Impulsive noise significantly impacts signal quality and system performance, necessitating effective methods for its reduction. This paper introduces two adaptive filtering techniques based on the fxlms algorithm, des...
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Impulsive noise significantly impacts signal quality and system performance, necessitating effective methods for its reduction. This paper introduces two adaptive filtering techniques based on the fxlms algorithm, designed to address this challenge. The first method employs dynamic input thresholding, incorporating gradient-based and SNR-driven adjustments to suppress impulsive noise while retaining essential signal components. The second method builds on this by introducing hybrid thresholding applied to both input signals and filter coefficients, supported by double error smoothing to improve stability and adaptability under varying noise conditions. To evaluate the proposed methods, a comparative analysis is conducted with the Variable fxlms Hybrid Thresholding (VFxLHT) technique, considering metrics such as steady-state noise suppression and computational efficiency. The results demonstrate that the proposed methods perform reliably across diverse noise conditions, maintaining signal fidelity while efficiently utilizing computational resources. These methods are intended as practical solutions for applications where impulsive noise control is essential to ensure reliable system operation without excessive computational complexity.
PurposeThis paper aims to address the limitations of the filtered-x least mean square (fxlms) control algorithm in terms of significant noise in filtered results and hindered convergence and steady-state error reducti...
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PurposeThis paper aims to address the limitations of the filtered-x least mean square (fxlms) control algorithm in terms of significant noise in filtered results and hindered convergence and steady-state error reduction due to fixed-step size *** this study, a new adaptive filtering algorithm based on error weight is proposed. Multiple moment weight errors are introduced into the objective function, and the error weights are automatically calculated during the iterative process. The step size is optimized to accelerate convergence speed and curtail steady-state error. The state space equation and transfer function expression of the simply supported plate system are calculated, and a hybrid control algorithm for plate vibration control is *** proposed algorithm is simulated and compared with various existing variable step size algorithms and gradient-based least-squares (GLS) algorithms using Mathematica software. The simulation results demonstrate that the proposed algorithm achieves a convergence rate at least six iteration steps ahead of other algorithms, with a minimum reduction of 0.00405 in the average absolute error. This indicates the superiority of the proposed algorithm in terms of convergence speed and steady-state error *** proposed algorithm demonstrates clear advantages in enhancing the rate of convergence of the fxlms control algorithm and reducing steady-state error. Future research can focus on reducing variable step input parameters and minimizing algorithmic computational complexity.
Implementation of a new Variable Step-Size Filter-x Least Mean Square (VSS-fxlms) algothrim is carried out for a piezoelectric intelligent blade active vibration control system based on ZYNQ7020. Four Macro Fiber Comp...
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ISBN:
(纸本)9798350366907;9789887581581
Implementation of a new Variable Step-Size Filter-x Least Mean Square (VSS-fxlms) algothrim is carried out for a piezoelectric intelligent blade active vibration control system based on ZYNQ7020. Four Macro Fiber Composite (MFC) patches are attached on the piezoelectric blade. Two are acted as piezoelectric actuators, attached at the center and root of the blade. The other two are used as piezoelectric sensors, attached near the piezoelectric actuators. Then, ZYNQ is used as the main controller, and variable step-size strategy is employed to achieve superior convergence performance than fixed step-size. Comparing with fxlms, the proposed VSS-fxlms algorithm has faster convergence rate and smaller steady-state error. Finally, several active vibration control experiments are conducted on the piezoelectric intelligent blade, and the results verify that the proposed algorithm has a better performance of the blade vibration suppression.
This paper presents a novel variant of the fxlms algorithm. This variant optimizes computational efficiency by utilizing a calculated imperfect secondary path model with a pure-delay impulse response, simplifying the ...
