Design and development of an automated paddy transplanting machine with a novel planting mechanism

Abstract

Paddy planting in Sri Lanka has a deficit in mechanization. The commercially available transplanters are mainly for the rice mat method and are less suited for the short-term rice varieties planted in Sri Lanka due to the high transplanting shock. The study aims to introduce an automated paddy transplanting machine that eliminates transplanting shock. The study focused on the rice pot seedling planting method, and a novel venturi-based vacuum ejection mechanism for the planting was developed. The planting mechanism was optimized through CFD to improve the ejection pressure. A nursery tray conveying mechanism was developed to feed the seedlings to the planting mechanism, along with a modified nursery tray design. A PLC-based control system was developed to control the planting and nursery tray conveying mechanisms. The final system was field-tested with paddy seedlings ejection with a success rate of 92.8%.