quaternion

First, a variation-the error quaternion vector can be attained. The non-single question of the end attitude of the spacecraft can be solved.
首先导出了误差四元数矢量，从而解决了航天器姿态控制中最终姿态表示的非单值性问题；
W component of the Quaternion. Don't modify this directly unless you know quaternions inside out.
四元数的W组件。不要直接修改这个，除非你很了解四元数。
Returns the square of the length of a quaternion .
Returns the length of a quaternion .
Returns the normalized form of the specified quaternion .
Returns the length of the specified quaternion .
Replaces the current quaternion with its exponential .
Replaces the current quaternion with its natural logarithm.
When optimizing synchro update of the quaternion, the quaternion differential equation is calculated by using minimum parametric method.
采用最小参数法求解四元数微分方程，优化了四元数实时更新算法。
In this paper, the quaternion is taken for positional parameters to control the attitude of a spacecraft.
以四元数作为定位参数对航天器进行姿态控制。