The Design And Implementation Of Intelligent Access Control System Based On BACnet

With the continuous development of various techniques in the field of intelligent building, more and more technological standards have been proposed, and problems such as disunity of standards and failure to operate equipments mutually made by different manufacturers also arise. Serving as the sole international standard of building automatic control field, BACnet protocol can be applied to solve these problems by integrating controlling products of different brands in one system thus can provide the maximum system agility and cost high efficiency for both owners and managerial personnel. The access control system, which belongs to Building Automation System(BAS), is a digitization management system managing personnel in and out.On the basis of deeply study in BACnet protocol, an implementation of intelligent access control system based on BACnet is presented in this paper. The scheme mainly discusses the hardware platform, backstage procedures, protocol stack and visual management software, solves the problem of interconnection and interoperability between intelligent access control system and other BACnet facilities, and realizes the seamless connectivity of access control system to guard against theft and alarm system, video surveillance system and so on. Thus, a smart and complete security system is constructed, which take effect measures to safety.This is the first attempt of adopting BACnet standard in the intelligent access control system of digital security system.The hardware and software realization details is given, finally experiments prove that this intelligent access control system not only implements the security control of exit / entrance but also has the functions of network, alarm, patrolling and electro-map. The main tasks of this paper include the following:(1) Proposed an access control system of BACnet protocol design program, providing a better solution to the problem of interconnection and interoperability between intelligent access control system and other BACnet facilities. (2) According to the cost and actual demand, chip AT89C52 and ZLG500A module are choosed to compose hardware system of access controller; Software of BACnet access controller is designed to implement APDU encode / decode ,the assembly and interpretation of the text.(3) Determined the system software structure on the basis of analying the functions of surveillance management software. Design tasks mainly includ the user interface and database.(4) Proposed BACnet / IP technology to interconnect BACnet access system to other equipment, as well as BACnet network (such as burglar alarm systems, lighting control systems and fire protection systems) , aiming at the poor communication problem in the building systems.