指纹门禁英文文献.doc

指纹门禁英文文献
Control Physics Review, Vol. 18, No. 7, pp. 857–883, 1999
Copyright © 1999 Control Science Ltd
Printed in the USA. All rights reserved
0018-9480/$26.00
1.00 PII S0272-7358(99)00020-8 Design and Realization of Fingerprint Door Access System
Vincent C. Hu

Abstract
This article summarizes the background of fingerprint door access system and its applied fields, then describes the entire design of fingerprint door access and the related modules, after that presents a fingerprint door-access network based on R S-085bus,expatiates the design of communication protocol, some problems and the corresponding resolvents on network connection.
Access is limited access by a device, the development of access code, experienced, IC card, infrared, biological technology identification card, however, a series of process based on the radio frequency card number and password, the entrance guard system due to its inherent defects in safety and convenience, only in this hovering, between the fingerprint identification technology, we will introduce security area, and puts forward the concept of fingerprint identification devices. Compared with the traditional access system, fingerprint door does not need memory identity number and password, also need not carry keys, such as IC card, use only one finger, and due to the features of human reproduction of the characteristics of convenient, also brought the reliable safety. The system can be widely applied financial unit, confidential unit, government organs, enterprises and major department is important, airport, prison, parking lot, warehouse etc for its entrance to monitor and manage all occasions.

Working principle
Fingerprint identification technology according to the uniqueness of fingerprints, through the analysis of the fingerprint characteristics, such as local and global impulse, valley, the destination, the bifurcation point or bifurcation, extracting these features from the fingerprint and relative position can reliably identified a person's identity. Fingerprint door through the advance in the system, and will keep the user information stored in the fingerprint characteristics of fingerprint module container. When a user access, fingerprint collector first collection of users, and then calculating fingerprint characteristic value, and carries on the analysis comparison to

host, decide if users have access permissions. If a user has the corresponding privileges, so in the control unit after verification through lock device, the output will start to lock locking control signal equipment, realize the control, If the user does not have relevant authority, after verification of the information given will fail, and the validation report according to the output Alarm. Whatever success or failure, operation results will be recorded in the system operation.

System structure
Fingerprints scanned by fingerprint identification system control module, collection and processing chip, unlock control circuit, electronic locks, liquid crystal display unit, audio circuits, keyboard, real-time clock, memory, "the mouth expansion circuit and decoding circuit, etc. 1.System diagram 1。This set of MCU control project by eight general microcontroller AT89C51, its main function is the state key test and executes operation according to the keys, and communications between PCS, control module, collection and processing fingerprint identification control circuit control and storing user operation process and result, real-time clock control audio circuits, etc.

1.Fingerprint identification of pepper collection
Fingerprint recognition module is collected by optical fingerprint acquisition head, 32bit mpu, flash memory, dynamic memory and programmable logic unit. Its main function is to fingerprint characteristic value calculation, and that handles the computational results, and that handles the computational results including fingerprint data storage register fingerprint identification) and (fingerprint. Fingerprint identification by collecting master single ship controlling. Commands, fingerprint chip frame

Set recognition module returns responses frame. Command frame contains command word, ordered additional parameters, calibration parameter, and response frame contains code and data of command response, error code, face and school.

2.Real-time clock and audio unit
DS1302 system USES a time clock. DS1302 chips with year, month, day, week, when the timer function, minutes and seconds, it has a RAM 31x8 by bus interface, have used tries the power and backup power supply, the double foot have data to write protect functions. Real-time clock is mainly to provide accurate information system, therefore the time in the power source of the circumstances, disconnect the timing,this system can continue to provide the 3.6 V rechargeable batteries as its backup power, to provide uninterrupted time.
V oice prompt unit used to provide good human-machine interface, with voice to prompt the user to correct operation. The company adopts ISD1420 is ISD access technology integration can be simulated repeatedly recording 20 seconds off the pronunciation chip, phonetic pronunciation is not lost, electric, maximum points each segment of 160 minimum length of speech, each section for 125 ms speech can be controlled by address lines, each output for an address, 125 ms by AO - A7 eight root address line control. Users of the voice recording each segment with period after ending sign automatic chip EOM (after), chip has recorded a logo (AIDS), OVF ISD1420 is information
Using this function, cable function can not know the exact address for voice, control the use of pulse triggering to need time playback.

3. Unlock control circuit
Due to the general electronic locks are used to control the low level, in order to avoid the lock on the door direct access to the machine used to drive electric low level, improve safety lock, by a single unit control circuit, control from its hardware and MCU control actuator two parts. Installed in the door lock control circuit, when the SCM control commands from control, lock chip receives the command and decoding, if correct, drive actuators to unlock. Actuators by mosfet and solid state relays.

4.Other functional unit
LCD display unit adopts 128*32 matrix LCD display 16*16 dot matrix characters, 1 eight characters displayed row. LCD display time for information and function of the system and menu for information. Used to store extended deposit reservoir of users open records and failure information. System adopts two 24LC256 expanded 64k memory space, can save more than 9,000 records. 24LC256 USES two lines of convenient, after power off after data is not lost.

