Visual-inertial slam system corrects indoor drift using floor plans
MVP-SLAM: Multi-Camera Visual-Inertial Floorplan-Prior SLAM
Robotics
Summary
Visual SLAM systems that map indoor spaces often drift because of poor lighting and repetitive walls. The authors created MVP-SLAM, which uses two cameras and motion sensors to track movement precisely inside buildings under construction. It corrects errors on the fly by matching detected walls to the building’s floor plan, helping keep location estimates accurate. This method was tested in real construction sites and ranked highly among similar teams for accuracy and online operation.
What this means in practice
- •For construction equipment operators: Navigate construction sites indoors without external sensors by using cameras and floor plans to maintain accurate location tracking.
- •For facility management teams: Maintain up-to-date indoor maps and monitor building progress in real time by integrating SLAM with existing floor plans for precise localization.
Authors
Asier Bikandi-Noya, Miguel Fernandez-Cortizas, Muhammad Shaheer, Holger Voos, Jose Luis Sanchez-Lopez
Abstract
Indoor building construction sites are demanding environments for visual SLAM, where variable lighting and repetitive, low-textured structures make the system drift over long trajectories, though structural elements such as walls remain distinguishable despite these conditions. These buildings are constructed according to their as-planned floor plans, available from the design phase, and although the actual as-built site can differ from this design, floor plans still provide a metric reference, both to localize the system in the building and to correct drift. Existing methods often use the floor plan to correct an already-built trajectory offline, and those that instead correct it online typically rely on depth sensors. We instead present MVP-SLAM, an online visual-inertial SLAM on two opposite-facing fisheye cameras that corrects drift from cameras alone by matching walls detected in its map to the floor plan, through a drift-aware policy. A multi-stage integration then turns each matched pair incrementally into a persistent correction, so the trajectory stays corrected and localized within the floor plan as it is built. MVP-SLAM was validated on the multi-floor construction sites of the Hilti-Trimble SLAM Challenge 2026, ranking 2nd of 22 teams in the Localization task (0.29 m mean RMSE) and 5th of 62 teams in the SLAM task (0.24 m), the top-ranked one in both tasks among those that operate online, integrate the floor plan, and localize within it.