Real-time Monitoring Device On The Vertical Displacement Of The Bridge

In the deformation monitoring of large bridges,the displacement and settlement of the bridge can be detected,which can reflect the absolute change of the bridge.It is an important parameter in the evaluation of the safety state of the bridge structure,which provides a scientific basis for the management and maintenance of the bridge.In this system,the laser transmitter is installed at the bottom of the bridge,and the photoelectric position sensor(PSD)is used to monitor the deviation of the laser.The signal is amplified,collected and processed to get the change of the vertical displacement of the bridge.The system developed in this paper is divided into three parts: optical system,circuit processing system and data processing system.Optical system complete the following task: when the bridge happens to make the vertical variation after laser position changes through the optical system can completely incident to PSD light-sensitive surface,and is not affected by bridge of immunity.Circuit processing system mainly includes three contents: 1)the position of the optical signal into two micro-amps of current signal level,2)completed the weak current signal extraction and amplifier,make its output can reach 1-5v,3)The addition and subtraction of two analog signals are completed.The data processing system can be calculated the vertical variation dsitance of the bridge.1)The voltage of the analog digital conversion is completed,and the vertical variation distance of the bridge is calculated,2)able to communicate with the computer,real-time display of the change in the position of the bridge.