20.500.12556/RUL-106226 Methodology for processing pressure traces used as inputs for combustion analyses in diesel engines This study proposes a novel methodology for designing an optimum equiripple finite impulse response (FIR) filter for processing in-cylinder pressure traces of a diesel internal combustion engine, which serve as inputs for high-precision combustion analyses. The proposed automated workflow is based on an innovative approach of determining the transition band frequencies and optimum filter order. The methodology is based on discrete Fourier transform analysis, which is the first step to estimate the location of the pass-band and stop-band frequencies. The second step uses short-time Fourier transform analysis to refine the estimated aforementioned frequencies. These pass-band and stop-band frequencies are further used to determine the most appropriate FIR filter order. The most widely used existing methods for estimating the FIR filter order are not effective in suppressing the oscillations in the rate-of-heat-release (ROHR) trace, thus hindering the accuracy of combustion analyses. To address this problem, an innovative method for determining the order of an FIR filter is proposed in this study. This method is based on the minimization of the integral of normalized signal-to-noise differences between the stop-band frequency and the Nyquist frequency. Developed filters were validated using spectral analysis and calculation of the ROHR. The validation results showed that the filters designed using the proposed innovative method were superior compared with those using the existing methods for all analyzed cases. diesel engines FIR filters harmonics spectral analyses dizelski motorji FIR filtri harmoniki spektralna analiza true false true Angleški jezik Slovenski jezik Članek v reviji 2019-02-13 10:12:39 2019-02-13 10:12:42 2025-02-25 09:13:56 0000-00-00 00:00:00 2017 0 0 Str. 1-22 iss. 5 Vol. 28 Apr. 2017 0000-00-00 PostprintKoncna Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 2018-04-06 621.43(045) 0957-0233 10.1088/1361-6501/aa5f9e 15304475 6000901 RAZ_Rasic_Davor_i2017.pdf RAZ_Rasic_Davor_i2017.pdf 1 34BD2CCF22BA3B2DA4ED9862D462D060 f349a98a2242f36b704fea29c09da29bc1683b304698e4d0fa1d529906aee003 4e3de805-a1b6-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=116980 http://iopscience.iop.org/article/10.1088/1361-6501/aa5f9e 1 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=116979 Fakulteta za strojništvo 0 0 0