A non-contact displacement sensor based on flexible photoelectric nanofilm

Abstract

The present invention provides a non-contact displacement sensor based on a flexible photoelectric nano film. The displacement sensor is fixed on the surface of the mid-span of the bridge, and the laser light source is arranged directly below the displacement sensor. When the After the deflection of the bridge is generated, the displacement sensor will be displaced together with the bridge, resulting in a corresponding change in the output current, and the change in the laser transmission distance can be obtained according to the output current signal, which is equivalent to the deflection of the bridge. Compared with other traditional deflection measurement devices, the non-contact displacement sensor based on flexible photoelectric nano-film has the advantages of simple structure, high measurement accuracy, fast response speed, wide application range, and real-time automatic measurement.

Description

technical field [0001] The invention relates to a non-contact displacement sensor based on flexible photoelectric nano film. Background technique [0002] Beams are important load-bearing components of bridge structures, and the deflection of beams is an important parameter to evaluate its dynamic state, measure fatigue damage, and ensure structural safety. In today's traffic engineering, the commonly used beam deflection measurement methods mainly include dial indicator measurement method, precision level measurement method, total station measurement method, connecting pipe measurement method, differential GPS observation method, etc. The dial gauge measurement method is to amplify the displacement value of the detected position by the gear rotating mechanism, and convert the detected linear reciprocating motion into the rotary rotation of the pointer to indicate its displacement value. This method is simple in equipment and can be used for multi-point measurement. Steel T...

AI Technical Summary

Problems solved by technology

The dial gauge measurement method is to amplify the displacement value of the detected position by the gear rotating mechanism, and convert the detected linear reciprocating motion into the rotary rotation of the pointer to indicate its displacement value. This method is simple in equipment and can be used for multi-point measurement. Steel The chord dial indicator measurement method can only be used to measure bridge deflection on land or on frozen water in the north, and cannot be used on high bridges or in the presence of water, or a high platform must be built

The precision level measurement method is a method of measuring the height difference between two points using a level and a leveling rod. Starting from the leveling origin or any known elevation point, the elevation of each point is measured station by station along the selected leveling route, and the level is read by the leveling rod. The relative deflection can be obtained by the difference, but this method can only measure the relative value, not the absolute value

The total station measurement method is a method of triangular elevation measurement. The height difference between two points is obtained by measuring the horizontal distance and vertical angle between two points. Observation errors caused by different observation methods and experience of the observer, even if the static measurement is performed, the data is often relatively discrete, and real-time and automatic measurement cannot be achieved

The connecting pipe measurement method is to use the principle of "the pressure of the static liquid on the same horizontal plane in the connecting device is the same" in physics, arrange the connecting pipe at each measuring point, fill water (or other colored liquid) to the position of the scale, when When the bridge deflects, the horizontal liquid level in the water pipe remains the same, but the relative water level of each measuring point will change. The deflection of the bridge can be obtained by reading the changed value. The calculation is simple, and due to the fully enclosed structure, it is not affected by the bridge site. High dust, high humidity and other environmental conditions, but this method has low accuracy and can only be used for low-frequency or ultra-low-frequency bridge static deflection detection, and is not suitable for bridges with large spans and large longitudinal slopes

The differential GPS observation method places a GPS mobile station at the required measuring point, and obtains the position of the deformation point relative to the reference point in real time through GPS observation, which can directly reflect the spatial position change of the measuring point to obtain the deflection value of the bridge structure, but its measurement accuracy Low, generally only up to centimeter level, not suitable for high-precision deflection detection of small and medium-sized bridges

Images