The Research on Robust LQ Control Applied to Uncertain Vibration Isolation System

2010 ◽  
Vol 34-35 ◽  
pp. 1289-1293
Author(s):  
Qiang Hong Zeng ◽  
Qi Wei He ◽  
Jing Jun Lou
Keyword(s):  
Optimal Control ◽  
Transfer Function ◽  
Vibration Isolation ◽  
Multi Objective Optimization ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Robust Optimal Control ◽  
Result Show ◽  
Isolation Performance ◽  
Lq Control

Synthesized considering several performance target, robust optimal control was applied to uncertain double layer vibration isolation system then the transfer function was got between input disturbance and out performance. By analyzing the amplitude-frequency characteristics of transfer function, the result show that the robust LQ control can successfully improve the isolation performance of uncertain hybrid vibration isolation system, realize the multi-objective optimization.

Active Control for Power-Train Vibration of Automotive Using Active Mounts

2013 ◽  
Vol 330 ◽  
pp. 598-601
Author(s):  
Guo Chun Sun ◽  
Li Meng He
Keyword(s):  
Optimal Control ◽  
Vibration Isolation ◽  
Linear Quadratic Regulator ◽  
Active System ◽  
Linear Quadratic ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Engine Vibration ◽  
Active Vibration ◽  
Piezoelectric Stack Actuator

In this work, a new active mount featuring piezostack actuators and a rubber element is proposed and applied to a vibration control system. After describing the configuration and operating principle of the proposed mount, an appropriate rubber element and appropriate piezostacks are designed. Through the analysis of the property of the rubber and piezoelectric stack actuator, a mechanical model of the active vibration isolation system with the active mounts is established. An optimal control algorithm is presented for engine vibration isolation system. the controller is designed according to linear quadratic regulator (LQR) theory. Simulation shows the active system has a better consequence in reducing the vibration of the chassis significantly with respect to the ACM and the optimal control than that in the passive system.

scholarly journals Experimental Validation of Fly-Wheel Passive Launch and On-Orbit Vibration Isolation System by Using a Superelastic SMA Mesh Washer Isolator

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Seong-Cheol Kwon ◽  
Mun-Shin Jo ◽  
Hyun-Ung Oh
Keyword(s):  
Vibration Isolation ◽  
Application Form ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Static Tests ◽  
Resolution Observation ◽  
Passive Vibration Isolation ◽  
Basic Characteristics ◽  
Vibration Isolation Performance ◽  
Isolation Performance

On-board appendages with mechanical moving parts for satellites produce undesirable micro-jitters during their on-orbit operation. These micro-jitters may seriously affect the image quality from high-resolution observation satellites. A new application form of a passive vibration isolation system was proposed and investigated using a pseudoelastic SMA mesh washer. This system guarantees vibration isolation performance in a launch environment while effectively isolating the micro-disturbances from the on-orbit operation of jitter source. The main feature of the isolator proposed in this study is the use of a ring-type mesh washer as the main axis to support the micro-jitter source. This feature contrasts with conventional applications of the mesh washers where vibration damping is effective only in the thickness direction of the mesh washer. In this study, the basic characteristics of the SMA mesh washer isolator in each axis were measured in static tests. The effectiveness of the design for the new application form of the SMA mesh washer proposed in this study was demonstrated through both launch environment vibration test at qualification level and micro-jitter measurement test which corresponds to on-orbit condition.

scholarly journals Modeling and Control of a Six Degrees of Freedom Maglev Vibration Isolation System

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3608 ◽  
Author(s):  
Qianqian Wu ◽  
Ning Cui ◽  
Sifang Zhao ◽  
Hongbo Zhang ◽  
Bilong Liu
Keyword(s):  
Dynamic Model ◽  
Nonlinear Dynamic ◽  
Degrees Of Freedom ◽  
Vibration Isolation ◽  
Nonlinear Dynamic Model ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Modeling And Control ◽  
And Control ◽  
Isolation Performance

The environment in space provides favorable conditions for space missions. However, low frequency vibration poses a great challenge to high sensitivity equipment, resulting in performance degradation of sensitive systems. Due to the ever-increasing requirements to protect sensitive payloads, there is a pressing need for micro-vibration suppression. This paper deals with the modeling and control of a maglev vibration isolation system. A high-precision nonlinear dynamic model with six degrees of freedom was derived, which contains the mathematical model of Lorentz actuators and umbilical cables. Regarding the system performance, a double closed-loop control strategy was proposed, and a sliding mode control algorithm was adopted to improve the vibration isolation performance. A simulation program of the system was developed in a MATLAB environment. A vibration isolation performance in the frequency range of 0.01–100 Hz and a tracking performance below 0.01 Hz were obtained. In order to verify the nonlinear dynamic model and the isolation performance, a principle prototype of the maglev isolation system equipped with accelerometers and position sensors was developed for the experiments. By comparing the simulation results and the experiment results, the nonlinear dynamic model of the maglev vibration isolation system was verified and the control strategy of the system was proved to be highly effective.

