• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.756-759
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• 2004

We present a piezoelectric actuator using stiffness control and stroke amplification mechanism in order to make large lateral displacement. In this work, we suggest stiffness control approach that generates lateral displacement by increasing the vertical stiffness and reducing the lateral stiffness using additional structure. In addition, an additional structure of a serpentine spring amplifies the lateral displacement like leverage structure. The suggested lateral PZT actuator (bellows actuator) consists of serpentine spring and PZT/electrode layer which is located at the edge of the serpentine spring. The edge of the serpentine spring prevents the vertical motion of PZT layer, while the other edge of the serpentine spring makes stroke amplification like leverage structure. We have determined dimensions of the bellows actuator using ANSYS simulation. Length, width and thickness of PZT layer are 135$\mu$m, 20$\mu$m and 0.4$\mu$m, respectively. Dimensions of the silicon serpentine spring are thickness of 25$\mu$m, length of 300$\mu$m, and width of 5$\mu$m. The bellows actuator has been fabricated by SOI wafer with 25$\mu$m-top silicon and 1$\mu$m-buried oxide layer. The bellows actuator shows the maximum 3.93$\pm$0.2$\mu$m lateral displacement at 16V with 1Hz sinusoidal voltage input. In the frequency response test, the fabricated bellows actuator showed consistent displacement from 1Hz to 1kHz at 10V. From experimental study, we found the bellows actuator using thin film PZT and silicon serpentine spring generated mainly laterally displacement not vertical displacement at 16V, and serpentine spring played role of stroke amplification.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.481-483
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• 2004

Many application in robotics, telecommunication, automation systems etc require powerful actuator. The powerful actuator have Speeds up to high speed and high output torque efficiencies. To accomplish a powerful actuator, these powerful motor have to be combined with gearheads of the same outer diameter. So, we have developed BLDC motor and planetary type gearheads as powerful actuator. The BLDC motor have advantages that compact structure, high efficiency, high reliability. The Planetary type gearheads have advantages that same-axle structure, high torque transmission, low noise in comparison with spur gearheads. In this study included BLDC motor and planetary type gearheads design, manufacture. This time study performed for actuator of precision mechanism.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1996년도 춘계학술대회논문집; 부산수산대학교, 10 May 1996
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• pp.130-135
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• 1996

This paper presents a proof-concept investigation on the active vibration control of two hybrid smart structures (HSSs). The first one is consisting of a piezoelectric film (PF) actuator and an electro-rheological fluid(ERF) actuator, and the other is featured by a piezoceramic (PZT) actuator and a shape memory alloy (SMA) actuator. For the PF/ERF hybrid smart structure, both the increment of the damping ratios and the suppression of the tip deflections are evaluated in order to demonstrate control effectiveness of the PF actuator and ERF actuator and the hybrid actuation. For the PZT/SMA hybrid smart structure, the PZT actuator takes account of the high frequency excitation, while the SMA actuator exerts large vibration control force. The experimental results exhibit superior abilities of the hybrid actuation systems to tailor elastodynamic responses of the HSS rather than a single class of actuation system alone.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.397-400
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• 2000

The demands of high data transfer rate and high recording density in optical disk memory device are being increased. In order to achieve high performance, lever actuator for optical disk is proposed. Firstly, the role of lever and structure are discussed and the flexure hinge is introduced to enhance the precise movement. Next is to present the magnetic circuit structure and concept design for the lever actuator. Finally, the dynamic modeling of the lever actuator is found and the analysis results are shown. Consequently, the lever actuator shows the possibility as a pickup actuator for the next generation optical disk.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3322-3324
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• 1999

This paper studies on the design and fabrication of a micro in-plane positioning actuator integrated with a microlens. Proposed in-plane actuator is a micro XY-stage which is composed of two linear comb drive actuators being orthogonal to each other. In the fabrication of actuator, the single crystalline silicon substrate anodically bonded with a #7740 glass substrate is used because of simple release and passivation. The structure of actuator is formed on the silicon facet of bonded fixture by chlorine-based deep RIE and then released by isotropic wet etching of glass (#7740) in hydrofluoric acid solution. Fabricated actuator has a large travel range up to $30({\pm}15){\mu}m$ and high resolution less than 0.01f1l1l in each direction. Experimented resonant frequency of this actuator is 630Hz. The micro-Fresnel lens is fabricated on the square-shape glass structure prepared in the center of actuator.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.785-788
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• 2003

Many application in robotics, telecommunication, automation systems etc require powerful actuator. The powerful actuator have Speeds up to high speed and high output torque efficiencies. To accomplish a powerful actuator, these powerful motor have to be combined with gearheads of the same outer diameter. So, we have developed BLDC motor and planetary type gearheads as powerful actuator. The BLDC motor have advantages that compact structure, high efficiency, high reliability. The Planetary type gearheads have advantages that same-axle structure, high torque transmission, low noise in comparison with spur gearheads. In this study included BLDC motor and planetary type gearheads design, manufacture. This time study performed for actuator of precision mechanism.

