ADAPTIVE-CONTROL OF UNCERTAIN COUPLED MECHANICAL SYSTEMS WITH APPLICATION TO BASE-ISOLATED STRUCTURES

A problem of feedback stabilization is addressed for a class of uncert ain nonlinear mechanical systems with n degrees of freedom and n(c) < n control inputs. Each system of the class has the structure of two co upled subsystems with n(c) and n(r) degrees of freedom, respectively, a prototype being an uncertain base isolated building structure with n degrees of freedom actively controlled via actuators applying forces to specific degrees of freedom of the base movement, n(c) < n in numbe r. A nonlinear adaptive feedback strategy is described, which, under a ppropriate assumptions on the system uncertainties, guarantees a form of practical stability of the zero state. Numerical simulations are al so presented to illustrate the application of the control strategy to a base isolated building.