• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2002.04a
• /
• pp.543-550
• /
• 2002

This work is concerned with the estimation of output derivatives and their use for the design of robust controller for linear systems with systems uncertainties due to modeling errors and disturbance. It is assumed that a nominal transfer function model and Quantitative bounds for system uncertainties are known. The developed control schemes are shown to achieve regulation of the system output and ensures boundedness of the system states without imposing any structural conditions on system uncertainties and disturbances. Output derivative estimation is first conducted trough restructuring of the plant in a specific parameterization. They are utilized for constructing robust nonlinear high-gain feedback controller of a SMC(Sliding Mode Controller) Type. The performances of the developed controller are evaluated and shown to be effective and useful through simulation study.

• Journal of the Korean Society for Precision Engineering
• /
• v.21 no.2
• /
• pp.153-159
• /
• 2004

A control-structure combined optimal design problem is discussed taking a 3-D truss structure as a design object. We use descriptor forms for a controlled object and a generalized plant because the structural parameters appear naturally in these forms. We consider not only minimum weight design problem for structure system, but also suppression problem of the effect of disturbances for control system as the purpose of the design. By minimizing the linear sum of the normalized structural objective function and control objective function, it is possible to make optimal design by which the balance of the structural weight and the control performance is taken.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.792-795
• /
• 2004

Despite is product that ship, vehicles, development equipment and Metal Bearing for plant equipment that is mass-produced by present domestic companies Cast White Metal Lining Bearing that is Bimetal Bearing standing 2 generation is accomplishing master and servant and this is foreseen to be used widely on industry whole in hereafter but Cast White Metal Bearing need minuteness processing, while price competitive power is depending on income from superior another thing area than itself manufacture already in advanced nation to lowdown that the technique is generalized widely, when take into account technology change aspect of industrial technology developing country, Go added value creation by deepening of price competition is judged to be difficult hereafter. Because domestic production and supply are wholly lacking almost in Metal Bearing Cladding that take advantage of these technology, Data-base about connection technology is weak with technique and Know-How for product. This research unites Back Steel and Aluminium Alloy different kind metal and make the Clad river studying technology about union of Gogangseong Dacheung metal bearing hereupon.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.3 no.4
• /
• pp.875-885
• /
• 1999

This paper presents an application of LMI-based techniques to the mixed $H_2/ H_\infty$ control of an inverted pendulum. The linear model of the inverted pendulum represented by an LFR(Linear Fractional Representation) model of uncertainties is derived. Considered uncertainties are three nonlinear components and a parameter uncertainty Augmenting the LFR model by adding weighting functions, we get a generalized plant, for which we design a mixed $H_2/ H_\infty$ controller using the LMI technique. To evaluate control performances and robust stability of the mixed $H_2/ H_\infty$ controller designed, we compare it with the $ H_\infty$controller through the simulation and experiment. The mixed $H_2/ H_\infty$ controller shows the better control performances and robust stability than the $H_\infty$controller in the sense of pendulum angle.

• Journal of Electrical Engineering and Technology
• /
• v.8 no.6
• /
• pp.1551-1558
• /
• 2013

$H_2$ design of decoupled control systems is treated in the generalized plant model. The existence condition of a decoupling controller is stated and a parameterized form of all achievable decoupled closed loop transfer matrices is presented by using the directional interpolation approaches under the assumption of simple transmission zeros. The class of all decoupling controllers that yield finite cost function is obtained as a parameterized form and an illustrative example to find the optimal controller is provided.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1995.04a
• /
• pp.958-961
• /
• 1995

