차량 실내공간의 가속 시 엔진음 음질 향상을 위한 실시간 능동음향증강 제어 구현

이영섭(Young-Sup Lee),김제관(Jeakwan Kim),유석훈(Seokhoon Ryu),김성현(Seonghyeon Kim),박동철(Dong Chul Park) 한국소음진동공학회 2016 한국소음진동공학회 논문집 Vol.26 No.2

In this study, a concept of active sound enrichment (ASE) control system was implemented and demonstrated for improving engine sound quality inside the cabin of a passenger car during acceleration. Unlike the active noise control cancels the noise for disturbance rejection, the ASE adds additional sound to the noise for tracking control. This approach requires a new algorithm to provide additional artificial sound to the original engine sound using active control strategy to achieve a target sound profile, which is predefined to satisfy required interior sound quality. The ASE algorithm was implemented in a digital controller dSPACE DS1401 and real-time control experiment was accomplished in an actual car. The ASE control results show that the actively enriched sound of each engine order against RPM tracks the target profiles precisely and quickly and improves the discontinuity, the level ratios and the sound pressure level of each engine order. Thus it is anticipated the ASE system can be applied for the improvement of the engine sound quality inside the cabin during acceleration.

Active Vibration Control of Trim Panel Using a Hybrid Controller to Regulate Sound Transmission

Insoo Kim,Yeung-Shik Kim 한국정밀공학회 2009 International Journal of Precision Engineering and Vol.10 No.1

This paper presents a method for actively controlling the sound transmission through an aircraft trim panel using a hybrid feedforward/feedback control technique. The method involves measuring the frequency transfer function of the trim panel system and then creating an autoregressive moving average model using frequency domain curve fitting. The control technique is designed to minimize the vibration of a panel that has a limited piston-like motion, The hybrid controller consists of an adaptive feedforward controller that operates in conjunction with a linear quadratic Gaussian feedback controller. The feedback controller increases the damping capacity of the secondary plant to augment the convergence rate of the adaptive feedforward controller. Experimental results indicate that the hybrid controller effectively reduces the vibration of active trim panels and therefore also reduces the sound transmission of the panel.

차량 실내 소음 제어를 위한 능동 음향 설계 기술 개발

김성현(Seonghyeon Kim),박동철(Dong Chul Park),유석훈(Seokhoon Ryu),이영섭(Young-Sup Lee) 한국소음진동공학회 2015 한국소음진동공학회 학술대회논문집 Vol.2015 No.10

Recently, an active control approach is widely used in vehicle industry. Particularly, the active sound design and control techniques for control the vehicle interior sound due to powertrain is mostly used. There are several challenges are exist and many know-how are demanded for the application to vehicle successfully. And the performance of control and stability are demanded basically. This paper investigates active sound design system of a road vehicle with audio system. The adaptive filter which can reduce or enhance the virtual engine sound generated by secondary path was developed for the real time control. The developed control algorithm was considered in terms of robust stability and performance. Next, engine sounds were developed by using developed active sound design system. Finally, the developed control system and sounds were verified in real driving test.

다수의 음원을 사용한 공간의 소리 제어 방법론

최정우(Choi, Joung-Woo),김양한(Kim, Yang-Hann),박영진(Park, Young-Jin) 한국소음진동공학회 2005 한국소음진동공학회 논문집 Vol.15 No.12

Spatial control of sound is essential to deliver better sound to the listener's position in space. As it can be experienced in many listening environments. the quality of sound can not be manifested over every Position in a hall. This motivates us to control sound in a region we select. The primary focus of the developed method has to do with the brightness and contrast of acoustic image in space. In particular, the acoustic brightness control seeks a way to increase loudness of sound over a chosen area, and the contrast control aims to enhance loudness difference between two neighboring regions. This enables us to make two different kinds of zone - the zone of quiet and the zone of loud sound - at the same time. The other perspective of this study is on the direction of sound. It is shown that we can control the direction of perceived sound source by focusing acoustic energy in wavenumber domain. To begin with, the proposed approaches are formulated for pure-tone case. Then the control methods are extended to a more general case, where the excitation signal has broadband spectrum. In order to control the broadband signal in time domain, an inverse filter design problem is defined and solved in frequency domain. Numerical and experimental results obtained in various conditions certainly validate that the acoustic brightness, acoustic contrast, direction of wave front can be manipulated for some finite region in space and time.

평판에서 방사되는 소음의 능동구조소음제어를 위한 변환기의 위치결정

김흥섭,홍진석,이충휘,오재응 한국소음진동공학회 2002 한국소음진동공학회 논문집 Vol.12 No.9

In this paper, through the study on locations of structural transducers for active control of the radiated sound from the vibrating plate, the active structural acoustic control (ASAC) system is proposed. And, for the evaluation of the proposed location, the experiment of the active structural acoustic control is implemented using the multi-channel filtered-x LMS algorithm and an additional filter (Acoustic Prediction Filter) to estimate the radiated sound using the acceleration signals of the plate. The structural transducers are piezoceramic actuator (PZT) and accelerometer. PZT is used as an actuator to reduce the vibration and the radiated sound. To maximize the control performance, each PZT actuator is located at the position that has the largest control sensitivity of the plate bending moment in the direction of x and y coordinates and the optimal PZT location is validated experimentally. Also, to find the acoustic prediction filter accurately, two accelerometers are located at the positions that have the largest radiation efficiencies of the plate, and the proposed locations are validated by simulation using the Rayleigh integral. The multi-channel filtered-x LMS algorithm is introduced to control a complex 2-D structural vibration mode. Finding the locations of structural transducers for active structural acoustic control of the radiated sound, the active structural acoustic control (ASAC) system can be presented and validated by experiments using a real time control system.

