應用影像量測技術於致動器位移回饋控制之研究

DISPLACEMENT FEEDBACK CONTROL OF SERVO-HYDRAULIC ACTUATORS USING IMAGE-BASED ANALYSIS TECHNOLOGY

鄭宇辰(Yu-Chen Cheng) ； 陳沛清(Pei-Ching Chen) ； 楊元森(Yuan-Sen Yang)

《中國土木水利工程學刊》 32卷8期 (2020/12) Pp. 721-732

https://doi.org/10.6652/JoCICHE.202012_32(8).0006

摘要

在傳統的結構反覆載重實驗中，若油壓致動器需要夾治具轉接後方與試體連接時，常使用外部位移計做為致動器位移控制的回饋訊號，以確保試體達到預期的變形。在實驗進行的過程中，若位移計與試體的連接脫落，無法將正確的位移訊號傳回控制器，恐造成致動器失控而導致實驗失敗。此外，對於高度較高或夾治具架設較複雜的實驗試體，不容易準確且安全地架設外部位移計。有鑑於此，本研究應用影像量測技術，透過即時運算機器分析試體的位移反應，並將其回饋至致動器控制器進行位移控制。實驗時將目標物標定於試體上，藉由高速相機拍攝並即時計算目標物的位移量，透過光纖共享記憶體以數位訊號的形式直接與控制器進行數據的交換，以達到致動器的即時位移回饋控制。實驗驗證結果顯示，本研究所開發的技術，可成功完成靜態反覆載重實驗以及動態位移加載實驗。未來在結構實驗應用方面，不僅不受安裝外部位移計所需的工作空間限制，亦可降低外部位移計鬆脫導致的實驗風險。

關鍵字

影像量測 ； 位移回饋控制 ； 油壓致動器 ； 反覆載重實驗 ； 動態實驗

並列摘要

Cyclic loading tests have been considered as the most effective approach to investigate force-to-displacement behavior of a structural specimen. In particular, an external displacement transducer is essential to measuring specimen deformation as displacement feedback for controlling the servo-hydraulic actuator on condition that fixtures are used to connect the actuator to the specimen. However, if the connection between the displacement transducer and specimen is loosen, incorrect feedback displacement could result in uncontrollable actuator response and fail the structural testing. In this study, image-based analysis technology has been applied to displacement feedback control of servo-hydraulic actuators for structural testing. A high-speed camera is used to capture images of the specimen which are sent to a real-time computational platform to calculate the specimen displacement in real time. The calculated displacement is transmitted to the digital controller of actuator through the Shared Common Random Access Memory Network, forming a closed-loop control system. Experimental results demonstrate that the proposed framework is applied to quasi-static cyclic loading tests and dynamic-loading tests successfully and stably with exceptional control performance.

並列關鍵字

image-based measurement ； displacement feedback control ； servo-hydraulic actuator ； quasi-static cyclic loading test ； dynamic loading test

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