基于惯性系重力的高精度水平姿态确定方法

针对舰载星敏感器定位需依赖外部提供的水平姿态基准,提出了一种基于惯性系重力的高精度水平姿态确定方法。该方法利用星敏感器输出的载体系相对于惯性系的姿态转换矩阵,将加速度计的测量信息投影转换至惯性坐标系,设计自适应滤波器对加速度计投影后信息进行滤波,最大限度地对风浪和加速度计的噪声等外部干扰信息进行剔除,根据提取出的较纯净的重力矢量信息解算高精度的水平姿态,把这一高精度水平姿态作为星敏感器定位所需外部水平基准。仿真结果表明,该方法能有效剔除舰船海上航行时的各种扰动信息,水平姿态精度较高且误差不随时间积累,进而提高了星敏感器的定位精度,满足舰船长时间海上航行对于导航精度的要求。

A Method of High precision Horizontal Attitudes Based on the Gravity in the Inertial Coordinate System

Aimed at the positioning dependence of shipboard star sensor on external horizontal attitudes, a method of high precision horizontal attitudes based on the features of gravity in the Inertial coordinate system was put forward.Making use of the output of star sensor,the attitude transformation matrix in the carrier coordinate system was related to the one in Inertial coordinate system.The measurement information projection of the accelerometer,filtering by adaptive filter,was then converted in the Inertial coordinate system,which could eliminate external interference like the noise of wind and the waves or the accelerometer.At last the more pure gravity information was utilized to calculate high precision horizontal attitudes,which would be the external horizontal standard needed for star sensor positioning. The simulation results showed that this method could calculate the horizontal disturbance information of the ship effectively.The horizontal precision was high without error accumulation. This method increased the location precision of the star sensor, which could well meet the requirements of navigation precision of ship for long time sailing on the sea.