Filtered Velocity Feedback 제어기를 이용한 양단지지보의 음향파워 저감

신창주(Changjoo Shin),홍진숙(Chinsuk Hong),정의봉(Weuibong Jeong) 한국소음진동공학회 2011 한국소음진동공학회 학술대회논문집 Vol.2011 No.10

This paper reports the filtered velocity feedback (FVF) controller to reduce the acoustic power from clamped beams. The instability problem due to the non-collocated sensor/actuator configuration when using PZT actuator should be resolved. The roll-off property of the FVF controller at high frequency helps to alleviate the instability. The dynamics of clamped beams under forces and moments pair and the FVF controller are first formulated. The formulation of the sound radiated power is followed. The open loop transfer function (OLTF) synthesized with 100 modes is used to determine the stability of the control system. The control performance is finally estimated. The levels of the vibration and the sound radiated power are reduced in the wide band below the tuning mode of the FVF controller.

공간에 소리의 그림을 그리는 방법

김양한(Yang-Hann Kim),최정우(Joung-Woo Choi) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.11

In this paper, we aim to control the sound field spatially, so that a desired or target acoustic variable is enhanced within a zone where the listener is located. This is somewhat analogous to have manipulators that can draw sound picture in any place we want. In order to manipulate sound field over a finite area in space, it is essential to control multiple sound sources. With all these regards, we propose a unified approach that can manipulate selected acoustic variables using multiple sources. However, the shape or color of the sound picture fully depends on the acoustic variable we want to enhance. Among the many possible choices, we focus on three acoustic variables that have to do with the magnitude and direction of sound: acoustic potential energy, sound intensity, and direction of wavefront. Various numerical and experimental results of the proposed methods certainly validate that we can draw our own sound picture in space and time.

차음 패널의 방사 소음 저감을 위한 다중 주파수 가상 임피던스 제어 시스템의 설계

전온유(Onyu Jeon),김현국(Hyun-Guk Kim),왕세명(Semyung Wang) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.8

The virtual mechanical impedance (VMI) control method, which does not require a sensor and can be implemented with a small number of actuators, is an active method that can replace the existing passive methods when mechanical tuning is difficult. However, the existing VMI control method has been studied only for single-tone noise. In this regard, we improved the VMI control system to enable the radiated sound power reduction of the enclosure panel at multiple frequencies. The control results obtained from the finite element-based model and the experimental model show that the radiated sound power of the enclosure panel is reduced at multiple target frequencies after control.

Filtered Velocity Feedback 제어기를 이용한 양단지지보의 음향파워 저감

신창주(Shin, Chang-Joo),홍진숙(Hong, Chin-Suk),정의봉(Jeong, Weui-Bong) 한국소음진동공학회 2011 한국소음진동공학회 논문집 Vol.21 No.12

This paper investigates the filtered velocity feedback(FVF) controller for the reduction of the acoustic power radiated from a clamped beam. The instability problem due to the non-collocated sensor/actuator configuration when using PZT actuator should be sorted out. The roll-off property of the FVF controller at high frequency helps to alleviate the instability. The dynamics of clamped beams under forces and moments pair and the FVF controller are first formulated. The formulation of the sound radiated power is followed. The open loop transfer function(OLTF) synthesized with 100 modes is used to determine the stability of the control system. The control performance is finally estimated. The levels of the vibration and the sound radiated power are reduced in the wide bandbelow the tuning mode of the FVF controller.

능동소음제어 기술을 이용한 층간소음 저감효과 분석

김호진(Hojin Kim),김중관(Joong-Kwan Kim),김준환(Junhwan Kim),김현석(Hyunsuk Kim),위혁(Hyuk Wee) 한국방재안전학회 2023 한국방재안전학회 논문집 Vol.16 No.3

본 연구에서는 능동소음제어(ANC) 기술을 층간소음 분야에 적용하기 위하여 40~500 Hz 대역의 중량충격음을 제어하기 위한 ANC 시스템을 구성하였다. ANC 시스템에는 Fx-LMS 알고리즘 기반의 적응형 필터를 활용한 피드포워드 방식의 제어기술을 도입하였다. ANC 시스템 설정을 위해 가상 시뮬레이션을 통해 ANC를 구성하는 변수 연구를 실시하였고, 이를 통해 최적 필터와 시스템 배치 방법을 정립하였다. 또한 본 연구에는 개발된 ANC 시스템을 한국건설생활시험연구원(KCL)의 층간소음 시험실에 설치한 후 표준시험방법에 따라 ANC 시스템 구동 전후 4 dB의 층간소음 저감효과를 확인하였다. 시험결과를 통해 본 연구에서 개발한 ANC 시스템이 중량충격음에 대한 등급 기준을 한 단계를 상향시킬 수 있는 수준의 효과가 있음을 확인하였다. In this study, the application of ANC (Active Noise Control) technology to address inter-floor noise was explored. To achieve this, an ANC system was developed to manage the heavy impact sound within the frequency range of 40 to 500 Hz. The ANC system utilized an adaptive filter employing a feedforward approach based on the Fx-LMS algorithm. To set up the ANC system, a comprehensive analysis of various variables within the system was performed using computational simulations. This process enabled the identification of optimal filter settings and system configuration arrangements. In addition, the ANC system was implemented in the inter-floor noise test room at the Korea Conformity Laboratories (KCL). Through a certified standard testing procedure, it was confirmed that the ANC system led to a 4 dB reduction in inter-floor noise when the system was activated compared to when it was turned off. The results of this study indicate that the developed ANC system has an effect significant enough to elevate the rating criteria by one level for heavy impact sound.