Research On Evacuation Guidance Lighting Control Technology Based On Smart Fire Fighting

To promote the construction of smart fire fighting,the digitalization and intelligence of fire evacuation facilities have become key objective.Improving the utilization of equipment and enhancing the effectiveness of fire evacuation are top priorities in engineering.The fire evacuation signs have the foundation of electricity lines,which can be reliable to upgrade at lower costs.Besides it has the characteristics of a wide range of layouts and high density.These characteristics make it possible to improve emergency guidance ability.This thesis suggests the digitization of fire evacuation signs and explores how to improve their guidance effectiveness using guidance lighting.Through the study of the two-line technology and the research on the low-cost time and space synchronization control method between the smart fire evacuation signs,solve the problem of guidance lighting,and lay the foundation for future digital fire construction.The research content is mainly as follows:Firstly,Powerbus two-wire technology is analyzed,its working principle is interpreted in detail,and basic theories such as time synchronization technology and Modbus are studied,and the advantages and disadvantages of them are discussed.Secondly,the implementation scheme of guidance lighting is determined,and focused on studying a LCTS(Low-cost Time Synchronization)method applied to the digital signal transmission system.The method captures the start time of physical layer data transmission through external interrupts of the microcontroller.By utilizing broadcast synchronization as the primary method and assistance of two-way synchronization,LCTS achieves a low-cost time synchronization method in low-speed networks.Finally,the experiment system of guidance lighting was built.The power supply,communication,synchronization integration of evacuation sign is realized based on Powerbus,and LCTS is implemented in the case of Modbus protocol compatibility.The experiment showed that we achieved a single synchronization accuracy within 50 us under a clock resolution of 30 us.The experiment synchronizes every 100 s,At the bus rate of9600 bps,it has 0.77% bus occupancy rate.The error of time synchronization was successfully kept less than 1 ms.Based on this method,the power consumption of evacuation signs and communication bandwidth are less.It realized a single broadcast Modbus message can switch the guidance light plans which are saved in sign controller efficiently.