Quality and Testing of Red Pepper Soft Picking Manipulator Based on RD-DEM Coupling

Abstract

Due to a shortage of labor, the harvesting of fruits and vegetables faces significant challenges. Soft robotic hands, adaptable to variable environments due to their high-curvature bending and twisting, have garnered widespread attention and usage. However, their application in Sichuan pepper picking remains largely unexplored. Therefore, this study proposes a picking soft robotic hand composed of a rigid skeleton and flexible skin for pepper harvesting. Through analyzing the characteristics of peppers, the structure of the robotic hand is determined. Inflatable airbags are employed to drive finger bending, utilizing a rotating–twisting method for Sichuan pepper picking. Structural parameters influencing the bending angle of the airbags were determined through theoretical analysis and validated via simulation. Optimal parameter combinations for the airbags were obtained through response surface experiments to establish the robotic hand model. To assess the feasibility of the robotic hand’s movement, dynamic simulations were conducted using R D (RecurDyn V9R2) software. Subsequently, a discrete element model of Sichuan pepper clusters was established and coupled with the simulation of the Sichuan pepper picking process. The results indicate that the robotic hand does not cause damage to the Sichuan peppers during picking. Finally, field tests were conducted in pepper orchards to validate the success rate of the robotic hand in picking, yielding an 85% success rate and a 0.3% damage rate.