SIAM Journal on Control and Optimization, Vol.48, No.4, 2719-2750, 2009
WELL-POSEDNESS AND CONTROLLABILITY OF A CLASS OF COUPLED LINEAR SYSTEMS
We consider coupled systems consisting of an infinite-dimensional part and a finite-dimensional part connected in feedback, such as, for example, the well-known SCOLE system (a beam with a rigid body attached at one end). The external world interacts with the coupled system via the finite-dimensional part, which receives the external input and sends out the output. The in finite-dimensional part is assumed to be such that it becomes well-posed and strictly proper when connected in cascade with an integrator. Under several assumptions, we derive well-posedness and exact controllability results for such coupled systems. The first main result concerns the case when the input signal of the finite-dimensional part is the difference between the external input and the feedback signal. The second main result allows a more general structure for the finite-dimensional part. We also prove a result for the approximate controllability of coupled systems.
Keywords:coupled system;well-posed system;admissible control operator;exact controllability;simultaneous controllability