• Suphattharachai Chomphan
  • Theerathan Kingrattanaset
  • Saereephap Boonsit


Vibration signal, Sound signal, Liquefied petroleum gas, Signal Power, Engine Fault


At the present time, the number of vehicles and the cost of gasoline has been immensely risen, liquefied petroleum (LPG) is a prominent alternative choice of fuel because of its popularity and economical cost. However, the LPG-installation may cause some degradations of the engine efficiency. The important perceptions of the driver are the engine vibration and sound. Therefore, an analysis of vibration signals and sound signals to distinguish between the LPG-modified and the normal oil-usage 2,200-cc engine has been reviewed in the first stage of this paper. The power of the signal is applied for both engines at five different engine speeds. A ten-second sample of the signal has been measured with the sampling rate of 2,048 Hz. The experimental results of the analysis of vibration signals show that the power of signals of the LPG-modified engine is mostly above that of the normal oil-usage engine. As for the analysis of sound signals, the LPG-modified engine has higher power than that of the normal oil-usage engine at low engine speed. Meanwhile, the normal oil-usage engine causes higher power of signals when comparing with the LPG engine at the engine speed over 1,300 rpm. In the second stage, a study of fault simulations has been reviewed. The fault simulations of the butterfly valve and the sparking plug have been studied. The results show that the vibration of the engine is directly proportional to the engine speed. Moreover, the engine faults cause significant engine vibration at the speed above 1,500 rpm for both normal gasoline and LPG modified engines. Last but not least, LPG-installation and engine faults cause degradations in engine efficiency which can be substantially evidenced by using the proposedapproach.





How to Cite

Suphattharachai Chomphan, Theerathan Kingrattanaset, & Saereephap Boonsit. (2019). SIGNAL ANALYSIS FOR LPG-MODIFIED GASOLINE ENGINE WITH ENGINE FAULTS. GEOMATE Journal, 16(56), 65–72. Retrieved from