edge direction detection

• 棱边方向检测

edge direction detection的用法和样例：

例句

1. A groove along the length direction of the upper surface of the bumper is provided, wherein a rectangular illuminator is provided.
   该防撞饰条的上表面，沿其长边方向设有一长沟槽，且于该一长沟槽内设有一长条形发光体。