Active Structural Acoustic Control of an Enclosure with Multi-Flexible Plates Using Different Point Force Actuators

2014 ◽  
Vol 574 ◽  
pp. 546-550
Author(s):  
Da Lin Chen ◽  
Nan Chen
Keyword(s):  
Cooperative Control ◽  
Sound Pressure ◽  
Control Method ◽  
Sound Field ◽  
Control Effect ◽  
Acoustic Control ◽  
Flexible Plates ◽  
Point Forces ◽  
Radiated Sound ◽  
Distributed Cooperative Control

This paper analytically demonstrates the use of some point forces actuators applied on different flexible plates to reduce the radiated sound in the cavity. A rectangular enclosure involving two opposite flexible plates is considered. We want to get the dominant factors that impact the coupling effects and the noise reduction in the cavity with the ASAC method, so we make some point forces located on different plates and to compare their different control effect. The formula was derivate to calculate the sound pressure in the enclosure when there some point forces applied on the flexible plates, and then analyzed and get the simulation of the sound pressure level (SPL) response in the local cavity sound field. The paper indicated that applying distributed cooperative control method can get the better reduction of noise.

Active Control of Structural Sound Radiation in an Acoustic Enclosure Using Distributed Point Force Actuators

2014 ◽  
Vol 1082 ◽  
pp. 517-520
Author(s):  
Da Lin Chen ◽  
Nan Chen
Keyword(s):  
Active Control ◽  
Sound Pressure Level ◽  
Cooperative Control ◽  
Sound Pressure ◽  
Control Method ◽  
Sound Radiation ◽  
Sound Field ◽  
Pressure Level ◽  
Point Force ◽  
Flexible Plates

This paper demonstrates an investigation about the active control of sound radiation in the enclosure cavity consists of two flexible plates. One of the flexible plates is driven by a point force to generate the primary sound field in the cavity, and using some point forces which are located at different locations on the receiving plate to suppressing the panel vibration and then to minimum the cavity sound pressure level (SPL); meanwhile some actuators are located on the other panel surfaces to reduce the sound pressure level at some frequencies that can’t be well reduced by only effect on one panel. The better result shows the possibility of applying distributed cooperative control method to the structural-acoustic coupled system.

Coupling Acoustic Analysis of Enclosure Consisting of Multi-Flexible Plates and its Active Structural Acoustic Control

2011 ◽  
Vol 50-51 ◽  
pp. 343-347
Author(s):  
Lin Ning Gu ◽  
Nan Chen
Keyword(s):  
Potential Energy ◽  
Cooperative Control ◽  
Acoustic Analysis ◽  
Control Method ◽  
Coupled System ◽  
Simply Supported ◽  
Acoustic Control ◽  
Flexible Plates ◽  
Control Forces ◽  
Distributed Cooperative Control

This paper develops a model of structural-acoustic coupled system of a rectangular enclosure involving two simply supported flexible plates. The acoustical potential energy and the optimal secondary control forces are derived theoretically. An example is presented to analyze the characteristics of the coupled system, the dominant factors that impact the coupling effects and the noise reduction with ASAC method. The paper shows the possibility of applying distributed cooperative control method to the structural-acoustic coupled system.

Using Multi-Agent System to Control the Radiation Noise in an Enclosure

2015 ◽  
Vol 724 ◽  
pp. 261-264 ◽  
Author(s):  
Da Lin Chen ◽  
Nan Chen
Keyword(s):  
Sound Pressure ◽  
Control Method ◽  
Fault Tolerant ◽  
Active Noise Control ◽  
Multi Agent System ◽  
Agent System ◽  
Flexible Plates ◽  
Point Forces ◽  
Radiation Noise ◽  
Multi Agent

Multi-Agent system (MAS) is used to control the radiation noise in a rectangular enclosure, which is surrounded by two flexible plates and four rigid plates. The noise is generateded by the vibration of the exciting flexible plane. A MAS is established to coordinate the active noise control method, and these agents are controlled by a coordination object which includes compete and cooperative rules. These agents are competitiveness, so the MAS can provide fault-tolerant capabilities for the control mechanism. Meanwhile, these agents are independent and modular, and can be used in “Plug-and-Play” control field. The formula is derivate to calculate the sound pressure in the enclosure when there some point forces applied on the flexible plates, and the simulation shows using MAS to control the noise in the cavity is effective.

