ABSTRACT
The paper presents the results of experimental validation of the Newton observer for estimation of the magnetic flux within the feedback control of a nonlinear active magnetic bearing (AMB) system. In the preliminary work the Newton observer was adapted for the exact discrete-time model of the simplified one-degree-of-freedom AMB system, operated with zero-bias flux and under the voltage switching strategy, and showed good results in case of numerical simulations. The objective of this paper is to confirm these results on the basis of experimentation. The experiments were conducted on the AMB test rig, developed and manufactured at Bialystok University of Technology.
Disclosure statement
No potential conflict of interest was reported by the authors.
ORCID
A. Mystkowski http://orcid.org/0000-0002-5742-7609
Ü. Kotta http://orcid.org/0000-0002-7697-769X
V. Kaparin http://orcid.org/0000-0002-4968-2474
Notes
1. In the case when the number of equations exceeds the number of states, the inverse in (5) should be replaced by a pseudoinverse.
2. Note that though we use the full-order Newton observer (estimating all three states), in (Equation6(6)
(6) ) the measured value of the state
is employed.
3. Note that the plots throughout the paper depict the trajectories of the physical parameters x, , and φ but not the non-dimensionalised variables
,
, and
. The physical parameters can be easily obtained from the non-dimensionalised variables using the relations (Equation1
(1)
(1) ).
4. The disturbance is the external load/force acting on the shaft supported by AMB. This force is used to test the shaft stability. For simplicity we represent the disturbance as voltage. The power amplifier converts this voltage into the disturbance current with amplitude ±1 A, resulting in the disturbance force generated by the electromagnets.