Error Analysis and Calibration Method of a Multiple Field-of-View Navigation System

Abstract

The Multiple Field-of-view Navigation System (MFNS) is a spacecraft subsystem built to realize the autonomous navigation of the Spacecraft Inside Tiangong Space Station. This paper introduces the basics of the MFNS, including its architecture, mathematical model and analysis, and numerical simulation of system errors. According to the performance requirement of the MFNS, the calibration of both intrinsic and extrinsic parameters of the system is assumed to be essential and pivotal. Hence, a novel method based on the geometrical constraints in object space, called checkerboard-fixed post-processing calibration (CPC), is proposed to solve the problem of simultaneously obtaining the intrinsic parameters of the cameras integrated in the MFNS and the transformation between the MFNS coordinate and the cameras’ coordinates. This method utilizes a two-axis turntable and a prior alignment of the coordinates is needed. Theoretical derivation and practical operation of the CPC method are introduced. The calibration experiment results of the MFNS indicate that the extrinsic parameter accuracy of the CPC reaches 0.1° for each Euler angle and 0.6 mm for each position vector component (1σ). A navigation experiment verifies the calibration result and the performance of the MFNS. The MFNS is found to work properly, and the accuracy of the position vector components and Euler angle reaches 1.82 mm and 0.17° (1σ) respectively. The basic mechanism of the MFNS may be utilized as a reference for the design and analysis of multiple-camera systems. Moreover, the calibration method proposed has practical value for its convenience for use and potential for integration into a toolkit.

A 6-DOF Navigation Method based on Iterative Closest Imaging Point Algorithm

“…The VNS parameter calibration is conducted using a checkerboard-fixed post-processing calibration, details of which are presented in our previous study 1 . The calibrated parameters are shown in the Supplementary Tables S2 and S3.…”

“…1) was proposed by Tsinghua University and China Manned Space Agency in 2015 to conduct algorithm evaluation and on-orbit service demonstration 1 . As the requirements of high-precision navigation and detection capability are considered, computer vision is an excellent choice for IS compared with other available navigation methods, such as infrared 2 , ultrasound 3 , UWB 4 , and Wi-Fi 5 .…”

Extrinsic Parameter Calibration Method for a Visual/Inertial Integrated System with a Predefined Mechanical Interface

“…Previous studies have attempted to address this problem by aligning the sensors frame to the system body frame. For instance, Wendel and Underwood [22] aligned the line scanning cameras to the ground vehicle frame and achieved an accuracy of 0.06 m in translation and 1.05° in rotation, while Shi et al [23] aligned three cameras to the body system frame and achieved 0.6 mm and 0.1° translation and rotation accuracies, respectively. Only the camera frame is aligned to the body frame and the accuracy can be further improved.…”