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ISBN:
(纸本)9798350325621
This paper presents a novel variant of the fxlms algorithm. This variant optimizes computational efficiency by utilizing a calculated imperfect secondary path model with a pure-delay impulse response, simplifying the filtered reference signal calculation and enhancing the convergence rate. Additionally, the algorithm includes a control parameter to adjust its dynamic response, further improving its convergence behaviour. We provide a theoretical framework based on root locus theory to optimize this parameter and the algorithm's performance. The theoretical contributions are substantiated through computer simulations, validating the enhanced effectiveness of the proposed approach in ANC applications.
Implementation of a new Variable Step-Size Filter-x Least Mean Square(VSS-fxlms) algothrim is carried out for a piezoelectric intelligent blade active vibration control system based on ZYNQ7020. Four Macro Fiber Compo...
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ISBN:
(数字)9789887581581
ISBN:
(纸本)9798350366907
Implementation of a new Variable Step-Size Filter-x Least Mean Square(VSS-fxlms) algothrim is carried out for a piezoelectric intelligent blade active vibration control system based on ZYNQ7020. Four Macro Fiber Composite(MFC) patches are attached on the piezoelectric blade. Two are acted as piezoelectric actuators, attached at the center and root of the blade. The other two are used as piezoelectric sensors, attached near the piezoelectric actuators. Then, ZYNQ is used as the main controller,and variable step-size strategy is employed to achieve superior convergence performance than fixed step-size. Comparing with fxlms, the proposed VSS-fxlms algorithm has faster convergence rate and smaller steady-state error. Finally, several active vibration control experiments are conducted on the piezoelectric intelligent blade, and the results verify that the proposed algorithm has a better performance of the blade vibration suppression.
Dynamics vibration absorbers are an effective solution to the problem of vibration. However, there are relatively few applications in low-frequency torsional vibration control. Therefore, for low-frequency torsional v...
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Dynamics vibration absorbers are an effective solution to the problem of vibration. However, there are relatively few applications in low-frequency torsional vibration control. Therefore, for low-frequency torsional vibration, this paper proposes an electromagnetic torsional active vibration absorber, and establishes an active control system based on the filter-x least mean square (fxlms) algorithm. First of all, the electromagnetic torsion actuator structure is designed with an electromagnetic-permanent magnetic hybrid structure, and the theoretical model of electromagnetic torque is established. Moreover, the influence of structural parameters on the linear stable interval of electromagnetic torque is analyzed, and the effective stroke range of electromagnetic torsion actuator is determined. Then, based on the fxlms algorithm, the control system of the electromagnetic torsion active vibration absorber is established, and the theoretical model of the secondary channel transfer function is obtained. Furthermore, it is verified by simulation analysis, the results show that the electromagnetic torsional active vibration absorber can achieve good low-frequency torsional vibration absorption performance and is significantly better than without control under the excitation of harmonic torque and white noise torque. Finally, an experimental investigation is carried out on the electromagnetic torsion active vibration absorber based on the fxlms algorithm to verify the feasibility and effectiveness of the electromagnetic torsion active vibration absorber.
A piezoelectric feedback system for active noise control (ANC) of vehicle interior noise is built in this paper. Firstly, a mathematical vibration model of a typical vehicle-used plate with piezoelectric patch is deri...
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A piezoelectric feedback system for active noise control (ANC) of vehicle interior noise is built in this paper. Firstly, a mathematical vibration model of a typical vehicle-used plate with piezoelectric patch is derived for revealing piezoelectric mechanism. An improved filtered-x least mean square (fxlms) algorithm based on the discrete wavelet transform (DWT), so-called DWT-fxlms, is presented. Comparisons with the common-used algorithms suggest that, the DWT-fxlms is superior to the time-domain fxlms (TD-fxlms) algorithm in terms of the computational complexity and the convergence speed. The DWT-fxlms can cope with both the stationary and nonstationary noises, but the frequency-domain fxlms (FD-fxlms) algorithm is failed to eliminate the nonstationary noise. Secondly, based on a simplified vehicle cavity model, some numerical simulations are performed for its structural vibration and acoustic characteristics. The top plate with maximum acoustic contribution is selected as a target for active control. The arrangement of piezoelectric sensor and actuator on the top plate is determined following the D-optimization criterion. Finally, the experimental verifications are conducted by using the established piezoelectric feedback system. The results suggest that, after applying ANC, the vibration acceleration of the top plate and the sound pressure level (SPL) at the passenger's ear sides are attenuated to a certain extent. The proposed method based on the piezoelectric feedback DWT-fxlms algorithm is effective and feasible for active control of vehicle interior noise, and can be regarded as a promising technique for developing the active noise and/or vibration control systems of other products with enclosed spaces in engineering. (C) 2020 Elsevier Ltd. All rights reserved.
