heading angle and can make long time operation continuously. The experiment was conducted 4 days after puddling. The deviation from the desired straight path was less than 10cm at 0.8m/s of travel velocity. During the rice transplanter went forward and back in a 30m*100m square field 5 times, we obtained satisfactory results.