프로펠라 샤프트의 능동진동제어 시스템

이재문(Jae-Mun Lee),이철희(Chul-Hee Lee) 한국자동차공학회 2009 한국자동차공학회 학술대회 및 전시회 Vol.2009 No.11

This paper presents a solution of the vibration reduction in the Propeller shafts. Generally, the vibration mode in propeller shafts can be divided into the bending and torsional vibrations. And the bending vibration is significant factor when it excites with the resonance frequencies in the propeller shafts. However, since the torsional vibration is also the critical source of vibration problem in the propeller shaft, it is necessary to analyze bending and torsion vibration together with the natural frequencies. In this paper, active vibration control system of propeller shafts is introduced to actively absorb the combined bending and torsional vibrations. Proposed active damping structure is built by embedding the piezofiber actuators that are composed of piezopatches based on the Macro Fiber Composite (MFC) technology. The MFC is an innovative actuator that offers high performance and flexibility. The MFC consists of rectangular piezo ceramic rods sandwiched between layers of adhesive and electroded polyimide film, which is heat and chemical resistant polymers. Since the MFC patch is more flexible, durable and powerful than other piezo-materials, it is the best candidate of actuator to apply to the curved surface of the shaft. In order to calculate the vibration modes in the propeller shafts, analytical method and Finite Element Method are used. And to simulate effect of vibration damping, Piezoelectric-thermal analysis is used, too. Experimental investigations are also conducted by PID controller. For the desired vibration damping performance with the limited number of MFC actuators, PID controller is designed and its gains are tuned. Finally, control results are shown. So, the results provide an outlook for the active control using the multi-mode resonance controllers.

Active Vibration Control Method Using Frequency Controllable Piezoelectric Transducer

김정순,김무준,하강렬,강성학,Kim, Jung-Soon,Kim, Moo-Joon,Ha, Kang-Lyeol,Kang, Sung-Hak The Acoustical Society of Korea 2007 韓國音響學會誌 Vol.26 No.e1

Hydraulic actuator and electro-magnetic liner actuator have been used as typical active vibration control methods. However these methods have many kinds of disadvantages such as causing space limit, difficult maintenance, complicate structures, etc. The purpose of this paper was to study on the possibility of active vibration control using piezoelectric transducer. Piezoelectric transducer generated a vibration and GIC (General Impedance Converter) amplifier was adopted to give adjustable vibration signal to transducer and high amplitude of vibration. Resonance frequency of piezoelectric transducer was controlled by GIC amplifier and higher amplitude of vibration was achieved. Finally active vibration control using piezoelectric transducer was performed.

Feedback control strategies for active control of noise inside a 3-D vibro-acoustic cavity

Ashok K. Bagha,Subodh V. Modak 국제구조공학회 2017 Smart Structures and Systems, An International Jou Vol.20 No.3

This paper presents and compares three feedback control strategies for active control of noise inside a 3-D vibro-acoustic cavity. These are a) control strategy based on direct output feedback (DOFB) b) control strategy based on linear quadratic regulator (LQR) to reduce structural vibrations and c) LQR control strategy with a weighting scheme based on structural-acoustic coupling coefficients. The first two strategies are indirect control strategies in which noise reduction is achieved through active vibration control (AVC), termed as AVC-DOFB and AVC-LQR respectively. The third direct strategy is based on active structural-acoustic control (ASAC). This strategy is an LQR based optimal control strategy in which the coupling between the various structural and the acoustic modes is used to design the controller. The strategy is termed as ASAC-LQR. A numerical model of a 3-D rectangular box cavity with a flexible plate (glued with piezoelectric patches) and with other five surfaces treated rigid is developed using finite element (FE) method. A single pair of collocated piezoelectric patches is used for sensing the vibrations and applying control forces on the structure. A comparison of frequency response function (FRF) of structural nodal acceleration, acoustic nodal pressure, and piezoelectric actuation voltage is carried out. It is found that the AVC-DOFB control strategy gives equal importance to all the modes. The AVC-LQR control strategy tries to consume the control effort to damp all the structural modes. It is seen that the ASAC-LQR control strategy utilizes the control effort more intelligently by adding higher damping to those structural modes that matter more for reducing the interior noise.

