Improved H2/H∞ controller design for polynomial fuzzy systems based on iterative sum-of-squares optimization
Qingliang Ma, Haiyan Yang, Rui-Hua Yue, Jun Pu · 2018
The problem of mixed H2/H∞fuzzy state feedback controller design is investigated for polynomial fuzzy systems. First, a novel mixed H2/H∞performance criterion is proposed for polynomial fuzzy systems, which employs different Lyapunov functions to satisfy H2and H∞design requirements. Then, the optimal H2/H∞controller design problem is converted a parameter optimization problem with sum-of-squares (SOS) constraints. Finally, the design method of optimal mixed H2/ H∞fuzzy controller of nonlinear systems is given by constructing an iterative sum-of-squares (ISOS) optimization algorithm. Simulation results show that, compared with the method with common Lyapunov function, the proposed ISOS optimization method with different Lyapunov functions can reduce the design conservatism effectively.