A neural network based adaptive control design approach for a class of uncertain nonlinear systems with unknown time delay

A neural network based robust adaptive control design scheme is developed for a class of nonlinear systems represented by input-output models with an unknown nonlinear function and unknown time delay. By on-line approximating the unknown nonlinear functions with a three layer feedforward neural networks, the proposed approach does not require the unknown parameters to satisfy the linear dependence condition. The control law is delay independent and possible controller singularity problem is avoided. It is proved that with the proposed neural control law, all the signals in the closed-loop system are semiglobally bounded in the presence of unknown time delay and unknown nonlinearity.