基于误差四元数的捷联惯导全姿态导航与控制

在舵偏控制回路中使用欧拉角姿态信息,是现有飞行器捷联惯导系统普遍采用的方法。为避免垂直状态时欧拉角姿态表示法的算法奇异问题,引入了四元数姿态表示法,但是最终形成偏差输入到舵机的仍旧是欧拉角姿态信息。对此问题,文中分析讨论了捷联惯导系统中,以欧拉角信号控制飞行器舵偏输出(推力矢量输出)的传统方法的两点不足之处:垂直状态时欧拉角姿态算法的物理奇异问题;控制路径过长问题。提出由误差四元数直接控制舵偏输出(推力矢量输出)的新的捷联导航方法。此方法控制路径最短,且克服了物理奇异问题,不局限于飞行器所处的姿态,因此,将其称之为全姿态导航方法。仿真结果表明了此方法的可行性与有效性。

All-attitude navigation and control in SINS based on error quaternions

Using Eulerian angle information in rudder-control-loop is a general method in the strapdown inertial navigation system(SINS) of aerocraft. In order to avoid algorithm stiff numerical problem, a quaternions attitude algorithm was introduced. But, what imported into rudder-control-loop is still the Eulerian angle information. Traditional methods of using Eulerian angle to control the rudder (thrust) of the aerocraft have two shortcomings, that is, the physic stiff numerical problem of using Eulerian angle attitude algorithm at vertical state, and long controlling path. This paper analyzed these two shortcomings, then presented a new navigation method of using error quaternions to control rudder (thrust) in SINS. This method has the advantage of controlling path being the shortest, and overcomes the physic stiff numerical problem. It is not limited to the attitude of aerocraft, so it is called as all-attitude navigation method. The simulation result shows its feasibility and validity.