Transfer function of an ultralow frequency vibration isolation system

1995 ◽  
Vol 66 (5) ◽  
pp. 3216-3218 ◽  
Author(s):  
Jiangfeng Liu ◽  
John Winterflood ◽  
David G. Blair
Keyword(s):  
Transfer Function ◽  
Vibration Isolation ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Ultralow Frequency

On an Improvement of Hybrid Vibration Isolation System

1997 ◽  
Author(s):  
Kazuki Mizutani ◽  
Yoshitaka Fujita ◽  
Ryojun Ikeura
Keyword(s):  
Hybrid System ◽  
Vibration Isolation ◽  
Control Method ◽  
Weighting Function ◽  
Phase Lag ◽  
Frequency Range ◽  
Active System ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Isolation Performance

Abstract This paper proposes a hybrid-type vibration isolation system controlled by a phase compensated LQ control method with a frequency shaped weighting function. The hybrid system is composed of a passive spring-damper system reducing vibrations of high frequency range and an active one reducing those of low frequency range. This system is controlled by the phase compensated digital LQ optimization method with a frequency shaped weighting function. By the proposed method, the phase-lag of the control system is compensated so that the vibration isolation performance is improved. Simulations for the active system are carried out and the effectiveness of the phase compensation is shown. Then, experiments for the hybrid system are carried out for sinusoidal or random excitations. It is confirmed that the purposed hybrid system has the excellent isolation performance for excited vibrations over the wide frequency range.

Vibration Isolation of Precision Payloads for Aerial Vehicles Using Magnetorheological Isolators

2005 ◽  
Author(s):  
Young-Tai Choi ◽  
Mikel Brigley ◽  
Norman M. Wereley
Keyword(s):  
Vibration Isolation ◽  
Control Input ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Aerial Vehicles ◽  
Lqg Control ◽  
Field Control ◽  
Aerial Vehicle ◽  
Vibration Isolation Performance ◽  
Isolation Performance

This study addresses the application of MR (magnetorheological) isolators to vibration isolation of precision payloads for aerial vehicles. To this end, a precision payload in an aerial vehicle is modeled as a six-degree-of-freedom (DOF) lumped parameter model of a sensor assembly. An MR isolator is modeled as a 3-DOF passive spring-damping element and a 3-DOF semi-active yield force due to the yield stress of an MR fluid. Three MR isolators are configured with equal installation angles between the precision payload and the base structure in the aerial vehicle. The governing equations of motion for the MR vibration isolation system of the precision payload for the aerial vehicle are derived and then key parameters of the MR isolators, such as stiffness, damping, and isolator orientation, are determined via a global optimization method. The simulated response of the passive MR vibration isolation system with no magnetic field control input and constant magnetic field control input are presented and analyzed under different excitation conditions. To improve the passive MR vibration isolation performance, a linear quadratic Gaussian (LQG) control algorithm is designed. Finally, simulated responses of the semi-active MR vibration isolation performance using LQG control are evaluated and compared with those of passive (zero or constant field) MR vibration isolation systems.

Vibration Isolation and Chaotic Vibration

2003 ◽  
Author(s):  
Rong-Jun Jiang ◽  
Shi-Jian Zhu
Keyword(s):  
Nonlinear Vibration ◽  
Vibration Isolation ◽  
Harmonic Excitation ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Chaotic Vibration ◽  
Vibration State ◽  
Vibration Isolation Performance ◽  
Isolation Performance ◽  
Better Than

Taking single degree of freedom vibration isolation system under simple harmonic excitation as an example, and considering the energy, the vibration isolation performance in different conditions was studied theoretically and numerically. The results shows that when the simple harmonic excitation import energy is definite, the vibration isolation performance at the primary harmonic frequency of the nonlinear vibration isolation system is better than that of the linear system, and the vibration isolation performance of the nonlinear vibration isolation system in chaotic vibration state is much better than that in non-chaotic vibration state. For the same isolated object, if can let the vibration isolation system vibrate chaotically, the system will possess the best isolation performance at the primary frequency.

System Identification Based on Recursive Least Square Method for the Magnetic Suspension Active Vibration Isolation System

2012 ◽  
Vol 150 ◽  
pp. 105-110 ◽  
Author(s):  
Bei Bei Yang ◽  
Ye Fa Hu ◽  
Guo Ping Ding
Keyword(s):  
System Identification ◽  
Transfer Function ◽  
Vibration Isolation ◽  
Isolation Effect ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Transfer Function Matrix ◽  
Active Vibration ◽  
System Transfer Function ◽  
Function Matrix

In this paper, we use recursive least squares method for magnetic single layer vibration isolation system identification to get the system transfer function matrix. By considering the fitting degree, pole-zero, the step response to adjust the order of model and noise structure for optimizing the model Identification. Applying the system transfer function matrix to the magnetic active vibration control system to improve the isolation effect. The results showed that: significantly improved isolation effect, verify the validity of this identification model for magnetic single isolation system.

Sign in / Sign up

Export Citation Format

Share Document