An Analysis of the Optimal Placement of Beacon in Bluetooth-INS Indoor Localization

Abstract

The placement of Bluetooth beacon has immediate impact on the accuracy and stability of indoor positioning. Affected by the shelter of building and human, Bluetooth shows uncertain spatial transmission characteristics. Therefore, the scientific deployment of the beacon nodes is closely related to the indoor space environment. In the study of positioning technology using Bluetooth, some scholars have discussed the deployment of Bluetooth beacon in different scenarios. In the principle of avoiding shelter, general method deploys Bluetooth beacon under the triangular grid staggered deployment with 6-8 meters of equal spacing. Although this kind of method can provide good positioning accuracy with a high-density placed Bluetooth, it also increases the cost and cause waste of resources. Bluetooth combined with INS (Inertial Navigation System) is a new trend in indoor positioning and has good performance in application. However current research mostly focused on the fusion of the two techniques during the positioning process, but rarely considers the influence of combinatorial positioning on the deployment of Bluetooth beacon. Also the study of the placement of Bluetooth has not yet fully utilized the characteristics of INS. This paper proposes an optimal Bluetooth beacon nodes placement method using the minimum number of beacons in the general space scene, making full use of the characteristics of the high efficiency of Bluetooth triangulation and the high accuracy of inertial navigation positioning in short-range. First of all, this paper studies the effective positioning distance of Bluetooth signal in corridor, room and other indoor space environment, analyzes the accuracy attenuation characteristics of INS and the relationship between pedestrian activity and INS. Next, constructs the indoor positioning spatial data model, obtains the probability distribution of common locating area by collecting the characteristics of pedestrian trajectory distribution in video surveillance data. Then, based on the experimental analysis, the paper summarizes the set of rules for the deployment of Bluetooth beacon nodes, and proposes the optimal scheme of Bluetooth beacon nodes under different positioning accuracy intervals. Finally, compared to current Bluetooth positioning system of large-scale shopping malls in the same accuracy, this method has wider applicable area using same number of Bluetooth beacons and same applicable using fewer beacons. In the next study, in order to improve the universality of the deployment method, we will carry out experiments in different space scenes.