中文说明：众所周知，欧拉角和四元数是存在对应关系的。后者用于导航等时不存在死区现象，而且，精度高，计算简单。
English Description：
As we all know, there is a corresponding relationship between Euler angle and quaternion. The latter has no dead time when it is used in navigation, and has high precision and simple calculation.