Adaptive Least-Mean Square Feed-Forward Control With Actuator Saturation by Direct Minimization

2005 ◽  
Author(s):  
Lei Zuo ◽  
Samir A. Nayfeh
Keyword(s):  
Vibration Isolation ◽  
Actuator Saturation ◽  
Ground Vibration ◽  
Lms Algorithm ◽  
Mean Square ◽  
Least Mean Square ◽  
Control Effort ◽  
Isolation System ◽  
Active Vibration ◽  
The Cost

The least-mean squares (LMS) adaptive feedforward algorithm is used widely for vibration and noise cancellation. If reference signals become large enough to saturate that actuators, the filter coefficients in such algorithms can diverge. The leaky LMS method limits the controller effort by augmenting the objective function by a weighted control effort, and is known to attain good performance and avoid growth of filter coefficients for well-chosen weights. We propose an algorithm that seeks to directly minimize the mean-square cost in the presence of saturation. We derive the true stochastic gradient of the cost for systems with saturation with respect to the filter coefficients and obtain an adaptation rule very close to that of the filtered-x algorithm, but in the proposed algorithm, the reference filter is a time-varying modification of the secondary channel. In simulations of an active vibration isolation system with actuator limits subject to random ground vibration, the leaky LMS algorithm attains its best performance with actuation weights small enough to allow significant actuator saturation but large enough to prevent divergence. The proposed algorithm attains performance better that attained by the leaky LMS algorithm, and does not require the selection of weights.

scholarly journals Numerical Analysis on the Ground Vibration Isolation of Duxseal

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
M. Gao ◽  
S. P. Tian ◽  
R. He ◽  
Y. Wang ◽  
Q. S. Chen
Keyword(s):  
Vibration Isolation ◽  
Damping Ratio ◽  
Free Field ◽  
Three Dimensional ◽  
Ground Vibration ◽  
Vibration Source ◽  
Isolation System ◽  
Vertical Excitation ◽  
Thin Layer Method ◽  
Active Vibration

A new kind of vibration screening material, Duxseal, with a high damping ratio is proposed to be used as an active vibration barrier in the free field. To investigate the influence of width, thickness, and embedded depth of using Duxseal on vibration reduction, numerical studies are performed using a three-dimensional (3D) semianalytical boundary element method (BEM) combined with a thin-layer method (TLM). The isolation effectiveness of Duxseal in ground vibration is also compared with the traditional wave impeding block (WIB). The numerical results show that Duxseal performed exceedingly well in screening ground vibrations in the free field. The effectiveness of the vibration isolation increases with the increase in the width, thickness, and embedded depth of the Duxseal material, within a certain range, under harmonic vertical excitation. In addition, Duxseal is much more effective for isolating ground vibration than the traditional WIB. The performance of Duxseal in isolating ground vibration is relatively stable along the distance away from the vibration source, while the amplitude attenuation ratio bounces upward when the distance away from the vibration source increases for the WIB isolation system.

A Study of Active Vibration Isolation

1985 ◽  
Vol 107 (4) ◽  
pp. 392-397 ◽  
Author(s):  
N. Tanaka ◽  
Y. Kikushima
Keyword(s):  
Vibration Isolation ◽  
Control Method ◽  
Feedforward Control ◽  
Ground Vibration ◽  
Design Parameters ◽  
Isolation Method ◽  
Isolation System ◽  
Active Isolation ◽  
Active Vibration ◽  
Active Vibration Isolation

For the purpose of suppressing ground vibration produced by vibrating machines, such as forging hammers, press machines, etc., this paper presents an active vibration isolation method. Unlike conventional isolators, the active isolator proposed in this paper permits rigid support of the machines. First, the principle of the active isolation method is shown, and the system equations are derived. Secondly, the characteristics and the design parameters of the active isolation system are presented. Thirdly, from the point of view of the feedforward control method, the dynamic compensators are designed so as to sufficiently suppress the exciting force. Finally, an experiment is carried out to demonstrate that the active isolator is applicable for suppressing the ground vibration.

scholarly journals New feedforward filtered-x least mean square algorithm with variable step size for active vibration control

