A Binocular Stereo Vision-Based Method for Aircraft Door Gap Measurement

To address the dynamic measurement challenges of aircraft cabin door gaps in complex testing environments, this study develops a binocular stereo vision system for real-time tracking of fiducial markers on both sides of door gaps. The proposed methodology incorporates both rigid and elastic deformation effects through an error compensation model that utilizes adjacent edge points for gap width and step measurements. Three distinct door material configurations were subjected to finite element analysis to characterize their deformation patterns under operational loads. System validation using a calibrated precision translation stage demonstrated measurement repeatability better than 0.025 mm for both gap width and step height parameters under rigid deformation conditions. Practical implementation in a pressurized cabin structural fatigue test revealed that the vision-based measurements exhibited strong correlation with actual engineering data, demonstrating real-world feasibility for cabin door gap monitoring under design limit loads.