Research On Indoor Firemen Positioning System

An available indoor firemen positioning system can not only improve the efficiency of fire rescue, but also ensure the safety of firemen themselves. GPS can’t be used for indoor positioning because the signal is weak or lost. Various kinds of current indoor positioning methods such as Bluetooth, Wi-Fi, ultra-wideband, RFID tags, etc. which need to install infrastructure in the building, are also not suitable for firemen emergency indoor positioning. Though inertial navigation system can realize autonomous navigation without external information, but due to the cumulative error problem, the accuracy of inertial navigation system is insufficient.This thesis attempts to research a method based on relative position measurement for firemen indoor positioning. Electronic buttons are mounted at the bottoms of two feet to detect whether both of the two feet are on the ground. Multi-target ranging circuits are installed on the inside of feet respectively to measure the relative position of two feet. After multi-target ranging between two feet measured, the step length and the stride vector between the two feet can be figured out, so the trajectory of pedestrian from starting position can be drawn out.In order to validate the feasibility of the method, this thesis designs an experimental demonstration system. The experimental system consists of the relative position measurement circuit and PC display software. The position measurement circuit contains FPGA control module and groups of ultrasonic ranging module. FPGA controls the trigger signal of ultrasound transmitter by time division, receives echo signal of ultrasonic receiver to figure out multi-target range, upload the ranges to PC through the UART serial, calculate the position and display in GUI.This paper studies an autonomous positioning method which based on relative position measurement preliminary, provides a new thought for the research and development on firemen indoor positioning.