Abstract

To solve the illumination sensitivity problems of mobile ground equipment, an enhanced visual SLAM algorithm based on the sparse direct method was proposed in this paper. Firstly, the vignette and response functions of the input sequences were optimized based on the photometric formation of the camera. Secondly, the Shi–Tomasi corners of the input sequence were tracked, and optimization equations were established using the pixel tracking of sparse direct visual odometry (VO). Thirdly, the Levenberg–Marquardt (L–M) method was applied to solve the joint optimization equation, and the photometric calibration parameters in the VO were updated to realize the real-time dynamic compensation of the exposure of the input sequences, which reduced the effects of the light variations on SLAM’s (simultaneous localization and mapping) accuracy and robustness. Finally, a Shi–Tomasi corner filtered strategy was designed to reduce the computational complexity of the proposed algorithm, and the loop closure detection was realized based on the oriented FAST and rotated BRIEF (ORB) features. The proposed algorithm was tested using TUM, KITTI, EuRoC, and an actual environment, and the experimental results show that the positioning and mapping performance of the proposed algorithm is promising.

Highlights

  • Many visual simultaneous localization and mapping (SLAM) systems have been proposed, since they are fundamental building blocks for many emerging technologies, such as autonomous cars, virtual reality, and augmented reality [1]

  • We demonstrated that the drift error of the proposed algorithm was significantly reduced with respect to LDSO and the performance on KITTI was similar to mono-ORBSLAM

  • The experimental results show that the real-time photometric calibration direct SLAM system can obtain a 19.7% higher accuracy performance and 4.7% bigger timing costs than LDSO

Read more

Summary

Introduction

Many visual simultaneous localization and mapping (SLAM) systems have been proposed, since they are fundamental building blocks for many emerging technologies, such as autonomous cars, virtual reality, and augmented reality [1]. Bergmann et al [14] proposed an online photometric calibration, which dynamically estimates the photometric parameters by solving the least squares equation of the feature tracker and adjusts the exposure situation of the input sequence. It is a milestone in improving the positioning and mapping accuracy for direct formulation. Inspired by [14] and [17], in order to further improve the robustness of the direct formulation visual SLAM system in positioning and mapping, we reinforced the LDSO algorithm by introducing real-time photometric calibration to update the exposure condition of the input sequence.

Photometric
Vignetting
Photometric Calibration Equation
Direct Sparse Model
Parameters Update
Window
Loop Closure Detection
The experimental results onon the
Experiments
Actual
Findings
Conclusions

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.