在連續變動的影像平面中，攝影機與環境之相對速度會造成影像平面上各個像素（Pixel）的亮度變化，此種像素的亮度變化即稱為光流（Optical flow）。以光流為基礎的視覺伺服（Visual servo）方法，其優點在於不用事先得知目標物的特徵，僅需取得其亮度資訊，因此可以廣泛地應用在各種定位與追蹤的工作上。
本文的目的為應用影像伺服的方式，結合離散滑動控制來針對目標物三軸方向的移動做追循定位的工作。運用光流變動的原理與離散滑動控制法則，再加上以影像金字塔為基礎之追循架構，從連續的影像中計算出攝影機與目標物的相對位移，並對攝影機的位置不斷地做修正，使其所傳回的影像保持不變，藉此達到定位追循的目的。

The brightness variance, caused by relative velocity of the camera and environment in a sequence of images, is called optical flow. The advantage of the optical-flow-based visual servo method is that feature of the object dose not need to be known in advance. Therefore, it can be applied for positioning and tracking implement tasks.
The purpose of this thesis is to implement the image servo technique and the sliding-mode control method to track an unknown image pattern in three dimensional motion. The goal of tracking is to maintain identical image captured by the camera based on the relative movement calculated from the optical flow.

目錄
目錄……………………………………………………………………….i
圖索引…………………………………………………………………...iii
表索引…………………………………………………………………..vii
摘要…………………………………………………………………….viii
Abstract…………………………………………………………………ix
第一章 緒論……………………………………………………………..1
1.1 前言……………………………………………………………..1
1.2 文獻回顧………………………………………………………..2
1.3 論文架構………………………………………………………..4
第二章 光流系統………………………………………………………..6
2.1 光流及影像流之定義…………………………………………..7
2.2 光流之演算……………………………………………………..8
2.3 幾何空間投影與平面光流……………………………………14
2.4 亮度變動方程式之修正………………………………………17
2.5 系統模式探討…………………………………………………19
第三章 控制架構探討…………………………………………………22
3.1 離散滑動模式控制……………………………………………23
3.2 光流伺服控制…………………………………………………28
3.3 追循架構探討…………………………………………………36
3.3.1 影像特徵探討…………………………………………..37
3.3.2 影像金字塔之應用……………………………………..39
3.3.3 影像濾波器……………………………………………..41
3.3.4 標準差門檻值…………………………………………..42
第四章 系統模擬與分析………………………………………………44
4.1 模擬裝置………………………………………………………44
4.2 模擬實驗結果…………………………………………………49
第五章 影像追循實驗…………………………………………………61
5.1 實驗設備說明…………………………………………………61
5.2 靜態定位………………………………………………………65
5.3 動態追循………………………………………………………72
5.4 可變動架構之動態追循………………………………………78
5.4.1 光流適用範圍分析……………………………………..78
5.4.2 追循架構切換…………………………………………..81
5.4.3 影像追循實驗…………………………………………..84
第六章 結論及未來展望………………………………………………89
參考文獻………………………………………………………………..91

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