It is shown that B.C. Moore's balancing model (1981) can be extended to unstable systems by utilizing two weighted Grammian matrices. It is proposed that the J omega axis can be shifted to handle unstable systems. The balanced approach involves the solution of two modified Lyapunov equations. Two numerical examples are given to illustrate the results. >
This project is directed at the third generation of heart pumps being developed in commercial research laboratories which employ feedback-controlled magnetically levitated pump impellers. Unique features of the control problem are the quasi-periodic pressure disturbances of the natural heart and nonlinearities of the magnetic levitation system. The main motivation for this paper is the power consumption due to quasi-periodic disturbance of natural heart. Since clinical studies are not possible for the vast majority of our work, there is a need for an apparatus to simulate the left ventricular assist device (LVAD) for controller design. Inspired by this need, we design a novel experimental apparatus to study the Maglev LAVDs. We develop a nonlinear model, then a linearized model followed by simulation and stabilization of the closed-loop system using a virtual zero power (VZP) controller.
Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights.