Stability analysis and robust control design on an AMB system

This paper describes a stability analysis and a H_infin robust control design for an electromechanical system consisting of a rotary flexible spindle hovered by active magnetic bearings (AMB), whose potential uses in the machine-tool industry have been well documented. Firstly, a complete experimental stability analysis is performed controlled by a previously designed PID controller. This is performed via the ISO 14839-3 standard, which reliability needs to probe the negligibility of some effects. Then, since the lack of robustness is concluded by the previous study, an H_infin control design is accomplished. Moreover, the ill-conditioning of the matrices when the DGKF algorithms are solved, is avoided performing a model reduction. This is carried out by means of the symmetry properties which characterize the system and hence, facilitating the design. The better behavior of the system is probed by simulation in a complete model of the real device.