• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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• pp.316-323
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• 1997

This paper compares input shaping techniques for controlling residual vibration of flexible structures. Input shaping generates vibration-reducing shaped commands through convolution of an impulse sequence with the desired command. Both feedforward and feedback control approaches with/without input shaper for uncertain dynamical systems are investigated to evaluate the control performances. The control objective is to achieve a fast settling time and robustness to plant uncertainty, to eliminate residual vibrations. It is shown by a series of simulation that a properly designed feedback controller with input shaper performs well, as compared with open-loop controller with input shaper.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.453-458
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• 2008

Pump of high lift use to development of a technological level according as a building grow big. Water-Hammer to increase by valve of fast to closing agreeably to pipe laying to accept electronic valve, because by a damage of piping-system and the devil knows injury of vibration. Water-Hammer take a low effect to various method for solve. A New type manufacture develop and testing of pipe line to same to axis use to accumulator for water-Hammer to low effect and liner control of pressure. Impact-pressure of absorption ability and confirmation to decrease of vibration level through to preexistence manufactures and comparative test. Water-hammer and pipe vibration make low of piping system.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.7
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• pp.401-409
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• 2003

This paper describes the design and the performance analysis of an $H_2$ controller for noncollocated active vibrating systems. An experiment for the active vibration control of a flexible structure is performed. The experimental model used is a cantilever beam controlled by an active damping system consisting of a laser sensor and an electromagnetic actuator. The $H_2$ controller design is based on the reduced order model and the designed system is capable of attenuating vibration without causing spillover instability. The design procedure to prevent spillover instability is described via the sensitivity analysis. The performances of the controller are verified by experimental results.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.7
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• pp.401-401
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• 2003

This paper describes the design and the performance analysis of an Ha controller for noncollocated active vibrating systems. An experiment for the active vibration control of a flexible structure is performed. The experimental model used is a cantilever beam controlled by an active damping system consisting of a laser sensor and an electromagnetic actuator. The $H_2$ controller design is based on the reduced order model and the designed system is capable of attenuating vibration without causing spillover instability, The design procedure to prevent spillover instability is described via the sensitivity analysis. The performances of the controller are verified by experimental results.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2073-2075
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• 2003

This paper presents the active vibration control of flexible cantilever beam using piezoceramic actuators. The transfer function from the force input to the bending displacement was obtained via modal analysis results and piezoelectric constitutive equations. For the active vibration control piezoceramic actuators and sensors were used to construct a flexible smart cantilever beam. To further enhance the sensing and actuation properties of the piezoceramics, a typical interdigitated electrode pattern was fabricated. The PID controller was designed via various simulation and experiment trials. It was shown that the PID controller could suppress vibration of the beam effectively. Simulations and experiments verified good performances of the designed controller.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.7
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• pp.612-618
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• 2004

This paper presents a robust vibration control methodology for smart structural systems. The governing equation and associated boundary conditions of the smart structural system are derived by using Hamilton's principle. The assumed mode method is used to discretize the governing equation into a set of ordinary differential equation. A robust controller is designed using a linear matrix inequality (LMI) approach for the multiobjective synthesis. The design objectives are to achieve a mix of H$_{\infty}$ performance and H$_2$ performance satisfying constraints on the closed-loop pole locations in the presence of model uncertainties. Numerical examples are presented to demonstrate the effectiveness of LMI approach in damping out the multiple vibration modes of the piezo/beam system.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.6
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• pp.169-174
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• 2001

Optimization of the collocated piezoceramic sensor/actuator placement is investigated numerically and verified experimentally for vibration control of laminated composite plates. The finite element method is used for the analysis of dynamic characteristics of the laminated composite plates with the piezoceramic sensor/actuator. The structural damping index(SDI) is defined from the modal damping(2$\omega$ζ) . It is chosen as the objective function for optimization. Weights for each vibrational mode are taken into account in the SDI calculation. The gradient method is used for the optimization. Optimum location of the piezoceramic sensor/actuator is determined by maximizing the SDI. Numerical simulation and experimental results show that the optimum location of the piezoceramic sensor/actuator is dependent upon the outer layer fiber orientations of the plate, and location and size of the piezoceramic sensor/actuator.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.10a
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• pp.432-437
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• 1997

In this paper, a pseudo-sensor-output-feedback(PSOF) control approach is applied to the active and semi-active systems for the vibration suppression of the flexible structures. This approach reduces the modeling error encounted in the output equation formulation and is easy to be implemented in practice. Experimental works are performed for the validation of theoretical predictions with a piezoelectric sensor and actuator bonded on the cantilever beam. The objective of this study is also to compare and analyze between active and semi-active systems. An algorithm based on the sliding mode control theory is developed and analyzed for the robustness to the modeling errors and parameter uncertainties.

• Journal of the Semiconductor & Display Technology
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• v.16 no.2
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• pp.98-105
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• 2017

In the display industry, the residual vibration of the transfer robot can increase the process time and cause the breakage of the glass substrate, which is critical to productivity of display manufacturing. In this paper, the natural frequencies of transfer robot are analyzed by finite element method. On the basis of the analyzed data, we investigated the response characteristics of input shaping control with or without the glass presence on the hand of the transfer robot using MATLAB program, and compared with the current response characteristics of input shaping control applied to the industry. Based on this, we suggest an optimal residual vibration control method for the practical application in display industry.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.388-392
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• 2002

Fault tolerant control algorithm for heteropolar magnetic bearings are presented. This fault tolerant control utilizes grouping of currents as C-cores in order to isolate magnetic fluxes. Hardware requirements to maintain fault tolerant control are reduced since decoupling chokes are not required in this control scheme. The currents supplied to each pole are redistributed, if some coils fail suddenly, such that the resultant magnetic forces should remain invariant through coil failure events. Load capacity before magnetic saturation is reduced through coil failures while maintaining the same magnetic forces before and after failure.