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

TL;DR

This paper introduces a novel divergent multi-aperture imaging system (DMAIS) for flight platforms that combines a large field of view with high spatial resolution, enabling accurate pose estimation through calibration and advanced algorithms.

Contribution

The paper presents a new DMAIS design, a calibration method based on 3D calibration fields, and an improved pose estimation algorithm transforming the problem into a nonlinear minimization task.

Findings

Achieves centimeter-level position accuracy in real flights.

Attains arc-minute-level orientation accuracy.

Demonstrates effectiveness of the calibration and pose estimation methods.

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.