Evaluation of Cutting Stability of a Natural-Rubber-Tapping Robot

Abstract

Natural rubber is a crucial raw material in modern society. However, the process of latex acquisition has long depended on manual cutting operations. The mechanization and automation of rubber-tapping activities is a promising field. Rubber-tapping operations rely on the horizontal cutting of the leading edge and vertical stripping of the secondary edge. Nevertheless, variations in the impact acceleration of the blade can lead to changes in the continuity of the chip, affecting the stability of the cut. In this study, an inertial measurement unit (IMU) and a robotic arm were combined to achieve the real-time sensing of the blade’s posture and position. The accelerations of the blade were measured at 21 interpolated points in the optimized cutting trajectory based on the principle of temporal synchronization. A multiple regression model was used to establish a link between impact acceleration and chip characteristics to evaluate cutting stability. The R-squared value for the regression equation was 0.976, while the correlation analysis for the R-squared and root mean square error (RMSE) values yielded 0.977 and 0.0766 mm, respectively. The correlation coefficient for the Z-axis was the highest among the three axes, at 0.22937. Strict control of blade chatter in the radial direction is necessary to improve the stability of the cut. This study provides theoretical support and operational reference for subsequent work on end-effector improvement and motion control. The optimized robotic system for rubber tapping can contribute to accelerating the mechanization of latex harvesting.