Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

Accurate Pose Estimation for Flight Platforms based on Divergent Multi-Aperture Imaging System

Shunkun Liang, Bin Li, Banglei Guan, Yang Shang, Xianwei Zhu, Qifeng Yu

TL;DR

The paper tackles the problem of achieving accurate pose estimation for flight platforms while simultaneously obtaining a large field of view and high spatial resolution. It introduces a Divergent Multi-Aperture Imaging System (DMAIS) comprising five long-focal cameras arranged to provide wide coverage without overlapping FoVs, modeled as a generalized camera. A 3D calibration field is proposed for intrinsic and extrinsic calibration, followed by a nonlinear absolute pose estimation method that uses Cayley parameterization and Gröbner-basis solving to produce centimeter-level position accuracy and arc-minute-level orientation in real flights. The work demonstrates real-time performance (sub-millisecond runtime) and robustness across camera configurations, highlighting DMAIS as a practical approach to high-precision vision-based pose estimation in challenging outdoor environments.

Abstract

Vision-based pose estimation plays a crucial role in the autonomous navigation of flight platforms. However, the field of view and spatial resolution of the camera limit pose estimation accuracy. This paper designs a divergent multi-aperture imaging system (DMAIS), equivalent to a single imaging system to achieve simultaneous observation of a large field of view and high spatial resolution. The DMAIS overcomes traditional observation limitations, allowing accurate pose estimation for the flight platform. {Before conducting pose estimation, the DMAIS must be calibrated. To this end we propose a calibration method for DMAIS based on the 3D calibration field.} The calibration process determines the imaging parameters of the DMAIS, which allows us to model DMAIS as a generalized camera. Subsequently, a new algorithm for accurately determining the pose of flight platform is introduced. We transform the absolute pose estimation problem into a nonlinear minimization problem. New optimality conditions are established for solving this problem based on Lagrange multipliers. Finally, real calibration experiments show the effectiveness and accuracy of the proposed method. Results from real flight experiments validate the system's ability to achieve centimeter-level positioning accuracy and arc-minute-level orientation accuracy.

Accurate Pose Estimation for Flight Platforms based on Divergent Multi-Aperture Imaging System

TL;DR

The paper tackles the problem of achieving accurate pose estimation for flight platforms while simultaneously obtaining a large field of view and high spatial resolution. It introduces a Divergent Multi-Aperture Imaging System (DMAIS) comprising five long-focal cameras arranged to provide wide coverage without overlapping FoVs, modeled as a generalized camera. A 3D calibration field is proposed for intrinsic and extrinsic calibration, followed by a nonlinear absolute pose estimation method that uses Cayley parameterization and Gröbner-basis solving to produce centimeter-level position accuracy and arc-minute-level orientation in real flights. The work demonstrates real-time performance (sub-millisecond runtime) and robustness across camera configurations, highlighting DMAIS as a practical approach to high-precision vision-based pose estimation in challenging outdoor environments.

Abstract

Vision-based pose estimation plays a crucial role in the autonomous navigation of flight platforms. However, the field of view and spatial resolution of the camera limit pose estimation accuracy. This paper designs a divergent multi-aperture imaging system (DMAIS), equivalent to a single imaging system to achieve simultaneous observation of a large field of view and high spatial resolution. The DMAIS overcomes traditional observation limitations, allowing accurate pose estimation for the flight platform. {Before conducting pose estimation, the DMAIS must be calibrated. To this end we propose a calibration method for DMAIS based on the 3D calibration field.} The calibration process determines the imaging parameters of the DMAIS, which allows us to model DMAIS as a generalized camera. Subsequently, a new algorithm for accurately determining the pose of flight platform is introduced. We transform the absolute pose estimation problem into a nonlinear minimization problem. New optimality conditions are established for solving this problem based on Lagrange multipliers. Finally, real calibration experiments show the effectiveness and accuracy of the proposed method. Results from real flight experiments validate the system's ability to achieve centimeter-level positioning accuracy and arc-minute-level orientation accuracy.

Paper Structure

This paper contains 13 sections, 22 equations, 9 figures, 6 tables.

Table of Contents

  1. Introduction
  2. Divergent Multi-Aperture Imaging System
  3. Geometric Calibration
  4. 3D Calibration Field
  5. Intrinsic Calibration
  6. Extrinsic Calibration
  7. Absolute Pose Estimation
  8. Generalized Camera Model
  9. Pose Estimation Algorithm
  10. Experimental Result
  11. Geometric Calibration Results
  12. Pose Estimation Results
  13. Conclusions

Figures (9)

  • Figure 1: Multi-aperture imaging is equivalent to simultaneous large field of view and high spatial resolution imaging.
  • Figure 2: Structure diagram of divergent multi-aperture imaging system.
  • Figure 3: The control point composed of diagonal patterns.
  • Figure 4: Projection diagram of generalized camera model.
  • Figure 5: The examples of DMAIS and 3d calibration field. (a) The divergent multi-aperture imaging system to be calibrated; (b), (c), (d) The distribution of control points and the results of marker extraction.
  • ...and 4 more figures