Active vibration isolation performance of the bistable nonlinear electromagnetic actuator with the elastic boundary

2021 ◽  
pp. 116588
Author(s):  
Kai Yang ◽  
Weihao Tong ◽  
Liquan Lin ◽  
Yurchenko Danill ◽  
Junlei Wang
Keyword(s):  
Vibration Isolation ◽  
Electromagnetic Actuator ◽  
Elastic Boundary ◽  
Active Vibration ◽  
Vibration Isolation Performance ◽  
Isolation Performance ◽  
Active Vibration Isolation

Experiment on Active Vibration Isolation of a Conical Shell Isolator

2014 ◽  
Author(s):  
H. Y. Li ◽  
H. Li ◽  
S. D. Hu ◽  
Z. B. Chen
Keyword(s):  
Conical Shell ◽  
Vibration Isolation ◽  
Fiber Composite ◽  
Active Vibration Control ◽  
Control Voltage ◽  
Conical Shells ◽  
Optimal Controllers ◽  
Active Vibration ◽  
Vibration Isolation Performance ◽  
Isolation Performance

Conical shells have advantages such as light weight, higher stiffness and strength, its stiffness ratio between axial and transverse directions can be easily adjusted by changing its apex angle. Thus conical shell can be utilized as an isolator to protect precision payloads and equipment from severe dynamic loads. In this study, vibration isolation performance of a conical shell isolator laminated with piezoelectric actuators is investigated. The conical shell isolator is manufactured from epoxy resin. The payload is at the minor of the isolator. The major end of the isolator is fixed at a flange installed on a shaker. Macro fiber composite (MFC) is used as actuator, which is laminated on the outer surface of the conical isolator. The sensing signals from sensors on the isolator is transferred to a dSPACE system and the control voltage is transferred to a power amplifier and then to the MFC actuator. The control voltage is calculated in the Matlab/Simulink environment. Both negative velocity feedback and optimal controllers are employed in the active vibration control. The payloads are simplified to be a rigid cylinder, and two payloads with different weight are investigated in the study. Experimental results show that the proposed conical shell isolator is effective for vibration isolation of payloads, and vibration amplitude of the payload can be significantly reduced.

Vibration-Isolation Characteristics of an Active Electromagnetic Force Generator and the Influence of Generator Dynamics

1990 ◽  
Vol 112 (1) ◽  
pp. 8-15 ◽  
Author(s):  
Hong Su ◽  
S. Rakheja ◽  
T. S. Sankar
Keyword(s):  
Control System ◽  
Vibration Control ◽  
Electromagnetic Force ◽  
Vibration Isolation ◽  
Active Vibration Control ◽  
Control Scheme ◽  
Active Vibration ◽  
Force Generator ◽  
Vibration Isolation Performance ◽  
Isolation Performance

Vibration-isolation characteristics of an active vibration control system incorporating an electromagnetic force generator (actuator) are investigated. The electromagnetic force generator is modeled as a first-order dynamical system and the influence of dynamics of the force generator on the vibration-isolation performance of the active isolator is investigated via computer simulation. It is concluded that the dynamics of the force generator affect the vibration-isolation performance significantly. An active control scheme, based upon absolute position, velocity, and relative position response variables, is proposed and investigated. In view of the adverse effects of generator dynamics, the proposed control scheme yields superior vibration isolation performance. Stability analysis of the active vibration control system is carried out to determine the limiting values of various feedback control gains.

A New Concept in Semi-Active Vibration Isolation

1987 ◽  
Vol 109 (2) ◽  
pp. 242-247 ◽  
Author(s):  
J. Alanoly ◽  
S. Sankar
Keyword(s):  
Relative Velocity ◽  
Vibration Isolation ◽  
Lower Cost ◽  
Relative Displacement ◽  
Active Suspensions ◽  
Control Scheme ◽  
Active Vibration ◽  
Active Damper ◽  
Vibration Isolation Performance ◽  
Isolation Performance

Semi-active suspensions can achieve performance close to that of active suspensions with much lower cost and complexity. They use an active damper in parallel with a passive spring. The forces in the damper are generated merely by the modulation of fluid-flow orifices based on a control scheme involving feedback variables. This paper presents an original control strategy employing only directly measurable variables in vehicle applications. The relative displacement and relative velocity across the suspension are the only feedback signals and the damper force can be continuously modulated (as opposed to on-off control). Vibration isolation performance of the new semi-active scheme is compared to semi-active sky-hook suspension, as well as passive and active suspensions.

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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