Active control of the scattered radiation with a reflecting surface

2019 ◽  
Vol 67 (3) ◽  
pp. 190-196
Author(s):  
Ning Han
Keyword(s):  
Control System ◽  
Active Control ◽  
Scattered Radiation ◽  
Sound Pressure ◽  
Sound Field ◽  
Control Area ◽  
Mirror Image ◽  
Three Dimension ◽  
Control Effect ◽  
Reflecting Surface

Based on a prediction method of the scattered sound pressure, an active control system was proposed in previous work for the three-dimension scattered radiation, where all the relevant simulations and experiments were implemented in three-dimensional free sound field. However, for practical applications, such as the anti-eavesdropping system or the stealth system for submarines, the sound field conditions are usually complex, and the most common case is the one with reflecting surface. It is questionable whether the previous control system is still effective in non-free sound field, or what improvements should be operated to ensure the control effect. In this article, based on the mirror image principle, two methods of calculating the control source strengths are proposed for the scattered radiation control, and numerical simulations with one-channel and multi-channel system are implemented to detect the corresponding control effect. It is seen that the local active control for the scattered radiation is still effective, and the reduction of the sound pressure level as well as the control area is extended with the increasement of the error sensors and control sources.

scholarly journals Integrated Guidance and Control of Multiple Interceptors with Impact Angle Constraints Considered

2019 ◽  
Vol 37 (2) ◽  
pp. 273-282
Author(s):  
Xiang Liu ◽  
Xiaogeng Liang
Keyword(s):  
Cooperative Control ◽  
Control Algorithm ◽  
Control Method ◽  
Impact Angle ◽  
Dynamic Surface ◽  
Guidance And Control ◽  
Integrated Guidance And Control ◽  
And Control ◽  
Impact Angle Constraint ◽  
Distributed Cooperative Control

To solve the multi-interceptor coordination problem and to intercept the target with impact angle constraint, a novel distributed cooperative control algorithm with impact angle constraint based on integrated guidance and control is proposed. First, the mathematic model of integrated guidance and control is established by combining the interceptor-target relative motion model with the dynamic equation of the interceptor on pitch plane. The time varying gain extended state observer is developed to estimate and compensate the unknown disturbance. Based on the estimated value and fast nonsingular dynamic surface sliding control method, the IGC algorithm of leader is given; Then, based on distributed cooperative "leader-follower" model, the cooperative control strategy of multi-interceptor is designed, and gives out speeds in two directions on pitch plane, which are transformed to the command of total velocity and trajectory angle based on kinematic relations. Finally, to control the follower, the time varying gain extended state observer and the dynamic surface sliding control method are adopted. The simulation results demonstrate the effectiveness of the distributed cooperative control algorithm.

scholarly journals The Influence of PZT Actuators Positioning in Active Structural Acoustic Control

10.14311/968 ◽  
2007 ◽  
Vol 47 (4-5) ◽  
Author(s):  
P. Švec ◽  
V. Jandák
Keyword(s):  
Sound Field ◽  
Structural Vibration ◽  
Structural Acoustics ◽  
The Finite Element Method ◽  
Ansys Software ◽  
Structural Vibrations ◽  
Radiated Power ◽  
Acoustic Control ◽  
Radiated Sound ◽  
The Mathematical Model

This paper deals with the effect of secondary actuator positioning in an active structural acoustics control (ASAC) experiment. The ASAC approach is based on minimizing the sound radiation from structures to the far field by controlling the structural vibrations. In this article a rectangular steel plate structure was assumed with one secondary actuator attached to it. As a secondary actuator, a specially designed piezoelectric stripe actuator was used. We studied the effect of the position of the actuator on the pattern and on the radiated sound field of the structural vibration, with and without active control. The total radiated power was also measured. The experimental data was confronted with the results obtained by a numerical solution of the mathematical model used. For the solution, the finite element method in the ANSYS software package was used. 

scholarly journals Evaluation and Improvement of the Sound Quality of a Diesel Engine Based on Tests and Simulations

