Biomechanical modeling of flexible citrus fruit stalks and cutting blade optimization for efficient cutting

Due to the high flexibility of citrus fruit stalks, conventional generic cutting tools often exhibit low efficiency in automated harvesting. To address this challenge, this study established a biomechanical model of citrus fruit stalks, identified optimal cutting parameters based on response surface methodology, and designed a high-efficiency stalk-cutting tool. Specifically, the fundamental physical and mechanical properties of citrus fruit stalks were determined, and corresponding constitutive and finite element model (FEM) were established to characterize their stress–strain behavior. Theoretical analysis of citrus fruit stalk cutting modes was performed to identify the key factors governing peak cutting force. Both single-factor and multi-factor orthogonal experiments were designed to determine the optimal combination of structural parameters for the moving blade. Field tests showed a cutting success rate of 99.38%, significantly higher than generic straight-blade configurations, with smooth and burr-free cutting surfaces, confirming the superior cutting reliability of the proposed tool in practical harvesting operations. The research provides theoretical and engineering guidance for the design of efficient robotic citrus harvesting end-effectors. • Establishing a constitutive model and an FEM model of citrus fruit stems. • Researching the mechanical response and cutting mechanism during the cutting process. • Verifying the accuracy and validity of both the constitutive and finite element models. • Providing technical support for optimizing the citrus harvesting end-effector.