An interval type-2 fuzzy linear quadratic regulator method for an overhead crane

The overhead crane systems contain parameter uncertainties and external disturbances, which will affect the control performance of the systems. To overcome this problem, an interval type-2 Takagi–Sugeno (T-S) fuzzy linear quadratic regulator (LQR) approach is proposed for overhead crane system in this paper. First, an interval type-2 T-S fuzzy model is constructed based on the nonlinear dynamic model of the overhead crane system. The type-2 model can capture the system uncertainties. Second, the fuzzy LQR is designed on the basis of the fuzzy model and the asymptotic stability of the closed-loop system is analyzed using Lyapunov method. Finally, simulations and experiments are studied. The results show that the proposed method can give the overhead crane system faster trolley positioning speed, smaller load swing, and better anti-disturbance ability than the existing LQR control method.