Resonance Suppression for Hydraulic Servo Shaking Table Based on Adaptive Notch Filter

In dynamic structure test, the specimen of hydraulic servo shaking table contains not only inertia load but also elastic load. The specimen herein is simplified as a spring-mass-damping system, and the mathematical model of the hydraulic servo shaking table is established by theoretical analysis. The coupling between specimen’s elastic load and shaking table itself produces resonance phenomenon in the required bandwidth when the elastic load is not negligible, which deteriorates the system’s dynamic performance and even leads to the instability of the control system. Also, the time-varying resonance frequency further aggravates the control performance of the system in the shaking test. In this paper, an adaptive notch filter based on least mean square (LMS) error principle is employed to identify the resonance frequencies online and real-time adjust the parameters of the notch filter. Simulation and experiment results show the effectiveness of frequency identification and resonance mode suppression. Compared with the existing resonance suppression scheme, the proposed method can suppress the appeared resonance mode adaptively.

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The resonant valley suppression of a hydraulic shaking table by using adaptive spectral line enhancer

Proceedings of the Institution of Mechanical Engineers Part I Journal of Systems and Control Engineering ◽

10.1177/0959651818783541 ◽

2018 ◽

Vol 232 (10) ◽

pp. 1379-1388

Author(s):

Tao Wang ◽

Jinchun Song

Keyword(s):

Spectral Line ◽

Coupling Effect ◽

Resonance Effect ◽

Shaking Table ◽

Resonance Phenomenon ◽

Resonant System ◽

Stability Range ◽

Elastic Load ◽

Hydraulic Servo ◽

The Stability

As an electro-hydraulic servo shaking table takes on an elastic load in a vibration test of a 2-mass dynamic system, a mutual coupling effect is exerted between the shaking table and the specimen, which will form a resonant system to weaken the dynamic characteristics of the system. As required by the system bandwidth, the resonant system contains a resonance valley and a resonance peak, and its amplitude commonly surmounts the stability range of the system’s acceleration amplitude. In this article, the resonance phenomenon is analyzed, and the structure and the parameters of the three-state controller are designed on the basis of a pole assignment system. The adaptive spectral line enhancer is adopted to suppress the resonant valley, and the power spectrum is analyzed to experimentally verify that it exerts an anti-resonance effect.

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Study on the Resonant Suppression of Electrohydraulic Servo Shaking Table of a 2-Mass Dynamic System

Shock and Vibration ◽

10.1155/2019/8592578 ◽

2019 ◽

Vol 2019 ◽

pp. 1-13

Author(s):

Tao Wang ◽

Jinchun Song

Keyword(s):

Dynamic System ◽

Coupling Effect ◽

Characteristic Curve ◽

Notch Filter ◽

Shaking Table ◽

Resonant Peak ◽

Least Mean Square ◽

Stability Range ◽

Suppression Effect ◽

Adaptive Notch Filter

Since the load of electrohydraulic servo shaking table is an elastic load, there is a mutual coupling effect that exists between the experimental object and the shaking table, forming the resonance to weaken the dynamic characteristics, and producing resonant peak and resonant valley in the bandwidth required by the system, in which the amplitude is often larger than the stability range of acceleration’s amplitude. In this paper, the mathematical modeling of hydraulic power mechanism in a two-mass dynamic system is established based on electrohydraulic servo shaking table, yielding the frequency characteristic curve in accordance with the transfer function of the model. A multifrequency adaptive notch filter based on the least mean square algorithm is proposed to suppress the resonance, and the suppression effect of the resonance is simulated and verified in line with various values of load stiffness. Finally, the power spectrum is used to demonstrate the effectiveness of the multifrequency adaptive notch filter in the resonant suppression.

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