Multi-function Intelligent Bracelet System Based On Augmented Reality Technology

Based on the rapid development of Internet and Internet of Things technology,the emergence of wearable devices enables users to monitor health and sports information in real time,which can greatly improve people living standards.Augmented reality technology,which superimposes virtual information on real background,can greatly improving visual experience and increasing the amount of information.With the development of wearable devices and augmented reality technology,they have gradually penetrated into all walks of life.This paper aims to combine wearable devices with augmented reality technology.On the basis of designing and building a smart wristband with simple functions,the corresponding APP design is carried out based on augmented reality technology.The main research work completed is as follows:(1)Hardware design of wearable information acquisition system.Aiming at the designing tasks of monitoring steps,heart rate,blood oxygen,ambient temperature and humidity,STM32L4R9 is used as the central processing module.ADXL345 sensor is selected for the motion module to obtain the three-axis acceleration and MAX30102 sensor is selected for the health monitoring module to obtain the users’ original PPG signal.The environmental monitoring module selects SHT35 sensor to obtain ambient temperature and humidity and the communication module adopts ATK＿BLE01-V1.9 to realize the information transfer between upper computer and lower computer.Through I2 C bus protocol and serial port,the functional modules and communication modules of the wearable information acquisition system are connected and controlled by the central processing module.(2)Software design of wearable information acquisition system.The original information collected by the hardware module is processed by algorithm to calculate the combined velocity,and the dynamic threshold method is used for signal processing to realize the step counting function.The original PPG signal was processed by sliding filtering and time interval.Then the heart rate value and blood oxygen saturation value were calculated by formula.Call Arduino sensor file library to realize the measurement of ambient temperature and humidity.The priority scheduling method of Free RTOS embedded system is adopted to complete the coordination of various functions.Experimental results show that the accuracy of step counting algorithm is 96.3%.The difference between the average heart rate measured by the heart rate oximetry algorithm and that measured by honor Bracelet 4 was 0.8 times /min,and the difference between the average blood oxygen saturation was 1.05 times.(3)APP design of augmented reality technology.Based on the Unity3 D platform,the scene construction and module selection are completed.According to the low power Bluetooth communication principle,the script is written.The one-click publishing function of Unity3 D was adopted to transfer the program to android mobile phone platform.Finally,the mobile phone is connected with the lower computer and AR glasses respectively to complete the system construction and function test.