由於資料通訊網路的技術進步迅速，特別是在網際網路上，使得網路在工業的應用越來越多，其可以很便利達成系統性的維護。由於將控制系統網路化後感測器、致動器與控制器透過網路的連結，可以帶來許多優點，例如節省配線、減少安裝和維護的成本與增加監控的距離。然而將控制系統網路化之後，也帶來了時間延遲與資料遺失的問題，這些問題輕則降低系統效能，重則使整個系統產生不穩定或是無法控制。因此，本研究提出基於線上即時量測網路時間延遲的估測方法導入傳統史密斯估測器的時間延遲項，將此時間延遲項變更為適應性的補償方法，再結合所設計之控制器，可克服實際網路控制系統因時間延遲所造成的控制性能劣化，達成可靠的性能響應。最後，實際應用於所建置的交流伺服馬達網路控制系統平台，且遠端控制器與馬達之間相隔15公里，驗證本研究所提出的方法，在網路間延遲的變化下，仍可達成精密而穩定的控制效能。

Real-time network control applications have increasingly gained attentions due to the rapid development of data communication network technologies. Network systems can be conveniently and systematically maintained in industrial applications. The networked control system (NCS), which simply interconnects all sensors, actuators, and controllers through the network, is promising in the future development of industrial technologies with low cost of installation, reconfiguration, and maintenance. However, NCS also unavoidably leads to problems of time delays and data dropout that seriously degrade control performance. In this study, online estimation of the delay time is developed by processing the on-line measurement of the round-trip time (RTT) between two nodes in real network environments. The adaptive Smith predictor scheme is developed by directly applying the estimated time delay to deal with network-induced delays. To prove the feasibility of the proposed remote control system, the developed design has been applied to an AC 400 W servo motor tested in 15 Km distance. Experimental results indicate that
significantly improved stability and motion accuracy can be reliably achieved by applying the proposed approach.