Study On A Portable Measurement And Analysis Instrument For Ships Shafting

With the development of the ship industry and the deeper understanding in shaft Vibration, people raise higher requirements on the shaft vibration measurement technology.The paper describes the purpose and significance of developing ship shaft vibration measurement instruments by analysising the formation and the harm of ships shafting vibration. And then studied recent developing status and trends of the measurement technology of shaft vibration. Then studied the vibration measurement technique, and finished the orignal design of a portable ships shafting vibration measurement and analysis instrument.The system uses laser sensor to realize the real-time collection of vibration signals; uses CPLD (Complex Programmable Logic Device) to realize signal collection and processing function; uses Microcontrollers to control the system; uses FLASH to realize large amount of data storage; uses LCD to realize real-time display of the vibration waveform and data; uses USB to realize high-speed data transmission with PC. The system can do simple signal processing, such as waveform display, FFT transformation, amplitude spectrum display and so on; Signal processing system on PC can do time-domain analysis, spectrum analysis , correlation analysis and time-frequency analysis which includes short-time Fourier transform and wavelet analysis.The paper has given the hardware design, the software design of the system as well as the signal processing system on PC. And then simulation of some function and data processing verification is gaven, what showed that the system is stably, every function goes well, data analysis is accurate, and of high precision. The system is proved to reach the design purpose.