Measurement of the Physical Parameters of Peanut Seeds and Calibration of the Discrete Element Parameters

Abstract

This study measured the intrinsic and contact parameters through physical experiments to improve the accuracy of discrete element simulation analysis of peanut seeds. Discrete element models for five different peanut seed filling ball numbers were established. The simulation parameters were calibrated through a combination of physical and simulation experiments. Firstly, the Plackett-Burman test was used to screen the significance of simulation parameters. Then, the steepest climbing test was conducted to determine the optimal range of significance parameters using the relative error be-tween the simulated and the physical experimental as the evaluation index. Finally, a response surface experiment with three factors and three levels was conducted using the repose angle as the response value. The static and rolling friction coefficients among peanut seeds were set as 0.43 and 0.50 separately, and the rolling coefficient between peanut seeds and steel plate was set as 0.12. During verification experiments, the simulated repose angle was 25.18°, with a relative error of 2.42% compared to the physical repose angle, further verifying the reliability of the simulation model. The re-search group used different numbers of filling balls with optimal parameters in the repose angle experiment. Then they evaluate the simulation time and the error value of repose angle between the simulated and physical experiment. The optimal number of filled balls is the Sphere 1178. The research results indicate that discrete element model of peanut seeds and calibration parameters are reliable. Based on the results of this research, an intelligent peanut precision sowing machine can be developed.