The tracking module of a visual-inertial SLAM system processes incoming image frames and IMU data to estimate the position of the frame in relation to the map. It is important for the tracking to complete in a timely manner for each frame to avoid poor localization or tracking loss. We therefore present a new approach which leverages GPU computing power to accelerate time-consuming components of tracking in order to improve its performance. These components include stereo feature matching and local map tracking. We implement our design inside the ORB-SLAM3 tracking process using CUDA. Our evaluation demonstrates an overall improvement in tracking performance of up to 2.8× on a desktop and Jetson Xavier NX board in stereo-inertial mode, using the well-known SLAM datasets EuRoC and TUM-VI.

In this paper, we introduce JacobiGPU, a technique that uses a GPU to improve the efficiency of loop closure in visual-inertial SLAM systems, particularly when approximating Jacobians using the Finite Difference Method (FDM). Traditional FDM techniques often face computational overhead due to repeated perturbations in pose graphs. We address this overhead with a novel methodology, leveraging strategic graph partitioning and an optimized approach to Jacobian approximation. By integrating JacobiGPU into ORB-SLAM3’s g2o, we enhance the linearization process. Our evaluation, conducted on 12 sequences of varying lengths from the EuRoC and TUM-VI datasets, demonstrated a speedup of up to 4.23x in the linearization stage and an overall enhancement of up to 2.08x in the overall optimization process.

In this paper, we present our approach to efficiently leveraging GPU resources to improve the performance of local bundle adjustment for visual-inertial SLAM. We observe that for local bundle adjustment (i) the Schur complement method, a technique often used to speed up bundle adjustment, has the largest overhead when solving for the parameter update, and (ii) the workload consists of operations on small- to medium-sized matrices. Based on these observations, we develop and combine several techniques that efficiently handle small- to medium-sized matrices. We then implement these techniques as a drop-in replacement block solver for g2o, a library frequently used for bundle adjustment, and integrate it with ORB-SLAM3, a well-known open-source visual-inertial SLAM system. Our evaluation done with two popular datasets, EuRoC and TUM-VI, shows that we can reduce the time taken by local bundle adjustment by 13.81%-33.79% with our techniques across an embedded device and a desktop machine.