94results about How to "Solve the low positioning accuracy" patented technology

The invention belongs to the technical field of positioning, and discloses a received signal strength and multi-path information combined neural network indoor positioning method. The method includes the offline stage and the online stage. In the offline stage, reference points distributed in the indoor environment are determined according to the characteristics of the indoor environment; each selected reference point is measured to obtain signals, from different access points, of each reference point; the RSS and multi-path characteristic parameters are extracted from the received signals; the extracted RSS and the extracted multi-path characteristic parameters are normalized. In the online stage, signals from all the access points are received in real time; the RSS and the multi-path parameters are extracted from the signals which are received in real time; the RSS and the multi-path parameters are normalized through the offline normalization value; the normalized parameters serve as input of an offline trained neural network, and output is obtained to serve as estimation of the current position. According to the method, the problem that positioning accuracy is low can be solved, and positioning accuracy can be effectively improved.

The invention belongs to the technical field of navigation and positioning and discloses a low-orbit navigation constellation enhanced network RTK (real-time kinematic) technology. The low-orbit navigation constellation enhanced network RTK technology comprises the following steps: design of a global navigation and positioning constellation and multiple low-orbit constellation schemes, a low-orbitsatellite collecting orbit determination and inter-satellite link autonomous orbit determination method, design of a low-orbit satellite broadcast ephemeris and a high, medium and low-orbit satellitefusion processing unified mathematical model. The problem in the prior art that the network RTK method is low in positioning precision is solved, the baseline distance can be increased, the network density can be reduced, the cost can be reduced, the precision and the ambiguity fixing rate are increased, and the convergence time can be shortened. The sub-satellite point track coverage range of the low-orbit constellation is wide and even covers polar regions, the three-dimensional orbit errors of 60 and 192-star constellation are 46 cm and 18 cm correspondingly, the forecast precision is increased by about 30 percent compared with that of a klobuchar model, and the final positioning precision is at horizontal millimeter and height centimeter level.

The invention provides a method for measuring an optical axis in aspheric surface detection by means of a self-aligning plane mirror, and belongs to the technical field of optical detection. According to the method, the problem that orientation measurement accuracy of the optical axis is low in aspheric surface detection is solved. The method is used for adjusting relative positions and angles of the plane mirror and an interferometer, and enabling the direction of the plane mirror to be perpendicular to emergent light of the interferometer to generate interference fringes which are in a zero fringe state. A laser tracker is adopted to respectively measure a space coordinate of one point in space and a space coordinate of the mirror point, in the plane mirror, of the point, and the direction of the optical axis is obtained through the coordinates of the two points; a compensator is adjusted to be aligned to the interferometer, and an adjustment definition instrument is adopted to be aligned to the concave surface of the outer surface of a lens of the compensator; the laser tracker is used for measuring the position of a converge center of the adjustment definition instrument, namely, the position of the center of sphere of the outer surface of the lens, and obtaining a space coordinate of one point on the optical axis, and therefore the optical axis in a detection optical path is obtained with the combination of the optical axis direction obtained in the step 2; after the optical axis is obtained, mirror body characteristics are measured for positioning an aspheric surface mirror, and measurement and precision analysis can be carried out many times.

The invention belongs to the technical field of surgical navigation, and particularly relates to an extension ultrasound vascular imaging device and method based on a catheter path. The extension ultrasound vascular imaging device comprises a three-dimensional ultrasound instrument, a set of electromagnetic positioning equipment, an interventional catheter and a computer, wherein the three-dimensional ultrasound instrument scans a vessel through an ultrasound probe to obtain a three-dimensional image. The electromagnetic positioning equipment comprises a magnetic field generator and two positioning sensors with six degrees of freedom, wherein the magnetic field generator defines a space coordinate system, one positioning sensor with six degrees of freedom is installed on the ultrasound probe to obtain the space coordinate of the ultrasound image, and the other positioning sensor with six degrees of freedom is embedded in an inflexible portion at the front end of the catheter to obtain the space coordinate of the front end of the catheter. The three-dimensional ultrasound instrument and the electromagnetic positioning equipment are both connected with the computer, and the obtained three-dimensional ultrasound image and the obtained catheter path are rebuilt in the same coordinate system through the computer. The extension ultrasound vascular imaging device can position branches of the vessel after the vessel of an area deforms, wherein ultrasound imaging cannot be conducted on the area.

