For some special occasions, it is necessary to obtain the location information of the train vehicles to facilitate vehicle management. For this reason, Anfudi launched a train vehicle positioning scheme based on 433MHz+125KHz RFID, which uses 433MHz+125KHz dual-frequency active RFID technology.
Program features and advantages
1. For low-power RF signals, the signal transmission in complex environments is mainly based on the diffraction transmission of RF signals. In the existing active RFID products, the 433MHz RF is compared with the RF signals of other commonly used frequency bands (such as 2.4). In terms of G), the longest wavelength and the strongest diffraction ability can overcome the effects of complex environments such as personnel intensive, obstacle obstruction, and increased air humidity on RF signal transmission, thereby maximizing the signal read rate. .
2. In view of the strong GaAs diffraction characteristics, the electronic tag can adapt to a variety of special vehicles at the same time, solving the problem of the recognition rate of active RFID for some special vehicles.
3. The electronic label is usually in the standby state. It only transmits signals when the vehicle carries the label into the positioning area and is activated. It has the characteristics of health and environmental protection, ultra-low power consumption, no radiation damage, and safe and reliable use.
4, 125KHz magnetic field range is flexible and controllable, the signal is stable, the excitation distance between the trigger and the electronic tag is adjustable from 1 to 10 meters, and the error range is controlled at about 0.3 meters.
5, 433MHz RF tag communication distance (up to 150 meters), compared to the same power 2.4GHz card reading distance of 80 meters, 433MHz card reading distance of up to 150 meters, the air signal is easier to capture the RFID trigger.
6. Due to the adoption of 433MHz frequency, the interference problem of 2.4GHz to train equipment and train communication is effectively avoided.
Principle of the scheme
The system consists of "exciters" and "RFID electronic tags", "management systems" and so on.
1. Install an "exciter" near the track and connect the 125K excitation antenna to install an "electronic tag" outside the train compartment.
2. When the car carrying the “electronic tag” is close to the exciter antenna, the electronic tag is activated and sends a signal. The “exciter” receives the corresponding signal and feeds back to the host management system to know the car position.