An Application of LabVIEW in Engine Condition Monitoring
Jui-Hong HORNG and Yung-Tai WANG
This paper presents an application of LabVIEW to develop a virtual instrument system in engine condition monitoring. The analog signals such as lubricate oil temperature, cooling water temperature, discharge air temperature, output torque, rpm, relative air/fuel ratio and air flow, etc. are acquired and converted to digital signals by data acquisition board, respectively. These data can be recorded and stored simultaneously in the LabVIEW environment and displayed on the screen. In this approach, the technique potentially provides a graphical interface with the operator for the real-time monitoring of engine parameters and illustrates the concepts that could form the basis of any future on-line engine health monitoring facility.
Key Words: LabVIEW, Virtual Instrument, Engine Condition Monitoring.
Engines, such as gas turbine engine and diesel engine, are now widely used in different fields of human activity. The monitoring of the engine performance is very important and many benefits can be obtained. These monitoring systems provide certain diagnostic and predictive information about developing fault conditions. By analyzing previous performance data, possible failures can be predicted. Components that are failed in the system can be removed and replaced before they completely fail and cause possible damage to other components. Therefore it is important to minimize the occurrences of extensive maintain outages. To achieve this objective, the condition of equipments must be known and monitored so that potential breakdown can be predicted and avoided before they occur.
Different approaches have been developed for engine condition monitoring. Howlett et al [1, 2] used statistical and neural network methods to monitor gas turbine engine condition. Denny  used neural networks to model critical engine parameters to predict engine malfunction. Brown  used the Rumbaugh Object Management Technique (OMT) to test the quality and performance of lubricating oil of car engine, it was found to be especially suitable for the real time engine health test application. Turley et al  used the graphical program to plan an engine test program. Commercial off the shelf (COTS) had been used to the Air force aircraft engine test system by Johnson [6, 7]. Barbara  used the virtual instruments to test engine systems on the personal computer. These approaches are applied to real engine data to assess their viability informing effective condition monitoring systems.
LabVIEW is a graphical programming language, it was generally used by industrial and academic research to develop the software tool for data acquired and instrument controlled. In references, Grinstead et al  used LabVIEW to acquire and analyze the biomedical signal. Srinivasan et al  also used LabVIEW to acquire the real-time data in the fan-motor system. In , Mike explained how to get the signals from the dynamometer, flow meter, etc, and converted to the actual data in LabVIEW environment. In this paper, we used the PCI-6025E data acquisition (DAQ) card to acquire LPG engine data and convert to digital signals. Then the PC-based system used LabVIEW to display the engine conditions. This implementation provides a clear and easy-to-use method for obtaining, analyzing and displaying the signal desired.
2. LabVIEW ENVIRONMENT
There are many software packages available for the acquisition and display of electrical signals in general. Of these packages, we chose LabVIEW, by National Instruments, as our software development environment, which is one of the most popular and powerful tools available.
Department of Mechanical and Marine Engineering
National Taiwan Ocean University. Keelung, Taiwan 202, R.O.C.