Journal Articles, Hindawi Press

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https://hdl.handle.net/10919/78797

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Browsing Journal Articles, Hindawi Press by Subject "Applications"

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    Application of Recursive Least Square Algorithm on Estimation of Vehicle Sideslip Angle and Road Friction
    Ding, Nenggen; Taheri, Saied (Hindawi Publishing Corporation, 2010)
    A recursive least square (RLS) algorithm for estimation of vehicle sideslip angle and road friction coefficient is proposed. The algorithm uses the information from sensors onboard vehicle and control inputs from the control logic and is intended to provide the essential information for active safety systems such as active steering, direct yaw moment control, or their combination. Based on a simple two-degree-of-freedom (DOF) vehicle model, the algorithm minimizes the squared errors between estimated lateral acceleration and yaw acceleration of the vehicle and their measured values. The algorithm also utilizes available control inputs such as active steering angle and wheel brake torques. The proposed algorithm is evaluated using an 8-DOF full vehicle simulation model including all essential nonlinearities and an integrated active front steering and direct yaw moment control on dry and slippery roads.
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    Control of Limit Cycle Oscillations of a Two-Dimensional Aeroelastic System
    Ghommem, Mehdi; Nayfeh, Ali H.; Hajj, Muhammad R. (Hindawi Publishing Corporation, 2010)
    Linear and nonlinear static feedback controls are implemented on a nonlinear aeroelastic system that consists of a rigid airfoil supported by nonlinear springs in the pitch and plunge directions and subjected to nonlinear aerodynamic loads. The normal form is used to investigate the Hopf bifurcation that occurs as the freestream velocity is increased and to analytically predict the amplitude and frequency of the ensuing limit cycle oscillations (LCO). It is shown that linear control can be used to delay the flutter onset and reduce the LCO amplitude. Yet, its required gains remain a function of the speed. On the other hand, nonlinear control can be efficiently implemented to convert any subcritical Hopf bifurcation into a supercritical one and to significantly reduce the LCO amplitude.