含有接觸問題之連續體機械臂運動分析

Motion Analysis of Continuum Robots with Contact Problems

郭奕瑄(I-Hsuan Kuo)

指導教授 ： 李志中

國立臺灣大學/工學院/機械工程學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202101001

摘要

連續體機械臂是一種可連續彎曲、具無限自由度的機構，結構本身由柔體支柱與剛體桿件組成，通常藉驅動纜繩、支柱或改變流體壓力操作。本研究應用向量式有限元素法，針對單一支柱型與多支柱型連續體機械臂進行運動分析，計算受外力驅動後之變形。該方法基於牛頓第二運動定律，採用一組不同於傳統力學理論架構的描述概念和簡化假設，針對空間中的結構進行模擬，在求解含大位移、大變形的非線性分析方面，計算效率與精準度較其他方法高。本文為進行模擬而簡化機械臂模型，提出以迭代與等效方式計算單一支柱型連續體機械臂結構內的接觸力，以及應用接觸演算法與罰函數法，分析多支柱連續體機械臂模擬中複雜的接觸問題。而後，藉影像處理技術設計量測平台，以非接觸方式量測機械臂變形，驗證模擬結果。對於空間中單一支柱型連續體機械臂受力後的變形，計算位置誤差落在4.5 mm以內，相對於機械臂全長的比例小於2.25%；而對多支柱型連續體機械臂的計算位置誤差落在4 mm以內，相對於機械臂全長的比例小於2%。

關鍵字

連續體機械臂 ； 向量式有限元素法 ； 力量分析 ； 接觸演算法 ； 非接觸式量測

並列摘要

This research studies the motion of continuum manipulators, mainly cable-driven single-backbone type and rod-driven multi-backbone type, via the vector form intrinsic finite element (VFIFE) method. For the cable-driven type of continuum manipulator, a process is developed such that the contact forces occurred between the driving cable and the disks on robot are converted to the equivalent external nodal forces. For the rod-driven type of continuum manipulator, the contact algorithm combined with penalty method is introduced to develop the contact forces between the driving rod and the disks. These equivalent external nodal forces or contact forces are then applied as the external load to the backbone nodes which are established in the process of VFIFE. The static deformation of the motion of the manipulator is further achieved by use of kinetic dynamic relaxation method. Finally, an imaged-based measurement system is established for measuring the deformation of continuum robots and experiments are performed to validate the simulated static model.

並列關鍵字

Continuum robot ； Vector Form Intrinsic Finite Element method ； Force analysis ； Contact algorithm ； Noncontact image-based measurement

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