Control and Simulation on Vertical Vibration of Subway Rail via Magnetorheological Isolators

2012 ◽  
Vol 482-484 ◽  
pp. 1313-1316
Author(s):  
Rui Li ◽  
Li Min He ◽  
Xue Qin Li ◽  
Ke Long Chen
Keyword(s):  
Low Frequency ◽  
Vertical Vibration ◽  
Vibration System ◽  
Medium Frequency ◽  
Slab Track ◽  
Vibration Model ◽  
Active Vibration ◽  
Force Transmissibility ◽  
Stiffness Characteristics ◽  
Isolation Performance

A semi-active vibration system via magnetorheological (MR) isolators can contribute to enhance isolation performance. In this study, a vertical vibration model of subway rail via MR isolators was proposed. The adjustable damping and stiffness characteristics of isolator were also analyzed. Based on a floating slab track (FST) isolation model, a variable domain fuzzy control system was proposed to decrease the vertical vibration force. The results simulated in MATLAB indicate that compared with passive isolators, FST system via MR isolators decease vertical vibration force transmissibility ratio to 40% at low frequency (15Hz) and to 31% at medium frequency (30Hz).

Research on Characteristics of Special Nonlinear Vibration System

2015 ◽  
Vol 724 ◽  
pp. 213-217
Author(s):  
Shu Yong Liu ◽  
Qing Chao Yang ◽  
Shi Jian Zhu ◽  
Xiu Lei Wei
Keyword(s):  
Low Frequency ◽  
Resonant Peak ◽  
Vibration System ◽  
Nonlinear Springs ◽  
Spring Element ◽  
Spring Force ◽  
Force Transmissibility ◽  
Isolation Performance ◽  
Nonlinear Vibration System ◽  
Better Than

<p>The characteristics of quasi-zero stiffness(QZS) system with nonlinear positive and negative stiffness is researched. A modified QZS model with nonlinear spring element is established and the stiffness curves are obtained based on the analysis of relationship between spring force and displacement. A non-dimensional form of QZS is deduced to discover its essential laws, and simulation is presented with different nonlinear springs. Then the force transmissibility of QZS is verified with the experiment, which shows that the QZS isolation performance is better than the linear one in the low frequency band, and there exists no resonant peak in this system.</p>

Design of an Active-Vibration System Based on Sky-Hook Damper and Impedance Control

2013 ◽  
Vol 416-417 ◽  
pp. 860-865
Author(s):  
Wu Sung Yao ◽  
Po Wen Hsueh ◽  
Mi Ching Tsai
Keyword(s):  
Impedance Control ◽  
Low Frequency ◽  
Control Design ◽  
Experimental Results ◽  
Vibration System ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Low Frequency Vibration ◽  
Model Reference Control ◽  
Active Vibration

This paper investigates an active anti-vibration system, and the isolation of low-frequency vibration is studied. A model reference control of the anti-vibration system with a sky-hook damper and impedance control is analyzed. An illustrated example of a single-degree-of-freedom anti-vibration system driven by a tubular linear servomotor is given to verify the performance of the proposed control design. Experimental results are given to show that the peak resonance value of 0dB within a frequency of 10Hz can be achieved successively.

scholarly journals Adaptive Deterministic Vibration Control of a Piezo-Actuated Active–Passive Isolation Structure

2021 ◽  
Vol 11 (8) ◽  
pp. 3338
Author(s):  
Feng Li ◽  
Shujin Yuan ◽  
Fanfan Qian ◽  
Zhizheng Wu ◽  
Huayan Pu ◽  
...  
Keyword(s):  
Control System ◽  
Vibration Control ◽  
Vibration Isolation ◽  
Active Vibration Control ◽  
Low Frequency ◽  
Residual Vibration ◽  
Central Controller ◽  
Active Vibration ◽  
Passive Isolation ◽  
Isolation Performance

With the improvement of the performance of optical equipment carried by on-orbit spacecraft, the requirements of vibration isolation are increasing. Passive isolation platforms are widely used, but the ability to suppress the low-frequency deterministic vibration disturbance is limited, especially near the system’s natural frequency. Therefore, an active vibration control strategy is proposed to improve passive isolation performance. In this paper, a Youla parameterized adaptive active vibration control system is introduced to improve the isolation performance of a piezo-actuated active–passive isolation structure. A linear quadratic Gaussian (LQG) central controller is first designed to shape the band-limited local loop of the closed-loop system. Then, the central controller is augmented into a Youla parameterized adaptive regulator with the recursive least square adaptive algorithm, and the Youla parameters (Q parameters) can be adjusted online to the desired value to suppress the unknown and time-varying multifrequency deterministic vibration disturbance. In the experiment, the residual vibration with respect to the combination of multiple frequencies is effectively suppressed by more than 20 dB on average, and a quick response time of less than 0.3 s is achieved when the deterministic residual vibration changes suddenly over time. The experimental results illustrate that the proposed adaptive active vibration control system can effectively suppress the low-frequency deterministic residual vibration.

