UKF 在 INS/GPS 组合导航直接法滤波中的应用

摘要

INS／GPS 组合导航系统直接法滤波中是直接以导航系统输出的导航参数（位置、速度等）作为状态，所以系统方程为非线性方程。 UKF（Unscented Kalman Filter）是一类以 UT 变换为基础，以卡尔曼线性滤波为框架，采用确定性采样策略逼近非线性分布的非线性滤波算法。由于它是对后验概率密度进行近似来得到滤波估计，所以避免了非线性系统中状态方程的线性化问题，能较好地解决系统方程非线性问题。论文 INS／GPS 组合导航系统中采取直接法，建立非线性模型进行 UKF 滤波解算，并与 EKF 方法比较，实验结果显示 UKF 方法能更好地解决系统状态方程非线性的问题，并得到更高的导航精度。%The INS/GPS integrated navigation system direct filter is using the navigation parameters which the naviga‐tion system outputs(position ,velocity and so on) directly as the state ,so the system equation is nonlinear .UKF(Unscented Kalman Filter) is a kind of nonlinear Kalman Filter based on UT transform .It can avoid the nonlinear‐state‐equation prob‐lem .Use UKF ,take the direct method in the INS/GPS integrated navigation system and compare with the EKF method ,the experimental results show that the UKF method can solve the system state equation of nonlinear problem better ,and obtain higher accuracy of navigation .