MODROC 기법이 대표적인 일반화된 기계-셀 형성 기법은 부품 생산비용, 부품가공시간, 공정순서, 로트 크기 등을 고려하여, 기계-셀을 형성함에 있어, 보다 현실적인 접근을 추구한 것이다. 그러나, 수리적 문제 해결의 한계로 인해 현실 접근성이 제한되며, 신경망을 이용한 기존의 기법들 역시 수리적 제한환경을 설정한 것이어서 현실적인 응용가능성이 떨어지고 있다. 본 논문에서는 공정순서와 공장배치를 고려하여 기계-셀의 효율적인 형성을 꾀하였다. 신경망 모델인 자기조직화 형성기법을 응용하였으며, 공장 작업영역과 기계-셀의 위치가 주어짐에 따라 공정순서를 고려하여 물류의 이동을 최소화하는 기계-셀의 형성 방법을 꾀하였다. 본 기계-셀 형성 방법은 기존의 방식에 비해 짧은 시간에 기계-셀을 형성할 수 있으며, 그에 따른 부품군의 형성은 공정을 고려하여 총 물류량을 감소시키는 방향으로 결정되는 장점을 갖고 있다. 또한, 다변화되는 환경에 대한 적응성과 예외적 요소(exceptional element)에 대한 셀 형성 및 처리가 매우 유연하게 나타내어 진다. 본 연구에서는 공정 간에 기계의 중복이 있는 경우의 기계-셀 형성 문제에 대해 제한된 기법을 적용하였다.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.3 no.1
• /
• pp.38-46
• /
• 2000

In this paper, robust depth and course controllers of AUV(autonomous underwater vehicles) using LMI-based H$_{\infty}$ servo control are proposed. The $H_{\infty}$ servo problem is modified to an $H_{\infty}$ control problem for the generalized plant that includes a reference input mode, and then a sub-optimal solution that satisfies a given performance criteria is calculated by LMI(Linear Matrix Inequality) approach. The robust depth and course controllers are designed to be satisfied the robust stability about the modeling error generated from the perturbation of the hydrodynamic coefficients and the robust tracking property under sea wave and tide disturbances. The performances of the designed controllers are evaluated by computer simulations, and these simulation results show the applicability of the proposed robust depth and course controller.

• Proceedings of the KIEE Conference
• /
• 1999.07b
• /
• pp.712-714
• /
• 1999

Ball-balancing control systems are ideal to demonstrate the design and hardware implementation Procedures of optimal controllers based on modern control theory. This paper presents the design of an $H_2$ optimal controller based on the generalized plant model of the ball-balancing system. The problem of balancing a metal ball on the midpoint of a beam is ultimately related to a regulating problem. So, the designed controller is correspond to this problem. The controller was experimented by DSP(digital signal processing) equipments and simulated by MATLAB. The performance of controller was verified through the experiments.

• 제어로봇시스템학회:학술대회논문집
• /
• 1999.10a
• /
• pp.88-91
• /
• 1999

The purpose of this paper is to propose an approach to design a robust servo controller based on the Mixed H$_2$/H$\sub$$\infty$/ theory. In order to do this, we first modify the generalized plant for the usual H$\sub$$\infty$/ servo problem to a structure of the Mixed H$_2$/H$\sub$$\infty$/ minimization problem by virtue of the internal model principle. By doing this, we can divide specifications adopted for robust servo system design into H$_2$and H$\sub$$\infty$/ performance criteria, respectively. Then, the mixed H$_2$/H$\sub$$\infty$/ problem is solved in order to find the best solution, by which we can minimize H$_2$-norm of the transfer function under the condition of H$\sub$$\infty$/-norm value, through Linear Matrix Equality (LMI).

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1992.04a
• /
• pp.385-389
• /
• 1992

The position control of the electro-hydraulic servo indexing system in a flexible forging machine was investigated. The role of an Electro-hydraulic servoindexing system is to rotate a workpiect fast and accurately to a desired position. Since the inertia of a workpiece changes during each forging step, an adapt control scheme could be adopted to the position control of the workpiece. A generalized predictive control method which depends on predicting the plant output over several steps ahead based on the assumption about future control actions is proposed. The perormance of the proposed GPC algorithm is investigated experimentally and compared with that of PID control. Experimental results show that the proposed GPC algorithm is satisfactory for the position control of the workpiece of an electrohydraulic indexing system.