Simultaneous Localization and Mapping (SLAM) for Room Exploration Using Ultrawideband Millimeterwave FMCW Radar

Simultaneous Localization and Mapping (SLAM) of indoor scenarios is usually based on camera or lidar sensors as data sources. However, radar based room scanning offers several complementary advantages to these systems. Among other features, radar sensors are more robust to optical opacities, for example, those caused by smoke and dust in emergency scenarios or in harsh environments. Furthermore, the coherent measurement principle of radar sensors provides highly precise distance information that can be utilized to track the exact position and dimensions of the visible objects. In contrast to camera and lidar, radar applications in room exploration are up to now limited by reduced spatial, i.e. mostly angular/lateral, resolution. This is due to the comparably large wavelength of the utilized signals. This work demonstrates the capabilities of ultrawideband millimeterwave Frequency Modulated Continuous Wave (FMCW) radar sensors operating around 80 GHz in conjunction with the Synthetic Aperture Radar (SAR) imaging method. To allow imaging whilst moving, self-localization techniques based on sub-aperture processing are evaluated. Therefore, we demonstrate a detailed mapping procedure for room exploration applications by exploiting large absolute bandwidths of more than 20 GHz with high resolution imaging techniques on a mobile robot platform.