• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.744-747
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• 2005

This research studied 6-Axes Articulated Robot Manipulator's gain Tuning in consideration of dynamic. First of all, search fur proportional gain of velocity control loop by dynamic signal analyzer. Proportional gain of velocity control loop is connected to dynamic signal analyzer. Next Select free Proportional Gain value. And Select amplitude X of sinusoidal properly so that enough Velocity Feedback Signal may be paid as there is no group to utensil department. Next step, We can get Bode Diagram of Closed loop transfer function response examination in interested frequency. Integral calculus for gain of velocity loop is depended on integral calculus correction's number. We can obtain open loop transfer function by integrator. And we can know bode diagram's special quality from calculated open loop transfer function. With this, Velocity Control Loop's Parameter as inner loop is controlled. Next In moving, when vibration occurs, it controls notch filter. And finally, we have to control fred-forward filter parameter for elevation of control performance.

• Korean Journal of Optics and Photonics
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• v.8 no.1
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• pp.58-62
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• 1997

A new, simple lasing loop configuration employing a fiber grating was proposed and demonstrated for all-optical gain control of erbium-doped fiber amplifier. The lasing loop was designed such that the fiber grating acts as a notch filter to cutoff the lasing light as well as selects the lasing wavelength. The operating gain was clamped to the same level as the loop loss and it could be varied with a tunable directional coupler in the loop. It is believed that this type of gain-controlled erbiumdoped fiber amplifier can have several advantages when used in wavelength-division-multiplexed transmission systems.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.163-167
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• 2000

This paper presents the digital control of single-phase power factor correction(PFC) converter which has the variable gain according to the condition of inner control loop error. Generally the gain of inner current control loop in single-stage PFC converter has a constant magnitude. This has a bad influence on the power factor because current loop doesn't operate smoothly in the condition that input voltage is low In particular a digital controller has more time delay than an analog controller and degrades This drops the phase margin of the total digital PFC system,. It causes the problem that the gain of current control loop isn't increased enough. In addition the oscillation happens in the peak value of the input voltage open loop PFC system gain changes according to ac input voltage. These aspects make the design of the digital PFC controller difficult The digital PFC controller presented in this paper has a variable gain of current control loop according to input voltage. The 1kW converter was used to verify the efficiency of the digital PFC controller.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.271-272
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• 2006

This paper presented a new experimental gain tuning technique for a Multi-Axis Servo System. First, the investigation for proportional gain of velocity control loop by using a Dynamic Signal Analyzer (DSA) was performed. Using the FUNCTION characteristic of DSA based on the Bode plot, the Bode plot of open loop transfer function was obtained. In turn, the integral gain of a servo controller can be found out by using the Integration time constant extracted from the Bode plot of open loop transfer function. In the meanwhile, the positional gain of the servo controller has been obtained by using the Bode plot of the closed loop transfer function. We have also proposed the technique to find out an optimal parameter of a notch filter, which has a great influence on vibration reduction, by using the damping factor extracted from the Bode plot of closed loop transfer function.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.9
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• pp.856-860
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• 2007

This paper presents a robust tracking controller design method for the track-following system of an optical recording device. A tracking loop gain adjustment algorithm is introduced to accurately estimate the tracking vibration quantity in spite of the uncertainties of the tracking actuator. A minimum tracking open-loop gain is calculated by the estimated tracking vibration quantity and a tolerable limit of tracking error. A robust tracking controller is designed by considering a robust $H_\infty$ control problem with the weighting function of a slightly larger gain than the minimum tracking open-loop gain. The proposed controller design method is applied to the track-following system of an optical recording device and is evaluated through the experimental result.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.242-246
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• 2001

The alternated forward multi resonant converter (AT forward MRC) is studied on the transient response and the measured loop gain for stability. The compensator is composed of the error amplifier with 3 poles and 2 zeros. This is optimized through the experiment with HP4194A network analyzer. We are initiated by the thinking of how to make the stabilization from the experimental results of loop gain curves. The loop gain, low frequency gain and gain margin are more improved through the experimental considerations. Also, the transient response is more enhanced effectively.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.4
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• pp.356-364
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• 2013

This paper presents a tracking gain-up controller design method to control effectively the vibration of tracking actuator caused by external shocks and remaining velocity after seek control. A pole placement constraint is considered to assure a desired transient response against the vibration of tracking actuator. A loop gain-up constraint is introduced to hold the tracking gain-up loop gain and control bandwidth within allowable bounds. The pole placement constraint is expressed by a matrix inequality and the loop gain-up constraint is considered as an objective function so that genetic algorithm can be applied. Finally, a tracking gain-up controller is obtained by integrating a genetic algorithm with LMI design approach. The proposed tracking gain-up controller design method is applied to the track-following system of a DVD recording device and its effectiveness is evaluated through the experimental results.

• International Journal of Control, Automation, and Systems
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• v.5 no.2
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• pp.161-169
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• 2007

The PLL equivalent augmented system incorporated with state feedback is proposed in this paper. The optimal value of filter time constant of loop filter in the phase-locked loop control system and the optimal state feedback gain designed by using linear quadratic regulator approach are derived. This approach allows the PLL control system to employ the large value of the phase-frequency gain $K_d$ and voltage control oscillator gain $K_o$. In designing, the structure of phase-locked loop control system will be rearranged to be a phase-locked loop equivalent augmented system by including the structure of loop filter into the process and by considering the voltage control oscillator as an additional integrator. The designed controller consisting of state feedback gain matrix K and integral gain $k_1$ is an optimal controller. The integral gain $k_1$ related to weighting matrices q and R will be an optimal value for assigning the filter time constant of loop filter. The experimental results in controlling the second-order lag pressure process using two types of loop filters show that the system response is fast without steady-state error, the output disturbance effect rejection is fast and the tracking to step changes is good.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.5 s.98
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• pp.578-585
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• 2005

In this paper, we present a schematic method estimating the tracking vibration quantity occurring in the track-following system of an optical recording device. A tracking loop gain adjustment algorithm is introduced to estimate accurately the tracking vibration quantity in spite of the uncertainties of the tracking actuator, Accordingly, the tracking vibration quantity can be estimated from the tracking error, the controller output, the nominal actuator model, and a compensated gain. An optimal tracking controller can be designed from a minimum tracking open-loop gain calculated by the estimated tracking vibration quantity The proposed vibration quantity estimation and controller design method are applied to the track-following system of an optical recording device and are evaluated through the experimental result.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.9
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• pp.743-749
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• 2002

A 1.5V 70㏈ 100MHz CMOS class-AB complementary operational amplifier is presented. For obtaining the high gain and the high unity gain frequency, the input stage of the amplifier is designed with rail-to-rail complementary differential pairs which are symmetrically parallel-connected with the NMOS and the PMOS differential input pairs, and the output stage is designed to the rail-to-rail class-AB output stage including the elementary shunt stage technique. With this design technique for output stage, the load dependence of the overall open loop gain is improved and the push-pull class-AB current control can be implemented in a simple way. The designed operational amplifier operates perfectly on the complementary mode with 180$^{\circ}$ phase conversion for 1.5V supply voltage, and shows the push-pull class-AB operation. In addition, the amplifier shows the DC open loop gain of 70.4 ㏈ and the unity gain frequency of 102 MHz for $C_{L=10㎊∥}$ $R_{L=1㏁}$ Parallel loads. When the resistive load $R_{L}$ is varied from 1 ㏁ to 1 ㏀, the DC open loop gain of the amplifier decreases by only 2.2 ㏈.a$, the DC open loop gain of the amplifier decreases by only 2.2 dB.