High-precision visual navigation device calibration method based on collimator

TL;DR

This work tackles the challenge of achieving high-precision camera and attitude calibration for visual navigation devices without the time and equipment burden of traditional multi-image or turntable-based methods. It introduces a collimator-based system that performs single-image camera calibration using virtual control points generated from a reference camera and a collimator-derived calibration frame, followed by attitude calibration via a rotation-transfer approach leveraging an encoded marker pattern (star-shaped pattern plus Apriltag). The method delivers sub-pixel reprojection accuracy ($<0.1463$ px) and precise attitude estimates ($<0.0586^\circ$ average; $<0.0257^\circ$ std) and is demonstrated to be robust across varying imaging conditions and setups. Practically, it enables fast, batch-capable calibration with reduced hardware complexity, benefiting UAVs, robots, and autonomous systems that rely on accurate visual navigation.

Abstract

Visual navigation devices require precise calibration to achieve high-precision localization and navigation, which includes camera and attitude calibration. To address the limitations of time-consuming camera calibration and complex attitude adjustment processes, this study presents a collimator-based calibration method and system. Based on the optical characteristics of the collimator, a single-image camera calibration algorithm is introduced. In addition, integrated with the precision adjustment mechanism of the calibration frame, a rotation transfer model between coordinate systems enables efficient attitude calibration. Experimental results demonstrate that the proposed method achieves accuracy and stability comparable to traditional multi-image calibration techniques. Specifically, the re-projection errors are less than 0.1463 pixels, and average attitude angle errors are less than 0.0586 degrees with a standard deviation less than 0.0257 degrees, demonstrating high precision and robustness.

Figures (9)

• Figure 1: Collimator design drawing. (a) Collimator structural sketch and (b) encoded marker pattern.
• Figure 2: Reference calibration system installation diagram.
• Figure 3: Coordinate system conversion schematics.
• Figure 4: Visual navigation device calibration process flowchart.
• Figure 5: Central projection model.