Design And Implementation Of Subway Station Lighting System Based On MQTT Protocol

With the rapid development of the rail transit industry,a large number of subway lines in major cities have appeared,and there are more and more subway stations that constitute subway line nodes.Subway stations are usually located underground,and lighting can only rely on the internal lighting devices.How to efficiently control the many lighting devices in the station,and promptly detect and deal with the faults and alarms generated by the lighting devices has become a problem that the staff need to solve.The subway station lighting system based on the Internet of Things can easily control the lighting device,find and solve problems in time,to improve the efficiency of staff lighting management.The subway station lighting system includes five functional modules: device management,lighting management,system management,statistical analysis,and log alarm management.As an Internet of Things system,it provides lighting device access,management,debugging,and monitoring functions.The system uses B/S architecture,and multi-platform access can be realized only through the browser.About the data transmission protocol between lighting devices and the system,considering that lighting device is a small Io T device with low power and poor network environment in subway station,the MQTT protocol with low power consumption and low bandwidth requirements is selected,and the MQTT platform is deployed in cluster mode to improve the availability.Based on JSON,a unified message format for interacting with a variety of lighting devices is designed,and the conversion function is provided,which reduces the complexity of accessing system for different types of lighting devices.The back-end of the system is developed using the Spring Boot framework,which can integrate various technologies and functional module codes in an orderly manner.In the alarm notification part,the Drools rule engine is used,which abstracts the staff’s requirements for alarm into rules,and then through the matching of the rule set and the data information in the system,the dynamic alarm requirements of the staff can be flexibly met.The number of connected lighting devices supported by the system exceeds 10,000.Deploy environment through cluster mode,in a scene where a large number of lighting devices publish messages,the average time for the system to process messages has been reduced by nearly 20%,and the CPU utilization of the server shall be controlled at about39%.As a bidding project of Hong Kong Metro,the system has met the expected functional requirements after being tested internally for a period of time,effectively improving management efficiency.