Development Of Torsional Vibration Test System Of Marine Diesel Engine Shafting Based On Labview

Torsional vibration is one of the basic mode of ship diesel engine shafting vibration.Significant impact occurs when the ship diesel engine shafting torsional vibration,so the ship diesel engine shafting have to take torsional vibration test in the design phase and put into operation to avoid failure accidents.Because the torsional vibration signal is weak and amplitude is small in the actual measurement,the torsional vibration test is difficult to carry out.The purpose of this paper is to develop a set of shafting torsional vibration test system with high precision and reliable for Marine diesel engines.The torsional vibration test has experienced the development from early mechanical methods to later electrical measurements and from contact measurement to non-contact measurement.Firstly,the mechanism of torsional vibration,the method of torsional vibration and the processing and analysis method of torsional vibration signal are studied in this paper and the non-contact electrical measurement method is established as the test method of this system.Then the errors of the system precision are analyzed and the processing and analysis methods of torsional vibration signal are studied which lay a solid theoretical foundation for the follow-up system development.In the specific development of torsional vibration testing system,this paper firstly selects the relevant hardware according to the functional requirements of the system.It mainly consists of three parts:sensor selection,collection card selection and conditioning circuit design.Then,according to the idea of modular design,this paper design the system software based on the virtual instrument software development tool Lab VIEW.The software includes the system setting,speed observation,data acquisition,data processing,time-frequency domain analysis,harmonic extraction and data preservation seven functional modules.Each function module realizes the corresponding function through independent programming.We have "CHUNHE" test data of torsional vibration,and the actual ship data is brought into the written software and the results obtained are the same.So the correctness of the developed torsional vibration test system is verified.