Study On The On-line Monitoring System For Controllable Pitch Propeller Based On LabVIEW

With the rapid development of shipbuilding industry, controllable pitch propeller(abbreviatedas CPP)has been applied gradually, especially in the tugs, dredgers, oil work boats, warships andother vessels which have higher requirements of maneuverability. However, due to the complexstructure, the CPP’s failure rate is higher than FPP(fixed pitch propeller), it is to a certain extentlimit the popularization of the CPP. Therefore, this paper takes a certain type of CPP as theresearch object, using the method of signal analysis to study on the monitoring and fault diagnosissystem, the whole process of research is as follows:Firstly, this paper reviews the development and application status of state monitoring and faultdiagnosis technology, and summarizes the principle and application of virtual instrument and CANbus, and then put forward a monitoring and fault diagnosis system based on CAN bus andLabVIEW software.Secondly, theoretically analyzes the mechanism and vibration characteristics of CPP’ typicalfault, through the analysis, determines the selection and installation of sensors, and design for theimplementation plan of fault simulation of CPP.Thirdly, wavelet analysis is used to extract fault signal of the CPP, through the experiments,extract the shafting characteristic signals in the state of normal, eccentric, misalignment,mechanical loosening; study the fault diagnosis method based on support vector machine,including traditional SVM, cross-validation SVM, GA-SVM, experiments show that GA-SVM notonly has the best diagnostic accuracy, better stability and effectiveness, but also shorten the cycleof fault diagnosis.Finally, based on CAN bus, Matlab, LabVIEW, develop a condition monitoring and diagnosissystem, which can monitor the CPP’s operating parameters including shaft system vibration, shaftspeed, pitch angle, liquid level of gravity tank, pressure and temperature of hydraulic system, thesystem can also alarm if three typical fault of shafting occurs. The system is proved to meet thedesign requirements after the experiments and long time of operation.