Research On Indoor And Outdoor Positioning Based On The Fusion Of WIFI And Multi-sensor Digital Information

Indoor and outdoor positioning is a positioning theory based on location services.With increasing applications of positioning technology,including public safety and emergency response,navigation maps,social networking,market expansion,etc.,especially in public safety and emergency response,accurate positioning results will reduce unnecessary accidents.Although there are remarkable research results of indoor and outdoor positioning,the stability,reliability and robustness of positioning are severely tested due to the changeable indoor environment.In this paper,the principle of high-precision image positioning is deeply studied.SIFT image processing algorithm and indoor WIFI positioning technology are used to provide an effective solution for accurate positioning in the case of "black box".It has important research significance and application value for indoor position tracking and aerial positioning of UAV.Based on the indoor and outdoor positioning algorithm,the indoor and outdoor positioning is improved and optimized.The specific results are as follows:1)WIFI indoor positioning based on weighted centroid algorithm is improved.The difficulty of indoor positioning lies in the changeable interference caused by the changeable indoor environment,among which the main interference comes from the multi-path effect.In the application of weighted centroid algorithm,WIFI nodes are set on three sides,and multi-position distribution is adopted to increase the coverage and enhance the signal strength.Three spheres with the node as the center of the sphere and the measured distance as the radius are drawn to get the intersecting area.When projected onto the two-dimensional plane,there are three circles.Since the distance is inversely proportional to the signal strength,by calculating the centroid coordinates of the triangle connected by the intersection of the three circles using the sum of the reciprocal of the square of the distance as the weight,the accuracy of the data is improved by weighting.2)A digital information fusion positioning method based on multiple sensors is researched.The difficulty of UAV positioning lies in the positioning speed and the accuracy of positioning,and the interference mainly comes from the air velocity and object occlusion.In terms of the way of positioning,the positioning method based on multi-sensor digital information fusion takes advantage of the fusion of images and sensors.The fusion of images reduces the jitter caused by the air velocity during drone operation,and improves the positioning speed.At the same time,the positioning and navigation failure in the absence of GPS environment is avoided,and the positioning accuracy is improved.In the positioning algorithm,the SIFT algorithm is used to set the number of matching points and the matching distance threshold so as to reduce the number of matches and increase the matching accuracy.Experimental results show that the accuracy of the new coordinates is 95%higher than that of the original coordinates and the positioning accuracy is about 10%higher on average within the range of 10m in the room.In terms of positioning accuracy,fusion positioning have a certain improvement than single sensor positioning.In terms of positioning speed,fusion positioning is faster than single sensor positioning.