9 results about "Absolute orientation" patented technology

The invention discloses an unmanned aerial vehicle image camera self-calibration method, system, medium and device, and relates to the technical field of camera self-calibration, and the method comprises the steps: carrying out the feature extraction and image matching of an unmanned aerial vehicle image, and constructing an undirected graph # imgabs0 #; according to the undirected graph # imgabs 1 #, generating an undirected graph # imgabs 2 # based on a minimum spanning tree; constructing an epipolar line geometric cost function based on three images of a triangular structure of an undirected graph # imgabs3 # and visible object space points in the three images; based on an undirected graph # imgabs4 #, seed three views and an optimal image of the incremental SFM are selected, an epipolar geometric cost function is used to carry out incremental unstructured bundle adjustment, and in the process, weighted iteration self-calibration is carried out on camera parameters to be calibrated; gNSS-assisted absolute orientation is utilized, GNSS constrained beam adjustment is carried out, the self-calibration precision is further improved, and optimal camera parameters after self-calibration are selected. The method can improve the precision of model reconstruction.

The invention relates to the technical field of signal processing, in particular to an electromagnetic source positioning method and system based on generalized cross-correlation. According to the invention, four electromagnetic probes are uniformly arranged on the unmanned aerial vehicle to collect electromagnetic signals of target equipment, and a generalized cross-correlation function is used to calculate the signal arrival time difference between the probes. And performing abnormal value elimination and optimization processing on the time difference by adopting a statistical analysis method, and calculating an azimuth angle and an elevation angle of the electromagnetic wave in combination with a plane wave hypothesis. The included angle between the orientation and the magnetic north direction is measured through a magnetometer of the unmanned aerial vehicle, and the azimuth angle is converted into an absolute direction reference. By using a two-point positioning method, data are collected at different positions and equations are established to solve three-dimensional space coordinates of the electromagnetic source. According to the method, the multi-source data acquisition and fusion technology is combined with the generalized cross-correlation and abnormal value processing algorithm, the multi-path effect and the measurement error in the complex electromagnetic environment are effectively overcome, and an efficient and reliable positioning scheme is provided for power equipment fault diagnosis.

The present invention provides a DSM generation method based on a long linear array and wide swath bidirectional swing-scanning image pair, which relates to the technical field of remote sensing mapping. Aiming at the complex imaging relationship of the linear array bidirectional swing-scanning, first, the rational function RFM model is used to describe the imaging geometric relationship of the swing-scanning image, and the relative spatial position of the forward and backward scan image pairs at the moment of photography is restored according to the RPC parameters to complete relative orientation; subsequently, the local orientation of the image pair at the imaging moment is determined based on ground control points to complete the absolute orientation of the stereo model; then, the approximate epipolar image is determined by the projection trajectory method, and the corresponding points are obtained through one-dimensional correlation matching; finally, the geodetic coordinates of the target points are obtained according to the RFM model to complete the DSM generation. By using the approximate epipolar image for one-dimensional correlation matching, the matching cost of the image pair is reduced, and the problem of DSM generation for the bidirectional swing-scanning image pair is solved.

According to the unmanned aerial vehicle multi-constraint aerial survey image rare control point orientation method, an error equation of a plumb line is derived from a linear equation of the plumb line, and an error model of image bottom points is established on the basis of a collinear condition; solving exterior orientation elements of the image according to least square adjustment, and reducing the number of control points by a plumb line; constructing a block adjustment method under the constraint of a plumb line, obtaining exterior orientation elements of the images again according to the leveled model, then solving a transformation matrix between the exterior orientation elements before and after leveling, and obtaining exterior orientation elements of each leveled image; the method comprises the following steps: performing absolute orientation on a regional free network after leveling under a plumb line coordination condition, erecting an absolute orientation model under the plumb line coordination condition, realizing absolute orientation of five parameters only by two level height control points, and optimizing a sparse matrix to establish an unmanned aerial vehicle adjustment model under a plumb line constraint condition. And absolute orientation can be realized when parameters and control points are few, and the orientation efficiency and precision are high.

