Experimental validation and comparison between different active control methods applied to a journal bearing supported rotor

Abstract

Summary Rotors supported by cylindrical hydrodynamic journal bearings usually face rotational speed limitations due to the unstable motion caused by oil whip effect. An active magnetic bearing is utilized as auxiliary component to suppress oil whip and reduce unbalance lateral vibration amplitude at critical speed. Three distinct control methods are considered for the actuation force (dynamic H∞, μ synthesis, and polynomially parameter‐dependent static H∞), which must be designed to perform in a situation with varying parameters and uncertainties. These techniques are tested in scenarios with collocated and noncollocated feedback (emulating a magnetic actuator with magnetic flux sensors). The different resultant performances are successfully compared with each other numerically and experimentally.

Vibration health monitoring of rolling bearings under variable speed conditions by novel demodulation technique

“…The rolling bearing is one of the most widely used mechanical parts in rotating machinery 1–6 . Because of tough working conditions, rolling element bearings are usually subjected to a local damage, such as a crack and a pitting.…”

Feedforward Rotor Fault Compensation

“…The tests are performed in distinct operation conditions to accentuate distinct effects to demonstrate the applicability potential. In further studies, it is intended to apply a twolayer (hybrid) control, 10,15,16 where the feedforward technique actuates to improve the overall performance of a stabilizing robust feedback loop 4,17 to deal, specifically, with the oil whip limitation described in the literature. 6,18 2 | NOTATION A particular notation is defined to provide a clear distinction between different coordinates, time, and frequency domains.…”