Multi-rate robust scale estimation of monocular SLAM

In the last decade, monocular simultaneous localization and mapping (mono-SLAM) has appeared as another alternative for pose estimation, but this last gives a localization up to scale, and suffers from scale drift due to the difficulty of depth evaluation; however, several approaches had been tackled to recover the scale and take off the ambiguity. Both methods were designed to get the accurate scale factor, but most of themes didn't give importance to the robustness in scale estimation process. So, in this context, we propose to utilize the smooth variable structure filter (SVSF) to find the absolute scale, under a multi-rate mechanism with the purpose of avoiding complex synchronization between sensors and ensuring a safe navigation.