Design Of Indoor Integrated Navigation System Based On Bluetooth/INS

The indoor integrated navigation of Bluetooth/INS has the advantages of low cost and moderate accuracy.According to distance,Wireless communication technology can be divided into short-distance and long-distance wireless communication in network communication.Among them,short-range wireless communication includes NFC,ZigBee,Bluetooth,WiFi and UWB,etc.Bluetooth which is relatively popular in indoor positioning research has the characteristics of low cost and low power consumption.Bluetooth versions vary from 3.0 traditional bluetooth(SPP protocol)to 4.x / 5.x low energe bluetooth(BLE protocol).The new version of Bluetooth technology not only has a breakthrough in low power consumption,but also improves the transmission rate and connection speed greatly.BLE5 as the new protocol adds support of positioning technology and direction finding technology,and is well on the way to combining other navigation abilities to achieve more accurate indoor positioning system.Based on bluetooth BLE5 technology,this article uses Received Signal Strength Indicator(RSSI)as the basis for ranging and positioning.BLE is integrated with the attitude information estimated by the INS system.Based on the JDY24M chip,ICM20602 and magnetometer,research and analysis has been carried out by the combined Bluetooth/INS positioning system is designed.The real-time system has specific features such as relatively high accuracy performance and anti-interference ability in a period of time.The system can provide reliable location information services for indoor positioning and navigation.The research of the combined positioning system in this article mainly involves hardware realization,writing of underlying driver code,acquisition of Bluetooth signal strength information,simulation and realization of positioning algorithm.The field of indoor navigation is taken as the background to study the key issues of the design,implementation and application of high-efficiency portable indoor navigation systems.The main research contained the following contributes:(1)The working principle and error sources of the Bluetooth positioning system are analyzed.The Bluetooth-based positioning method is introduced,and an optimized RSSI-based distance measurement method is proposed,the influence of different filtering processing on Bluetooth signal positioning is analyzed.It is introduced that the error of the 9-axis sensor of the INS system in the attitude estimation and the attitude fusion model with different attitude calculation algorithms analyzed.(2)It is discussed that the fusion method of the position information measured by Bluetooth and predicted position information by the INS.The algorithm simulation model of the combined positioning system is established,the gradient descent method with dynamic weighting system is designed to accelerate the convergence of the INS system.The system can maintain accurate positioning for a certain period of time even when the Bluetooth signal is abnormal or lost.Calculation speed and effect requirements.Based on the gradient descent method,an optimized attitude position navigation algorithm is designed,which effectively reduces the hardware platform requirements for the algorithm.It's able to meet the requirements of lowpower embedded chips for computing speed and effect.(3)It is developed that the host computer operating software and data visualization software system based on the NMEA/PNI protocol,which can continuously store high-rate sensor data,real-time playback,online detection and demonstration of the host computer system.A simulation experiment was designed to verify the performance of the algorithm,and the simulation results were analyzed.We designed and implemented a simple but effective indoor navigation test platform,established an experimental platform,and verified the performance of the integrated navigation method based on gradient descent-Kalman filter of the Bluetooth/INS positioning system.