The application relates to the technical field of marine orientation sensing of ships, and discloses a ship marine target sensing method and system based on machine vision, which comprises the following steps: using an AD-YOLOv9 algorithm to process incoming image information, obtaining position information and category information of a target image; establishing a coordinate system according to the position information of the target image, marking a target on the target image by using a target prediction box, determining the center point coordinates of the target prediction box based on a deep learning network to determine the center point coordinates of the target, and associating the bow of the ship to determine the absolute orientation and the relative orientation of the target; determining the position of the target relative to the reference point of the ship to determine the direction angle of the target; determining a straight line where the center point of the target and the reference point of the ship are located according to the direction angle of the target, and recording the straight line as a target direction line; calculating and formatting the angle label of the target according to the target direction line, and selecting a position on the target direction line to draw angle label information; and displaying the processed target image.

The invention discloses a stereophotography automatic absolute orientation method and device without sea surface control points and a medium, and the method comprises the steps: employing a left camera and a right camera to shoot the sea surface of the same area at the same time, and obtaining a sea surface image pair sequence; extracting feature points and matched homonymy points on the basis of the sea surface image pair sequence, calculating object point coordinates of the homonymy points in a camera coordinate system, fitting a plurality of object point coordinates to obtain a plurality of fitting planes, and summing unit normal directions of all the fitting planes to obtain a gravity direction; averaging the intercept of the z-axis of the camera coordinate system and all the fitting planes to obtain an average intercept; establishing a synthetic plane according to the gravity direction and the average intercept, and establishing an object space coordinate system based on the synthetic plane; determining a conversion relation between the camera coordinate system and the object space coordinate system, and calculating a distance average value from each object point of the object space coordinate system to the synthetic plane; and based on the distance average value, determining a stereophotogrammetry area according to a sea wave theory.

A method and system for determining a refined absolute position and refined absolute orientation of an entity in a navigation space is provided. The system includes a plurality of sensors, a coarse absolute position and orientation estimation unit to determine a coarse absolute position and / or a coarse absolute orientation, of entity based on a position data captured by sensors at predefined frequency / interval, a relative position and orientation estimation unit to determine a relative position and / or a relative orientation, of the entity based on a set of data captured from sensors, a navigation guidance unit to provide and update unique attributes of the navigation space, and an analytics unit to determine refined absolute position or refined absolute orientation of the entity by fine tuning: the coarse absolute position based on relative position and the coarse absolute orientation based on relative orientation using the navigation map.

The present application discloses a direction finding method, an apparatus and a system. The method comprises: a positioning device acquires first information, the first information being related to the following two items: an absolute direction of a target device, and direction information of the positioning device relative to the target device; and the positioning device determines direction information of the target device relative to the positioning device on the basis of the first information and second information, the second information being used for indicating an absolute direction of the positioning device. In the solution, a signal measurement process can be performed by the target device, so that the hardware design complexity of the positioning device can be reduced, the manufacturing costs of the positioning device can be reduced, the use costs of users can be reduced, the portability of the positioning device can be improved, and user experience can be improved. In addition, no additional hardware costs are required for the target device. The solution has a wide range of application and great commercial value.

The present invention discloses a self-calibration method, system, medium, and device for unmanned aerial vehicle (UAV) imaging cameras, relating to the technical field of camera self-calibration. The method comprises: extracting features and matching images from UAV images to construct an undirected graph #imgabs0#; generating an undirected graph #imgabs2# based on a minimum spanning tree from the undirected graph #imgabs1#; constructing an epipolar geometry cost function based on three images of a triangular structure in the undirected graph #imgabs3# and object-space points visible in all three images; selecting three seed images and an optimal image for an incremental SFM based on the undirected graph #imgabs4#, and performing an incremental unstructured bundle adjustment using the epipolar geometry cost function. During this process, weighted iterative self-calibration is performed on the camera parameters to be calibrated; utilizing GNSS-assisted absolute orientation to perform GNSS constrained bundle adjustment to further improve the self-calibration accuracy, and selecting the optimal camera parameters after self-calibration. The present invention can improve the accuracy of model reconstruction.