46results about How to "Precise navigation and positioning" patented technology

The invention discloses a WiFi-based indoor positioning and navigation method for large-scale shopping malls. Firstly, a mobile terminal with an AP signal scanner scans the AP signals of wifi tags around to obtain the MAC address of the scanned AP signal; The intensity of the signal is sampled and measured to obtain measurement data; calculate the positions of all scanned Wifi tags according to the MAC address of the AP signal scanned in step 1 and the measurement data in step 2, and then use the positioning algorithm to locate. The specific process is: Estimation The location of the Wifi tag of the next location that the mobile terminal will arrive at; predict the location of the Wifi tag of the next location that the mobile terminal will arrive at; and then perform positioning according to the estimated location and the predicted location. The present invention dynamically predicts node positions, filters out RPs with no similar RSS vector at the label from the map to find the nearest neighbor, reduces the time and calculation complexity of the KNN algorithm, and greatly improves the positioning accuracy.

The invention relates to a method for calculating coordinates of an intersection point D of an optical axis and a celestial surface based on a star sensor. The method comprises the steps of establishing a space rectangular coordinate system under a celestial coordinate system, performing translation or rotation transformation on the space rectangular coordinate system to enable the space rectangular coordinate system to coincide with a star sensor coordinate system to obtain a transformation relationship between the two coordinate systems, and representing a coordinate expression of the pointD in the celestial coordinate system by using each parameter; obtaining the relationship among the coordinates according to the cosine law, and obtaining an approximate expression of the distance f from the projection center to the projection point on the star sensor light-sensitive surface by using a Taylor expansion formula; substituting the approximate expression into the coordinate expressionof the point D in the celestial coordinate system to obtain a celestial coordinate approximate value expression of the point D; performing error analysis in combination with a median theorem, and obtaining a fixed star selection standard to further improve the coordinate precision of the point D. The invention aims to establish a mathematical model, solve the coordinates of the intersection pointD of the optical axis and the celestial surface, enables coordinates of the point D to be accurate through an optimization algorithm, and improve the attitude measurement precision of the star sensor.