2018 ◽  
Vol 38 (1) ◽  
pp. 187-198 ◽  
Author(s):  
Yubin Fang ◽  
Xiaojin Zhu ◽  
Zhiyuan Gao ◽  
Jiaming Hu ◽  
Jian Wu
Keyword(s):  
Vibration Control ◽  
Active Vibration Control ◽  
Lms Algorithm ◽  
Variable Step Size ◽  
Mean Square ◽  
Least Mean Square ◽  
Step Size ◽  
Large Step ◽  
Variable Step ◽  
Active Vibration

The step size of least mean square (LMS) algorithm is significant for its performance. To be specific, small step size can get small excess mean square error but results in slow convergence. However, large step size may cause instability. Many variable step size least mean square (VSSLMS) algorithms have been developed to enhance the control performance. In this paper, a new VSSLMS was proposed based on Kwong’s algorithm to evaluate the robustness. The approximate analysis of dynamic and steady-state performance of this developed VSSLMS algorithm was given. An active vibration control system of piezoelectric cantilever beam was established to verify the performance of the VSSLMS algorithms. By comparing with the current VSSLMS algorithms, the proposed method has better performance in active vibration control applications.

Nonlinearity of Maglev Actuator and Adaptive Vibration Control Using Improved FxLMS Algorithm

2013 ◽  
Vol 390 ◽  
pp. 434-439 ◽  
Author(s):  
Yan Li ◽  
Lin He ◽  
Chang Geng Shuai
Keyword(s):  
Vibration Isolation ◽  
Least Mean Square ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Fxlms Algorithm ◽  
Active Vibration ◽  
Spectrum Excitation ◽  
Least Mean Square Algorithm ◽  
Adaptive Vibration Control ◽  
Active Vibration Isolation

Maglev actuator is excellent for active vibration isolation, with non-contact form, low stiffness and rapid response. However, the actuators nonlinearity has to be restrained by the control algorithm. In this paper, the nonlinearity of maglev actuator was studied through theoretical analysis and experiment. An improved multi-channel FxLMS(filtered-x least mean square) algorithm was proposed, which considers the nonlinearity-induced harmonic frequency as extra line-spectrum excitation to control. Experiments showed that the improved FxLMS algorithm could efficiently compensate the nonlinearity of the actuators, thus had better effect when used in active vibration isolation system with non-linear actuators, compared with the traditional FxLMS method.

Momentum Least Mean Square Paradigm for the Measurement of Nonlinear CARAR System Parameters

2020 ◽  
Vol 15 (3) ◽  
Author(s):  
Naveed Ishtiaq Chaudhary ◽  
Mateen Ahmed ◽  
Nebojsa Dedovic ◽  
Muhammad Asif Zahoor Raja
Keyword(s):  
Mean Squared Error ◽  
Model Identification ◽  
Lms Algorithm ◽  
Superior Performance ◽  
Mean Square ◽  
Least Mean Square ◽  
State Behavior ◽  
Final Steady State ◽  
Proximity Measures ◽  
The Cost

Abstract This study presents a variant of least mean square (LMS) algorithm, i.e., momentum LMS (M-LMS), with faster convergence speed for measuring the system parameter of linear as well as nonlinear control autoregressive autoregressive (CARAR) models. The M-LMS effectively exploits the input/output data by utilizing the previous gradients information in update rule to avoid trapping in local minimum (MNM) and yields better convergence behavior than conventional LMS approach. The speedy convergence of M-LMS is achieved by increasing the proportion of previous gradients but at the cost of little compromise in final steady-state behavior. The correctness of the M-LMS is established by effective optimization of the linear as well as nonlinear CARAR model identification. The robustness of the scheme is verified through accurate measurement of CARAR systems parameters for various noise levels. The statistical analyses based on multiple independent trials through proximity measures in terms of fitness, mean squared error, and Nash Sutcliffe efficiency further validated the superior performance of M-LMS for identification of CARAR models.

