The Application Of Vibration Sensor In Pipeline Leakage Detection Based On Self-mixing Interference

The phenomenon of self-mixing interference refers to the light emited from LD reflected by the external vibration object to the laser resonant cavity causing the output power of photoelectric diode changed. The mixed interference phenomenon is widely used in displacement measurement, vibration sensors.Self-mixing interference theory is analyzed in this paper,then self-mixing interference model is concluded. different optical feedback of self-mixing interference model is analyzed, then numerical simulation was carried out, and the self-mixing interference wave was simulated by Matlab simulink toolbox.Phase unwrapping algorithm was analyzed to make the self-mixing interference signal processed, and the issue in the phase unwrapping algorithm processing was discussed.The phase unwrapping based on data reverse processing algorithm was put forward to solve the issue that peak and valley positioning deviation of SMI signal in unwrapping algorithm, and simulation and experiment was test to make the algorithm validated, the precision of displacement reconstruction of vibrating objects by phase unwrapping algorithm was improved.Detection means in pipeline leakage were analyzed, self-mixing interference displacement vibration sensor was adopt to detect pipeline leakage. Comparing with PCB vibration acceleration sensor in pipeline leak detection results, the self-mixing interference vibration displacement sensor was verified in experiment in the actual indoor pipeline leakage model and a good measurement effect was got to prove the design of vibration displacement sensor based on laser mixing-interference in pipeline leak detection has prospect in application...