Actuating Force Required for Operating Various Controls of a Walk-Behind Type Paddy Transplanter Leading to Development of a Remotely Operated System

HIGHLIGHTS The actuating force, torque, and application rate needed to operate the control levers of a walk-behind type paddy transplanter were determined. The results will be beneficial for the development of a remote-control or autonomous system for the transplanter. Such a system will reduce operator fatigue, resulting in increased work efficiency and safety. ABSTRACT. An enormous amount of human fatigue is involved in operating the walk-behind type paddy transplanters widely used in South Asian countries, especially India. To operate a transplanter remotely, accurate estimation of the actuating force needed to operate the control levers (push/pull type), the stroke length of the levers, and the frequency of use of the levers is required so that the mechanical levers can be replaced with appropriate electronic sensors, control units, and actuators. In this study, the actuating forces and required torques of the control levers of a walk-behind type paddy transplanter (Kubota NSP-4W, model MZ175-B-1) were measured using three load-measuring instruments. The results revealed that about 24.1 N of force was required to control the accelerator lever, while the left and right steering levers required an actuating force of 24.0 N each. To start the transplanting mechanism, a much higher actuating force (78.1 N) and torque (15.47 N-m) were required 54 times per hour for the planting clutch lever; however, to stop the mechanism, a comparatively smaller force (28.3 N) and torque (5.71 N-m) were required 54 times per hour. Movement of the transplanter was controlled with the shift clutch lever, which required 14.30 N of force and 2.72 N-m torque for forward movement of the transplanter in field conditions, while 12.7 N of force and 2.88 N-m torque were required for forward movement of the transplanter on paved roads. These findings will be beneficial for selecting the force and stroke length of actuators for the development of a remote-control or autonomous system for walk-behind type paddy transplanters and similar machines, which is expected to substantially reduce the operator workload and enhance both workability and safety.