过约束空间连杆机构的柔性体建模、运动学辨识与装配精度

中文摘要 AI 辅助

过约束有理单环连杆机构是高效、紧凑且低成本的定制机构，但其在工业环境中的部署受到限制。在仿真中，刚性体公式因冗余约束而失效。本研究提出了一种基于浮动坐标系公式的柔性多体建模框架，并对装配后的连杆机构原型进行了整体精度分析。该方法通过与Bennett四杆机构的3D打印PLA原型进行验证，其中包括具有故意关节轴线错位的变体，这些变体从刚性体理论角度看无法装配。本文还补充贡献了一种适用于此类具有病态雅可比矩阵机构的运动学参数辨识方法。实验与仿真结果的对比表明，这些过约束机构表现出自装配趋势——结构柔顺性驱动装配趋向理想几何构型，并将约束应力分布到整个结构中。使用纸板管和竹签作为连杆构建模块的额外定性演示证实，功能机构可由制造精度有限的低成本非常规材料实现。所提出的建模流程完全算法化，为未来的设计优化奠定了基础。

英文摘要

Overconstrained rational single-loop linkages are efficient, compact, and low-cost custom mechanisms, yet their deployment in industrial settings is limited. In simulations, rigid body formulations fail due to redundant constraints. This study presents a flexible multibody modeling framework based on the floating frame of reference formulation, and delivers an overall accuracy analysis of assembled linkages prototypes. The approach is validated against 3D-printed PLA prototypes of a Bennett four-bar mechanism, including variants with intentional joint-axis misalignment, which theoretically, from the rigid body point of view, cannot be assembled. A supplementary contribution is delivered in the form of a kinematic parameter identification methodology suited for this type of mechanism with ill-conditioned Jacobian. The experimental and simulation results are compared and reveal that these overconstrained mechanisms exhibit a self-assembling tendency -- structural compliance drives the assembly toward the ideal geometric configuration, distributing constraint stress throughout the structure. Additional qualitative demonstrations using cardboard tubes and bamboo sticks as link building blocks confirm that functional mechanisms can be realized from low-cost, unconventional materials with limited manufacturing accuracy. The proposed modeling pipeline is fully algorithmic and enables design optimization in the future.

发表机构

• Ulsan National Institute of Science and Technology (UNIST)（蔚山国立科学技术院）
• University of Innsbruck（因斯布鲁克大学）
• VSB – Technical University of Ostrava（VSB – 俄斯特拉发技术大学）

机构由 AI 辅助整理，请以论文原文为准。