Design Of On-line Monitoring And Analysis System For Ship Propulsion Shafting Vibration Signal

The working state of the ship propulsion shafting has a direct impact on the driving safety of the ship.Based on the principle of compressed sensing,this paper proposes an online monitoring and analysis system based on the vibration signal of the ship propulsion shafting.The main research contents of this paper are as follows:(1)In this system,a large number of sensors are needed to collect vibration signals in multiple parts of the ship's propulsion shafting.Based on the traditional sampling method,the Nyquist sampling theorem will bring great pressure to the storage and transmission of system data.Therefore,this paper studies the vibration state monitoring method of ship propulsion shafting based on compressed sensing theory.Based on the compressed sensing sampling method,the signal reconstruction and fault analysis of the inner and outer ring faults of rolling bearings are carried out.When the orthogonal matching pursuit(OMP)method is used to reconstruct the signal,the threshold or the number of times is determined dynamically to determine the number of reconstructions.The identification of the fault frequency of the VMD component envelope spectrum of the reconstructed signal determines the threshold value,which verifies the feasibility of its sampling analysis for the vibration signal of the ship propulsion shafting.(2)The compression reconstruction method based on random demodulation analog converter and the compression reconstruction method based on Nyquist sampling are compared and simulated.The hardware design feasible scheme for the compression sampling of marine propulsion shafting vibration signal is proposed.The system mainly includes three modules: data acquisition module,data compression module,signal reconstruction module.The ADS1256 is used to complete the vibration signal acquisition.The main control chip is determined as the single chip STM32L151C8T6,and the communication circuit selects the MAX3485 transmission signal to the upper computer.Part of the main completion of ship vibration signal acquisition,compression and transmission.Based on their functions,this paper theoretically shows the feasibility of using these devices to build an improved AIC analog information converter.(3)The system software design includes the lower computer software and the upper computer software.The lower computer software mainly includes the microcontroller software design,A/D conversion software design.The host computer uses MATLAB and LabVIEW for signal reconstruction and analysis,uses MATLAB to generate random sequences for data compression,and combines LabVIEW for data reception,data display,data analysis,data management and other functions to achieve monitoring of the state of the ship's propulsion shafting vibration signal.