particle filter for tracking

edit

Hi, i have implemented particle filter for tracking an object. It works well when the object is stationary , at that instance the particle converge . However, when i move the object to another location suddenly, the particles cant move .

This is because i eliminate low weighting particle and replace them with high weighting ones at first object's position which results in particle concentrating in that position. When i move the object to position that is far away from the first position, the particle swarm is not spread out enough to converge to the second position.

Any suggestion to improve on the resampling part, i use stratified resampling . help me please on the redistribution of particles