Fixed wing aircraft vision-auxiliary landing navigation method under low visibility

Abstract

The present disclosure provides a fixed wing aircraft vision-auxiliary landing navigation method under low visibility. The method comprises a visual feature extraction process, a relative position andattitude solution process, and a visual inertia fusion process, wherein the visual feature extraction process comprises the following steps: receiving position and attitude parameters output by an inertial measurement unit, collecting 2D images, extracting runway areas from the 2D images, performing straight-line detection in the runway areas, extracting the edge lines of the runway areas, and calculating pixel coordinates of four corner points of a runway; the relative position and attitude solution process comprises the following steps: inputting the geographic coordinates and pixel coordinates of the four corner points of the runway, and calculating the relative position and attitude of a camera relative to the runway combined with internal parameters of the camera; the visual inertiafusion process comprises the following steps: defining system states, establishing an inertial error transfer equation, and obtaining measurement information, and nonlinear Kalman filtering and correcting position and attitude parameters.

Description

technical field [0001] The invention relates to a landing navigation method, in particular to a vision-assisted landing navigation method for a fixed-wing aircraft under low visibility. Background technique [0002] Currently widely used assisted landing navigation technologies include instrument landing system (ILS) and inertial / GPS (INS / GPS) integrated navigation. Among them, the ILS navigation accuracy is low, it is easily affected by the reflection of the surrounding terrain, and the software, hardware and maintenance costs are high, so it is not suitable for mountainous airports or general airports. Although the accuracy of INS / GPS is high, the GPS signal is easily interfered or shielded, and its navigation reliability is not high. Aiming at the problems of low precision and poor reliability of the existing landing navigation, by using the infrared camera’s remarkable perspective effect under low visibility conditions, image processing technology is used to extract vis...

AI Technical Summary

Problems solved by technology

Among them, the ILS navigation accuracy is low, it is easily affected by the reflection of the surrounding terrain, and the software, hardware and maintenance costs are high, so it is not suitable for mountainous airports or general airports

Although INS / GPS has high precision, the GPS signal is easily interfered or shielded, and its navigation reliability is not high

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