Enterprise application case of identity fingerprint recognition attendance system
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Among the many biometric technologies used for identity verification, fingerprint recognition technology is currently the most convenient, reliable, non-invasive and inexpensive solution. Fingerprint recognition has a long history as an identification technology. By analyzing the global and local features of fingerprints, the feature values extracted from fingerprints can be very detailed in order to reliably confirm a person’s identity through fingerprints. On average each fingerprint has a few unique measurable feature points, each feature point has about seven features, our ten fingers produce a minimum of 4900 independently measurable features – this is enough to confirm whether the fingerprint recognition is A more reliable way of identification.
Fingerprints are unique features of the human body, and they are complex enough to provide sufficient features for identification; if we want to increase reliability, we simply enroll more fingerprints, identify more fingers, up to ten , and each fingerprint is unique; the speed of scanning the fingerprint is very fast and the use is very convenient; when reading the fingerprint, the user must contact the finger with the fingerprint collection head, and the direct contact with the fingerprint collection head is the best way to read human biometrics. reliable method. This is also one of the main reasons why fingerprint recognition technology can occupy most of the market.
The estimated number of employees in the company’s factory area is 3-5,000 people. There are 3 gates and 10 small gates in the factory. The fingerprint attendance points of employees are distributed at the entrance of each small gate, and the number of attendance at each small gate is about 400. That is, the system solution needs to complete the daily fingerprint attendance management of 3-5 thousand employees.
Main technical difficulties and their solutions:
(1) Large number of people
·Fingerprint recognition algorithm
Although Biokey is currently the fastest fingerprint identification algorithm, if 4,000 people register 2 fingerprints per person, the entire system needs to register 8,000 fingerprints, and the average verification time for attendance on the Pentium III 800 computer It reaches 3 seconds, and the verification time of attendance failure reaches 5 seconds, which is obviously unacceptable, so necessary measures must be taken to solve this problem. During attendance, people can accept a verification time of up to 3 seconds, so a verification terminal can search for no more than 4,000 fingerprints when verifying fingerprints.
Method 1: In a certain verification terminal, limit the number of searchers to an acceptable range. For example, only employees of a branch factory are allowed to sign in with their fingerprints on the attendance machine in front of the factory, but they cannot be recognized when they sign in elsewhere. Under normal circumstances, employees only need to check attendance in their own branch factory, and can only enter and leave their own branch factory, so this method can be used in branch factories with less than 2,000 employees, and it is feasible to perform attendance. However, for the attendance management at the gate, employees of each branch may use it, so this method cannot be used.
Method 2: Enter the job number before comparing the fingerprints. In this way, the system only needs to compare the registered fingerprint with the same job number to verify the identity of the employee, which is a one-to-one comparison, so there is no limit to the number of employees who can be verified here. The disadvantage of this method is that it is necessary to input the employee’s job number, which increases the memory burden of the employee and the operation time when using it.
staff operation
Due to the concentrated commuting time, many employees will gather for attendance during commuting. It is necessary to ensure that they can complete the attendance in a short time, and there should be no long queues. The time of each person’s attendance cannot be simply calculated as the time for the computer to compare the fingerprints, because the employee also needs to go to the attendance machine and press the fingerprint. In addition, the fingerprint may not be recognized at one time, or the employee may operate improperly, resulting in recognition failure, etc. Etc., according to practical experience, the average pass time per employee is 3 seconds. Taking 20 minutes as an attendance time estimate, one attendance point can accommodate 450 people attending attendance at the same time. Considering the existence of emergencies, each attendance point can only be counted as 400 people.
For a branch factory with more than 400 people, it is recommended to set up the number of attendance points according to the actual number of people. For example, a branch factory with 1,000 people commuting to get off work at the same time should set up 3 attendance points, or connect one computer to 3 attendance terminals. Branches with less than 400 employees can only set up one attendance point.
(2) Unreliability of fingerprint recognition technology
Fingerprint recognition technology is not 100% reliable, there are two indicators “rejection rate” and “false recognition rate” to describe the reliability of a fingerprint recognition system:
Rejection rate: refers to the percentage of probability that the system cannot recognize an already registered fingerprint.
False recognition rate: refers to the percentage of the probability that the system mistakenly recognizes one fingerprint as another fingerprint.
The Biokey fingerprint recognition technology of Zhongkong Technology is one of the most reliable fingerprint recognition technologies at present. The nominal rejection rate is 1.0% and the false recognition rate is 0.001%, which means that among the 4,000 employees, there are about 50 employees. Fingerprint identification is difficult to pass, and at the same time, according to the branch factory with a maximum of 4,000 employees, there may be one misjudgment per month.
The rejection rate and the false confession rate are two mutually restrictive indicators. If one of them is lowered, the other will increase. Since the false recognition rate is a very critical indicator, we must ensure that there will not be too many false positives for at least a month. In case of misjudgment, the administrator must modify the record in the management program to ensure the correctness of attendance.
Entering a number and using it in conjunction with a card is the most effective way to address system recognition performance. When comparing fingerprints, it is only compared with your own fingerprints, so there is no possibility of false recognition. In order to prevent attendance on behalf of others, the false recognition rate can be adjusted to about 0.1%, and the rejection rate at this time is 0.6%. Difficult people were reduced to 24 people.
(3) Summary
If there is a special person in charge of attendance statistics, then only fingerprints can be used for attendance, which is the first choice for large factories and enterprises. If you do not want to misjudgment, you can use ID+fingerprint to check attendance.
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