Active vibration isolation using negative stiffness and displacement cancellation controls: Comparison based on vibration isolation performance

2015 ◽  
Vol 37 ◽  
pp. 55-66 ◽  
Author(s):  
Mhia Md. Zaglul Shahadat ◽  
Takeshi Mizuno ◽  
Yuji Ishino ◽  
Masaya Takasaki
Keyword(s):  
Vibration Isolation ◽  
Negative Stiffness ◽  
Active Vibration ◽  
Vibration Isolation Performance ◽  
Isolation Performance ◽  
Active Vibration Isolation

Multi-layer electromagnetic spring with tunable negative stiffness for semi-active vibration isolation

2019 ◽  
Vol 121 ◽  
pp. 942-960 ◽  
Author(s):  
Huayan Pu ◽  
Shujin Yuan ◽  
Yan Peng ◽  
Kai Meng ◽  
Jinglei Zhao ◽  
...  
Keyword(s):  
Vibration Isolation ◽  
Negative Stiffness ◽  
Active Vibration ◽  
Active Vibration Isolation

An innovative X-shaped vibration isolation mount with tunable quasi-zero-stiffness property

2021 ◽  
Vol 263 (3) ◽  
pp. 3011-3022
Author(s):  
Jing Bian ◽  
Xingjian Jing ◽  
Yishen Tian
Keyword(s):  
Vibration Isolation ◽  
Negative Stiffness ◽  
Design Parameters ◽  
Property A ◽  
Vibration Displacement ◽  
Stiffness Property ◽  
Passive Vibration Isolation ◽  
Engineering Practices ◽  
Vibration Isolation Performance ◽  
Isolation Performance

Passive vibration isolation is always preferable in many engineering practices. To this aim, an innovative, compact, and passive vibration isolation mount is studied in this paper. The novel mount is adjustable to different payloads due to a special oblique and tunable stiffness mechanism, and of high vibration isolation performance with a wider quasi-zero-stiffness range due to the deliberate employment of negative stiffness of the X-shaped structure. The X-shaped structure has been well studied recently due to its excellent nonlinear stiffness and damping properties. In this study, by using of the negative stiffness property within the X-shaped structure, the X-shaped mount (X-mount) can have an obviously larger vibration displacement range which maintains the quasi-zero-stiffness property. A special oblique spring is thus introduced such that the overall equivalent stiffness can be much easily adjusted. Systematic parametric study is conducted to reveal the critical design parameters and their relationship with vibration isolation performance. A prototype and experimental validations are implemented to validate the theoretical results. It is believed that the X-mount would provide an innovative technical upgrade to many existing vibration isolation mounts in various engineering practices and it could also be the first prototyped mount which can offer adjustable quasi-zero stiffness conveniently.

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.

Improvement of Vibration Isolation Performance of Isolation System Using Negative Stiffness Structure

2016 ◽  
Vol 21 (3) ◽  
pp. 1561-1571 ◽  
Author(s):  
Thanh Danh Le ◽  
Minh Truong Ngoc Bui ◽  
Kyoung Kwan Ahn
Keyword(s):  
Vibration Isolation ◽  
Negative Stiffness ◽  
Isolation System ◽  
Vibration Isolation Performance ◽  
Isolation Performance

scholarly journals Pneumatic Active Vibration Isolation Systems Using Negative Stiffness

2005 ◽  
Vol 41 (8) ◽  
pp. 676-684
Author(s):  
Takeshi MIZUNO ◽  
Masato MURASHITA ◽  
Masaya TAKASAKI ◽  
Yuji ISHINO
Keyword(s):  
Vibration Isolation ◽  
Negative Stiffness ◽  
Active Vibration ◽  
Isolation Systems ◽  
Active Vibration Isolation

scholarly journals Theoretical Modeling and Vibration Isolation Performance Analysis of a Seat Suspension System Based on a Negative Stiffness Structure

2021 ◽  
Vol 11 (15) ◽  
pp. 6928
Author(s):  
Xin Liao ◽  
Ning Zhang ◽  
Xiaofei Du ◽  
Wanjie Zhang
Keyword(s):  
Vibration Isolation ◽  
Vibration Suppression ◽  
Ride Comfort ◽  
Dynamic Stiffness ◽  
Suspension System ◽  
Negative Stiffness ◽  
Nonlinear Dynamic Model ◽  
Seat Suspension ◽  
Vibration Isolation Performance ◽  
Isolation Performance

In this study, to improve the vibration isolation performance of a cab seat and the ride comfort of the driver, we propose a mathematical model for a seat suspension system of a construction machinery cab based on a negative stiffness structure (NSS). First, a static analysis of a seat suspension system is conducted and the different parameters and their influences on the dynamic stiffness are discussed. Thereby, the ideal configuration parameter range of the suspension system is obtained. Moreover, the nonlinear dynamic model of the designed seat suspension system is established. The frequency response and the stability are analyzed by using the HBM method and numerical simulation. The vibration transmissibility characteristics and vibration suppression effects of the seat suspension system are presented in detail. The results show that, as compared with a quasi-zero-stiffness system, the QZS-IE system has higher vibration suppression advantages under large excitation and small damping, as well as lower transmissibility and a wider vibration isolation frequency range. In addition, an inerter element with a larger mass ratio and relatively shorter distance ratio is better for vibration isolation performance of the QZS-IE system in a practical engineering application. The results of this study provide a scientific basis for the design and improvement of a seat suspension system.

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.

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