Theoretical Investigation on Cross-Coupling Effect of Two-Dimensional Compound Pendulum Tiltmeter

2018 ◽  
Vol 07 (02n03) ◽  
pp. 1850007
Author(s):  
Lihua Wu ◽  
Yu Huang
Keyword(s):  
Dynamic Response ◽  
Vibration Isolation ◽  
Coupling Effect ◽  
Low Frequency ◽  
Cross Coupling ◽  
Coupling Factor ◽  
Two Dimensional ◽  
Coupling Coefficients ◽  
Coupling Effects ◽  
The Cross

The active vibration isolation of low-frequency tilt is important for precise scientific measurement. However, the cross-coupling effects in tilt sensitive probes introduce negative effects on the performance of active isolation devices. In this paper, we show the structure and basic principle of compound pendulum (CP)-type tiltmeter, and analyze the dynamic response of the CP to the two-dimensional tilt vibrations. Besides, we deduce theoretically the mathematical model of the capacitive sensing of the displacements of the CP. Finally, we evaluate numerically the cross-coupling effects of a tilt sensitive probe including the cross-couplings of dynamic response and the different capacitance variations in two orthogonal degrees of freedoms. The maximum of the mechanical dynamic coupling factor is less than −60[Formula: see text]dB. The total cross-coupling coefficients including the different capacitance variations of the probe are both less than [Formula: see text]. Therefore, the cross-coupling effects don’t have to be considered for this kind of two-dimensional tilt sensitive probe.

Low Frequency Vibration Isolation Through an Active-on-Active Approach: Coupling Effects

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Qiao Sun ◽  
Robert A. Wolkow ◽  
Mark Salomons
Keyword(s):  
Vibration Isolation ◽  
Low Frequency ◽  
Noise Cancellation ◽  
Frequency Noise ◽  
Active Stage ◽  
Coupling Effects ◽  
Active Approach ◽  
Low Frequency Vibration ◽  
Wide Range ◽  
Coupling Characteristics

The extreme sensitivity of a scanning probe microscope demands an exceptional noise cancellation device that could effectively cut off a wide range of vibration noise. Existing commercial devices, although excellent in canceling high frequency noise, commonly leave low frequency vibration unattenuated. We design an add-on active stage that can function together with a standalone existing active stage. The objective is to provide a higher level of noise cancellation by lowering the overall system cut-off frequency. This study is concerned with the theoretical aspects of the coupling characteristics involved in stacking independently designed stages together to form a two-stage isolator. Whether an add-on stage would pose a stability threat to the existing stage needs to be addressed. In addition, we explore the use of coupling effects to optimize the performance of the overall system.

Origami-Based Bistable Metastructures for Low-Frequency Vibration Control

2021 ◽  
Vol 88 (5) ◽  
Author(s):  
Mingkai Zhang ◽  
Jinkyu Yang ◽  
Rui Zhu
Keyword(s):  
Vibration Isolation ◽  
Energy Analysis ◽  
Geometrical Nonlinearity ◽  
Low Frequency ◽  
Quantitative Relationship ◽  
Vibration Modes ◽  
Two Dimensional ◽  
Low Frequency Vibration ◽  
Dynamic Experiments ◽  
Unit Cells

Abstract In this research, we aim to combine origami units with vibration-filtering metastructures. By employing the bistable origami structure as resonant unit cells, we propose metastructures with low-frequency vibration isolation ability. The geometrical nonlinearity of the origami building block is harnessed for the adjustable stiffness of the metastructure’s resonant unit. The quantitative relationship between the overall stiffness and geometric parameter of the origami unit is revealed through the potential energy analysis. Both static and dynamic experiments are conducted on the bistable origami cell and the constructed beam-like metastructure to verify the adjustable stiffness and the tunable vibration isolation zone, respectively. Finally, a two-dimensional (2D) plate-like metastructure is designed and numerically studied for the control of different vibration modes. The proposed origami-based metastructures can be potentially useful in various engineering applications where structures with vibration isolation abilities are appreciated.

Cross-Feedback Stabilization of the Digitally Controlled Magnetic Bearing

1992 ◽  
Vol 114 (1) ◽  
pp. 54-59 ◽  
Author(s):  
Y. Okada ◽  
B. Nagai ◽  
T. Shimane
Keyword(s):  
Pid Control ◽  
High Speed ◽  
Coupling Effect ◽  
Cross Coupling ◽  
Magnetic Bearing ◽  
Feedback Stabilization ◽  
Time Interval ◽  
Rotating Disc ◽  
Digitally Controlled ◽  
The Cross

A method of stabilizing a high speed rotor supported by magnetic bearings is presented. The magnetic bearing is controlled by a digital controller with rotationally synchronized interruption. The main problem with the rotating disc is the cross-coupling effect caused by the gyroscopic or inductive forces which sometimes make the high speed rotor unstable. Standard PID control is carried out with constant time interval interruption, while the rotational interrupt subroutine performs the cross-coupling feedback. The cross-feedback in the x-y directions well compensates for the undesirable coupling effect. This scheme is applied to a four-mass, two-bearing rotor system and its capability is tested.

scholarly journals Time-Sharing Control Strategy for Multiple-Receiver Wireless Power Transfer Systems

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 599 ◽  
Author(s):  
Weikun Cai ◽  
Dianguang Ma ◽  
Xiaoyang Lai ◽  
Khurram Hashmi ◽  
Houjun Tang ◽  
...  
Keyword(s):  
Control Strategy ◽  
Output Voltage ◽  
High Efficiency ◽  
Coupling Effect ◽  
Cross Coupling ◽  
Time Sharing ◽  
Voltage Control Strategy ◽  
Bridge Rectifier ◽  
The Cross ◽  
Target Output

The cross-coupling effect between the induction coils of a multiple-receiver wireless power transfer (MRWPT) system severely weakens its overall performance. In this paper, a time-sharing control strategy for MRWPT systems is proposed to reduce the cross-coupling between receiver coils. An active-bridge rectifier is introduced to the receivers to replace the uncontrollable rectifier to achieve synchronization of the time-sharing control. The synchronization signal generated by an active-bridge rectifier can be directly used to realize the synchronization of time-sharing control and hence saved the traditional zero-crossing point detection circuits for time-sharing circuits. Moreover, the proposed time-sharing system has the advantages of both operating under a resistance-matching condition and providing target output voltage for each receiver. Furthermore, a voltage control strategy was developed to provide both high efficiency and a target output voltage for each receiver. Finally, the simulation and experimental results show that the time-sharing MRWPT system reduced the cross-coupling effect between the receiver coils, and the voltage control strategy provided both a high efficiency and a target output voltage for each receiver.

Alternative soft fault model of the cross-coupling effect correlated at hydroelectric power energy system

2014 ◽  
Vol 58 ◽  
pp. 274-280
Author(s):  
G. Mino-Aguilar ◽  
G.A. Muñoz-Hernández ◽  
J.F. Guerrero-Castellanos ◽  
E. Molina-Flores ◽  
A. Díaz-Sánchez ◽  
...  
Keyword(s):  
Coupling Effect ◽  
Cross Coupling ◽  
Energy System ◽  
Fault Model ◽  
Hydroelectric Power ◽  
Soft Fault ◽  
The Cross
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