捷联惯导动态粗对准算法研究与仿真

Study and Simulation on Dynamic Coarse Alignment of SINS

动态环境下无法直接根据陀螺和加速度计的输出计算出姿态阵。针对这一问题,研究了一种基于重力加速度和惯性坐标系的粗对准算法。算法以初始时刻的导航系和机体系为基础,定义两个与其重合的惯性坐标系,利用重力加速度在这两个惯性坐标系中的投影来构造观测向量,通过q-method求解Wahba问题确定初始时刻的姿态阵。而导航坐标系的变化可根据地理位置信息、地球自转角速度和时间信息来计算,机体系的变化亦可通过陀螺信息实时跟踪,因而就能确定对准完成时刻的姿态阵。理论分析和仿真表明,该方法能有效解决捷联惯导的动态粗对准问题。

Attitude matrix can＇t be directly calculated from the measurement of the gyros and accelerometers in dynamic environment. Aiming to overcome these difficulties,a gravity and inertial coordination based coarse alignment method was introduced. Based on the initial navigation coordination and body coordination,the gravity was projected to the two inertial coordinate to makeup the vector measurements,and the q-method was employed to determinate the initial attitude matrix. The change of the navigation coordination can be calculated from the geography and time information,and the change of body coordination can be tracked by the gyro,and then the final attitude matrix can be calculated. Simulation results show that the algorithm is efficiency for the dynamic coarse alignment of the SINS.