具故障安全特性之腱驅動機構設計

近年來腱驅動機構已成功的應用到機器人輔助醫療手術，這種機械需要較高的安全性，且必需具有故障安全特性。故障安全特性可以從增加感測器、防止軟體失效、防止硬體失效、使用緊急關斷按鈕等各種不同的方向加強。本文所採用的是使用多餘的腱驅動機構來加強硬體失效時的故障安全特性。多餘的腱還可以提供額外的設計彈性，例如可以讓性能最佳化、降低各腱的負荷並提供更高的容錯能力等等。本文先以公式及構造矩陣的零空間的觀念，推導出腱驅動機構在斷掉任何一條驅動腱的情況下，仍能維持在可控制狀態，不致產生嚴重損害的條件。然後分別以幾何法及最佳化方法，來設計出滿足這些限制條件的腱驅動機構。使用幾何法可以很快的得到一些可行的機構，將這些可行的機構再做為使用最佳化方法合成時的初始估計值，即可找到最佳的解。在本文中，最佳化方法的目標是要找出滿足限制條件且具有最低條件數的機構；這種多餘腱驅動機構中各腱的負荷最為平均，也較節省成本。

關鍵字

腱驅動；構造矩陣；故障安全；零空間；條件數

並列摘要

Tendon-driven manipulators have been widely used in many applications. Recently, tendon-driven manipulators have successfully been used for some robot-assisted medical surgery. Fail-safe design features should be incorporated into such manipulators to increase safety. There are many safety features to be concerned, e.g., fail-safe design of hazard detectors, protection against software/hardware failures, intrusion monitoring, or use of panic buttons. In this paper, a tendon-driven manipulator with redundant tendons is used to increase fail-safe feature in the event of hardware failure. A tendon-driven manipulator having redundant tendons may also possess additional flexibility in operation such as capable of optimizing the performance of tendons, reducing the burden of each tendon, and allowing fault tolerance for actuation. The purpose of this paper is to develop a methodology for synthesizing tendon-driven manipulators with redundant tendons and fail-safe features, and to optimize the distribution of tendons force of the system. Characteristics of tendon-driven manipulators and fail-safe features are briefly discussed. Criteria for the tendon-driven manipulator with fail-safe features are derived from the null space of the structure matrix. With these constraints, manipulators can remain controllable when any of the tendons fails to function. Finally, procedures for determining the structure of the tendon-driven manipulator are developed via geometric method and optimization-based numerical method. Solutions found by geometric method can be used for the initial estimate of optimization method. The objective of optimization method is to even the burden of each tendon and to reduce cost.

並列關鍵字

tendon-driven ； structure matrix ； fail-safe ； null space ； condition number

參考文獻

[12] 呂瑞安，“線驅動平台工作空間與線張力調整之探討”，碩士論文，台灣大學機械工程學系 (2008).

[1] B. C. Yoseph and C. Breazeal, Biologically Inspired Intelligent Robots, SPIE Press, 2003.

[3] J. K. Salisbury, “Kinematic and Force Analysis of Articulated Hands,” Ph.D. Dissertation, Dept. of Mechanical Engineering, Stanford University, Stanford, CA, (1982).

[4] L. W. Tsai and J. J. Lee, “Kinematic Analysis of Tendon-Driven Robotic Mechanisms Using Graph Theory,” ASME JOURNAL OF Mechanisms, Transmissions and Automation in Design, Vol. 111, No. 1, (1989), pp. 59-65.

[5] J. J. Lee and L. W. Tsai, “The Structural Synthesis of Tendon-Driven Manipulators Having a Pseudotriangular Structure Matrix,” Journal of Robotics Research, Vol. 10, No. 3, (1991), pp. 255-262.

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具故障安全特性之腱驅動機構設計

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