光學讀頭平面定位器之實作

Abstract

在工業的領域□，工程師經常面臨到一些需要使用感測器去量物體 的位置、速度、加速度來獲得系統運動時相關的資訊。在本篇論文裡， 我們提出使用三個光學讀頭來實現平面定位的方法，利用讀頭在循軌時 產生的循軌誤差訊號來計算跨越的軌數，因此可以得知讀頭所移動的距 離及位置。 當物體只進行平移的運動時，只需要兩個讀頭就可以知道物體移動 的距離及位置，但當物體並非進行平移時，也就是同時進行旋轉之運動 時，兩個讀頭則無法得知物體真正的運動量，而必須使用三個讀頭。利 用每一個光學讀頭所能量測到之移動量，經由計算後即可得知物體真正 的位移量及旋轉角度。由於光碟片的軌距為1.6 ，因此整個定位的精密 度可以達到1.6 之內，而物體旋轉量在90度以內均可利用本系統來量測 。

In the field of industry, the engineer often confronts with problems demanded with transducers for position, velocity, and acceleration of the object. In the thesis, we present a method for measuring plane position with a commercially available compact disc optical pickup. The method is used the tracking error signal generated by the optical pick-up head during tracking to count the track numbers. Thus, the distance which the pick-up head has been moved, and the position of the pick-up head can be measured. When the object is doing translation, we only need two pick-up heads to measure the displacement and the position of the object. But if the motion of the object is not only the translation but also the rotation, two pick-up heads are not enough for us to measure. Thus, we need three optical pick-up heads. The displacement of the pick-up head can be measured to calculate the actual displacement and rotation angles of the object. The distance of track is 1.6 , hence, the accuracy of the positioning system is achieved to 1.6 . In this implement we can measure displacement of pickup set which rotation less 90-degree.