Unmanned Rice-Transplanting Operation Using a GPS-Guided Rice Transplanter with Long Mat-Type Hydroponic Seedlings

Abstract

A low-cost guidance system was developed for a global positioning system (GPS)-guided automated rice transplanter. In 2005, the already available GPS-guided automated rice transplanter was modified to carry long mat-type hydroponic rice seedlings and attached an herbicide-dripping machine. The use of long mat-type hydroponic rice seedlings allows ricetransplanting operations to be carried out on a 0.3 ha standard-size Japanese field without the need to supply additional seedlings. Fully automated rice transplantation was achieved with the modified transplanter. To reduce the costs of the transplanter, the expensive fiber-optic posture sensor was replaced by a low-cost posture sensor, developed at Hokkaido University, for measuring the heading angle and inclination. The processing program of this posture sensor was modified to adapt it to rice-transplanting operation. Instead of establishing a reference station, a real-time, kinematic GPS was used. The modified rice transplanter, when tested in planting a farmer’s paddy field took about one hour between entering and leaving the field. The trial was almost successful, with a few minor problems.