Secondary loopback detection positioning method based on IMU and vision in similar environment

Abstract

The invention discloses a secondary loopback detection positioning method based on IMU and vision in a similar environment. The secondary loopback detection positioning method comprises the followingsteps of 1, calibrating and synchronizing parameters of a binocular camera and IMU, 2, image feature extraction and image matching, 3, pose estimation and movement track formation, 4, loopback detection, 5, a secondary loop-back detection mechanism, and 6, repositioning. According to the method, coarse comparison constraint can be performed on the current image frame pose through the IMU pose information, that is, direction consistency constraint pre-judgment is performed by comparing the IMU current position direction with the primary closed-loop image position direction, surrounding scene similarity is prevented, a closed loop can be judged according to the image similarity, according to the problem that the current actual position of the IMU cannot be the same position, wrong loopback is caused, positioning errors caused by similar images in a similar environment are prevented through direction pre-judgment of the IMU, the updated high-precision pose after repositioning is used forcorrecting the IMU accumulated drift error, and the robustness of the secondary loopback detection positioning method is improved.

Description

technical field [0001] The invention relates to a secondary loop detection and positioning method, in particular to a secondary loop detection and positioning method based on IMU and vision in a similar environment. Background technique [0002] UAVs are developing in the direction of intelligent UAVs and intelligent systems, and the ability of autonomous positioning and navigation determines the level of intelligence of UAVs. Unmanned aerial vehicle (UAV) puts forward an urgent demand for its autonomous positioning ability in the fields of military reconnaissance, power inspection, geological exploration, forest fire prevention, etc., especially with the emergence of satellite navigation signal interference and deception technology, UAV requires It has completely autonomous positioning and navigation capabilities to get rid of the dependence on satellite navigation signals. Vision and inertial (Inertial measurement unit, IMU for short) combined SLAM (Simultaneous Localizat...

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