• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.1041-1044
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• 2002

Inchworm linear motor is one of the ultra precision position apparatuses and has many kinds of forms and structures according to the conditions of working space and range. In this paper, the Inchworm linear motor consists of three PZTs(Piezo-electric transducer), three columns ma two plates. finite element method was used to determine the type or hinges installed in column of inchworm linear motor DOE(Design of experiment) was used to determine the optimal design condition of a column by comparing the von-mises stresses according to the change of thickness of hinge, round of hinge, height of arm, angle of v-notch, round of v-notch and thickness of column. From the result, round of hinge, height of arm and thickness of hinge were determined a effective design parameters.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.8
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• pp.685-690
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• 2007

The new design of inchworm-type piezoelectric actuator is presented in this paper, Compared to conventional inchworm-type actuators, which are composed of more than three piezoelectric bodies, we can reduce the number of piezoelectric bodies by employing the proposed design, resulting in only one piezoelectric body. The overall size of the proposed actuator which consists of one piezoelectric body, two clamping parts and one extending part, is only $5{\times}6{\times}9 [mm^3]$ (DWL). The actuating characteristics of fabricated Monolithic Inchworm Type Actuator(MITA), were found to be a displacement of $0.3{\mu}m$, a generating force of 0.6N and an electric power of 0.5W.

• Journal of the Semiconductor & Display Technology
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• v.6 no.1 s.18
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• pp.37-41
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• 2007

Recently PZT is used in ultra precision mechanism field. PZT has a small motion range although it has a high resolution. Many methods, such as inchworm, impact driving, etc., have been applied for the expansion of the motion range.? In this study, the new actuating mechanism for rotational motion with two PZT actuators is proposed. The ultra precision rotational actuator which is made by proposed mechanism is able to operate both coarse and fine motion. The design parameters of the proposed mechanism are considered to improve the performance of the system. The rotational stage which is applied by the proposed mechanism is fabricated. The resolution and velocity for fabricated rotational stage are measured by laser interferometer.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.195-200
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• 2008

This paper presents motion control of the Inchworm composed of the piezoelectric actuators and mechanical elements. Piezoelectric actuator shows nonlinear response characteristics including hysteresis due to the ferroelectric characteristics. This paper proposes feedback control scheme to improve the ability of tracking response to complex input signal and suppress the phenomenon of hysteresis using the sliding mode control technique with the integrator. The sliding mode control system has the limit to minimize both the settle time and overshoot. For making up this limit, this paper also suggests input shaping technique suitable to the inchworm control system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.630-637
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• 2003

This paper proposes a new modeling scheme to describe the hysteresis and the dynamic characteristics of piezoelectric actuators in the inchworm and develops a control algorithm for the precision motion control. From the analysis of piezoelectric actuator behaviors, the hysteresis can be described by the functions of a maximum input voltage. The dynamic characteristics are also identified by the frequency domain modeling technique based on 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. Therefore, the sliding mode control and the Kalman filter are developed for the precision motion control of the inch-warm. To demonstrate the effectiveness of the proposed modeling schemes and control algorithm, experiment validations are performed.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.2
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• pp.169-175
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• 2009

This paper presents motion control of the Inchworm composed of the piezoelectric actuators and mechanical elements. Piezoelectric actuator shows nonlinear response characteristics including hysteresis due to the ferroelectric characteristics. This paper proposes feedback control scheme to improve the ability of tracking response to complex input signal and suppress the phenomenon of hysteresis using the sliding mode control technique with the integrator. The sliding mode control system has the limit to minimize both the settle time and overshoot. For making up this limit, this paper also suggests input shaping technique suitable to the inchworm control system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.87-88
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• 2011

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.228.2-228.2
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• 2005

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.319-320
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• 2013

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.4
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• pp.414-420
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• 2015

In this study, the linear quadratic Guassian loop transfer recovery (LQG/LTR) control technique was combined with an integrator and applied to an inchworm having piezoelectric actuators for precise motion tracking. The piezoelectric actuator showed nonlinear response characteristics, including hysteresis, due to its ferroelectric characteristics and the residual displacement phenomenon. This paper proposes a feedback control scheme using the LQG/LTR controller with an integrator to improve the ability to track the response to complex input signals and to suppress the phenomenon of hysteresis and residual vibration. Experimental results show that the developed feedback control system for an inchworm can track the various motion contours quickly without residual vibration or overshoot.