Simple adaptive robust output tracking control schemes of uncertain parametric strict-feedback non-linear systems with unknown input saturations

In this study, the problem of robust output tracking control is considered for a class of uncertain strict-feedback non-linear systems with any input saturation. A new design approach, called an adaptive design approach, is proposed to deal with saturated input non-linearities. The main merits of the proposed adaptive design approach can be summarised as follows. (i) It is completely unnecessary to know any information on input saturation non-linearities. (ii) By utilising the proposed adaptive design approach, the resulting control schemes will have a specially simple structure. (iii) The adaptive design approach proposed in this study is also easy to understand for the system designers, and by combining the proposed adaptive design approach with other control ones, a number of interesting results can be expected for a rather large class of dynamical systems with saturation in the actuators. Finally, a numerical example is given to illustrate the design procedure, and the corresponding simulations are also implemented to show the validity of the theoretical results.