非线性系统卡尔曼滤波新方法(英文)

New approach of Kalman filter to nonlinear system

为了在非线性、非高斯系统估计中获得更好的精度,提出一种新的unscented卡尔曼滤波(UKF).采用确定性采样方法,通过选择unscented变换中的参数α=0 85,β=2和l=0,确定出2n+1个σ点,使这些σ点完全符合非线性系统Yi=F(Xi)的高斯随机变量的均值和方差.仿真结果表明:σ点通过实际的非线性系统Yi=F(Xi)传递后,其后验均值和协方差可以达到泰勒展开式的三阶精度,广义卡尔曼滤波(EKF)只能达到一阶精度.该UKF滤波与EKF算法复杂度相近,但具有比EKF更好的估计精度.

In order to achieve higher accuracy in nonlinear/non-Gaussian state estimation, this paper proposes a new unscented Kalman filter (UKF). It uses a deterministic sampling approach. We choose the unscented transformation (UT) scaling parameters α=0.85, β=2, l=0 to construct 2n + 1 sigma points. These sigma points completely capture the mean and covariance of the Gaussian random variables of the nonlinear system Yi=F(Xi). Simulation results show that the posterior mean and covariance of the sigma points can achieve the accuracy of the third-order Taylor series expansion after having propagated through the true nonlinear system Yi=F(Xi). Extended Kalman filter (EKF) only can achieve the first-order accuracy. The computational complexity of UKF is the same level as that of EKF. UKF can yield better performance and higher accuracy than EKF.