Xin Li

Shanghai Jiao Tong University, Shanghai, Shanghai Shi, China

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Publications (2)0 Total impact

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    ABSTRACT: Pressure ripple in electric power steering (EPS) system can be caused by the phase lag between driver’s steering torque and steer angle, the nonlinear frictions, and the disturbances from road and sensor noise especially during high frequency maneuvers. This paper novelly applied the robust fuzzy control method of active reduction of pressure ripple for EPS system, which achieves remarkable progress on steering maneuverability. First, an EPS dynamics are described by an eight-order nonlinear state-space model and approximated by a Takagi-Sugeno (T-S) fuzzy model with time-varying delays and external disturbances. Then, a fuzzy controller is applied based on the fuzzy model of the EPS system. The closed loop stability conditions of EPS system with the fuzzy controller are parameterized in terms of Linear Matrix Inequality (LMI) problem, which can be solved efficiently by using the convex optimization techniques. The numerical simulation of the EPS system with and without the use of the developed controller has been carried out. The simulation result shows that the proposed fuzzy control method can reduce the torque ripple to achieve a better steering feel and more stable driving.
    Fuzzy Systems, 2008. FUZZ-IEEE 2008. (IEEE World Congress on Computational Intelligence). IEEE International Conference on; 07/2008
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    [Show abstract] [Hide abstract]
    ABSTRACT: Pressure ripples in electric power steering (EPS) systems can be caused by the phase lag between the driver’s steering torque and steer angle, the nonlinear frictions, and the disturbances from road and sensor noise especially during high-frequency maneuvers. This paper investigates the use of the robust fuzzy control method for actively reducing pressure ripples for EPS systems. Remarkable progress on steering maneuverability is achieved. The EPS dynamics is described with an eight-order nonlinear state-space model and approximated by a Takagi-Sugeno (T-S) fuzzy model with time-varying delays and external disturbances. A stabilization approach is then presented for nonlinear time-delay systems through fuzzy state feedback controller in parallel distributed compensation (PDC) structure. The closed-loop stability conditions of EPS system with the fuzzy controller are parameterized in terms of the linear matrix inequality (LMI) problem. Simulations and experiments using the proposed robust fuzzy controller and traditional PID controller have been carried out for EPS systems. Both the simulation and experiment results show that the proposed fuzzy controller can reduce the torque ripples and allow us to have a good steering feeling and stable driving.
    International Journal of Automation and Computing 6(2):198-203.