• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.405-410
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• 2002

Linear motor food system control algorithm was extended to the two axis system. Among several factors considered, overshoot of the response was the most important one in minimizing position tracking error. Balance between overshoot and settling time has to be adjusted to guarantee to best tracking performance. Tracking route was carefully executed to eliminate the possible error during the machining process. Even though there exists slight discrepancy between desired mute and cutting track at the corner, precision machining could be implemented using the cutting scheme introduced.

• Structural Engineering and Mechanics
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• v.62 no.2
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• pp.209-224
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• 2017

Elevated water tanks are considered as important structures due to its post-earthquake requirements. Elevated water tank on reinforced concrete frame staging is widely used in India. Different response reduction factors depending on ductility of frame members are used in seismic design of frame staging. The study on appropriateness of response reduction factor for reinforced concrete tank staging is sparse in literature. In the present paper a systematic study on estimation of key components of response reduction factors is presented. By considering the various combinations of tank capacity, height of staging, seismic design level and design response reduction factors, forty-eight analytical models are developed and designed using relevant Indian codes. The minimum specified design cross section of column as per Indian code is found to be sufficient to accommodate the design steel. The strength factor and ductility factor are estimated using results of nonlinear static pushover analysis. It was observed that for seismic design category 'high' the strength factor has lesser contribution than ductility factor, whereas, opposite trend is observed for seismic design category 'low'. Further, the effects of staging height and tank capacity on strength and ductility factors for two different seismic design categories are studied. For both seismic design categories, the response reduction factors obtained from the nonlinear static analysis is higher than the code specified response reduction factors. The minimum dimension restriction of column is observed as key parameter in achieving the desired performance of the elevated water tank on frame staging.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.291-294
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• 1996

By far the PID controller is most widely sed in the process industries. However, current tuning methods yield PID parameters only for a restricted class of process models. There is no general methodology of PID controller tuning for arbitrary process models. In this paper, we generalize the IMC-PID approach and obtain the PID parameters for general models by approximating the ideal controller with a Maclaurin series. Further, the PID controller tuned by the proposed PID tuning method gave more closer closed-loop response to the desired response than those tuned by other tuning methods.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.301-306
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• 2003

PID controller is applied mostly to two-order system. In third-order or higher- system, it's impossible to get high response quality because of having more zero point than the number of zero point being in the PID controller. To solve those, Jung & Dorf suggested a new type of PIDA controller and solved problen of a third-order system. But, as the result of getting step response using PIDA controller, rising time is very quickly but wide overshoot is happened. Beside designing PIDA controller with using CDM(Coefficient Diagram Method) suggested by shunji manabe. But, In Performance standard, CDM decreases overshoot to desired but rising time is very slow. Therefore this paper suggest a PD-PIDA controller for low overshoot with PD type Pre-compensator. This paper applied designed PD-PIDA controller to position control of 3-Phase induction motor.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.965-969
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• 2003

In this paper, the implementation technique of digital crossover network using perfect linear phase IIR filters is presented. This system has various advantages which cannot be obtained from analog crossover network such as linear phase response, flat group delay and sharp cut-off at low-order over audio frequency band. The simulation results show that the group delay response is maximally flat and twice more attenuation in stop-band than the prototype elliptic IIR filter at all desired frequency.

• Smart Structures and Systems
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• v.16 no.6
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• pp.1133-1145
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• 2015

A new neural network (NN) predictive controller (NNPC) algorithm has been developed and tested in the computer simulation of active control of a nonlinear structure. In the present method an NN is used as a predictor. This NN has been trained to predict the future response of the structure to determine the control forces. These control forces are calculated by minimizing the difference between the predicted and desired responses via a numerical minimization algorithm. Since the NNPC is very time consuming and not suitable for real-time control, it is then used to train an NN controller. To consider the effectiveness of the controller on probability of damage, fragility curves are generated. The approach is validated by using simulated response of a 3 story nonlinear benchmark building excited by several historical earthquake records. The simulation results are then compared with a linear quadratic Gaussian (LQG) active controller. The results indicate that the proposed algorithm is completely effective in relative displacement reduction.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.337-342
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• 1998

A new fuzzy control algorithm for the control of active magnetic bearing (AMB) systems is proposed in this paper. It combines PDC design of Joh et al. [8][9] and Namdani-gype control rules using fuzzy singletons to handle the nonlinear characteristics of AMB systems efficiently. They are named fine mode control and rough mode control , respectively. The rough mode control yields the fastest response for large deviation of the rotor and the fine mode control fives desired transient response for small deviation of the rotor. The proposed algorithm is applied a AMB systems to verify the performance of the method, The comparison of the proposed method to a linear controller using a linearized model about the equilibrium point and PDC algorithm in [7] show the superiority of the proposed algorithm.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.6 s.165
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• pp.1055-1064
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• 1999

In this wort ER(electro-rheological) clutch and MR(magneto-rheological) clutch are devised and their performance characteristics such as response time and controllability are compared. As a first step, field-dependent yield stresses of ER and MR fluids are distilled in shear mode. For reasonable comparison between two clutches, a nondimensional design model is established by choosing same design parameters of gap size and number. Following the manufacturing of two clutches, field-dependent torque level, response time to step input, mechanical Power generation to electric power consumption are experimentally measured and compared. In addition, in order to investigate torque controllability of the clutches a sliding mode controller is formulated and experimentally realized. Control bandwidths of two clutches are identified and tracking control responses for desired torque trajectories are presented.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1521-1523
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• 2005

PID controller is applied mostly to two-order system. In third-order or higher- system, it's impossible to get high response quality because of having more zero point than the number of zero point being in the PID controller. To solve those, Jung & Dorf suggested a new type of PIDA controller and solved problen of a third-order system.. But, as the result of getting step response using PIDA controller, rising time is very quickly but wide overshoot is happened. Beside designing PIDA controller with using CDM(Coefficient Diagram Method) of Shunji Manabe decreases overshoot to desired but rising time is very slow. Therefore this paper suggest a I-PDA controller for low overshoot and fast responsibility. This paper applied designed PD-PIDA controller to position control of 3-Phase induction motor.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.863-864
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• 2005

In recent years, we use overdriving scheme to improve the response time of the liquid crystal. Since conventional overdriving scheme uses memory to perform ideal processing, it is desired to reduce system cost by decreasing the data stored in these SDRAMs. As a general compression method, quantization, sub-sampling and Block Truncation Coding ( BTC ) are used, which process data in block base and cause block effect. So we proposed new data compression method by color space conversion. Because this method compresses luminance and chrominance signal by different ratio, it can efficiently reduce error of block effect in decompression image.