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 777 ◽  
Author(s):  
Zhengwei Yang ◽  
Huihua Feng ◽  
Bingjie Ma ◽  
Ammar Abdualrahim Alnor Khalifa
Keyword(s):  
Diesel Engine ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Subjective Evaluation ◽  
Sound Field ◽  
Sound Quality ◽  
Pressure Level ◽  
Sound Power ◽  
Improvement Strategy ◽  
Radiated Sound

Traditional acoustic evaluation of a diesel engine generally uses the A-weighted sound pressure level (AWSPL) and radiated sound power to assess the noise of an engine prototype present in an experiment. However, this cannot accurately and comprehensively reflect the auditory senses of human subjects during the simulation stage. To overcome such shortage, the Moore–Glasberg loudness and sharpness approach is applied to evaluate and improve the sound quality (SQ) of a 16 V-type marine diesel engine, and synthesizing noise audio files. Through finite element (FE) simulations, the modes of the engine’s block and the average vibrational velocity of the entire engine surface were calculated and compared with the test results. By further applying an automatically matched layer (AML) approach, the engine-radiated sound pressure level (SPL) and sound power contributions of all engine parts were obtained. By analyzing the Moore–Glasberg loudness and sharpness characteristics of three critical sound field points, an improvement strategy of the oil sump was then proposed. After improvement, both the loudness and sharpness decreased significantly. To verify the objective SQ evaluation results, ten noise audio clips of the diesel engine were then synthesized and tested. The subjective evaluation results were in accordance with the simulated analysis. Therefore, the proposed approach to analyze and improve the SQ of a diesel engine is reliable and effective.

A compact active structural acoustic control method for minimizing radiated sound power

2021 ◽  
Vol 263 (3) ◽  
pp. 3396-3406
Author(s):  
Scott Sommerfeldt
Keyword(s):  
Control Method ◽  
Acoustic Radiation ◽  
Structural Vibration ◽  
Sound Power ◽  
Flat Plates ◽  
Spatial Gradients ◽  
Acoustic Control ◽  
Radiated Sound ◽  
Radiated Sound Power ◽  
Structural Acoustic Control

Active structural acoustic control is an active control method that controls a vibrating structure in a manner that reduces the sound power radiated from the structure. Such methods focus on attenuating some metric that results in attenuated sound power, while not necessarily minimizing the structural vibration. The work reported here outlines the weighted sum of spatial gradients (WSSG) control metric as a method to attenuate structural radiation. The WSSG method utilizes a compact error sensor that is able to measure the acceleration and the acceleration gradients at the sensor location. These vibration signals are combined into the WSSG metric in a manner that is closely related to the radiated sound power, such that minimizing the WSSG also results in a minimization of the sound power. The connection between WSSG and acoustic radiation modes will be highlighted. Computational and experimental results for both flat plates and cylindrical shells will be presented, indicating that the WSSG method can achieve near optimal attenuation of the radiated sound power with a minimum number of sensors.

Near-Field Acoustic Holography of Cyclostationary Sound Field

2013 ◽  
Vol 631-632 ◽  
pp. 1318-1323
Author(s):  
Min Peng
Keyword(s):  
Time Series ◽  
Sound Pressure ◽  
Near Field ◽  
Sound Field ◽  
Rotating Machinery ◽  
Stationary Field ◽  
Acoustic Holography ◽  
Complex Sound ◽  
Radiated Sound ◽  
Slice Method

The radiated sound field of rotating machinery or reciprocating machinery has a significant periodically time-variant nature. This is a kind of non-stationary sound field and called cyclostationary sound field. In the conventional planar near-field acoustic holography(PNAH), this kind of sound field is treated as stationary field, so the information relating to the change of frequency with time will be loss inevitably. In this article, the cyclic spectral density(CSD) instead of the complex sound pressure was adopted as reconstructing physical quantity in the PNAH, and the cyclostationary PNAH(CPNAH) technique was proposed. Meanwhile, focusing on the calculation complex of CSD and the accuracy of the cyclic nature extracted, the gathering slice method of CSD was proposed by referring time aliasing methods on time series. The experiment results illustrate that the cyclic nature of cyclostationary sound field may be extracted directly and the location of the source determined exactly as well.

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