scholarly journals A New Method for Active Cancellation of Engine Order Noise in a Passenger Car

2018 ◽  
Vol 8 (8) ◽  
pp. 1394 ◽  
Author(s):  
Sang-Kwon Lee ◽  
Seungmin Lee ◽  
Jiseon Back ◽  
Taejin Shin
Keyword(s):  
Active Control ◽  
Adaptive Filter ◽  
Weight Vector ◽  
Noise Signal ◽  
Interior Noise ◽  
Frequency Variation ◽  
Engine Noise ◽  
Optimal Weight ◽  
Engine Order ◽  
Optimal Weight Vector

This paper presents a novel active noise cancellation (ANC) method to reduce the engine noise inside the cabin of a car. During the last three decades, many methods have been developed for the active control of a quasi-stationary narrowband sinusoidal signal. However, since the interior noise signal is non-stationary with a fast frequency variation when the car accelerates rapidly, these methods cannot stably reduce the interior noise. The proposed method can reduce the interior noise stably even if the speed of the car is changed quickly. The method uses an adaptive filter with an optimal weight vector for the active control of such an engine noise. The method of determining the optimal weight vector of an adaptive filter is demonstrated. In order to validate the advantages of the proposed method, a conventional method and the proposed method are simulated with three synthesized signals. Finally, the proposed method is applied to the cancellation of booming noise in a sport utility vehicle. We demonstrate that the performance of the ANC system with the proposed algorithm is excellent for the attenuation of engine noise inside the cabin of a car.

scholarly journals IMAGE RESTORATION METHOD, INVARIANT TO SIGNAL CORRELATION IN THE INFORMATION SYSTEM WITH ADAPTIVE ANTENNA ARRAY

2020 ◽  
pp. 64-76
Author(s):  
V.V. Skachkov ◽  
Keyword(s):  
Information System ◽  
Image Restoration ◽  
Antenna Array ◽  
Correlation Matrix ◽  
Signal To Noise Ratio ◽  
Weight Vector ◽  
Adaptive Antenna ◽  
Adaptive Antenna Array ◽  
Optimal Weight ◽  
Optimal Weight Vector

The problem of image signal processing in the information system with adaptive antenna array based on the inversion of sample estimates of correlation matrix of observations is considered. The example of the maximum signal-to-noise ratio criterion shows the problem, inherent in classical methods of finding the optimal weight vector under a priori uncertainty conditions when detecting correlated image signals. It has been concluded that the dependence of these methods on the inverse of estimation of the correlation matrix of observations leads to the impossibility of separating correlated image signals. As a consequence, the use of classical methods of finding the optimal weight vector in the information system with adaptive antenna array is effective only in the case of image restoration from a single signal source, with the signal received on the set of independent jamming background. A novel method, invariant to the correlation of image signals, has been developed for finding the optimal weight vector without the usage of correlation matrix of observations. An image restoration algorithm invariant to correlation of image signals in the information system with adaptive antenna array is proposed. Statistical models have been constructed for the classical method based on the criterion of maximum signal-to-noise ratio and invariant to correlation method of image restoration in following cases: a single source against the jamming background of two independent sources; two independent sources against the jamming background. Simulation results in the information system with adaptive antenna array are presented, showing to visually assess efficiency of proposed methods of image signal restoration using optimal weight vector. Detailed analysis of the results obtained is carried out.

scholarly journals Mitigation of narrowband stationary interference in the telemetry complex based on an autocompensator with remote channels.

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
V.Yu. Semenov ◽  
◽  
A.V. Korotyshev ◽  
◽  
Keyword(s):  
Numerical Simulation ◽  
Computational Complexity ◽  
Analytical Solution ◽  
High Power ◽  
Correlation Matrix ◽  
Weight Vector ◽  
Optimal Weight ◽  
Direct Inversion ◽  
Optimal Weight Vector ◽  
Standard Arrangement

The problem of combating stationary interference in the areas of operation of ground-based telemetry systems is considered. One of the most annoying types of interference is high-power narrowband TV interference. They are emitted from television towers and their position is known in advance. A solution to this problem is proposed by using a multichannel auto-compensator with a non-standard arrangement of compensation channels. An analytical solution is obtained for the optimal weight vector of the auto-compensator of interference, based on the method of power vectors. This method does not require direct inversion of the interference correlation matrix. The computational complexity of the proposed method is estimated and it is shown that it has a much lower computational complexity compared to the method of direct inversion of the interference correlation matrix. The results of numerical simulation of the interference suppression coefficient are presented. Its effectiveness has been shown.

