顶丝 meaning in English

jbckscrew
terminal strand

First , we can use a camera to take over the laser beam at one end , record the position of the light - spot , and calculate the centroid of the light - spot , then , move the laser on the guide rail . we should rectify the screw until the position of light - spot is unchangeable . then , the camera should be moved to the other end of the guide rail
先用摄像机在一端接收激光器发出的光斑,并记录光斑的位置,求出其质心,然后在导轨上移动激光器,调节顶丝,直到摄像机上的光斑位置不动为止,然后将激光器移到导轨另一端,让激光器在导轨上滑动,调节顶丝,直到摄像机上光斑位置不变,而且与前一次测试时的位置在误差允许的范围内,则认为激光器直线性校准完毕。