It is an important way to research the IC engine combustion process by calculating the heat release rate from the cylinder pressure. Basing on the NI PXI-8196 embedded platform system, the PXI-6229 multi-function data acquisition card is put into use to realize cylinder pressure curve point sampling, and then, the combustion process heat release rate is calculated from the cylinder pressure curve data. To solve the problem of determination of the combustion starting point considering the oscillating of the heat release rate curve, a new simple and convenient method is introduced for the combustion starting determination which can make us research the combustion process more directly and exactly. Through the combustion heat release rate calculation, many more useful parameter values can be got, and the combustion starting point's determination criteria brought forward in this paper is also proofed to be very effective. The combustion heat release rate calculation method and combustion starting point criteria that is presented in this paper can be used effectively and directly, which can make a good foundation for further improvement design and research upon engine combustion system.
