並聯式機械手臂之運動控制器設計與實現

近幾年來，自動化產業的要求日漸上升，目前已有多種類型的多軸系統需要控制技術來提升其產業上的效能。非均勻有理B型曲線(Non-Uniform Rational B-Splines，NURBS)被廣泛應用於電腦輔助設計或數值加工控制，其概念是藉由調整控制點和權重值來實現各種曲線模型之擬合設計。由於傳統的自動化設備配置的控制系統容易遇到多軸同步與即時性的問題，以及受限於配線繁雜與外界雜訊干擾，EtherCAT通訊協定便因此產生。EtherCAT架構是透過簡易封包傳輸方式、硬體設計才能夠在多個裝置中進行高速傳輸，同時保證傳送過程不會因為延遲而遺失封包資料。本論文以運動控制平台為基礎，發展出具有高精度與穩定性之運動控制系統於並聯式機械手臂。並聯式機械手臂是由永磁式交流伺服馬達所組的結構，其中並聯式機械手臂在運動控制的過程中必須考慮到其架構設計與工作空間，因此運動控制設計為此研究並聯式機械手臂之重要議題。首先，在並聯式機械手臂上建立EtherCAT架構的工作環境，並透過NURBS補插器技術對並聯式機械手臂進行任意運動軌跡規劃，最後藉由人機介面可自行調整控制點與權重值，以便設計所需要之運動軌跡，結合NURBS補插器與EtherCAT架構以便提高控制精度與縮短控制時間。

關鍵字

並聯式機械手臂； EtherCAT ； NURBS曲線；運動控制；路徑規劃

並列摘要

In recent years, the requirements of the automation industry have been increasing. At present, many types of multi-axis systems require control technology to enhance their industrial performance. Non-Uniform Rational B-Splines (NURBS) is widely used in computer-aided design or numerical processing control. The concept is to achieve various curve models by adjusting control points and weight values Design. The EtherCAT protocol is created because the control system of the traditional automation equipment is susceptible to multi-axis synchronization and immediacy, as well as problems caused by complicated wiring and external noise interference. The EtherCAT architecture enables high-speed transmission in multiple devices through simple packet transmission and hardware design, while ensuring that the transmission process does not lose packet data due to delay. Based on the motion control platform, this study develops a motion control system with high precision and stability in a parallel mechanical arm. The parallel type mechanical arm is a structure composed of two permanent magnet type AC servo motors. Parallel manipulators must consider their architectural design and working space in the process of motion control. Therefore, motion control is an important topic for studying parallel manipulators. Firstly, the working environment of the EtherCAT architecture is established on the parallel manipulator, and the arbitrary manipulators are planned for the parallel manipulator through the NURBS interpolator technology. Finally, the control points and weight values can be adjusted by the human-machine interface to design the required motion trajectory. Combined with the NURBS interpolator and EtherCAT architecture to improve control accuracy and reduce control time.

並列關鍵字

Parallel Robot ； EtherCAT ； NURBS curves ； Motion control ； Path planning

參考文獻

[1]Y. Gao, R. Qu, D. Li and F. Chen, “Force Ripple Minimization of a Linear Vernier Permanent Magnet Machine for Direct-Drive Servo Applications,” IEEE Transactions on Magnetics, vol. 53, no. 6, pp. 1-5, June 2017, Art no. 7001905. Z. Chang-Cheng, X. Jian-Ming, J. Yao, M. Jie and X. Lin-Tao, "Design of servo drive slaves based on EtherCAT," The 27th Chinese Control and Decision Conference (2015 CCDC), Qingdao, 2015, pp. 5999-6004.

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