전단형 MR 댐퍼 및 Clipped-optimal 제어알고리즘을 이용한 사장교의 실시간 준능동 진동제어

허광희,전준용,전승곤 한국지진공학회 2016 한국지진공학회논문집 Vol.20 No.2

This paper is concerned with an experimental research to control of random vibration caused by external loads specially in cable-stayed bridges which tend to be structurally flexible. For the vibration control, we produced a model structure modelled on Seohae Grand Bridge, and we designed a shear type MR damper. On the center of its middle span, we placed a shear type MR damper which was to control its vibration and also acquire its structural responses such as displacement and acceleration at the same site. The experiments concerning controlling vibration were performed according to a variety of theories including un-control, passive on/off control, and clipped-optimal control. Its control performance was evaluated in terms of the absolute maximum displacements, RMS displacements, the absolute maximum accelerations, RMS accelerations, and the total power required to control the bridge which differ from each different experiment method. Among all the methods applied in this paper, clipped-optimal control method turned out to be the most effective to reduces of displacements, accelerations, and external power. Finally, It is proven that the clipped-optimal control method was effective and useful in the vibration control employing a semi-active devices such MR damper.

Multicyclic Vibration Control of a Helicopter Rotor with Active Twist Actuation

김도형,홍성현,정성남 한국항공우주학회 2022 International Journal of Aeronautical and Space Sc Vol.23 No.2

The vibration control performance of a Mach scaled Bo-105 rotor is evaluated using the active twist multicyclic control. The simulation data for the baseline flight condition are generated using CAMRAD II. A linear, quasi-static, frequency domain model with up to 6 multicyclic higher harmonic control inputs and 12 harmonic response outputs of non-rotating hub loads are identified offline by the least squared error estimate. The optimal control input for minimizing the quadratic performance function along with the output response to the optimal control are calculated. The vibration reduction performances with the obtained optimal control input are examined. The single harmonic control results show close agreement with the low vibration conditions by the amplitude and phase sweep method. When the multicyclic control is applied, the vibration reduction performance is improved compared to the single harmonic control case, and the hub vibration is reduced by up to 64%. A coupling of MATLAB and CAMRAD II is used to evaluate closed-loop multicyclic control systems. The coupled closed-loop analysis result shows good agreement with the simulation result using identified linear system model. The closed-loop control using the gradient descent algorithm shows excellent vibration reduction performance with the reduced vibration level converges to the optimal solution.

Review of Active Rotor Control Research in Canada

Daniel Feszty,Fred Nitzsche 한국항공우주학회 2011 International Journal of Aeronautical and Space Sc Vol.12 No.2

The current status of Canadian research on rotor-based actively controlled technologies for helicopters is reviewed in this paper. First, worldwide research in this field is overviewed to put Canadian research into context. Then, the unique hybrid control concept of Carleton University is described, along with its key element, the “stiffness control” concept. Next, the smart hybrid active rotor control system (SHARCS) project`s history and organization is presented, which aims to demonstrate the hybrid control concept in a wind tunnel test campaign. To support the activities of SHARCS, unique computational tools, novel experimental facilities and new know-how had to be developed in Canada, among them the state-of-the-art Carleton Whirl Tower facility or the ability to design and manufacture aeroelastically scaled helicopter rotors for wind tunnel testing. In the second half of the paper, details are provided on the current status of development on the three subsystems of SHARCS, i.e. that of the actively controlled tip, the actively controlled flap and the unique stiffness-control device, the active pitch link.

