• Journal of the Korean Society for Precision Engineering
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• v.22 no.6 s.171
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• pp.40-46
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• 2005

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.6
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• pp.612-619
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• 2004

Servo motor systems with ball-screw and timing-belt are widely used in NC, robot, FA and industrial applications. However, the nonlinear friction torque and damping effect in machine elements reduce the control performance. Especially tracking errors in trajectory control and very low velocity control range are serious due to the break-away friction and Stribeck effects. In this paper, a new double speed controller is proposed for compensation of the nonlinear friction torque. The proposed double speed controller has outer speed controller and inner friction torque compensator. The proposed friction torque compensator compensates the nonlinear friction torque with actual speed and speed error information. Due to the actual information for friction torque compensator without parameters and mathematical model of motor, proposed compensator is very simple structure and the stability is very high. The proposed compensator is verified by simulation and experimental results.

• Journal of Aerospace System Engineering
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• v.14 no.5
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• pp.1-8
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• 2020

The aeroservoelastic analysis that deals with the interactions of the inertial, elastic, and aerodynamic forces and the influence of the control system have been performed. MSC Nastran was used for the free vibration analysis of the structure model as the pre-analysis. ZAERO was used to calculate the unsteady aerodynamic forces. The unsteady aerodynamic forces were verified by comparing with Doublet Hybrid Method. Karpel's Minimum-State Approximation method was used for approximation of the aerodynamic forces to the Laplace domain in the frequency domain. The aeroservoelastic state-space equation was obtained by combining the aeroelastic equation with the actuator dynamics. The analysis of aeroservoelastic stability concerning the elevator input of the high aspect ratio model was performed. The root-locus method and time-integration method were used for the analysis of aeroservoelastic in frequency and time domain.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.5
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• pp.1050-1057
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• 2004

The purpose of study is development of a fuzzy controller which independent of a computer and its software for fuzzy control of servo system. This paper describes a method of approximate reasoning for fuzzy control of servo system, based on decomposition of $\alpha$-level fuzzy sets, It is propose that fuzzy logic algorithm is a body from fuzzy inference to defuzzificaion in cases where the output variable u directly is generated PWM. The effectiveness of quantified $\alpha$-levels on input/output characteristics of fuzzy controller and output response of DC servo system is investigated. It is concluded that $\alpha$-cut 4 levels give a sufficient result for fuzzy control performance of DC servo system. The experimental results shows that the proposed hardware method is effective for practical applications of DC servo system.

• Aerospace Engineering and Technology
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• v.7 no.1
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• pp.151-160
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• 2008

In this paper, the analysis results of synthetic resonance characteristics are described for the electrohydraulic thrust vector control actuation system. The synthetic resonance is induced by integration of position servo actuation system on the flexible launch vehicle mounting structure. The new resonance mode is synthesized due to composition of hydraulic resonance for electrohydraulic position servo system with inertia load condition and structural resonance for flexible mounting structure. This synthetic resonance can make stability of control system worse by feedback and amplification of control system. The exact nonlinear analysis model of this phenomenon is developed to predict and design a control algorithm for improvement characteristics. The DPF (Dynamic Pressure Feedback) control algorithm has been designed and has excellent resonance suppression capability.

• ICROS
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• v.5 no.1
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• pp.35-40
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• 1999

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.897-900
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• 2007

This paper presents a study on the DSP controller and IGBT inverter driver design for the power-by-wire(PBW) system using BLDC servo motor. This BLDC servo motor system was realized with DSP(Digital Signal Processor) and IGBT inveter module. The PBW system needs speed control of servo motor for linear thrust action. This paper implements a servo controller with vector control and min-max PWM technique. As CPU of controller, TMS320F2812 DSP was adopted because it has PWM(Pulse Width Modulation) waveform generator, A/D(Analog to Digital) converter, SPI( Serial Peripheral Interface) port and many input/output port etc.

• Journal of the Institute of Convergence Signal Processing
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• v.5 no.3
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• pp.210-215
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• 2004

The dynamic model of ac servo motor is influenced very much due to rotor resistance change and nonlinear characteristic. By using the sliding mode control the dynamic behavior of system can be made insensitive to plant parameter change and external disturbance. This paper describes the application of the sliding mode control for position control of ac servo motor. The control scheme is derived and designed. A design method based on external load parameters has been developed for the robust control of ac induction servo drive. The proposed control scheme are given based on the variable structure controller and slip frequency vector control. Simulated results are given to verify the proposed design method by adoption of sliding mode and show robust control for a change of shaft initial J, viscous friction B and torque disturbance.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.424-427
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• 2002

Pneumatic control systems have the potential to provide high output power to weight and size ratios at a relatively low cost. However, they are mainly employed in open-loop control applications where positioning repeatability is not of great importance. This paper presents precision positioning control of pneumatic servo cylinder with on-off valve, Pneumatic low-friction cylinder with servo valve and DC servo motor under parameter variations. Basically positioning control uses PID controller, where needs a linearized model. A neural network is added to a PID controller to compensator nonlinearity of the system and an influence of friction force is consider as disturbance. The performances of the proposed algorithms were compared by experiments with them of PID controller. From those experiments is was shown that the proposed algorithms are more efficient about settling time, steady 7tate error and overshoot than PID control algorithm.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1428-1432
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• 2007

The object of this paper is development of pneumatic servo actuator technique for energy saving type. In this paper, consist of pneumatic servo actuator technique is pneumatic servo valve, pneumatic motor and cylinder. This technique applied a automobile, aerospace engineering, a ship, defence industry and industrial machine because it have high response, high speed, high precision control, low friction etc., compare with previously technique. But it depend on import the whole quantity. So this study, suggest that through the development of servo actuator applicable the use of industrial field.