Feature-constrained real-time simultaneous monitoring of monocular vision odometry for bridge bearing displacement and rotation

The displacement and rotation are critical indicators of bridge's health, especially for the key components of the bridge such as bridge bearings. This study presents a real-time simultaneous measurement method of bridge bearing displacement and rotation to realize round-the-clock structure monitoring. The main contributions include: (1) A displacement and rotation simultaneous measurement algorithm and system is developed based on feature-constrained monocular visual odometry (VO), which uses image sequences of infrared array lamp targets with multiple feature constraints as visual input to construct the mathematical relationship between displacement and rotation and coordinate system transformation matrix. (2) A two-step parameter optimization strategy is proposed based on adaptive multi-window centroid array tracking and transformation matrix purification and refinement, effectively improving displacement and rotation measurement accuracy and robustness. The effectiveness of the proposed method is verified in the laboratory experiment and the actual bridge bearing monitoring of the Huangpu Pearl River Bridge.