Laser Speckle Method Real-time Measurement Of The Vibration Of The Target Angle

A new method to measure the angular vibration of object by a laser is researched in this thesis. The system based on this method has several advantages: Real time, remote sensing and non-exigent for the capability of components. Based on the theory of laser speckle, a new method to measure the angular vibration of object by the laser speckle is suggested in this thesis. The principle of this method has been explained and analyzed in this thesis from the views of interference pattern. After that, a simulate system is built with a computer and the MATLAB. The influence of system's parameters on measuring has been discussed when the shape of the receiver's aperture is both foursquare and circular. At last, a primary experiment system is built on this new method.From simulation and experiment, we can draw some conclusion: Firstly, the method that using laser speckle to measure angular vibration of object real time is feasible. Secondly, the parameter, the size of illuminated area on the surface of object, is smaller; the change of laser power that was detected by detector is bigger. Its means the signal is better. Thirdly, the undulation of laser power is change according to the one-order Bessel function with the parameter, the optical receiver aperture, increase. So, the aperture of detector should be adjustable in order to get the optimization. At last, the measurable range of system is restricted by the parameter ().In conclusion, the parameter, the amplitude of angular vibration, the parameter and the parameter are interrelated. So, considering the parameter is unknown, we must think over the size select of the parameter and the parameter when we design a system to measure angular vibration.