The invention discloses a method and device for selecting a visible base station, and the method and device provided by the invention are used for solving the problem that the location precise is low when the base station selected by using a visible base station selecting method which is provided by the prior art locates a terminal. The method for selecting the visible base station disclosed by the invention comprises the following steps: respectively determining statistical parameter values of wireless signals sent by various base stations according to the signal strength of the wireless signals which are sent by various visible base stations and received by a terminal to be located and a statistical probability distribution rule to which the wireless signals are amenable; according to the statistical parameter values, determining relativity values among the wireless signals sent by different visible base stations; and according to the determined relativity values, selecting the visible base station, by which the relativity values of the wireless signals sent are less than a predetermined relativity threshold value, from the visible base stations. The invention also discloses a method and device for locating a terminal based on the visible base station.

The invention discloses a real beam foresight scanning radar target two-dimension locating method which comprises the steps that S1. imaging system parameter initialization is carried out, the distance between an imaging system any point target and a moving platform is computed, and real beam scanning radar point target simulation parameters are set; S2. distance direction matched filtering is carried out; S3. distance direction moving compensation processing is carried out; S4. scanning radar orientation direction echo signals are subjected to modeling; S5. aweighting least square objective function is established; and S6. target orientation locating is carried out. According to the method, emitted signals and antenna direction image parameter information are used, a target range estimation problem is converted into the problem of a objective function optimal solution relative to a weighting vector wn, by solving the objective function optimal solution, the position information of a target orientation dimension is solved, the problem that a target orientation dimension locating accuracy in a moving platform foresight effect zone is low is effectively solved, and two-dimension accuracy locating of a moving platform foresight zone target distance dimension and an orientation dimension is achieved.

The invention discloses a real time image splicing method used for a low-precision micro-imaging system, relates to an image snap method for a microscope and specifically relates to an image snap method for image splicing technology in automatic snap of the microscope. The invention solves a problem of low positioning precision in traditional image snap and improves reliability and quality of acquisition of spliced images with a low cost, reduces cost of a positioning device in an image acquiring process and improves image splicing efficiency and accuracy.

The invention discloses an iterative method for optimizing positions of an indoor target and a scatterer. The method comprises the following steps: constructing a multipath signal propagation model ofan indoor scatterer and a single AP according to multipath signal propagation characteristics; constructing a differential delta top equation of a target position relative to each scatterer by utilizing a position relationship between a multipath signal parameter differential delta top and the single AP, the target and each scatterer and converting a performance optimization problem of a positioning system into a weighted least square solving problem; and then carrying out iteratin based on a WLS algorithm to solve the differential delta top equation so as to obtain final estimated positionsof the scatterer and the target. According to the invention, an indoor target and scatterer position optimization iteration method based on a WLS algorithm is put forward; and with the disclosed method, a problem that the positioning precision is low in a multipath environment is solved; and the robustness of the positioning system is enhanced while the equipment deployment cost is lowered.

The invention discloses an indoor positioning weighted K nearest neighbor method based on a WiFi fingerprint and belongs to the indoor positioning field. The invention mainly relates to a matching point selection in a fingerprint database based on WiFi fingerprint matching and pedestrian position calculating technology. When a target node matches with a node in the fingerprint database, a new weight calculating method is provided. In a traditional WKNN algorithm, when a weight is calculated, a Euclidean distance is only considered. In the method of the invention, a weight calculation formula considers the Euclidean distance, and also considers a WiFi number that the target node can be matched with the node in a fingerprint information database in an actual matching calculation process. A problem that a WiFi matching quantity is not considered in traditional WKNN algorithm calculation so that positioning precision is low is solved. In the invention, in an actual positioning scene, the positioning precision can be effectively increased and a good positioning effect is possessed.

The invention relates to cutting equipment and a rotating worktable thereof. The rotating worktable comprises a base, a rotating table plate, a driving assembly, a plurality of floating assemblies, acarrying table, sensing pieces and photoelectric switches. The rotating table plate is rotatably connected to the base, the driving assembly is arranged on the base, and the power output end of the driving assembly is connected with the rotating table plate; the multiple floating assemblies are all arranged on the base, and each floating assembly is located between the rotating table plate and thebase, and used for supporting the rotating table plate in a floating mode; the carrying table is arranged on the side, away from the base, of the rotating table plate; the sensing pieces are arrangedon the rotating table plate; and the photoelectric switches are arranged on the base and correspond to the sensing pieces, and the photoelectric switches are in communication connection with the control end of the driving assembly and are used for sensing the sensing pieces and sending out sensing signals. The rotating worktable enables the rotating table plate to rotate to the predetermined angle position accurately and stably, and the problem of low positioning precision of a positioning mechanism is solved.