능동마운트 제어를 위한 제어기 비교 실험

양동호(Dong-Ho Yang),곽문규(Moon K. Kwak),김정훈(Jung-Hoon Kim),박운환(Woon-Hwan Park),심호석(Ho-Seok Kim) 한국소음진동공학회 2010 한국소음진동공학회 학술대회논문집 Vol.2010 No.10

Vibrations caused by automobile engine are absorbed mostly by a passive-type engine mount. However, user specifications for automobile vibrations require more stringent conditions and higher standard. Hence, active-type engine mount have been developed to cope with such specifications. The active-type engine mount consists of sensor, actuator and controller where a control algorithm is implemented. The performance of the active engine mount depends on the control algorithm if the sensor and actuator satisfies the specification. The control algorithm should be able to suppress persistent vibrations caused by the engine which are related to engine revolution. In this study, three control algorithms are considered for suppressing persistent vibrations, which are the positive position feedback control algorithm, the strain-rate feedback control algorithm, and the modified higher harmonic control algorithm. Experimental results show that all the control algorithms considered in this study are effective in suppressing resonant vibrations but the modified higher harmonic controller is the most effective controller for non-resonant vibrations.

Active vibration control of clamped beams using positive position feedback controllers with moment pair

Shin, Chang-Joo,Hong, Chin-Suk,Jeong, Weui-Bong 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.3

This paper investigates the active vibration control of clamp beams using positive position feedback (PPF) controllers with a sensor/ moment pair actuator. The sensor/moment pair actuator which is the non-collocated configuration leads to instability of the control system when using the direct velocity feedback (DVFB) control. To alleviate the instability problem, a PPF controller is considered in this paper. A parametric study of the control system with PPF controller is first conducted to characterize the effects of the design parameters (gain and damping ratio in this paper) on the stability and performance. The gain of the controller is found to affect only the relative stability. Increasing the damping ratio of the controller slightly improves the stability condition while the performance gets worse. In addition, the higher mode tuned PPF controller affects the system response at the lower modes significantly. Based on the characteristics of PPF controllers, a multi-mode controllable SISO PPF controller is then considered and tuned to different modes (in this case, three lowest modes) numerically and experimentally. The multi-mode PPF controller can be achieved to have a high gain margin. Moreover, it reduces the vibration of the beam significantly. The vibration levels at the tuned modes are reduced by about 11 dB.

Test and Simulation of an Active Vibration Control System for Helicopter Applications

김도형,김태주,정세운,곽동일 한국항공우주학회 2016 International Journal of Aeronautical and Space Sc Vol.17 No.3

A significant source of vibration in helicopters is the main rotor system, and it is a technical challenge to reduce the vibration in order to ensure the comfort of crew and passengers. Several types of passive devices have been applied to conventional helicopters in order to reduce the vibration. In recent years, helicopter manufacturers have increasingly adopted active vibration control systems (AVCSs) due to their superior performance with lower weight compared with passive devices. AVCSs can also maintain their performance over aircraft configuration and flight condition changes. As part of the development of AVCS software for light civil helicopter (LCH) applications, a test bench is constructed and vibration control tests and simulations are performed in this study. The test bench, which represents the airframe, is excited using a pair of counter rotating force generators (CRFGs) and a multiple input single output (MISO) AVCS that consists of three accelerometer sensors and a pair of CRFGs; a filtered-x least mean square (LMS) algorithm is applied for the vibration reduction. First, the vibration control tests are performed with uniform sensor weights; then, the change in the control performance according to changes in the sensor weight is investigated and compared with the simulation results. It is found that the vibration control performance can be tuned through adjusting the weights of the three sensors, even if only one actuator is used.

고차 발란서를 이용한 선박 거주구 능동 진동 제어

서윤호,김성훈,주원호,배종국 대한조선학회 2011 대한조선학회 학술대회자료집 Vol.2011 No.11

Active vibration control by a vibration compensator has become popular due to effective vibration reduction and immediate countermeasure of high vibration. General vibration compensator is operated by using constant control phase with respect to the rotational speed of the propeller. Even if the constant control phase can reduce the vibration level over a part of the operation range, the vibration compensator may increase the vibration level over the other part of the operation range. In this paper, a new method to calculate optimal control phase from an additional accelerometer was developed. The method is a kind of system identification methods from two test excitations. By using the method, the vibration compensator can reduce the vibration level over all operational range regardless of loading conditions and propeller speeds. During the sea trial of the container carrier, the new method is validated to be able to reduce the vibration level by 90% in maximum.