DESIGN AND IMPLEMENTATION OF STEREO VISUAL ODOMETRY SYSTEM BASED ON ROP ADJUSTMENT
Keywords: Stereo Visual Odometry, Dual-camera System, Relative Orientation, Network Adjustment, Vision-based Navigation
Abstract. Stereo Visual Odometry (SVO) is a technique used to estimate the continuous position and orientation of a moving platform using a dual-camera system that captures stereo image pairs. To obtain accurate results, A SVO system must be calibrated before use. System calibration is necessary to determine the intrinsic camera parameters (ICPs) and the relative orientation parameters (ROPs) between the cameras at real scale. Compared to monocular visual odometry, a calibrated SVO system can recover the real scale of the translation vector without additional sensors.
The proposed method in this study utilizes ROP adjustment for SVO. Instead of conventional bundle adjustment, this method adopts all sets of ROPs as measurements in the designed network adjustment model. Specifically, there are six sets of ROPs among time-adjacent stereo image pairs.
A SVO system was designed to implement the proposed SVO method. Two experiments were conducted in outdoor and indoor test fields to evaluate the performance. Several ground check points were set up for distance and position verification. The drift ratio was also evaluated. The results demonstrate that the designed SVO system has great feasibility and accuracy for navigation applications.