以即時網路為基礎的運動控制技術之研究

Abstract

本論文研製完成一個以即時網路為基礎的多軸運動控制系統，此系統以PC為控制核心，在PC Windows NT的多工操作系統下，利用RTX即時多工核心程式配合本實驗室自行發展的PC-SERCOS通訊介面卡，完成一個利用即時網路為通訊介面的多軸運動與伺服控制系統。伺服控制架構採用串聯式的多迴路控制架構，此架構具有先天上的強韌性，且各迴路的控制器可獨立設計，此外，為了降低伺服相位延遲所造成的追隨誤差，特別設計了兩個前饋式控制器。此運動控制系統的通訊介面，採用以光纖為傳輸媒介的即時控制網路(SERCOS)協定，藉由一個SERCOS專用控制晶片- SERCOS410B，本實驗室完成了一個PC-SERCOS通訊介面卡。透過此通訊介面卡，系統軟體可以設定、調整與監控各伺服控制軸的操作狀況，同時產生以SERCOS為通訊協定的位置、速度或扭矩命令。此運動控制系統的軟體設計主要包含三個部分：即時多工運動控制程式、SERCOS介面卡驅動程式、以及一個以視窗為基礎的互動式人機監控程式。使用者可以藉由人機監控程式線上取得系統相關資料，包括控制參數的調整、系統的運動狀態、錯誤診斷、以及系統的極限設定值等等。本論文說明了此即時網路運動控制系統的設計架構並完成實驗整合，研究結果顯示應用SERCOS即時控制網路協定於高階運動控制系統，具有系統設計模組化、開放式的架構、簡化配線、易於擴充等多重優點，是未來多軸運動控制技術發展的方向。

This thesis presents the application of a real-time communication network protocol, the SERCOS, to advanced motion control system. A multi-axis motion control system has been constructed using a PC, a designed PC-SERCOS interface card, and two servo drives with SERCOS interface. A real-time multi-tasking kernel (RTX) under the Microsoft Windows NT has been employed for the development of the motion and servo control software. Cascaded multi-loop control structure has been adopted in the design of the servo controller. This control architecture has inherent robustness and its control loop can be independently designed. Two additional feedforward controllers have been designed to reduce tracking error due to servo lag. The backbone of this motion control system is a PC-SERCOS interface card using a SERCOS control IC – SERCON410B. Motion and motor control commands generated by the host controller, the PC, can be sent to specified servo axis via the SERCOS optical fiber. Through the SERCOS interface and the PC0-based real-time kernel, the host controller can interactively monitor and control the multi-axis motion control system in real-time. The software design of the motion control system consists three major parts: a real-time multi-task motion control program, a SERCOS interface program, and a windows-based man-machine interface program. Experimental results reveals the designed system has good features of open architecture, modular design, flexibility, easy expansion, simple wiring, etc., and real-time network control will become the major approach in development of high-performance motion control system.