• 한국소음진동공학회논문집
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• 제18권7호
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• pp.756-763
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• 2008

This paper presents an inchworm with three piezoelectric actuators. The dynamic stiffness of the inchworm is generally low compared to its driving condition, so mechanical vibration may degenerate the motion accuracy of the inchworm. The dynamic model of inchworm is identified by curve fitting technique based on the experimental frequency response function. For the precision motion control and low residual vibration of inchworm, driving input signal is designed by using cycloid step input and LQG control technique. Experimental result shows that proposed input shaping method is applicable effectively to the inchworm.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.44-44
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• 2007

New inchworm type piezoelectric actuator design, which can reduce the number of the piezoelectric body for manufacturing inchworm type actuator, is suggested in this work. Inchworm type actuator consists of three or more piezoelectric bodies, on the other hand the new-designed inchworm type actuator has only one piezoelectric body. The one piezoelectric body that size is $2\;{\times}\;2\;{\times}\;4\;[mm^2]$ (DWL) has 2 clamping part and 1 extending part. The size of the new-designed actuator with one piezoelectric body is $5\;{\times}\;6\;{\times}\;9\;[mm^2]$ (DWL). The new-designed inchworm type actuator performed the operation at a cycle (6 steps) of $0.3{\mu}m$ per $33.3{\mu}s$ and a generated force of 0.6N.

• 로봇학회논문지
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• 제2권2호
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• pp.178-182
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• 2007

Precision stages are essential device for micro machines, fiber optic assembly systems, and biology instruments. In this paper, a precision inchworm type actuator for a linear stage is proposed and evaluated. An analytic method to design an inchworm type motor is proposed. Developed actuator provides fast motion compared with a commercial inchworm actuator, and can be used as an actuator for a stage in substitution for a conventional rotary actuator.

• 한국소음진동공학회논문집
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• 제15권7호
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• pp.878-884
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• 2005

This paper presents an algorithm for the precision motion control based on the dynamic characteristics of piezoelectric actuators in the inchworm. The dynamic characteristics are identified by the frequency domain modeling technique using the experimental data. For the motion control, the hysteresis behavior is compensated by the inverse hysteresis model. The dynamic stiffness of an inchworm is generally low compared to its driving condition, so mechanical vibration may degenerate the motion accuracy of the inchworm. The Sliding mode controller and the Kalman filter are designed for motion control of the inch-worm.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.843-848
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• 2000

In general, inchworm actuators are composed of two clamping piezoelectric elements and one expansion piezoelectric element. In this paper, two electromagnetic clampers are used for higher speed and high load. Dynamic equation is derived to simulate the behavior of the inchworm actuator with electromagnets. Electromagnetic clamper is used to improve the performance of the inchworm actuator. The electromagnetic clamper is composed of two permanent magnets and one traditional electromagnet. The permanent magnets play the role of the source of magnetic field to make clamping force higher, and the electromagnet is to change the mode between clamping and free. The driving voltage profile is also analyzed to improve the speed of inchworm actuator. The real system was manufactured and experimented to find dynamic characteristics and the maximum speed is obtained. Dynamic model is verified by comparing with experimental results.

• 한국공작기계학회논문집
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• 제18권2호
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• pp.137-143
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• 2009

This paper presents the fabrication of inchworm motor for high precision actuator system of large displacement and high force. The inchworm motor consists of a extend actuator that provides displacement of tool guide and two clamping actuators which provide the holding force. In order to avoid the PZT fracture, design of pre-load housing was conducted by flexure hinge structure, because PZT actuator has low tensile and shear. To design the pre-load housing and optimize the clamping mechanism, the static and dynamic analysis were conducted by finite element method. From these results, a prototype of the inchworm motor was fabricated and dynamic characteristic with respect to the various frequency was tested. The maximum velocity of the inchworm motor was $41.1{\mu}m/s$ at 16Hz.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.1239-1240
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• 2010

• 한국정밀공학회지
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• 제21권12호
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• pp.174-181
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• 2004

Ultra precision positioning mechanism has widely been used on semiconductor manufacturing equipments, optical spectrum analyzer and cell manipulations. Ultra precision positioning mechanism is consisted of several actuators, sensors, guides and control systems. Its efficiency depends on each performance of components. The object of this study is to design, analysis and manufacture all of the inchworm linear motor system, which is one of the equipments embodied in ultra precision positioning mechanism. Inchworm linear motor system is consisted of a controller system and an inchworm linear motor, and its driving form is similar to a motion of spanworm. A design and manufacture of inchworm linear motor, which is consisted of three PZT actuators, a rod, two columns and a guide plate, are performed. Minimizing the von-Mises stress of the hinge using Taguchi method and simulation by FEM software optimizes the structural design in a column of flexure hinge. The designed columns and guide plates are manufactured by a W-EDM and NC-milling. A controller system, which is an apparatus to drive inchworm linear motor, can easily adjust driving conditions by varying resonance frequency and input-output voltage of actuators and amplifiers. The performance of manufactured inchworm linear motor system is verified and valuated. In the future, inchworm linear motor system will be used to make a more precision positioning by reinforcing a sensor and feedback system.

• 대한영상의학회지
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• 제81권5호
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• pp.1194-1203
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• 2020

목적 본 연구의 목적은 수술 전 표재성 방광암(T1 또는 그 이하 병기)을 확인하기 위한 자기공명영상의 stalk sign 및 inchworm sign의 진단적 능력을 평가하는 것이다. 또 다른 목적은 두 sign 간의 진단적 능력의 차이를 비교하는 것이다. 대상과 방법 방광전절제술을 시행 받은 총 240명의 환자들(505개의 종양들)을 후향적으로 검토하였다. 모든 종양은 3.0 테슬러 자기공명영상에서 T2 강조영상의 stalk sign 또는 확산강조영상의 inchworm sign을 발견함으로써 표재성 종양 및 침윤성 종양으로 분류하였다. 이를 수술 후 병리학적 T 병기와 비교함으로써 통계학적으로 진단적 의의를 평가하였고 두 sign 간의 진단적 능력 차이를 비교하였다. 결과 Stalk sign 및 inchworm sign은 높은 특이도(93%, 91%), 양성예측도(89%, 90%), 정확도(70%, 74%)를 보였으나 낮은 민감도(54%, 61%)와 음성예측도(60%, 63%)를 보였다. 두 sign 간의 진단적 능력에서 통계학적 유의미한 차이는 없었다(p > 0.05). 결론 수술 전 T2 강조영상의 stalk sign과 확산가중영상의 inchworm sign을 발견함으로써 표재성 방광암을 쉽게 진단할 수 있다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.1088-1091
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• 1997

This paper describes the characteristic of hinges on which a lever pivots within a limited angle due to the torque. The hinges are exerted by the thermally expanded actuators connected with a level through hinges. To enhance the stroke of inchworm actuator, FEM(Finite Element Method) was utilized for the characterization in view of stress displacement according to the variation of notch radius and notch width. As a result, notch width of the hinges plays an important part in improvement of micro inchworm actuator.