The Research And Design Of Linkage System Between Elevator Access Control Based On UHF And Building Intercom

Access control system and building intercom system are indispensible devices in moderm buildings.With the advancement of technology,people have more and more requirements for the performance of the system.At present,the short-distance access control and wired intercom system can not meet the demands of users.Radio Frequency Identification(RPID)is a kind of wireless automatic identification technology.It uses the electromagnetic wave to identify target and read the data.UHF technology is a kind of radio frequency technology,and can identify further distance.In the thesis,based on RFID technology,a linkage system of elevator control and building intercom system is designed.The main tasks are described as follows:First of all,through the analysis of the existing problems and the actual demands of users,the overall design scheme of the linkage system is proposed.Secondly,the elevator control system is designed.Aiming at the shortcoming of short distance identification of elevator access control system,based on the research of RFID,6C card is chosen to solve the problem.Meanwhile,a new card reading circuit is designed in the thesis,which realizes long-range reader.At the same time,considering the stability and scalability of the system,the hardware circuit is designed to be the master control board and extended control board.The function of the master board is to process the data and the other is actuator.The main circuit comprises a power supply circuit,a reader circuit,a clock circuit,a memory circuit and a relay selection circuit.Software,in order to avoid the data collision problem in the access control system,the Q value anti-collision algorithm is used.Finally,the wireless intercom system is designed.At present,the intercom system is generally wired,which causes inconvenience for construction and installation.In addition,the intercom system in elevator is special calling equipment,which has no information exchange with the elevator system.Considering the problems,the GSM module is chosen to realize wireless intercom communication.Meanwhile,use RS-485 communication to achieve linkage with the elevator access control system.After the debugging of the system,the results show that UHF technology is used in long-distance reader and GSM technology is used in wireless intercom,which is feasible.