An algorithm of 3-axis interference-free tool path is researched and realized by cutter location surface and protection surface of discrete triangular facets of machined surface.

介绍和扩大了数控加工中的刀位面和保护面的概念，研究和实现了一种基于曲面离散生成三轴加工无干涉刀具轨迹的算法。

youdao

To explore the surface of the moon, astronauts must be able to survive outside the protection of their spacecraft.

VOA: special.2009.07.01

The ocean accounts for 70% of the surface of the Earth, but only one percent of their area benefits from protection.

UNESCO: Indigenous Peoples