Linearization of T-S fuzzy systems and robust H_∞ control

Takagi-Sugeno (T-S) fuzzy model is difficult to be linearized because of membership functions included. So, novel T-S fuzzy state transformation and T-S fuzzy feedback are proposed for the linearization of T-S fuzzy system. The novel T-S fuzzy state transformation is the fuzzy combination of local linear transformation which transforms local linear models in the T-S fuzzy model into the local linear controllable canonical models. The fuzzy combination of local linear controllable canonical model gives controllable canonical T-S fuzzy model and then nonlinear feedback is obtained easily. After the linearization of T-S fuzzy model, a robust H _∞ controller with the robustness of sliding model control (SMC) is designed. As a result, controlled T-S fuzzy system shows the performance of H _∞ control and the robustness of SMC.     

三路带通混叠信号数字接收机设计

为解决三路带通信号混叠问题,提出了一种延时可调的三阶带通采样结构,通过设计数字抗混叠滤波器,可实现对三路带通信号的无混叠接收。给出了仿真实现结果,并对信号进行重构,分析了抗混叠性能,三路带通信号经过抗混叠滤波器后,信号输出信噪比可在28 dB以上。该方法解决了带通采样中多信号混叠问题,增加了采样频率选择范围,可以减少硬件负担,提高了软件无线电的灵活性。