Optimal Design of Active Vibration Isolation System

1988 ◽  
Vol 110 (1) ◽  
pp. 42-48 ◽  
Author(s):  
N. Tanaka ◽  
Y. Kikushima
Keyword(s):  
Optimal Design ◽  
Vibration Isolation ◽  
Optimization Technique ◽  
Design Procedure ◽  
Ground Vibration ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Active Vibration ◽  
Series Type ◽  
Active Vibration Isolation

In order to eliminate ground vibration produced by machines such as forge hammers, press machines, etc., this paper presents a systematic and optimal design procedure of an active vibration isolation system which permits rigid support of machines. First, the principle of the active vibration method is presented. Secondly, from the viewpoint of feedback control, the active vibration isolation system with a series-type dynamic compensator is constructed. Thirdly, with the air of a parameter optimization technique, the necessary conditions for optimality of the system are derived. Fourthly, for the purpose of solving the conditions, an iterative algorithm based upon a quasi-Newton method is proposed. Finally, by using the design procedure, the active vibration isolation system is designed, and the effectiveness to isolate the vibration is discussed.

Non-Uniformity Correction Algorithm Research Based on One FPGA Processor

2014 ◽  
Vol 568-570 ◽  
pp. 265-269
Author(s):  
Qiang Wu ◽  
Han Liu ◽  
Xu Wen Li
Keyword(s):  
Lms Algorithm ◽  
Mean Square ◽  
Least Mean Square ◽  
Correction Algorithm ◽  
Volume Weight ◽  
The Cost ◽  
The Ideal

The two-point non-uniformity correction based on Least mean square (LMS) algorithm which was proposed by Suxia Xing need one FPGA processor, one DSP processor and four SRAM chips. This will increase the cost and volume of the whole infrared system. In the LMS algorithm, this paper improves the estimation of the ideal signal, so that it can reduce the influence of blind elements and improve the effect of non-uniformity correction. Besides, this paper realizes the two-point non-uniformity correction based on LMS algorithm with only one FPGA processor and two SRAM chips in the final, this will reduce the volume, weight, cost of the whole infrared system. Comparing with the two-point non-uniformity correction based on one FPGA processor, this paper did not need blackbody with uniform radiation in system. Above all, the method of this paper is useful and practical.

Research on Adaptive Feedforward Control Algorithm of Electromagnetic Active Vibration Isolation System

2012 ◽  
Vol 150 ◽  
pp. 80-84
Author(s):  
Jin Guang Zhang ◽  
Nan Xiang ◽  
Zuo Chao Xiao ◽  
Guo Ping Ding
Keyword(s):  
Vibration Isolation ◽  
Feedforward Control ◽  
Lms Algorithm ◽  
Vibration Source ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Active Vibration ◽  
Simulation Results ◽  
Adaptive Feedforward ◽  
Active Vibration Isolation

Feedforward control method to control vibration in the active vibration isolation system was discussed. By introducing the FIR filter as the feedforward link, using the mean-square deviation of system error as the performance index and utilizing the LMS algorithm to obtain the optimal parameters of controller, the design of adaptive feedforward controller was fulfilled. The simulation results showed that: for the active vibration isolation system with regularly vibration source, adopting adaptive filter method of feedforward control has notable effect. The contrast experiment with using the PID controller further verified the simulation results.

scholarly journals An Effective Adaptive Combination Strategy for Distributed Learning Network

2021 ◽  
Vol 11 (12) ◽  
pp. 5723
Author(s):  
Chundong Xu ◽  
Qinglin Li ◽  
Dongwen Ying
Keyword(s):  
Minimum Variance ◽  
Iteration Scheme ◽  
Estimation Problem ◽  
Lms Algorithm ◽  
Unbiased Estimation ◽  
Mean Square ◽  
Least Mean Square ◽  
Combination Strategy ◽  
Adaptive Combination ◽  
Diffusion Networks

In this paper, we develop a modified adaptive combination strategy for the distributed estimation problem over diffusion networks. We still consider the online adaptive combiners estimation problem from the perspective of minimum variance unbiased estimation. In contrast with the classic adaptive combination strategy which exploits orthogonal projection technology, we formulate a non-constrained mean-square deviation (MSD) cost function by introducing Lagrange multipliers. Based on the Karush–Kuhn–Tucker (KKT) conditions, we derive the fixed-point iteration scheme of adaptive combiners. Illustrative simulations validate the improved transient and steady-state performance of the diffusion least-mean-square LMS algorithm incorporated with the proposed adaptive combination strategy.

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