说明：  虽然粒子滤波算法可以作为解决SLAM问题的有效手段，但是该算法仍然存在着一些问题。其中最主要的问题是需要用大量的样本数量才能很好地近似系统的后验概率密度。
(Although the particle filter to solve the SLAM problem can be an effective means, but the algorithm still exist some problems. One of the most important issue is the need for a large number of samples with the number of systems can be a good approximation of the posterior probability density.)