Analysis of the Mechanism of Weeding with Rotary Weeding Wheel in Paddy using Dynamic Software

Abstract

Mechanical weeding in paddy is getting popularized only after dry sowing method i.e., where line sowing is done by tractor drawn seed drill/planter at desired row to row and hill to hill spacing. In the actual operation process in the field, weeding device needed to perform not only efficient weeding but also its effect on quality of tillering in puddled soil to increase the porosity of soil and effectively promote nutrient absorption from the soil. To simulate the soil tillering condition of optimized weeding wheels, the explicit dynamics software LS-DYNA was used to establish the fluid–solid coupling model of weeding wheels and water soil. Based on the working state of the optimized weeding wheel and the agronomic requirements for weeding, the forward speed of 0.58 m/s, the rotating speed of 150 revolution/min and the weeding depth of 50 mm were selected. The density of soil increases significantly after the disturbance of the weeding wheel, which is due to the effect of the tillering the soil layer in the water layer. From the analysis, it was observed that, the weeding wheels greatly disturbed the soil and could bury weeds and churn the soil. In addition, when the weeding wheels moved in the simulated paddy field environment, the mud mixture move freely and the overall coupling stress is low, which indicated that the resistance of the weeding parts was small and the energy consumption of the weeding wheels was low.