Optical Measurement Of Displacement Based On Digital Image Processing Technology

Vibration displacement measurement is an important aspect of engineering and construction health monitoring, Especially, it is significant for multidimensional simulation tests of earthquake and long, big, high, soft structures. Most of existing engineering vibration sensors are designed by inertia theory, and they only could used in contact measurement. The vibration displacement was figured out by general by integration of the speed or double integration of acceleration, but there is some inevitable error, In addition, these sensors are easy to bring mass effect in small-scale model test; and they take seriously affected in multidimensional of random vibration measurement. Accordingly these situations, this paper propose a design about a optical relative displacement measurement methods and system, which are base on digital image processing technology. And it overcome the shortcomings of general inertia vibration sensors. In this paper, the main research work and results as following:1. After researching the literature, we have analysed existing research situation of engineering vibration measurement, and we have summarized the work characteristics of main measurement methods and sensors, than we have pointed out some problems of the contact- inertial- type sensor.2. Advance an optical displacement measurement method which is based on digital image processing technology. And this optical displacement measurement System of fit the scale of vibration table and large-scale structure.3. We have made a computer simulation test for this measurement system. Then we have had a compare experiment whit 941B sensor in the vibration table measurement and achieved satisfactory results.4. This optical displacement measuring system have had an application in the displacement measuring of large pier static test, The measurement results was similar with the displacement meter.5. After careful studied of waveforms and measurement data, we have given the technical specifications of the measurement system and have pointed out some problems which will be research in the future. By doing this, we have established some foundation about the realization of large-scale structure measure using multi-camera or multi-dimensional measurement system using a single camera.This optical displacement measurement in this paper, which is based on digital image processing is simple, low cost and accuracy. It will effectively improve the existing displacement measurement. And our design will provide a new instrument for engineering vibration measurement.