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A novel robust approach for the obedience control of Furuta pendulum with uncertainty is proposed. The uncertainty considered in this paper is (possibly fast) time-varying and bounded, which may exist in any stage of the pendulum subsystem. By the Lagrangian formulation of the nonlinear pendulum system, a robust control, based on a general Lyapunov function, is designed to render the Furuta pendulum a position obedience. As a consequence of the Lyapunov approach, the control design is not restricted to linearize the pendulum system. The system performance under the proposed control is guaranteed as uniform boundedness and uniform ultimate boundedness. The salient features of this new control are demonstrated both analytically and numerically. The experiment is conducted in the Furuta pendulum system to prove the validity and effectiveness of the control design. [ABSTRACT FROM AUTHOR]

The problem of laminar natural convection on a vertical baffled plate subjected to a periodic oscillation is investigated numerically. Of particular interest of this paper is the heat transfer characteristic with the oscillatory velocity being close to the flow velocity in the velocity boundary layer under nonoscillation condition. The results show that a sevenfold increase in space-time averaged Nusselt number is achieved. Three mechanisms that are responsible for the heat transfer enhancement are identified. In addition, the effects of the governing parameters on the heat transfer are studied over a wide range. The heat transfer enhancement is found to be increased with dimensionless oscillation frequency and amplitude, but decreased with the Grashof number. Another interest of this paper is to optimize the geometry of baffle plates and an optimal baffle height-spacing ratio 0.25-0.50 is found for higher heat transfer rate. [ABSTRACT FROM AUTHOR]