Prescribed Performance RISE-based Control of Euler-Lagrange Systems under Saturation

This paper spotlight on the problem of output tracking for a class of uncertain multi-input multi-output (MIMO) nonlinear systems with unmatched nonlinearities and non-vanishing disturbances. Most existing prescribed performance control (PPC) can only guarantee uniformly ultimately bounded (UUB) stability, while the robust integral of the sign of the error (RISE) based control, although is able to realize asymptotic stability, does not ensure transient behavior. For this reason, a new method about the neural network (NN) based adaptive control embedded with the RISE technique is presented based on the idea of PPC. Moreover, the constraints imposed on the inputs are addressed by the hyperbolic tangent function, resulting in a solution capable of guaranteeing zero-error tracking with prescribed transient performance. Finally, a numerical simulation is performed to show the validity of presented strategy.