Development Of Gasoline Data Acquisition And Combusition Analysis System

Analysis based on indicator diagram information is important to investigate in-cylinder working process in engine. The technology of data acquisition and processing, including the technology of sensor, signal acquisition and conversion, computer, is important means and method to acquire the information. At present, the method of cylinder pressure detection is usually used in engine working process. We can use it to draw the indicator diagram with the signals of cylinder pressure , crank angle and top dead center(TDC) acquired by high speed A/D card. Based on the indicator diagram, we can obtain many physical parameters of in-cylinder combustion such as fire initial point, indicator work, the maximal pressure and corresponding crank angle and heat release rate, thus measure the precise function of engine. Foreign specialized combustion analyzers on in-cylinder have advanced and powerful function but expensive, hard to repair. It entails the correlation equipment make fast and wide development.Using current equipment in laboratory, multi-cylinder , engine signal acquisition and combustion analysis system is developed. The system consists of data acquisition system and combustion analysis system. Hardware components include A/D card, spark plug cylinder pressure sensor, charge amplifier, photoelectric encoder, computer, etc. The booming of Windows operation system especially the emerging of visual programming, provides a strong graphic interface and friendly man-machine interactive function. So, Visual C++ and Visual basic are adopted to the develop the data acquisition and combustion analysis system respectively. Based on Software Engineer guidance, the idea of object-oriented programming is used to develop most process. The interface contains many functions such as data acquisition, drawing indicator diagram, calculating heat release rate, rate of pressure rise diagram, cyclical fluctuations, and so on. The interface is designed direct-viewed, easily operated. Independent modules are convenient for extending more functions.The system has made the data acquisition on engine BJ492QA for the first time. Manyprimary functions have been realized such as: drawing the p-V diagram and the p-φdiagram, the influence to mean indicator pressure by TDC position, and finish heat release rate with analysis.