This paper deals with state estimation of stochastic models with linear state dynamics, continuous or discrete in time. The emphasis is laid on a numerical solution to the state prediction by the time-update step of the grid-point-based point-mass filter (PMF), which is the most computationally demanding part of the PMF algorithm. A novel way of manipulating the grid, leading to the time-update in form of a convolution, is proposed. This reduces the PMF time complexity from quadratic to log-linear with respect to the number of grid points. Furthermore, the number of unique transition probability values is greatly reduced causing a significant reduction of the data storage needed. The proposed PMF prediction step is verified in a numerical study.
翻译:本文研究具有线性状态动力学的随机模型状态估计问题,模型时间域可为连续或离散。重点研究了基于网格点的点质量滤波器(PMF)中时间更新步骤的状态预测数值解法——这是PMF算法中计算量最大的部分。提出一种新型网格操作方式,将时间更新转化为卷积形式。该方法将PMF时间复杂度从网格点数的二次型降至对数线性型。此外,转移概率唯一值的数量大幅减少,显著降低了所需数据存储量。通过数值实验验证了所提PMF预测步骤的有效性。