Exhaust gas recirculation valves used in internal combustion engines are highly nonlinear due to its nonlinear mechanism and dry friction dominated at low valve speed that could lead to large steady-state displacement errors. A multiple friction factor model is adopted in this article using a switched linear parameter-varying (LPV) modeling approach, where the scheduling parameter is the friction coefficient as a function of valve speed. Switched gain-scheduling LPV controllers are designed based on the hysteresis switching logic with guaranteed ${\mathscr{H}}_{\infty }$ performance, where parameterized linear matrix inequality (LMI) conditions are relaxed to a set of LMI conditions for synthesizing the switched LPV controllers by convex optimization. The LPV control performance is compared with that of proportional–integral–derivative controllers through both simulation and experimental studies, showing a notable improvement in the system response performance and robustness.

中文翻译：

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考虑非线性干摩擦的发动机EGR气门建模和LPV切换控制

内燃发动机中使用的排气再循环阀由于其非线性机理和在低阀速下占主导的干摩擦而具有高度非线性，这可能导致较大的稳态位移误差。本文采用开关线性参数变化（LPV）建模方法采用多摩擦系数模型，其中调度参数是摩擦系数与阀速的函数。开关增益调度LPV控制器基于磁滞开关逻辑进行设计，并确保$ {\ mathscr {H}} _ {\ infty} $性能，其中将参数化线性矩阵不等式（LMI）条件放宽到一组LMI条件，以通过凸优化来合成开关LPV控制器。通过仿真和实验研究，将LPV控制性能与比例积分微分控制器的性能进行了比较，显示出系统响应性能和鲁棒性方面的显着改善。