Three Simple and Efficient Methods for Vibration Control of Slewing Flexible Structures

1993 ◽  
Vol 115 (4) ◽  
pp. 725-730 ◽  
Author(s):  
Y. C. Liu ◽  
S. M. Yang

Three simple and efficient methods are presented for the vibration control of slewing flexible structures. These methods are developed based on the constrained motion method in which the rotational maneuver is formulated as prescribed trajectory constraint. The constrained motion method in two stage, CMM-TS, accomplishes the first stage rigid-body slewing motion and minimizes the flexible body vibration at terminal state by an optimal control law. The constrained motion method with active damping, CMM-AD, employs piezoelectric actuator with velocity feedback for active damping control. The required slewing time and settling time is governed by the control torque and control voltage, respectively. The third method, CMM-CO, combines the active damping and optimal torque control for vibration suppression during and after the slewing motion. All methods are shown to be efficient in computation, concise in formulation, and effective in hardware realizable application.

1995 ◽  
Vol 117 (3) ◽  
pp. 432-435 ◽  
Author(s):  
Y. C. Liu ◽  
S. M. Yang

Two high-authority control/low-authority control algorithms are presented and experimentally validated on a fast slewing beam system. The first one termed the constrained motion method in two-stage (CMM-TS) accomplishes the rigid-body motion control and the optimal control of vibration suppression by a stepping motor. Another termed the constrained motion method in combination (CMM-CO) combines both the optimal control from stepping motor and active damping control from piezoelectric actuator for vibration suppression. Experimental results show that these algorithms are concise in formulation, efficient in hardware realization, and effective in vibration suppression.


2020 ◽  
Vol 20 (08) ◽  
pp. 2050095
Author(s):  
Yifan Lu ◽  
Qi Shao ◽  
Fei Yang ◽  
Honghao Yue ◽  
Rongqiang Liu

Different kinds of membrane structures have been proposed for future space exploration and earth observation. However, due to the low stiffness, high flexibility, and low damping properties, membrane structures are likely to generate large-amplitude (compared to the thickness) vibrations, which may lead to the degradation of their working performance. In this work, the governing equations are established at first, taking into account the modal control force induced by the polyvinylidene fluoride (PVDF) actuator. The optimal vibration control of the membrane structure is explored subsequently. A square PVDF actuator is attached on the membrane to achieve the vibration suppression. The influence of actuator position and control gains on the vibration control performance are studied. The optimal criteria for actuator placement and energy allocation are developed. Several case studies are numerically simulated to demonstrate the validity of the proposed optimization criteria. The analytical results in this study can serve as guidelines for optimal vibration control of membrane structures. Additionally, the proposed optimization criteria can be applied to active control of different flexible structures.


Author(s):  
H. Gu ◽  
G. Song

Positive position feedback (PPF) control is widely used in active vibration control of flexible structures. To ensure the vibration is quickly suppressed, a large PPF scalar gain is often applied in a PPF controller. However, PPF control with a large scalar gain causes initial overshoot, which is undesirable in many situations. In this paper, a fuzzy gain tuner is proposed to tune the gain in the positive position feedback control to reduce the initial overshoot while still maintaining a quick vibration suppression. The fuzzy system is trained by the desired input-output data sets by batch least squares algorithm so that the trained fuzzy system can behave like the training data. A 3.35 meter long I-beam with piezoceramic patch sensors and actuators is used as the experimental object. The experiments include the standard PPF control, standard PPF control with traditional fuzzy gain tuning, and PPF control with batch least squares fuzzy gain tuning. Experimental results clearly demonstrate that PPF control with batch least squares fuzzy gain tuner behaves much better than the other two in terms of successfully reducing the initial overshoot and quickly suppressing vibration.


2020 ◽  
Vol 26 (21-22) ◽  
pp. 2026-2036
Author(s):  
Xiangdong Liu ◽  
Haikuo Liu ◽  
Changkun Du ◽  
Pingli Lu ◽  
Dongping Jin ◽  
...  