fxlms (Filtered-x Least Mean Square) algorithm and PID (Proportional Integral Derivative) controller have been widely used for AVC (Active Vibration Control). Yet, the convergence rate and vibration suppression perfor...
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fxlms (Filtered-x Least Mean Square) algorithm and PID (Proportional Integral Derivative) controller have been widely used for AVC (Active Vibration Control). Yet, the convergence rate and vibration suppression performance are restricted by each other for both the classical fxlms algorithm and the traditional PID controller. A hybrid PID-fxlms algorithm which combines the feedback fxlms algorithm and PID controller is proposed, and applied to improve the vibration control efficiency of piezoelectric cantilever beam. In order to conveniently install the piezoelectric stack on the beam structures, a new piezoelectric stack actuator is designed and installed at the root of cantilever beam. Meanwhile, a coupled finite element model of the piezoelectric stack actuator and cantilever beam is established in ABAQUS, and the state-space model of the coupled system is obtained. Subsequently, based on the obtained state-space model, an AVC simulation and experimental system is built to verify the effectiveness of the proposed algorithm. Numerical and experimental results show that convergence rate and vibration suppression performance of the hybrid PID-fxlms algorithm are much better than that of the classical fxlms algorithm or traditional PID controller alone, while the hybrid controller also has strong adaptability and anti-noise ability.
In order to reduce the induction noise of automobile engine, an active control system model of engine induction noise is established with the fxlms algorithm, the off-line identification method is used to identify the...
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In order to reduce the induction noise of automobile engine, an active control system model of engine induction noise is established with the fxlms algorithm, the off-line identification method is used to identify the secondary channel, and the engine speed signal is used to construct the sound source reference signal to avoid the interference from secondary sources to the reference signal. The influence of filter length and convergence factor on the convergence speed and stability of the system is studied by simulation, the average power of the noise signal and the error signal is calculated, the noise variation at different engine speeds is analyzed, and the noise reduction effect and system stability are evaluated. The results show that when the filter order L is 20 and the convergence factor is 0.01, the engine induction noise can be effectively reduced, the noise reduction can reach 15dB, and the system stability can be improved at the same time. This paper optimizes the convergence factor and the filter order in the fxlms algorithm, and can effectively control the induction noise in the car and improve the indoor sound quality of the car. It has important reference significance for practical engineering applications.
fxlms(Filtered-x Least Mean Square) algorithm and PID(Proportional Integral Derivative) controller have been widely used for active vibration control(AVC). Yet, the convergence rate and vibration suppression performan...
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fxlms(Filtered-x Least Mean Square) algorithm and PID(Proportional Integral Derivative) controller have been widely used for active vibration control(AVC). Yet, the convergence rate and vibration suppression performance are restricted by each other for both the classical fxlms controller and the traditional PID controller. A hybrid feedforward PID-fxlms algorithm which combines the feedforward fxlms algorithm and PID controller is proposed, and applied to improve the vibration control efficiency of piezoelectric cantilever beam. Subsequently,AVC experiments under harmonic excitation with variable amplitude and phase are carried *** and experimental results show that the convergence rate and vibration suppression performance of the hybrid PID-fxlms algorithm are much better than that of the fxlms algorithm or PID controller alone, and the hybrid PID-fxlms controller also has strong adaptability.
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