Accuracy Analysis of Visual Odometer for Unmanned Rollers in Tunnels

Rollers, integral to road construction, are undergoing rapid advancements in unmanned functionality. To address the specific challenge of unmanned compaction within tunnels, we propose a vision-based odometry system for unmanned rollers. This system solves the problem of tunnel localization under conditions of low texture and high noise. We evaluate and compare the performance of various feature extraction and matching methods, followed by the application of random sample consensus (RANSAC) to eliminate false matches. Subsequently, Perspective-n-Points (PnP) was employed to establish a minimal-error analysis for pose estimation and trajectory analysis. The findings reveal that binary robust invariant scalable key points (BRISK) exhibits larger errors due to fewer correctly matched feature points, while scale invariant feature transform (SIFT) falls short of real-time requirements. Compared to Oriented FAST and Rotated BRIEF (ORB) and the direct method, the maximum relative error and the median error between the compaction trajectory estimated by speed-up robust features (SURF) and the actual trajectory were the smallest. Consequently, the unmanned rollers employing SURF + PnP improved the accuracy and robustness. This research contributes valuable insights to the development of autonomous road construction equipment, particularly in challenging tunnels.