The invention discloses a state
estimation method based on mixed features and adaptive
key frame selection, and belongs to the field of autonomous navigation of unmanned systems. The implementation method comprises the following steps of: acquiring a plurality of images, and synchronously acquiring inertial measurement data of a six-axis IMU (
Inertial Measurement Unit); the method comprises the following steps: performing
key frame decision on a current frame image according to inertial measurement data, and classifying the image into a
key frame image and a non-key frame image: acquiring a key frame
feature matching set through an entropy maximization self-supervision feature extractor and an image attention matcher, and constructing a visual
reprojection error term based on
triangulation map points; non-key frame feature points are extracted by adopting an improved
corner detector, feature displacement is obtained through IMU constraint
optical flow tracking, and a visual re-projection error and an IMU pre-integration residual term are generated; and based on a vision-
inertia tight
coupling optimization module
solution system, combining a vision
reprojection error, an IMU pre-integration residual error and a pneumatic constraint residual error to construct a tight
coupling optimization problem, and solving an optimal
pose state. The method is beneficial to navigation of the small-sized high-speed unmanned aerial vehicle.