I. Introduction
Simultaneous localization and mapping (SLAM) in robotics is usually described as follows: a robot uses its self-contained sensors to measure the operating environment and incrementally build environment map, while concurrently determine its pose relative to the map [1]. The research of the SLAM technology has important theoretical significance and application value, which can provide a theoretical basis and technical support for the development of autonomous underwater robots, space exploration robots, unmanned aerial vehicles and other autonomous systems.