• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.255-256
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• 2007

본 논문에서는 주파수 응달특성의 해석을 통하여 제어기를 설계하는 방법을 제안하였다. 모델의 오차가 없다는 가정 하에 완벽 제어가 가능한 IMC-PID 구조를 사용 한으로 하나의 변수인 제어 조절 인자만으로 제어기를 설계하였다. 이 변수를 선정하는 방법으로는 위상여유와 이득여유를 고려한 방법을 수학적으로 유도하였다. 이는 설계자가 이미 알고 있는 일반적인 유도 식을 이용함으로 설계를 보다 쉽게 할 수 있다. 이를 통하여 원하는 설계사양을 만족 시키도록 하는 IMC-PID제어기의 설계 변수 값들을 수학적으로 제시하고, 그 유용성을 사례 연구와 분석을 통해 검토하였다.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.4
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• pp.187-194
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• 2002

Recently, the application of the linear machine far industrial field is remarkable increased, especially for the gantry machine, machine tool system and CNC. In these application fields, high dynamics position control performance Is essentially required in both the steady and the transient state. This pacer presents simple but powerful position control loop based on traditional PID controller. The presented position control algorithm, named 'Unified PID Position Controller'has great features for the linear machine drives such as no over-shoot phenomena and simple gain tuning strategy. Through the experimental results with commercial linear motors, it is shown that the proposed algorithm has excellent dynamics suitable fur linear motions.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.717-719
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• 2003

Recently Neural Network techniques have widely used in adaptive and learning control schemes for production systems. However, generally it costs a lot of time for learning in the case applied in control system. Furthermore, the physical meaning of neural networks constructed as a result is not obvious. And in practice since it is difficult to the PID gains suitably lots of researches have been reported with respect to turning schemes of PID gains. A Neural Network-based PID control scheme is proposed, which extracts skills of human experts as PID gains. This controller is designed by using three-layered neural networks. The effectiveness of the proposed Neural Network-based PID control scheme is investigated through an application for a production control system. This control method can enable a plant to operate smoothy and obviously as the plant condition varies with any unexpected accident.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.7
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• pp.618-626
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• 2011

In order to complete missions in a complicated terrain or highly dangerous area, an unmanned aerial vehicle(UAV) needs a fine controller to precisely follow the desired path. A PID controller used for the path following feeds forward path curvature information to the control input to improve the path following performance. High gain for PID controller is necessary to follow path tightly. However the high gain could cause instability or performance degradation when the vehicle has slow dynamics. We present PID controller design method which considers response delay of vehicle as well as path curvature. In order to obtain path curvature the desired path is described as a 3rd order polynomial by applying cubic spline interpolation. We apply the proposed controller to the path following of a UAV which is operated in high altitude and has very slow lateral dynamics. The lateral dynamics are modelled as a first order delayed system in the controller design. Nonlinear simulation shows the UAV with proposed controller follows an arbitrary path very tightly.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.1
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• pp.19-24
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• 2007

In this paper, we propose a tuning method of PID-PD controller to satisfy design specifications in frequency domain as well as time domain. The proposed tuning method of PID-PD controller consists of the convex set of PID and PI-PD controller. PID-PD controller controls the closed-loop response to be located between the step responses, and Bode magnitudes of closed-loop transfer functions controlled by PID and PI-PD controller. The controller is designed by the optimum tuning method to minimize the proposed specific cost function subject to sensor noise insensitivity and robust stability. Its effectiveness is examined by the case study and analysis.

• Journal of Advanced Navigation Technology
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• v.19 no.6
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• pp.473-483
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• 2015

This paper reports the single-input-single-output cascade control by using 1-axis attitude control test-bench for quad-rotor UAV. The test-bench was designed as a see-saw shape using 2 motors and propellers, and to enable changing the center of gravity with the center of gyration using ballast. The experiment was carried out by constructing a PID-PID controller having a cascade structure with the test-bench. The SIMC based PID gain tuning process, which makes PID gain tuning easy, was grafted to cascade control. To graft SIMC method, the system parameter estimation result was conducted with second order time delay model by using Matlab-Simulink. Gain tuning was conducted by simulating with estimated system parameter. In this paper, the conventional application of SIMC was conducted and improved application was proposed for improving stability at tuning process.

• Journal of Advanced Navigation Technology
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• v.17 no.1
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• pp.107-114
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• 2013

In this paper, we propose controller to control the acceleration of unmanned aircraft turbojet engine. The high-gain observer to estimate the rotational speed of compressor is used, and the turbojet engine controller applying fuzzy heuristic techniques and PID control algorithm are designed. fuzzy PID controller produces the flow control input to prevent the surge and flame-out phenomena at the acceleration and deceleration of the turbojet engine. The standard acceleration is set and the fuel flow control is defined by the fuzzy heuristic. Computer simulations are performed using MATLAB in order to verify the performance of the proposed controller.

• Journal of Drive and Control
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• v.13 no.3
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• pp.15-23
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• 2016

The direct-drive servo valve(DDV) is a kind of one-stage valve because the main spool valve is directly driven by the dc motor. Since the DDV structure is simple, it is less expensive, more reliable, and offers a reduced internal leakage and a reduced sensitivity to fluid contamination. The control system of the DDV is highly nonlinear due to a current limiter, a voltage limiter, and the flow-force effect on the spool motion. The shape of the step response of the DDV-control system varies considerably according to the magnitudes of the step input and the load pressure. The system-design requirements mean that the overshoots should be less than 20%, and the errors at 0.02s should be less than 2%, regardless of the reference-step input sizes of 1V and 5V and the load-pressure magnitudes of 0MPa and 20.7MPa. To satisfy the system-design requirements, the PID-controller parameters of $K_c$, $T_i$ and $T_d$, and the derivative-feedback gain of $K_{der}$ are designed using the root locus and manual tuning.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2609-2614
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• 2011

A proportional integral derivative (PID) controller is designed and applied to a magnetic levitation conveyor system to control the levitation gap length of the electromagnet constantly. The PID gain parameters are optimized by response surface methods (RSM). The controller is verified with the state-space model of electromagnetic suspension by MATLAB/SIMULINK program. And, the controller and the state-space model are also verified experimentally. Simulation and experimental results shows the effectiveness of the PID gain tuning by RSM as compared with the classical PID tuning.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.306-308
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• 2006

산업현장에서 가장 많이 활용되고 있는 PID제어기의 이론적인 배경을 토대로 실제 DCS 기반 플랜트에서 PID Tuning Method에 의한 PID제어기를 구현하고 제어성능을 확인한다. 또한 DCS(Distribute Control System)의 PID Controller를 분석하고 전 공정제어 System 중 일부분을 ARMA Modeling하여 만족스런 성능이 구현되도록 최적의 PID gain Parameter를 찾는다.