Design And Optimization Of Passive Cabinet Smart Lock Based On NB-IOT Communication

Passive cabinet is an important part of broadband communication system.It has a large number,wide distribution,long distance and complex environment.At present,most of the cabinet locks of the three major telecommunication operators in China adopt traditional mechanical cabinet locks.Inspectors need to carry a large number of keys when maintaining and configuring.It is extremely inconvenient to use keys to unlock locks.Often,because they can't find keys,they can't unlock in time,resulting in a decline in work efficiency.In addition,due to well-known reasons,passive cabinet locks are damaged a lot,cabinet internal components are exposed for a long time,and communication network abnormal interruption occurs from time to time.How to improve the safety of passive cabinet,improve the efficiency of patrol inspection and reduce the outage accidents in communication network has become a common concern of the communication operation department.Compared with traditional mechanical locks,smart locks are easy to manage and have higher security.Therefore,the research of passive cabinet smart lock is of great significance.Based on the comparative analysis of power consumption and transmission distance of several current wireless communication technologies,this paper proposes a design and optimization scheme of passive cabinet smart lock based on NB-IOT communication.Focus on the following three aspects of research:(1)The overall scheme design of passive cabinet smart lock.Intelligent lock of passive cabinet is based on microcontroller MSP430.The peripheral circuit mainly includes voltage stabilization circuit,lock state detection,lock motor and NB-IOT communication module.The smart locks are powered by batteries,and the locks are driven by DC push-pull solenoid valves.The micro-controller MSP430 controls the on-off and on-off of the voltage stabilizing circuit of the motor to achieve the purpose of the switch lock.The intelligent lock connects with the server through NB-IOT,and uploads the detected lock status information to the server.(2)Design of power supply control circuit.The design of passive cabinet smart lock uses BC95 communication module.It needs instantaneous high current when communication and motor drive,and the power supply potential of communication module and motor drive is inconsistent.The large current they needwhen they work will affect each other.In order to make the smart lock work stably,two voltage stabilizing circuits are designed to supply power to communication module and motor respectively.In order to reduce the power consumption,a power supply switch circuit is designed to control the power supply of communication module and motor separately.When the smart lock is not working,the power supply switch circuit is closed to cut off the power supply of communication module and motor.(3)Software design and sleep strategy optimization.The program control of each functional module is realized,including power supply control,lock switch control,voltage detection,BC95 communication and so on.There is a conflict between effective communication and low power consumption in passive cabinet smart lock.In order to meet the need of effective communication and reduce power consumption,the sleeping strategy of passive smart lock is optimized based on double-objective fitting method.