Radiofrequency technology-based special electronic attendance checking system for students

Abstract

The invention relates to the technical field of electricians and electronics, and especially relates to a radiofrequency technology-based special electronic attendance checking system for students. The system includes a student card and an entry and exit radiofrequency emission device, the entry and exit radiofrequency emission device comprises two radiofrequency emission antennas, and the two radiofrequency antennas emit identification signals in a time sharing same frequency manner; the student card comprises a radiofrequency receiving circuit, a microprocessor and a GSM / GPRS communication module, the radiofrequency receiving circuit and the GSM / GPRS communication module are respectively connected with the microprocessor; and the microprocessor of the student card determines an entry or exit state according to the change of the strength of different identification signals received by the radiofrequency receiving circuit, and sends the determination result to the server of the system through a GSM / GPRS wireless data channel. The system supports the entry and exit of batch people, does not need close card punching, does not cause the jam or delay of people at the entry and the exit, and realizes accurate and reliable attendance checking information; the two emission antennas of an entry and the exit apparatus emit in a time sharing same frequency manner, so the frequency resource occupation is little, a pass-by distance needed by entry and exit identification is short, accurate identification can be realized within 10M, and the apparatus has a simple structure and a low cost.

Description

technical field [0001] The invention relates to the field of electrical and electronic technology, in particular to a student-specific electronic attendance system based on radio frequency technology. Background technique [0002] Passive RFID access control system or fingerprint access control requires students to swipe their cards or press their fingerprints on one or more fixed devices one by one. Active RFID also requires a short distance between student cards and receivers or a door frame receiver. When a large number of students pass through, it will cause crowded queues and waste unnecessary time. [0003] The traditional student electronic attendance system installs electronic attendance equipment at the school gate. Among them, the passive RFID access control system or fingerprint access control requires students to swipe their cards or press their fingerprints on one or more fixed devices one by one. When students pass the school gate, they swipe their cards to ach...

AI Technical Summary

Problems solved by technology

This method of electronic attendance and SMS notification still has major defects in practice: first, students must swipe their cards or press their fingerprints one by one, which may easily cause congestion and retention of students at the school gate; second, the initiative to swipe their cards is in the hands of students Students may forget to swipe their cards when they pass the school gate, or they may return after swiping their cards, resulting in inaccurate attendance

[0005] For active RFID, the two receivers need to be placed at two ends about 30 meters apart to be able to identify correctly. The data sent by a large number of active RFID cannot be guaranteed not to collide. Only some algorithms can be used, such as making a mathematical model at the transmitter The collision can be avoided only after the second or third collision. At the receiving end, the collision data overlap rate is not very high (generally less than 30% of the theoretical limit of 50%), and data recovery is performed, which increases the complexity of the access control equipment. and the harshness of cost and conditions of use

Moreover, the defects caused by this kind of data collision can only be reduced by technical means and algorithms such as multiple data confirmation of data wireless data recovery in the later stage to reduce the lack of access and attendance information

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