• 유공압시스템학회논문집
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• 제3권2호
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• pp.14-20
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• 2006

A controller design procedure for an electro-hydraulic positioning systems has been developed using $H{\infty}$ control. The generalized plant models and weighting function for multiplicative uncertainty modelling error was presented along with $H{\infty}$ controller designs in order to investigate the robust stability and performance. Both disturbance rejection and command tracking performances were improved with the $H{\infty}$ controller, and the better uniformity of time response is achieved across wide range of operating conditions than the PID, LQR and LQG control scheme. The multiplicative uncertainty case was specifically suited for the design of an electro-hydraulic positioning control systems using $H{\infty}$ control.

• 제어로봇시스템학회논문지
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• 제4권1호
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• pp.32-37
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• 1998

This paper deals with the implementation of a robust multivariable controller using DSP board and the application to real systems. The LQG/LTR (Linear Quadratic Gaussian with Loop Transfer Recovery) controller proposed by Doyle et al.[1,2] is adopted to design the control system. A helicopter propeller setup is taken as the controlled system in the current paper, and the mathematical model is derived to design the multivariable controller. The performance of the controller is evaluated via simulations, and implementation and application to the MIMO system shows that the control performances are satisfactory and superior to those of the PID controller.

• 반도체디스플레이기술학회지
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• 제23권2호
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• pp.92-99
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• 2024

As semiconductor processes require several nanometers precision, the importance of motor control is increasing in semiconductor equipment. Due to unpredictable uncertainties such as friction and mechanical vibrations achieving precise position control in semiconductor processes is challenging. The internal model principle-based controller is a control technique that ensures robust steady-state performance by incorporating a model of the reference and disturbance. The disturbance observer-based controller is a prominent robust control technique implemented to cope with various nonlinearities and uncertainties. Provided that the two controllers can be designed to exhibit equivalent performance under certain conditions, this paper demonstrates through experiments that they yield identical results for the case of a BLDC position control problem. The experimental results also indicate that they can offer enhanced robustness compared with the conventional PID controller in the presence of a time-varying disturbance.

• 드라이브 ㆍ 컨트롤
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• 제12권3호
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• pp.1-10
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• 2015

In this paper, the authors propose a method to easily recognize and reproduce the robot motion made by an operator. This method is targets for applications similar to painting and welding, and it is based on a process of that identifies a family of plants, by control design and by conducting an experimental evaluation. In this study, the models and controllers for all joints of 3DOF robot system are obtained individually. And a robust control system for motion control of the individual joints is designed based on $H_{\infty}$ control framework. An experimental comparison is made between the proposed control method and existing PID control method. And the results indicate that the proposed designing method is more efficient and useful than conventional method.

• 조명전기설비학회논문지
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• 제17권1호
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• pp.112-115
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• 2003

산업 자동화의 고정밀도에 따라 서보 제어시스템은 강인제어가 요구되고 있다. 그러나 서보 제어시스템이 외란의 영향을 받게 되면 제어시스템의 강인제어는 어렵게 된다. 이에 대한 보완적인 한 방법으로 본 논문에서는 주 제어기(PID)와 미분 관리제어기의 혼합형 제어기법을 제시하였다. 주 제어기는 궤환제어기로서 동작하고, 미분 관리제어기는 외란에 의한 불안정한 상태에서 보조적인 동작을 한다. 미분 관리제어기의 강인성은 전통기의 속도제어에 의해서 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 B
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• pp.732-734
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• 1997

This paper describes the design and implementation of a fuzzy temperature control system to control the water temperature in plant. For evaluating the performance of a fuzzy controller, the experiment results of a fuzzy controller are compared with these of a conventional PID controller which provides an auto-tuning function. The experiment results show that the proposed controller has a good control performance and is robust to external disturbance.

• 전기학회논문지
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• 제58권1호
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• pp.187-192
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• 2009

This paper presents a method for designing a robust controller that alleviates disturbance effects and compensates performance degradation owing to the time-delay. Disturbance observer(DOB) approach as a tool of robust control has been widely employed in industry. However, since the Pade approximation of time-delay makes the plant non-minimum phase, the classical DOB cannot be applied directly to the system with time-delay. By using a new DOB structure for non-minimum phase systems together with the Smith Predictor, we propose a new controller for reducing the both effects of disturbance and time-delay. Moreover, the closed-loop system can be made robust against uncertain time-delay with the help of a Pill controller tuning method that is based on a second-order plus dead time modeling technique.

• 대한전기학회논문지:시스템및제어부문D
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• 제49권3호
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• pp.124-132
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• 2000

In this paper, presented are an active surface-micromachined silicon accelerometer, force rebalance loop using parametric robust control method, and experimental results with a real micromachined accelerometer. And finally, a robust controller of the form of PID compensator was designed to construct force rebalance loop. Through the frequency response analysis, it is shown that the loop guarantees appropriate stability and robustness. Experiments with a real accelerometer demonstrated that the proposed loop effectively controls the position of the accelerometer's proof mass. It also demonstrated that the resolution of the fabricated accelerometer is better than 1mg. Compared with a commercial accelerometer the proposed force rebalance silicon accelerometer showed better performances.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.11-14
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• 2000

This paper presents the vibration control of a glass-fiber reinforced thermoplastic composite beam with a distributed PVDF sensor and piezo-ceramic achlator. The three types of different controllen which are PID, H$\infty$ , and p-synthesis ontrollcr are employed to achieve vibration suppression in the transient vibration of composite beam. In the H$\infty$ , controller design, 1st and 2nd natural frequencies are considered in the modeling, because robust control theory which has robustness to struchred uncertainty is adopled Lo suppress the vibration. If the controller designed by H$\infty$ , theory does not satisfy control performance, it is improved by $\mu$ -synthesis method with D-K iteration so that the$\mu$-contoller based on the structured singular value satisfies the nominal performance and robust performance Simulations and experiments were carried out with the designed controllers m order to demonstrate the suppression efficiency of each controller.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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• pp.407-412
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• 1998

A design technique based on the root locus approach for the SISO (Single-Input Single-Output) systems using PID (Proportional-Integral-Derivative) ${\times}$ (n-1) stage PD as a controller for the n$\^$th/ order plant is presented. The controller is designed based on transient and steady state response specifications. This controller can be used instead of a conventional PID controller. The overall system is approximated as a stable and robust second order system. The desired performances are achieved by increase the gain of the controller. In addition, the controller gain can be adjusted to obtain faster response with a little overshoot. The simulation results show the merits of this approach.