異質網路之遠端同步控制系統設計

Abstract

在網路控制系統中，時間延遲與資料遺失對系統的穩定性有很大的影響，本研究結合時間延遲完全補償策略(PDC)與最小平方估測法處理網路延遲的問題。PDC將延遲的影響簡化為原閉迴路系統串接一時間延遲，避免系統不穩定；而最小平方估測用既有資料產生估測項，避免空白取樣發生時，資料沒有更新使誤差增加，由實驗得到，加入最小平方估測後，當突發性的大延遲發生時可避免突然增加的控制誤差量。 本研究建立異質性網路雙軸系統並進行循圓實驗，雙軸延遲不同造成兩軸在循圓的結果為橢圓，藉由量測網路傳輸延遲並建立雙軸的等待機制使其同步，將真圓度由0.157改善到0.013。延遲測量實驗結果顯示傳輸延遲會變動，本論文進一步加入即時補償機制可達成即時同步調整。 將交叉耦合控制器(CCC)與PDC結合並應用於雙軸異質性網路控制系統，克服CCC雙軸誤差計算上的不匹配之後，能夠進一步改善循圓的輪廓誤差。進行新竹到台中的遠端控制實驗並以上述同步方法改善，真圓度可降低為1/10，輪廓誤差降為原本的1/4。

The data dropout and time delay in the network control system (NCS) have a great effect in control performance. In this Thesis, we combine both the perfect delay compensation (PDC) and the least square estimation (LSE) to recover the dropout data caused by the network-induced time delay. In this study, experiments were constructed through NCS with different time delays. As the command is circular, the contour becomes elliptical due to the different delays in two NCS, one is CAN and another is Ethernet. The round trip time (RTT) between two network nodes was measured and furthermore, the faster NCS is designed to wait for the slower NCS to result in the synchronized motion. The roundness is then significantly improved from 0.157 to 0.013. As the time delay is varied in the commercial Ethernet, the adaptive compensation based on the real measured RTT was adopted to match the real time delay. The cross-coupled control (CCC) was further applied and experiments between Hsinchu and Taichung show that roundness and IAE for the 2-axis motion control system can be improved by 90% and 25%, respectively, in the roundness and IAE.