• 한국정밀공학회지
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• 제22권9호
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• pp.147-154
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• 2005

A precision hi-directional actuator for a high precision leveling system with $Z{\Theta}_x{\Theta}_y$ motions is proposed and designed in this paper. The actuator is composed of a force generation structure, a guide mechanism, and a symmetric structure. At first, its driving force is generated by a change of flux in air gaps by permanent and changeable flux. The permanent flux is generated by a permanent magnet. The changeable flux is created by variable current flowing through coil. The combination of permanent and changeable flux makes various flux densities in air gaps between moving part and fixed yokes. And then, the difference between flux densities in lower and upper gaps creates forces fur the $bi-direction({\pm}z)$ motion. The guide mechanism of this actuator is composed of two circular plates and one shaft. Reducing motions generated by forces except z-motion, these circular plates endow the actuator with high stiffness for fast settling time. And the function of the shaft is to transfer motion to an object. At last, total body has a symmetric structure to be stable on thermal error. The actuator is designed by MAXWELL 2D and ProMECHANICA. The designed actuator is evaluated by 8nm laser doppler vibrometer, dynamic signal analyzer, and simple PID controller.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 추계학술발표대회 논문집
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• pp.228-231
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• 2000

The active vibration control of laminated composite shell has been performed with the optimized sensor/actuator system. PVDF film is used fur the material of sensor/actuator. Finite element method is utilized to model the whole structure including the piezoelectric sensor/actuator system, The distributed selective modal sensor/actuator system is established to prevent the adverse effect of spillover. In the finite element discretization process, the nine-node shell element with five nodal degrees of freedoms is used. Electrode patterns and lamination angles of sensor/actuator are optimized using genetic algorithm. Sensor is designed to minimize the observation spillover, and actuator is designed to minimize the system energy of the control modes under a given initial condition. Modal sensor/actuator profiles are optimized for the first and the second modes suppression of singly curved cantilevered composite shell structure. Discrete LQG method is used as a control law. The real time vibration control with profile optimized sensor/actuator system has been performed. Experimental result shows successful performance of the integrated structure for the active vibration control.

• Journal of Magnetics
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• 제19권2호
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• pp.130-139
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• 2014

This paper focuses on the modeling and analysis a novel two-axis rotary normal-stress electromagnetic actuator with compact structure for fast steering mirror (FSM). The actuator has high force density similar to a solenoid, but its torque output is nearly a linear function of both its driving current and rotation angle, showing that the actuator is ideal for FSM. In addition, the actuator is designed with a new cross topology armature and no additional axial force is generated when the actuator works. With flux leakage being involved in the actuator modeling properly, an accurate analytical model of the actuator, which shows the actuator's linear characteristics, is obtained via the commonly used equivalent magnetic circuit method. Finally, numerical simulation is presented to validate the analytical actuator model. It is shown that the analytical results are in a good agreement with the simulation results.

• Smart Structures and Systems
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• 제4권1호
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• pp.85-98
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• 2008

In this paper, excitation systems using a linear mass shaker (LMS) and an active tuned mass damper (ATMD) are presented to simulate the wind induced responses of a building structure. The actuator force for the excitation systems is calculated by using the inverse transfer function of a target structural response to the actuator. Filter and envelop functions are used to prevent the actuator from exciting unexpected modal responses and an initial transient response and thus, to minimize the error between the wind and actuator induced responses. The analyses results from a 76-story benchmark building problem for which the wind load obtained by a wind tunnel test is given, indicate that the excitation system installed at a specific floor can approximately reproduce the structural responses induced by the wind load applied to each floor of the structure. The excitation system designed by the proposed method can be effectively used for evaluating the wind response characteristics of a practical building structure and for obtaining an accurate analytical model of the building under wind load.