Research On Long-distance Laser Vibration Measurement Technology

In recent years,laser vibration measurement technology has been widely applied in military interception,industrial warning,aviation detection,medical examination,agricultural production and etc,due to its advantages such as wide range of application,high measurement accuracy,and remote-and-contactless measurement.At present,it mainly classified into two categories: interferometric and light reflection conditioning vibration measurement technology.With the purpose of developing a more practical device according to existing advantages and disadvantages of this technology,and current situation of related products.In this work,The research on "Long-distance Laser Vibration Measurement Technology" about its use in examining audio range vibration signals in long distance was studied.This research adopts light reflection conditioning vibration measurement technology,because its system compare to interferometric measurement system has more convenient and better integration.It can be used long-distance measurement and can be operated in adverse environments,such as it can be used in the outdoor.And the light path of interferometric measurement system has higher requirements with higher costs and limited operating environment,it may be adverse to system productization.In this work,the reflection-receiving separated struct has been designed,taking usability,portability,and distance measuring into full consideration,thus featuring minitype and easy operation and greatly increasing of the system.The best detection area for complex reflection spots is also found,and debases the signals with noise to acquire improved signal intelligibility.The main work in this research is completed as following:(1)The design and development of long-distance laser vibration measurementsystem has been finished.The miniature and portable device deals with acoustic signals as vibration source,thus succeeds in examining vibration source in long distance and signals in obscured detection devices,with a effective distance of 200 meters.(2)This research auout system testing has been carried out including a)the performance test of the laser device,such as the size of optical spots,divergence angle,and radiator performance;b)the system parameter test,such as detection range,sensitivity,frequency response range;c)the test and inversion analysis of acoustic signals.(3)Through the analysis of optical spots,the method of finding the best detection area has been finded,which lays the foundation for an upgraded automatic vibration measurement system.(4)This research speech noise reduction processing of detected signals with noise has been completed,and has further evaluated the identification degreeof acoustic signal before and after processing.Overall,this research of the development of long-distance laser vibration measurement system has been completed,which provides some valuable suggestions on automatization of the system.