Pei Fujun, Wu Mei, Zhang Simin
School of Electronic Information & Control Engineering, Beijing University of Technology, Beijing 100124, China.
ScientificWorldJournal. 2014;2014:239531. doi: 10.1155/2014/239531. Epub 2014 Apr 27.
The distributed SLAM system has a similar estimation performance and requires only one-fifth of the computation time compared with centralized particle filter. However, particle impoverishment is inevitably because of the random particles prediction and resampling applied in generic particle filter, especially in SLAM problem that involves a large number of dimensions. In this paper, particle filter use in distributed SLAM was improved in two aspects. First, we improved the important function of the local filters in particle filter. The adaptive values were used to replace a set of constants in the computational process of importance function, which improved the robustness of the particle filter. Second, an information fusion method was proposed by mixing the innovation method and the number of effective particles method, which combined the advantages of these two methods. And this paper extends the previously known convergence results for particle filter to prove that improved particle filter converges to the optimal filter in mean square as the number of particles goes to infinity. The experiment results show that the proposed algorithm improved the virtue of the DPF-SLAM system in isolate faults and enabled the system to have a better tolerance and robustness.
分布式同步定位与地图构建(SLAM)系统具有相似的估计性能,与集中式粒子滤波器相比,其计算时间仅为后者的五分之一。然而,由于通用粒子滤波器中应用的随机粒子预测和重采样,尤其是在涉及大量维度的SLAM问题中,粒子贫化不可避免。本文从两个方面对分布式SLAM中使用的粒子滤波器进行了改进。首先,我们改进了粒子滤波器中局部滤波器的重要性函数。在重要性函数的计算过程中,使用自适应值来替代一组常数,这提高了粒子滤波器的鲁棒性。其次,通过混合创新方法和有效粒子数方法提出了一种信息融合方法,该方法结合了这两种方法的优点。并且本文扩展了先前已知的粒子滤波器收敛结果,以证明改进后的粒子滤波器在粒子数趋于无穷大时在均方意义下收敛到最优滤波器。实验结果表明,所提出的算法提高了DPF-SLAM系统在孤立故障方面的性能,并使系统具有更好的容错性和鲁棒性。