Research On Pedestrian Navigation And Positioning Method Based On MEMS Devices

Common navigation systems have the problem of ineffective navigation in the event of interference with the guard-guide signal or beacon signals unavailable.Inertial navigation systems have the advantages of good stealth,high stability and resistance to interference,and are an autonomous navigation system that can work in arbitrary unfamiliar and unprepared,indoor and outdoor environments,and have been attracting increasing interests in the field of pedestrian navigation.However,the accumulation of navigation errors is the main drawback of pure inertial navigation,so error correction is needed to improve the long-endurance accuracy of inertial guidance systems.In this paper,a personal navigation hardware system is built using Micro-Electro-Mechanical System(MEMS)inertial devices as the measurement unit and selecting STM32F405 as the core processor of the MEMS pedestrian navigation system,and a zero-speed correction pedestrian navigation algorithm is designed by analysing the characteristics of pedestrian foot movements,and simulation analysis of the navigation algorithm and semi-physical experimental verification of shoe navigation are carried out.The main contents of this paper are as follows:(1)Shoe-mounted personal navigation system solution based on MEMS was designed.Based on an analysis of the characteristics and patterns of human walking,a mathematical model of common forms of walking movement was developed and a navigation scheme was selected in which an inertial measurement unit(IMU)was mounted on the walker’s shoe.A multi-conditional zero velocity detection algorithm is designed for this scheme using accelerometer output specific force and gyro output angular velocity information.Based on the analysis of the MEMS inertial device error and the navigation solution error,a Kalman filter was designed to implement the zero velocity correction.(2)The hardware platform system was built and the system software design was carried out.In this paper,a small and light weight pedestrian navigation system is built by using a four-layer PCB board design with IMU sensors,MS5611 modules and circuit boards closely fitted.The STM32 is used as the core,through which and with IMU to acquire data and calculate navigation information.The software of inertial measurement system is designed based on the principles of the overall hardware block diagram(3)Simulation analysis and experimental validation of the navigation algorithm of the MEMS personal navigation system.In order to verify the effectiveness of the designed PNS algorithm,Matlab simulation of walking motion was carried out based on the established mathematical model of human walking motion,and the MEMS IMU was fixed on the walker’s shoe and walking experiments were conducted in a real environment.Simulation and experimental results show that the proposed algorithm is effective.