Combined navigation method and system based on large-displacement optical flow method

Abstract

The invention relates to a combined navigation method based on a large-displacement optical flow method, which comprises the following steps: S1, acquiring continuous video images shot by a camera in strapdown connection with a navigation carrier, and acquiring a first image and a second image from the continuous video; S2, calculating a gray average value of the first image and the second image, comparing the gray average value with a preset gray threshold value, and performing preprocessing according to a comparison result; S3, performing optical flow calculation on the preprocessed first image and second image by using an optical flow method, and rejecting mismatching values by using a linear interpolation method to obtain a total optical flow value of the first image and the second image; S4, scaling the total optical flow value through an optical flow-motion field transfer model; and S5, according to the zoomed optical flow, performing compensation by combining angular velocity information of the IMU to obtain velocity information in the longitude direction and the latitude direction. According to the invention, autonomous, stable and accurate navigation of the navigation carrier is realized under the conditions of large displacement and violent illumination change.

Description

technical field [0001] The invention relates to the technical field of navigation, in particular to a combined navigation method and system based on a large-displacement optical flow method. Background technique [0002] In recent years, with the wide application and surge in demand of small unmanned aerial vehicles such as quadrotor drones in film and television, agriculture, news, firefighting, rescue, energy, remote sensing mapping, wildlife protection and other fields, the application of small unmanned aerial vehicles Research on high-precision, low-cost, and intelligent navigation technology for aircraft has been paid more and more attention. Traditional quadrotor drones usually use GPS / INS (inertial navigation system) integrated navigation, which works well in open areas; but in mountainous and indoor areas, due to poor GPS signals; result. Due to the above reasons, vision-based navigation algorithms are receiving more and more attention from major research instituti...

AI Technical Summary

Problems solved by technology

In addition, when the drone flies to different scenes, the lighting conditions are different, and the situation that will cause tracking errors should also be considered

Although the existing optical flow algorithm can track the feature points more accurately, many algorithms need to obtain the final result through iterative calculation, so it is difficult to guarantee real-time processing

At the same time, most existing optical flow algorithms are derived based on the basic equations of optical flow constraints, so large-displacement optical flow calculations are difficult to achieve

Due to the above shortcomings of the optical flow algorithm, it is difficult to develop a stable navigation method based on the optical flow method

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