Design And Implementation Of Gateway For LoRa Intelligent Helmet System

The rapid development of the Internet of Things technology has prompted more and more urgent needs for intelligent construction sites in construction,exploration and other industries,and intelligent helmets are an important part of intelligent construction sites.The existing intelligent helmets sold on the market have shortcomings such as high power consumption,limited positioning scene,without danger prediction and high cost of communication modules.Therefore,the development of a truly intelligent helmet system has good economic value and social significance.This thesis mainly completes completes the design and implementation of the hardware and software of the gateway device in the intelligent helmet system.Communication technology is the key in the intelligent helmet system,which directly affects the function and performance of the whole system.Based on the demand ananlysis of system power consumption,cost,positioning,deployment and application scenarios,this thesis analyses and researches representative Internet communication technologies such as Narrow Band Internet of Things,Wireless Fidelity and Long Range Radio,and chooses Lo Ra as the communication technology between helmet terminal and gateway.This thesis has completed in-depth analysis and research on Lo Ra physical layer,MAC layer and other protocol technologies,and combines the requirements of the gateway for system resource scheduling and power control,and designes a wireless resource scheduling scheme and a low power consumption scheme.According to the hardware function and performance requirements of the gateway equipment,this thesis has the completed the selection and circuit design of key components such as Lo Ra chip,main controller and communication module of the gateway.In this thesis,anti-interference design methods such as analog digital ground and power supply design separately,strong and weak signal isolation,thermal design are adopted to complete PCB scheme design in order to reduce PCB area and optimize routing rationality.Based on the software function and performance requirements of gateway device,this thesis proposes a Dynamic Power Management method and a dynamic TDMA resource allocation scheme.By adjusting the working sequence of each process of the system,the effect of low power consumption is achieved and the power consumption control scheme is optimized.This thesis adopts the modular design to complete gateway software system,which has many advantages such as low complexity,high efficiency and convenient code reuse.On the basis of system scheme design,this thesis completes the interface design of the terminal and the gateway,the gateway and the platform.and this thesis completes the process design and implementation of the main processes such as terminal access,terminal system low-power control,gateway resource allocation,and system data transmission and reception.Finally,the terminal,gateway and server and other system verification environment and platform are built,and test cases are constructed to test and verify the data transceiver,data transmission rate,power consumption,transceiver reliability and other functional and performance indicators of the gateway.The experimental data show that the functional indexes and performance indexes of the gateway meet the design requirements,and the design scheme has good engineering significance.