The objective of this work was to suppress the vibration of flexible structures by using a distributed cooperative control scheme with decentralized sensors and actuators. For the application of the distributed cooperative control strategy, we first propose the multiple autonomous substructure models for flexible structures. Each autonomous substructure is equipped with its own sensor, actuator, and controller, and they all have computation and communication capabilities. The primary focus of this investigation was to illustrate the use of a distributed cooperative protocol to enable vibration control. Based on the proposed models, we design two novel active vibration control strategies, both of which are implemented in a distributed manner under a communication network. The distributed controllers can effectively suppress the vibration of flexible structures, and a certain degree of interaction cooperation will improve the performance of the vibration suppression. The stability of flexible systems is analyzed by the Lyapunov theory. Finally, numerical examples of a cantilever beam structure demonstrate the effectiveness of the proposed methods.


2020 ◽  
Vol 125 (1283) ◽  
pp. 244-255
Author(s):  
G. Ma ◽  
M. Xu ◽  
J. Tian ◽  
X. Kan

ABSTRACTThis paper provides a solution to the active vibration control of a microsatellite with two solar panels. At first, the microsatellite is processed as a finite element model containing a rigid body and two flexible bodies, according to the principles of mechanics, and that the dynamic characteristics are solved by modal analysis. Secondly, the equation involving vibration control is established according to the finite element calculation results. There are several actuators composed of macro fibre composite on the two solar panels for outputting control force. Furthermore, the control voltage for driving actuator is calculated by using fuzzy algorithm. It is clear that the smart structure consists of the flexible bodies and actuators. Finally, the closed-loop control simulation for suppressing harmful vibration is established. The simulation results illustrate that the responses to the external excitation are decreased significantly after adopting fuzzy control.


2020 ◽  
pp. 089270572093074
Author(s):  
Rajeshkumar Selvaraj ◽  
Manoharan Ramamoorthy

Magnetorheological (MR) materials are kinds of smart materials whose rheological characteristics are controllable with the application of external magnetic fields. In the last few decades, MR materials are well established as one of the leading smart materials for use in adaptive sandwich structures and systems for salient vibration control. This article reviews the semi-active vibration suppression of flexible structures with smart materials of MR fluids (MRFs) and MR elastomers (MREs). Stiffness and damping characteristics of beams, plates, panels, and shells integrating the core layer of MRFs and MREs are discussed in terms of field-dependent controllability. To keep the integrity of the knowledge, this review includes a study on free and forced vibration characteristics of sandwich structures with fully and various configurations of partial MR treatments, stability analysis of MR sandwich structures under rotating conditions and developments in identifying the optimal locations of MR sandwich structures for better vibration control are also discussed. Further, this article focuses on the role of carbon nanotubes in enhancing the field-dependent stiffness and damping properties of MR materials. A few of the most relevant research articles are reviewed and presented here briefly.


2013 ◽  
Vol 20 (4) ◽  
pp. 693-709 ◽  
Author(s):  
R.B. He ◽  
S.J. Zheng ◽  
H.T. Wang

Photostrictive actuator, which can produce photodeformation strains under the activation of ultraviolet lights, is a new promising non-contact photoactuation technique for active vibration control of flexible structures. Generally, the membrane control action plays a major role in vibration control of flexible thin shell structures. However, it is unfortunate that the existing photostrictive actuator configuration can not induce negative membrane control forces. In this paper, a novel multi-layer actuator configuration is first presented to remedy this deficiency, followed by presenting the photostrictive/shell coupling equations of thin cylindrical shells laminated with the proposed multi-layer actuator configuration. Moreover, considering the time-variant and nonlinear dynamic characteristics of photostrictive actuator, variable structure self-adjusting parameter fuzzy active controller is explored to overcome disadvantages of conventional control schemes, in which off-line fuzzy control table is adopted. The optimal switching surface is derived to increase the range of sliding mode to facilitate vibration suppression. A continuous function is used to replace the sign function for reducing the variable structure control chattering. Finally, two case studies are carried out to evaluate the effectiveness of the proposed actuator configuration and the control scheme. Numerical simulation results demonstrate that the proposed actuator configuration is effective in shell actuation and control. It is also suggested that the proposed control strategy could give better control responses than the proportional velocity feedback.


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