A Method of Multi-Classifier Combination Based on Dempster-Shafer Evidence Theory and the Application in the Fault Diagnosis

2012 ◽  
Vol 490-495 ◽  
pp. 1402-1406
Author(s):  
Feng Lv ◽  
Ni Du ◽  
Hai Lian Du
Keyword(s):  
Objective Function ◽  
Evidence Theory ◽  
Weight Vector ◽  
Training Sample ◽  
Data Set ◽  
Output Vector ◽  
Optimal Weight ◽  
Classifier System ◽  
Training Samples ◽  
Optimal Weight Vector

A problem is aroused in multi-classifier system that normally each of the classifiers is considered equally important in evidences’ combination, which gone against with the knowledge that different classifier has various performance due to diversity of classifiers. Therefore, how to determine the weights of individual classifier in order to get more accurate results becomes a question need to be solved. An optimal weight learning method is presented in this paper. First, the training samples are respectively input into the multi-classifier system based on Dempster-Shafer theory in order to obtain the output vector. Then the error is calculated by means of figuring up the distance between the output vector and class vector of corresponding training sample, and the objective function is defined as mean-square error of all the training samples. The optimal weight vector is obtained by means of minimizing the objective function. Finally, new samples are classified according to the optimal weight vector. The effectiveness of this method is illustrated by the UCI standard data set and electric actuator fault diagnostic experiment.

A complementary webometric ranking system based on the website quality and traffic measures: A study focusing on top-ranked world universities

2021 ◽  
pp. 1-18
Author(s):  
Sajjad Farashi ◽  
Saeed Bashirian
Keyword(s):  
Weight Vector ◽  
Quality Factors ◽  
Ranking System ◽  
Web Based ◽  
Website Quality ◽  
Scientific Advancement ◽  
Standard Models ◽  
Algorithm Framework ◽  
Scientific Results ◽  
Optimal Weight Vector

Ranking of universities regarding their web-based activities plays a pivotal role in promoting scientific advancement since it motivates the open access accessibility to scientific results. In this study, a new ranking system based on the website quality factors and traffic evaluation was proposed. Since top-ranked universities are usually considered as the standard models for lower ranked ones, the focus of this study was on top-ranked universities. The proposed ranking was compared with well-known Webometrics ranking system. The website traffic and quality assessment were acquired for websites of top-ranked world universities and the correlation between these indices and the Webometrics ranking was evaluated. The summation of the weighted value of obtained measures according to an optimal weight vector obtained by a genetic algorithm framework was used for ranking purposes. The results showed that the website total traffic size was correlated with Webometrics rank (R≈-0.6, p< 0.01). Also, using the weighted value of website quality and traffic measures, the proposed ranking system could predict Webometrics ranking by the accuracy of up to 69%. Even though the method was proposed for universities, it could be applied for ranking other types of centers or companies, provided that the suitable cost function for the genetics algorithm framework was defined.

Mechanism of interior noise generation in high-speed vehicle based on anti-noise operational transfer path analysis

2020 ◽  
Vol 235 (1) ◽  
pp. 273-287
Author(s):  
Ningning Liu ◽  
Yuedong Sun ◽  
Yansong Wang ◽  
Pei Sun ◽  
Wenwu Li ◽  
...  
Keyword(s):  
Path Analysis ◽  
High Speed ◽  
Noise Signal ◽  
Interior Noise ◽  
Analysis Model ◽  
Noise Sources ◽  
Wind Noise ◽  
Transfer Path ◽  
Transfer Path Analysis ◽  
Path Analysis Model

Owing to the continuous development of the automobile industry, increasingly stringent performance requirements for noise, vibration, and harshness of automobiles are being presented. Interior noise control in high-speed vehicles has not been adequately addressed, owing to the complex mechanism of noise generation. As simulations performed previously focused on vehicle wind noise and tyre noise cannot adequately predict the effect on passenger ear-side noise, these issues are investigated in this study. Their effects on passengers are investigated using transfer path analysis. An anti-noise operational transfer path analysis is proposed to study noise generated in high-speed vehicles. The established anti-noise operational transfer path analysis model can eliminate crosstalks between noise source signals of different transmission paths. The model is validated by comparing the measured and calculated values of the anti-noise operational transfer path analysis model. The coherence of the input noise signal and the ear-side noise signal of the passenger is assessed using coherence analysis. By calculating and categorising the contributions of different noise sources in different locations and types, the main noise sources affecting passenger comfort are determined. The result indicates that the main noise sources affecting the passenger’s ear-side noise change from engine noise to left-A wind noise and tyre radiation noise with increasing vehicle speed, in which the proportion also increase. The proposed anti-noise operational transfer path analysis is suitable for the interior-noise analysis of high-speed vehicles, and this study may serve as a reference for future studies regarding active and passive noise control in high-speed vehicles.

Active control of interior noise using piezoceramic actuators.

1991 ◽  
Vol 90 (4) ◽  
pp. 2269-2269
Author(s):  
R. J. Silcox ◽  
S. Lefebvre ◽  
T. B. Beyer ◽  
V. L. Metcalf
Keyword(s):  
Active Control ◽  
Interior Noise
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