The Design Of A Vibration Testing System For Diesel Engine Based On LabVIEW

Diesel engine vibration signal is the information carrier of fault symptom, and also reflects the working condition of the engine. The acquisition and analysis of the vibration signal is the first step to notice the unusual working condition and fault diagnosis, and also provides valuable information for the design and the optimization of the engine structure.The purpose of the task is to design a vibration signal acquisition and signal analysis testing system based on the vibration signal acquisition and processing technology, the virtual instrument technology and computer technology. The testing system is programmed by Lab VIEW which can be operated in the windows operating system. Real-time data acquisition and analysis can be achieved to monitor the engine's working conditions and to store the useful information needed. The system can also be used to process the stored data including time-domain analysis and frequency domain analysis.In the paper the basic knowledge of the virtual instrument and vibration signal acquisition and processing technology is introduced. And it focuses on introducing the design of the hardware and software of the system. The hardware of the system includes a portable computer, some acceleration sensors, and the DAQCard6042 card of the NI Company and so on. The modularization idea is exhibited evidently from the system design. Each Module is design individually. And all the Modules are connected by the main function. The system is applicable to different kinds of bad conditions. Especially with the preprocessing and spectrum zoom modules, the accuracy of data processing and the resolution of spectrum analysis could be improved significantly.The system is improved its feasibility and efficiency through a vibration test of a MAN B&W's 6S70MC-C marine diesel engine.