The purpose of the System for Automatic Noise Source Identification and Classification (SANSIC) is automatic identification of the dominant noise source direction and its classification. These two processes are carried out autonomously, without the support of human intervention. The biggest advantage of the SANSIC is its algorithm for achieving sufficient Signal to Noise (SN) ratio of the input signal into the automatic noise source classification subsystem. It is known, that implementation of sensor array and calculation of reconstructed signal for desired noise source direction significantly improves the SN ratio. Such approach is already implemented for the signal to noise improvement in the speech recognition algorithms used within the conference rooms. This invention introduces an adaptation and upgrade of such approach. Invention enables the identification and classification of noise sources during the environmental noise measurements, industrial noise measurements, traffic noise and other specific noise measurements. This invention relates to an apparatus for automatic sound source identification and classification, system and method for identifying, recognizing and classifying of sound sources.
F.33 Slovenian patent
COBISS.SI-ID: 13844507Adaptive muffler upgrades the conventional muffler with a variable geometry to extend its working range. Adaptive muffler systems, described in the available literature, operate on the principle of controlling only single property of th e muffler to tune its working range. During the adaptation process of these systems the basic principle of operation is not changed. Based on the literature review, the question arises whether it would be possible to control the principle of operation. At one instant it would work as a Helmholtz resonator, in the other as an expansion chamber or side branch resonator. Analytical calculations provided a positive answer and a muffler with four active valves was designed and constructed to confirm the theoreti cal expectations. Properties of proposed muffler were simulated with Finite Element Method. Results of simulations were validated with measurements. Finally, simulations of proposed muffler, working at different operating conditions , were performed. Simula tio ns have shown that the proposed system allows tuning of the muffler to a wide working frequency range. Such approach to muffler design eliminates the need for additional mufflers used in IC exhaust systems . Therefore a smaller volume of the proposed muffler enables the same effect as multiple non - adaptive conventional mufflers.
F.07 Improvements to an existing product
COBISS.SI-ID: 14180635A necessity for suitable recognition of different machinery and equipment based on sound they generate is constantly present and will increase in the future . The main motivation of discrimination between different types of machinery sounds is to develop algorithms which can be used not only for end quality inspection, but for whole production line monitoring. Objective of our study is to recognize operation of individual machine in a production hall, where background noise level is high and is constantly changing. An exp erimental plan was designed and performed in order to confirm the hypothesis proposing that Automatic Speech Recognition algorithms can be applied for Automatic Machine Recognition. Design of the automatic machine recognition procedure used in our study wa s divided into three stages; Feature extraction, Training and Recognition (Classification). Additionally, a traditional MFCC (Mel - Frequency Cepstral Coefficient ) procedure was adjusted for machinery noise by using different filter compositions. Finally, tw o classifiers were compared, the k - NN classifier and the multivariate Gaussian distribution. Results of experiment show that machinery noise features (F requency C epstral C oefficient s) should be extracted by using linear filter compositions and processed wi th recognition algorithm based on the multivariate Gaussian distribution.
F.15 Development of a new information system/databases
COBISS.SI-ID: 14265627Purpose – The purpose of this paper is the investigation of eddy currents induced in the axial‐flux permanent‐magnet machine housing by the leakage flux and the introduction of permanent magnets in the steady‐state AC finite element analysis and coupling their effects with the transient thermal analysis. Design/methodology/approach – The proposed approach is based on the finite‐element method as well as on using the basic analytical equations. The approach was first applied in the magneto transient analyses. Because of the different physical transient‐time constants, the steady‐state AC analysis coupled with transient thermal should be used. Findings – The permanent magnets in the steady‐state AC analysis coupled with the transient thermal analysis can be simulated by coils with an imposed current of a frequency depending on the number of pole pairs and rotation speed. Using any of the electrically conductive materials for the axial‐flux inner slotless stator permanent‐magnet machine housing should be avoided. Originality/value – The leakage flux induced by permanent magnets and spreading into the axial‐flux permanent‐machine housing is first defined by using the magneto‐transient finite‐element analysis and further used in the steadystate AC analysis coupled with the transient thermal analyses, all in 3D. Based on the results of these analyses, the temperature distribution in entire machine is calculated and compared with the measurement results.
F.09 Development of a new technological process or technology
COBISS.SI-ID: 10358356Thesis presents active control of reactive mufflers, or so called adaptive muffler, using flow controlled valves. The proposed adaptive muffler is able to adapt to changes in IC engine operating conditions, HVAC operating conditions or chimney systems. It consists of a Helmholtz resonator, expansion chamber and quarter wavelength resonator. Different combinations of the control valves' states at different operating conditions define the main working principle and characteristics of the muffler and consequently its properties as such. To control the valve's position, an active noise control approach was used. Adaptive muffler upgrades the conventional muffler with a variable geometry to extend its working range. Such approach to muffler design eliminates the need for additional mufflers used in IC exhaust systems. Therefore a smaller volume of the proposed muffler enables the same or even better effects as multiple non-adaptive conventional mufflers.
D.09 Tutoring for postgraduate students
COBISS.SI-ID: 14240283