Damping Optimization on Magnetorheological Grease Isolator of Floating Slab Track

2012 ◽  
Vol 485 ◽  
pp. 217-220 ◽  
Author(s):  
Rui Li ◽  
Ke Long Chen ◽  
Li Min He
Keyword(s):  
Low Frequency ◽  
Pso Algorithm ◽  
Vertical Vibration ◽  
Vibration Energy ◽  
Single Degree Of Freedom ◽  
Slab Track ◽  
Damping Characteristics ◽  
Low Frequency Vibration ◽  
Adaptive Pso ◽  
Variable Damping

The bearings with variable damping characteristics are very important for floating slab track (FST) to restrain vibration in low frequency. A model with single degree of freedom of FST is built. Based on analyzing the characteristic of the magnetorheological grease (MRG) materials, a MRG isolator is proposed to instead of passive bearings of FST. For attenuating the vertical vibration, the method of adaptive particle swarm optimization (PSO) with variable inertial parameter is proposed to adjust the damping. The results simulated in MATLAB show that MRG isolators with the adaptive PSO algorithm can optimize damping at different excitations effectively and conspicuously decrease the low frequency vibration energy of FST.

Dynamic Damping and Stiffness Characteristics of the Rolling Tire

2001 ◽  
Vol 29 (4) ◽  
pp. 258-268 ◽  
Author(s):  
G. Jianmin ◽  
R. Gall ◽  
W. Zuomin
Keyword(s):  
Dynamic Behavior ◽  
Variable Parameter ◽  
Low Frequency ◽  
Vertical Load ◽  
Frequency Range ◽  
Inflation Pressure ◽  
Vehicle Simulation ◽  
Dynamic Damping ◽  
Speed Range ◽  
Stiffness Characteristics

Abstract A variable parameter model to study dynamic tire responses is presented. A modified device to measure terrain roughness is used to measure dynamic damping and stiffness characteristics of rolling tires. The device was used to examine the dynamic behavior of a tire in the speed range from 0 to 10 km/h. The inflation pressure during the tests was adjusted to 160, 240, and 320 kPa. The vertical load was 5.2 kN. The results indicate that the damping and stiffness decrease with velocity. Regression formulas for the non-linear experimental damping and stiffness are obtained. These results can be used as input parameters for vehicle simulation to evaluate the vehicle's driving and comfort performance in the medium-low frequency range (0–100 Hz). This way it can be important for tire design and the forecasting of the dynamic behavior of tires.

Beneficial performance of a quasi-zero stiffness vibration isolator with generalized geometric nonlinear damping

2020 ◽  
pp. 095745652097238
Author(s):  
Chun Cheng ◽  
Ran Ma ◽  
Yan Hu
Keyword(s):  
Damping Ratio ◽  
Nonlinear Damping ◽  
Vibration Isolator ◽  
Equivalent Damping ◽  
Frequency Responses ◽  
Geometric Nonlinear ◽  
Resonant Region ◽  
Force Transmissibility ◽  
Isolation Performance ◽  
Force And Displacement Transmissibility

Generalized geometric nonlinear damping based on the viscous damper with a non-negative velocity exponent is proposed to improve the isolation performance of a quasi-zero stiffness (QZS) vibration isolator in this paper. Firstly, the generalized geometric nonlinear damping characteristic is derived. Then, the amplitude-frequency responses of the QZS vibration isolator under force and base excitations are obtained, respectively, using the averaging method. Parametric analysis of the force and displacement transmissibility is conducted subsequently. At last, two phenomena are explained from the viewpoint of the equivalent damping ratio. The results show that decreasing the velocity exponent of the horizontal damper is beneficial to reduce the force transmissibility in the resonant region. For the case of base excitation, it is beneficial to select a smaller velocity exponent only when the nonlinear damping ratio is relatively large.

scholarly journals Tilt Active Vibration Isolation Using Vertical Pendulum and Piezoelectric Transducer with Parallel Controller

2021 ◽  
Vol 11 (10) ◽  
pp. 4526
Author(s):  
Lihua Wu ◽  
Yu Huang ◽  
Dequan Li
Keyword(s):  
Piezoelectric Transducer ◽  
Vibration Isolation ◽  
Vertical Vibration ◽  
Open Loop ◽  
Negative Effects ◽  
Voltage Controller ◽  
Hysteresis Nonlinearity ◽  
Passive Vibration Isolation ◽  
Active Vibration ◽  
Active Vibration Isolation

Tilt vibrations inevitably have negative effects on some precise engineering even after applying horizontal and vertical vibration isolations. It is difficult to adopt a traditional passive vibration isolation (PVI) scheme to realize tilt vibration isolation. In this paper, we present and develop a tilt active vibration isolation (AVI) device using a vertical pendulum (VP) tiltmeter and a piezoelectric transducer (PZT). The potential resolution of the VP is dependent on the mechanical thermal noise in the frequency bandwidth of about 0.0265 nrad, which need not be considered because it is far below the ground tilt of the laboratory. The tilt sensitivity of the device in an open-loop mode, investigated experimentally using a voltage controller, is found to be (1.63±0.11)×105 V/rad. To compensate for the hysteresis nonlinearity of the PZT, we experimentally established the multi-loop mathematical model of hysteresis, and designed a parallel controller consisting of both a hysteresis inverse model predictor and a digital proportional–integral–differential (PID) adjuster. Finally, the response of the device working in close-loop mode to the tilt vibration was tested experimentally, and the tilt AVI device showed a good vibration isolation performance, which can remarkably reduce the tilt vibration, for example, from 6.0131 μrad to below 0.0103 μrad.

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