• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.556-560
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• 2007

In this paper, the research results for the improvement of tracking performance of a hydraulic shaking table are presented. A servo-hydraulic shaking table is not only highly nonlinear but also has a lot of time delay. In addition, the shaking table, which consists of multi axial hydraulic actuators, is a MIMO system coupled by kinematics and dynamics of each other's actuators. And it is demanded for the shaking table to track arbitrary trajectories up to high frequency even at the extreme situations such as substantial external loads and large disturbances. For this purpose, an iterative feed-forward control based on the inverse of a measured frequency response function is used for the shaking table. To solve the dynamic coupling, a pressure feedback control as numerical damping is used. It is shown through numerical simulations that the tracking performance of shaking table is improved up to 100Hz.

• International Journal of Aeronautical and Space Sciences
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• 제10권1호
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• pp.46-58
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• 2009

This paper deals with design procedure of online guidance and control law for future missiles that requires agile maneuverability. For the purpose, the missile with high powered side thruster is proposed. The guidance and control law for such missiles is discussed from a point of view of optimal control theory in this paper. Minimum time problem is solved for the approximated system. It is derived that bang- bang control is optimal input from the necessary conditions of optimal solution. Feedback guidance without iterative calculation is useful for actual systems. In this paper. multiple design point method is applied to design feedback gains and feed forward inputs of the guidance and control law. The numerical results show that the proposed guidance and control law has a high -performance for wide-ranging boundary conditions.

• 동아시아경상학회지
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• 제1권1호
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• pp.17-21
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• 2013

Purpose: Forecasting of petroleum consumption is useful in planning and management of petroleum production and control of air pollution. Research Design, Data and Methodology: ARMA models, sometimes called Box-Jenkins models after the iterative Box-Jenkins methodology usually used to estimate them, are typically applied to auto correlated time series data. Results: Petroleum consumption modeling plays a role key in big urban air pollution planning and management. In this study three models as, MLFF, MLFF with GARCH (1,1) and ARMA(1,1), have been investigated to model the petroleum consumption forecasts. Certain standard statistical parameters were used to evaluate the performance of the models developed in this study. Based upon the results obtained in this study and the consequent comparative analysis, it has been found that the MLFF with GARCH (1,1) have better forecasting results.. Conclusions: Survey of data reveals that deposit of government policies in recent yeas, petroleum consumption rises in Tehran and unfortunately more petroleum use causes to air pollution and bad environmental problems.