Winqi: A System for 6D Localization and SLAM Augmentation Using Wideangle Optics and Coded Light Beacons

Simultaneous Localization and Mapping (SLAM) systems use commodity visible/near visible digital sensors coupled with processing units that detect, recognize and track image points in a camera stream. These systems are cheap, fast and make use of readily available camera technologies. However, SLAM systems suffer from issues of drift as well as sensitivity to lighting variation such as shadows and changing brightness. Beaconless SLAM systems will continue to suffer from this inherent drift problem irrespective of the improvements in on-board camera resolution, speed and inertial sensor precision. To cancel out destructive forms of drift, relocalization algorithms are used which use known detected landmarks together with loop closure processes to continually readjust the current location and orientation estimates to match "known" positions. However this is inherently problematic because these landmarks themselves may have been recorded with errors and they may also change under different illumination conditions. In this note we describe a unique beacon light coding system which is robust to desynchronized clock bit drift. The described beacons and codes are designed to be used in industrial or consumer environments for full standalone 6dof tracking or as known error free landmarks in a SLAM pipeline.