Research ArticleModular design using feedback domination method for adaptive regulation of high-order lower-triangular nonlinear systems

In this paper, a new modular design technique for global adaptive asymptotic regulation of high-order lower-triangular nonlinear systems is proposed. These systems include strict-feedback nonlinear systems. So, this new design technique which is quite different from the well-known design techniques like backstepping, and completely uses feedback domination method, can be used for the latter systems. Besides, contrary to the so-called adding a power integrator technique, in which the choice of a parameter update law is limited to a Lyapunov-type algorithm, the present method does not have this restriction and uses the passive identifier as its parameter update law. This new method is also completely different from the modular design in Immersion & Invariance (I&I) based method, because it relies on the control design module, and not on the performance of parameter identification.

► This new design method for global adaptive asymptotic regulation of the parametric high-order lower-triangular nonlinear systems does not rely on certainty equivalence principle. ► Also, contrary to the design method based on adding a power integrator, the identifier is based on passive observer and derived separately from the controller design, in this new method. ► Besides, This modularity of designing the controller and the identifier, which relies on control design using feedback domination approach, is completely different from modular design in I&I based method [7], which relies on identifier design and desired features of parameter identification.