Designing of viaduct automatic height limit device based on dual radio frequency recognition

This paper proposed a method of viaduct automatic height limit device based on dual radio frequency recognition. It determined the height of the vehicle by getting the feedback information from the tag reader based on radio frequency identification. Then the height could be compared with the limited height. The category of the vehicle could also be determined by the same method. If the height of the city special vehicle was more than the limited height, the single chip microcontroller would send a list of Pulse Width Modulation wave to drive the motor. The limited height would be permitted, then the city special vehicle would be allowed to pass. If the height of normal vehicle was more than the limited height, the single chip microcontroller sent a signal to open video monitoring and covenanted for the cognizance of the related responsibility. The proposal makes an effective improvement for the traditional limit high gantry, to overcome the shortcomings of the high cost, poor flexibility and special low management capability. The city special vehicle can be easily passed and emergency response efficiency will be improved.