• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.10
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• pp.583-590
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• 2003

This paper deals with speed control of DC servo motor using a high gain obserber. It was designed to estimate rotor speed of DC servo motor and it carries out speed control from the feedback of the estimated speed signal. Also, PI controller was used in speed controller. In order to verify the performance of the high gain observer which is proposed in this paper, it is compared estimate performance of Luenberger Observer and High Gain Observer with the computer simulation. Effectiveness of the proposed high gain observer is proved from the experiment to compare the case with a speed sensor to the case with high gain observer in the speed control of DC servo motor.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.841-843
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• 1999

This paper presents a design of stabilization controller for combat vehicle. A Stabilization system reject disturbances while vehicle moving. The conventional stabilization controller used to constant gain. We can improve the aiming performance by appropriate controller gain. We can find the proper controller gain for road frequencies by evolution strategy(ES). The relationship between the frequencies and proper control gains are generalized by use of the neural network. The road frequency estimated by wavelet transform of disturbance signal. The simulation result show that proposed controller is superior to the conventional stabilization controller.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1009-1010
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• 2007

This paper presents Fuzzy-Neuro PI controller of IPMSM drive using fuzzy and neural-network. In general, PI controller in computer numerically controlled machine process fixed gain. To increase the robustness, fixed gain PI controller, Fuzzy-Neuro PI controller proposes a new method based fuzzy and neural-network. Fuzzy-Neuro PI controller is developed to minimize overshoot and settling time following sudden parameter changes such as speed, load torque, inertia, rotor resistance and self inductance. The results on a speed controller of IPMSM are presented to show the effectiveness of the proposed gain tuner.

• Journal of the Semiconductor & Display Technology
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• v.16 no.3
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• pp.25-30
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• 2017

Arago's disk system consists of a speed controller of the DC motor (inner loop controller) and a position controller of the magnetic bar angle (main controller), which are implemented by the design of the PI and PID controller, respectively. First, we analyzed the nonlinear characteristics of the Arago disk system and found the operating point range of three locations as a result. In this paper, a gain scheduler method was applied to guarantee a constant control performance in the range of $0{\sim}130^{\circ}C$, and a structure to change the controller according to the control reference value based on the previously obtained operating points was experimentally implemented. The Distributed Control Systems (DCS) configuration using the Controller Area Network (CAN) was used to verify the proposed method by improving the operational efficiency of the entire experimental system. So, simplicity of the circuit and easy diagnosis were achieved through a single CAN bus communication.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.2
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• pp.126-132
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• 2016

The root-locus method is often employed when a controller is designed to find controller gain. It is usually used to determine one parameter gain while most controllers for industrial applications have more than one controller gain. For example PID controller has three controller gains, i.e. P, I, and D gains. Thus the conventional root-locus technique cannot complete the design of a controller with more than one controller gain. One way to overcome this drawback has been to apply the root-locus technique for one parameter while other parameters are assumed to be proportional to the parameter or to be constant. However this approach could lead to limited performance of the controller and if we try to adjust the proportional ratio or constants then it could be a long and tedious process of trial and error. Thus it is required to find an effective method for the root-locus technique to design controllers with more than one parameter. To this end this paper proposes an extended root-locus method for controllers with two parameters. In this paper Matlab is used as a computation tool to show the effectiveness of our method by solving examples numerically. As a result we obtained an extended root-locus illustrated in two-dimensional space for a control system with two parameters. The paper then presents how to find two controller gains based on this result of the extended root-locus. The main idea is that we can find the parameters by approaching the desired poles. It is expected that the proposed idea will help control engineers to easily design control systems using the root-locus technique, resulting in more accurate and faster control systems. Note that the extended root-locus idea can be applied to controller design problems with multiple parameters.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2001.06a
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• pp.101-104
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• 2001

In this paper, we propose the Digital Automatic Gain Controller for IEEE 802.11a High-speed Physical Layer in the 5 GHz Band. The input gain is estimated by calculating the energy of the training symbol that is a synchronizing signal. The renewal gain is calculated by comparing the estimated gain with the ideal gain. The renewal gain is converted into the controlled voltage for GCA to reduce or amplify the input signals. We used a piecewise-linear approximation to reduce the hardware size. The gain control is performed seven times to provide more accurate gain control. The proposed automatic gain controller is designed with VHDL and verified by using the Xilinx FPGA.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.8
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• pp.126-133
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• 2000

This paper is a study on robust PID controller tuning technique using the frequency region model matching method.To design the robust PID controller satisfying disturbance attenuation and robust tracking property for a reference input first an {{{{ETA _$\infty$}}}} controller satisfying given performances is designed using an H$_{\infty}$ control method, And then the parameters(proportional gain integral gain and derivation gain) of the robust PID controller with the performances of the desinged H$_{\infty}$ controller are determined using the model matching method at frequency domain. in this paper this PID controller tuning technique is applied to PID speed controller design for BLDC motors. Consequently simulation results show that the proposed PID speed controller satisfies load torque disturbance attenuation and robust tracking property and this study has usefulness and applicability for the speed control system; design of BLDC motors.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.3
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• pp.279-286
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• 2010

In this paper, we provide a robust track-following controller design method for the stable coarse seek control. Due to the inaccurate velocity control during a coarse seek, the shake of fine actuator is generated and thus a gain-up track-following control is required to complete stably the coarse seek. To this end, a loop gain adjustment algorithm is introduced to estimate accurately the shake of fine actuator. A weighting function can be properly selected from a minimum tracking gain-up open-loop gain, calculated from the estimated shake quantity of fine actuator. A robust tracking gain-up controller is designed by considering a robust $H_{\infty}$ control problem using the weighting function. The proposed design method is applied to the coarse seek control system of an optical rewritable drive and is evaluated through the experimental results.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.732-735
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• 1997

Variable Structure Controller(VSC) is usually known to have robustness to bounded exogenous disturbances. The robustness is attributed to the discontinuous term in the control input. However, this discontinuous term also causes an undesirable effect called chattering. To alleviate chattering, a hybrid controller consisting of VSC and Fuzzy Logic Controller(FLC) is proposed, which belongs to the category of Fuzzy Sliding Mode Controller(FSMC). The role of FLC in FSMC is to replace a fixed gain of a discontinuous term with a time-varying one based on a specified rule base. The characteristics of proposed controller are shown to be similar to those of VSC with a saturation function instead of sign function. The only remarkable difference is the nonlinearity whose form can be adjusted by free parameters, normalize gain, denormalize gain, and membership functions. Applied to AC servo motor, the proposed controller is compared with VSC in a regulation problem as well as a speed tracking problem. The simulation results show a substantial chatter reduction.

• Journal of the Korean Society of Industry Convergence
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• v.18 no.1
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• pp.1-9
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• 2015

This research dealt with a two-degree-of-freedom controller which was used for 2-dimensional force generator based on an linear motor. The gain margin of the controller may be reduced when the time constant is near to the sampling time of a discrete controller. In case of low gain controller, it cannot satisfy the control performance. A two-degree-of-freedom controller based on PI-control was proposed. It can manage performance and stability respectively. It also had a kind of a feed-forward control. This scheme can not only lessen gain of conventional PI controller in order to stability but also obtain high tracking performance.