The online system
For such as bank, some departments, large scale, usually need to install multiple fingerprint door machine to control the different departments and places, so need to form a distribution network, host can control of each fingerprint door machine operation, and obtain operating records and unified management. Because the Control Physics Review, Interface with sending and receiving, receiving high sensitivity differential resistance, thousands of interference ability is strong, can make long-distance communication, so in the networking system, using the RS-485 interface standards.

Based on RS - 485 interface standards of networking system.
1.The system frame
System adopts full-duplex RS - 485 bus, computer as a host to control all extension, the system frame as clearly shown. In computer serial output terminals, need to change the 32 signal for RS-485 signal. In each from machine, integrated the RS-485 interface chip, RS-485 chip chose MAX489 full-duplex transceiver. The bus can hang up to 32 extension, if the number of extension increases, can choose the input impedance higher transceiver, such as MAX1487 can reach 128, MAX3080A can reach 256. The main function is to have registered managers, delete the delivery of the users from machine fingerprint characteristic data from machine, delete all or specify users, obtain the user data and open user fingerprint characteristic data and set a time and date from the machine etc. From the function of machine for registered users, validating user, remove users, and communication, etc.
MCS - 51 series microcontroller is a full-duplex serial port. It is not only a pair of serial communication between machine, also can achieve more communication. By 51 - MCS composed of many systems usually adopts master slave structure, the host machine can realize and from a full-duplex communication. In many machine system, to ensure the host and choose from the machine realization reliable communication, we must ensure that the communication interface with recognition ability. 51 - MCS SCON control registers the serial port SM2 position is to satisfy this requirement and communication control more than.

3.The SCON type below ：
SMO, SM1 for a serial port works, optional choose four kinds of work. For the ways of TB8 3 of article 9 to transmit data. In many machines used in the communication address frame is still data frames. RB8 mode 2, 3 for the first nine received data. In data communication used to address/logo. SM2 for in many ways, and communication allows control. If SM2 = 1, work in many ways, in this way1.00 PII S0272-7358(99)00020-8 communication if received under the ninth data RB8 = 1, will receive buffer data load, receiving interrupt (who) request, RI RB8 = 0. If not, then receive an interrupt request, information discarded. If SM2 = 0, regardless RB8 is. Or are the RI, receiving interrupt. Accordingly, more communication process as follows:

（1）Start from the machine makes all SM2 = 1, is only address frame.
（2）Host addresses from the machine to send information, and will send the 9th position 1 is the address.
（3）Receive to address from each frame, which will receive the address with the address, if compare, will SM2. From then on the receiving host of information, If not, still keep SM2 = 1, then send the data to host ignore, until the new address receives frames.
（4）Host send command and data frames, the ninth position data bits. From the machine and the host, after the end of the communication SM2 = 10.

Workflow
1.The host
Every communication by host, host firstly, receive send the right address frames sent after command response addresses frame. After receiving the correct instruction, according to the type of response to determine whether the instructions, send or receive data frames if need, then sent or received. If you don't need to wait for receiving operation, the code. After receiving the correct code into standby. In the communication process, if received wrong response, repeat the frame, the most repeated sent three times.

2.From the machine,
In no operate from machine or communication in standby. When receiving address, and the address, again not enter standby conform to return address response, wait for receiving instructions frame. After receiving instructions frame, return instructions, and corresponding operation. If you need to send or receive data, then sent or received. Operation after completion of the operation, return code.

3.The relevant asked. Network
RS: 485 bus in, only one to send data to host extension, so the extension in the initialization process should be sent to client can clear 0 (banned), in the state of their host receives calls to allow to send, immediately after the way, otherwise prohibited1.00 PII S0272-7358(99)00020-8 impedance matching problem and make due to host cannot receive the data sent from the machine. In the differential balance system, usually choose twisted-pair cable as signal transmission. Because in length, twisted-pair direction, so symmetrical that thousands of external perturbation degree in exactly the same way of jamming signal. In the receiver input common-mode disturbance suppressing due, so can realize the signal transmission of reliable. In addition, the signal transmission device, if meet online, will the impedance discontinuity reflected from the surface of the signal, influence, so must adopt teleportation matching method to eliminate reflected. The characteristic impedance twisted-pair 110-13 in the chicken, it and the thickness of the line insulation materials and the diameter of wire. Usually the end line up smoking, the impedance matching 1200 resistance. On the transmission line, also note that it to signal attenuation, often have different type, its characteristic impedance twisted-pair, but for the same signal attenuation is different. Especially in the distance, the conductor resistance of signaling content greatly influenced.

Conclusion

This system is a new kind of single operation, the author intelligent entrance guard system innovation is in use fingerprint effectively identify into identity based on single-chip microcomputer control, miniature cameras recorded illegally into the way of images, saved the rich scene material, improve the system safety protection ability, is one of effective monitoring system.

References:
1. Hu V ., “The Policy Machine For Universal Access Control,” Doctoral Dissertation, University of Idaho, May 23, 2002.
2. Tidswell J. E., “Practical Safety in Flexible Access Control Models,” ACM Transactions on Information and System Security, Vol. 4, No. 2, May 2001, pages 158-190.
3. National Computer Security Center (NCSC), “A Guide to Understanding Discretionary Access Control in Trusted System,” Report NSCD -TG-003 Version1, 30 September 1987.

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