New north finding algorithm for strapdown compass based on FOG
-
摘要: 舰船的摇摆使陀螺仪无法测出地球自转角速度(Ω),进而光纤捷联罗经系统无法根据陀螺仪和加速度计的输出直接计算出载体航向.针对这一问题,提出了一种寻北新算法.该算法以"固定"的参考系——惯性坐标系为参考基准,建立了过渡惯性坐标系和初始时刻捷联惯组惯性坐标系,利用加速度计敏感重力加速度在惯性坐标系中的投影计算出Ω的空间指向,得到地理真北.光纤捷联罗经系统寻北算法的实现分解为3个步骤:建立初始时刻捷联惯组惯性坐标系,利用加速度计获得稳定的水平坐标系;根据捷联惯组坐标系与初始时刻捷联惯组惯性坐标系的转换,将加速度计信息投影到初始时刻捷联惯组惯性坐标系,采用空间圆拟合法求出Ω的空间指向;将平行于Ω的矢量向水平面投影得到地理真北.仿真结果表明:载体晃动环境下的寻北精度达到了0.23°(1σ) .Abstract: The ship rolling prevents a gyroscope from reliably measuring the angular velocity of the earth's rotation (Ω). Consequently,the strapdown compass system based on fiber optic gyroscopes (FOG) cannot compute the heading of the carrier based on the outputs of gyroscopes and the accelerometers. To address this issue, a new north finding algorithm was proposed. By taking the inertial frame as the reference coordinate frame, this algorithm established the transitional inertial frame and the initial-time strapdown compass body inertial frame. The direction of vector Ω was then calculated according to the projection of the accelerometer sensitive to grivity in the initial-time body inertial frame. And this in turn recovers the true north of geographic direction. The proposed north finding algorithm consists of three steps. It established the initial-time body inertial frame. Then it obtained a stable level frame via the initial-time body frame and the outputs of gyroscope and accelerometer. By projecting the output of accelerometer from the strapdown compass body frame to the initial-time body inertial frame, the direction of vector Ω was calculated by the space circle fitting method. Then the true north was recovered by projecting the vector parallel with Ω from the initial-time body inertial frame to the stable level frame. The simulation result shows that the error of azimuth can be reduced to as low as 0.23°(1σ) .
-
[1] 秦永元,严恭敏,顾冬晴,等.摇摆基座上基于g信息的捷联惯导粗对准研究[J].西北工业大学学报,2005,23(5):681-684 Qin Yongyuan,Yan Gongmin,Gu Dongqing,et al.A clever way of SINS coarse alignment despite rocking ship[J].Journal of Northwestern Polytechnical University, 2005,23(5):681-684(in Chinese) [2] Napolitano F,Gaiffe T.PHINS: the first high performances inertial navigation system based on fiber optic gyroscopes //9th Inter-national Conference on Integrated Navigation Systems.Saint Petersburg,Russia: ,2002:296-304 [3] Gaiffe T,Cottreau Y,Faussot N,et al.Highly compact fiber optic gyrocompass for applica-tions at depths up to 3000 meters //IEEE Underwater Technology,Proceedings of the Inter-national Symposium.Tokyo,Japan: ,2000:155-160 [4] 肖正林,钱培贤.方位罗经自对准原理的修正[J].战术导弹技术,2006,3(2):75-79 Xiao Zhenglin,Qian Peixian.The correction of azimuth compass auto-aligning principle[J].Tactical Missile Technology,2006,3(2):75-79(in Chinese) [5] Rawlings A L.The theory of the gyroscopic compass and its deviations [M].New York:The Macmillan Company,1994 [6] 严恭敏,秦永元,卫育新,等.一种适用于SINS动基座初始对准的新算法[J].系统工程与电子技术, 2009, 31(3):634-637 Yan Gongmin,Qin Yongyuan,Wei Yuxin, et al.New initial alignment algorithm for SINS on moving base [J].Systems Engineering and Electronics,2009,31(3):634-637(in Chinese) [7] Gaiffe T. From R&D brassboards to navigation grade FOG-based INS:the experience of photo-netics/ixsea //IEEE 15th Optical Fiber Sensors Conference Technical Digest,Vol 1. Portland:IEEE,2002:1-4 [8] 练军想,汤永刚,吴美平,等. 捷联惯导惯性系动基座对准算法研究[J].国防科技大学学报,2007,29(5):95-99 Lian Junxiang,Tang Yonggang,Wu Meiping,et al.Study on SINS alignment algorithm with inertial frame for swaying bases [J].Journal of National University of Defense Technology,2007,29(5):95-99(in Chinese) [9] 李瑶,徐晓苏,吴炳祥.捷联惯导系统罗经法自对准[J].中国惯性技术学报,2008,16(4):386-389 Li Yao,Xu Xiaosu,Wu Bingxiang.Gyro-compass self-alignment of SINS[J].Journal of Chinese Inertial Technology,2008,16(4):386-389(in Chinese) [10] Ali J,Fang Jiancheng.SINS/ANS/GPS integration using federated Kalman filter based on optimized information-sharing coefficients //AIAA Guidance,Navigation,and Control Conference and Exhibit.San Francisco,California:AIAA,Inc,2005:6030-6033
点击查看大图
计量
- 文章访问数: 3239
- HTML全文浏览量: 200
- PDF下载量: 852
- 被引次数: 0