Active Control of Vehicle Transient Powertrain Noise Using a Twin-FXLMS Algorithm

Author(s):  
Jie Duan ◽  
Mingfeng Li ◽  
Teik C. Lim ◽  
Ming-Ran Lee ◽  
Wayne Vanhaaften ◽  
...  

Powertrain noise is a major component of vehicle interior noise and thus has a significant effect on the overall sound quality. It is typically dominated by harmonics in the lower audible frequency range, which are directly related to the engine firing orders. In order to achieve a more comfortable environment and pleasing driving experience, an active noise control (ANC) applying advanced filtered-x least mean squares (FXLMS) algorithm is employed to reduce the vehicle interior noise by targeting these harmonics. The proposed ANC system is designed to control multiple orders of the engine noise response simultaneously. It is also uniquely formulated with a twin-FXLMS algorithm to prevent harmonic interference that often resulted in overshoot at some adjacent orders, especially at low engine speed range where the reference sinusoids are close together. In fact, the interference issue is one of the critical problems that previously plagued the use of the conventional FXLMS algorithm. The basic design of the twin-FXLMS algorithm splits the adaptive filter into two sets. This allows different sum of reference sinusoids to be fed into each adaptive filter in order to widen the frequency separation between two adjacent harmonics. Finally, the performances of proposed twin-FXLMS are validated by numerical simulations.

Author(s):  
Gangping Tan ◽  
Gang Jie ◽  
Ming Cao

An optimization strategy of sound quality was proposed to improve sound quality inside a vehicle. The frequency of vehicle interior noise was divided into sub-bands by equivalent rectangular bandwidth (ERB) in the frequency domain, and the intensity of sub-band noise located in the mid-low frequency can be modified by using the measure of active noise control (ANC) in order to analyze its influence on the sound quality of original noise. Orthogonal experiments of vehicle interior noise were conducted according to experimental design. A model of sound quality objective evaluation (SQOE) was proposed as an experimental index. The role of sub-band on the model of SQOE was analyzed at different speeds so as to achieve the optimum level, optimum combination of sound quality and main factors. The results, obtained by implementing the optimization strategy of sound quality, were verified by means of tests. By validation, it showed that optimum sound quality can be achieved by changing the intensity of sub-band noise.


Author(s):  
In Hyung Yang ◽  
O. Cheol Kwon ◽  
Jung Youn Lee ◽  
Jae-Eung Oh

The reduction of the Vehicle interior noise has been the main interest of NVH engineers. The driver’s perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. In particular, the HVAC sound among the vehicle interior noise has been reflected sensitively in the side of psychology. In previous study, we have developed to verify identification of source for the vehicle HVAC system through multiple-dimensional spectral analysis. Also we carried out objective assessments on the vehicle HVAC noises and subjective assessments have been already performed with 30 subjects. In this study, the linear regression models were obtained for the subjective evaluation and the sound quality metrics. The regression procedure also allows you to produce diagnostic statistics to evaluate the regression estimates including appropriation and accuracy. Appropriation of regression model is necessary to R2 value and F-value. And testing for regression model is necessary to Independence, Homoscedesticity and Normality. To enhance sound quality, we applied active noise control (ANC) which is effective in the low-frequency bandwidth. Primary noise of the HVAC system is less than 500Hz. As a result of ANC application, sound quality is improved by more quiet, powerful, expensive, smooth.


1995 ◽  
Vol 23 (1) ◽  
pp. 2-10 ◽  
Author(s):  
J. K. Thompson

Abstract Vehicle interior noise is the result of numerous sources of excitation. One source involving tire pavement interaction is the tire air cavity resonance and the forcing it provides to the vehicle spindle: This paper applies fundamental principles combined with experimental verification to describe the tire cavity resonance. A closed form solution is developed to predict the resonance frequencies from geometric data. Tire test results are used to examine the accuracy of predictions of undeflected and deflected tire resonances. Errors in predicted and actual frequencies are shown to be less than 2%. The nature of the forcing this resonance as it applies to the vehicle spindle is also examined.


2019 ◽  
Vol 67 (6) ◽  
pp. 405-414 ◽  
Author(s):  
Ningning Liu ◽  
Yuedong Sun ◽  
Yansong Wang ◽  
Hui Guo ◽  
Bin Gao ◽  
...  

Active noise control (ANC) is used to reduce undesirable noise, particularly at low frequencies. There are many algorithms based on the least mean square (LMS) algorithm, such as the filtered-x LMS (FxLMS) algorithm, which have been widely used for ANC systems. However, the LMS algorithm cannot balance convergence speed and steady-state error due to the fixed step size and tap length. Accordingly, in this article, two improved LMS algorithms, namely, the iterative variable step-size LMS (IVS-LMS) and the variable tap-length LMS (VT-LMS), are proposed for active vehicle interior noise control. The interior noises of a sample vehicle are measured and thereby their frequency characteristics. Results show that the sound energy of noise is concentrated within a low-frequency range below 1000 Hz. The classical LMS, IVS-LMS and VT-LMS algorithms are applied to the measured noise signals. Results further suggest that the IVS-LMS and VT-LMS algorithms can better improve algorithmic performance for convergence speed and steady-state error compared with the classical LMS. The proposed algorithms could potentially be incorporated into other LMS-based algorithms (like the FxLMS) used in ANC systems for improving the ride comfort of a vehicle.


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