A method, medium, and system reducing the computational complexity of a Simultaneous Localization And Mapping (SLAM) algorithm that can be applied to mobile robots. A system estimating the pose of a mobile robot with the aid of a particle filter using a plurality of particles includes a sensor which detects a variation in the pose of a mobile robot, a particle filter unit which determines the poses and weights of current particles by applying the detected pose variation to previous particles, and an evolution unit which updates the poses and weights of the current particles by applying an evolution algorithm to the poses and weights of the current particles.