Energy cost assessment of a polar based controller applied to a flexible rotor supported by AMB

From a designer point of view, optimizing the energy necessary for the control is an important element that could lead to downsize the control cabinet and to an increase of margins according to power amplifier capabilities. Also, reducing the energy used, generates a less significant environmental impact. The aim of this work was to develop and to assess a new approach using polar coordinates to observe and actuate the control of a flexible rotor supported by Active Magnetic Bearings (AMBs). Two fuzzy logic based controllers used to modulate the actuating forces were developed and assessed. The first is a SISO fuzzy PID controller for which the input is the displacement measured along an action line while the output is the force applied in the same direction. The second controller considers each bearing as a single MIMO system with the displacements in the two orthogonal directions as inputs, by managing two significant physical quantities, namely tangential and radial speeds. The "mechanical" performances are compared to those of an augmented PID controller. Then, the energy necessary for the control is compared. The study is first performed numerically and then validated experimentally. The results obtained show that the polar fuzzy controller presents the most suitable mechanical performances and energy costs