机载捷联惯导的导航计算模型与精度分析

Navigation Calculation Model for Airborne SINS and Its Accuracy Analysis

摘要:

探讨了当地水平坐标系中捷联惯导的导航计算模型和详细计算步骤.通过实测数据解算,分析捷联惯导系统的误差特性.采用卡尔曼滤波进行全球定位系统/捷联惯导(GPS/SINS)松散组合,并对组合导航计算结果作卡尔曼平滑.实验表明,捷联惯导的坐标误差呈抛物线形式增长,短时间内能提供高精度的导航参数,其1 min以内的坐标误差小于2 m.将SINS与GPS构成组合导航系统,可以集两者之所长,使整个系统的可靠性和完整性优于其中任何一个子系统.

关键词:捷联惯性导航系统; 导航计算; 捷联导航算法; 松散组合

Abstract:

A study was made of the navigation calculation model in local frame and detailed steps for strapdown inertial navigation system(SINS).Then the error characteristics of SINS was analyzed through navigation calculation with the measured data.Finally,GPS/SINS loose coupling was implemented by using Kalman filter and Kalman smooth.The results show that,coordinate error of SINS grows as parabola function,in a short time it can provide accurate navigation parameters,with coordinate error less than 2 meters within one minute.SINS/GPS integrated navigation system,which combines advantages of the two systems,gains more reliability and integrity respect to each subsystem.

Key words:strapdown inertial navigation system; navigation calculation; strapdown navigation algorithm; loose coupling