Click on “Download PDF” for the PDF version or on the title for the HTML version.

If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

Abstract. Understanding soil-tool interaction can enable better maneuvering of weeding tools to achieve higher weeding efficacy. The interaction between vertical tine of a rotating tine mechanism and soil was investigated using a mathematical model that estimated forces on a tine of a rotating tine mechanism operating at different linear and rotational velocities. The kinematics associated with linear and rotational velocities of a rotating tine mechanism were modelled, and the magnitude of shearing and inertial forces were estimated. A soil bin experiment was conducted using artificial soil with one tine to estimate the shear and inertial force coefficient values. Experimental conditions were the same for both the sets of tests. Experimental factors were longitudinal velocity at three levels (0.09 m/s, 0.29 m/s and 0.5 m/s) and speed ratio, the ratio of longitudinal velocity to peripheral velocity of the tines, at three levels (1, 1.5 and 2). Horizontal draft force and torque on the tine mechanism were measured. The nonlinear least squares method was used to estimate model parameters from experimental data, resulting in the shear force coefficient ranging from 2.96 to 37.5 N and the inertial force coefficient ranging from 16.6 to 528 N-s²-m^-2. These variations in shear and inertial forces on the tine were due to differences soil failure patterns across the treatments.