In this paper, an indirect adaptive fuzzy control scheme is presented for a class of multiinput
and multi-output (MIMO) nonlinear systems whose dynamics are poorly understood.
Within this scheme, fuzzy systems are employed to approximate the plant’s unknown
dynamics. In order to overcome the controller singularity problem, the estimated gain
matrix is decomposed into the product of one diagonal matrix and two orthogonal matrices,
a robustifying control term is used to compensate for the lumped errors, and all parameter
adaptive laws and robustifying control term are derived based on Lyapunov stability
analysis. The proposed scheme guarantees that all the signals in the resulting closed-loop
system are uniformly ultimately bounded (UUB). Moreover, the tracking errors can be made
small enough if the designed parameter is chosen to be sufficiently large. A simulation
example is used to demonstrate the effectiveness of the proposed control scheme.