在影像光流的估測方法中，運動能量法為一種廣被使用的追蹤法，然此法並不適合應用於主動式攝影機，此問題雖可透過背景補償法解決，然而此法之缺點即是當目標物移動速度太慢時，其無法被偵測出來，導致無法有效完成追蹤任務，因此本文嘗試結合視訊壓縮技術領域中所使用的三步搜尋法(3-step searching method)，首先利用運動能量法在壓縮過之影像中進行粗搜尋，接著再以三步搜尋法在原始影像中相對應位置附近作細搜尋，得到精確的目標物位置。另外在伺服部分，將探討所選用之不同馬達伺服驅動模式，對視覺回授控制器所造成之影響，並且以穩態響應中常用之標準測試訊號，包括步階與斜坡命令輸入，來測試視覺伺服系統對其命令之穩態誤差，並嘗試以前饋補償架構來消除二階輸入命令之穩態誤差，使其達到更佳之追蹤效果。

In this study, a prototype real-time visual servo tracking system is developed. It consists of two parts ¾ image-processing unit and servo control unit. For the image-processing unit, the background compensation technique is used to align the images taken at different positions so that static motion energy method can be applied. However, inaccurate image mapping due to noise is inevitable. Thus to desensitize the noise effect, the morphological filter is employed in this work. Nevertheless, for the cases of slowly moving targets, it is possible that the targets will not be detected. The reason is that the morphological filter will remove any insignificant moving portion in the image. To overcome this difficulty, an approach that combining the motion energy method and the 3-step hierarchical search method ¾ a fast motion estimation algorithm for video coding, is proposed in this study. Experimental results show that the proposed approach can lead to a good motion tracking result. For the servo control unit, it is found that the mode of servo drive will affect the type of visual servo system. Hence the visual controller should be designed properly so that steady state tracking error will satisfy the performance criterion. In addition, to eliminate the tracking error corresponding to the ramp input, the feed-forward compensation is incorporated into the control structure. Experiment results indicate that the feed-forward compensation can indeed reduce the tracking error.

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