Multiharmonic Adaptive Vibration Control of Misaligned Driveline via Active Magnetic Bearings

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Hans A. DeSmidt ◽  
K. W. Wang ◽  
Edward C. Smith
Keyword(s):  
Vibration Control ◽  
Closed Loop ◽  
Explicit Knowledge ◽  
Operating Conditions ◽  
Magnetic Bearings ◽  
Active Magnetic Bearings ◽  
Load Torque ◽  
Stability Robustness ◽  
Adaptive Vibration Control ◽  
Loop Stability

Active magnetic bearings (AMBs) have been proposed by many researchers and engineers as an alternative to replace traditional contact bearings in rotor and driveshaft systems. Such active, noncontact bearings do not have frictional wear and can be used to suppress vibration in sub- and supercritical rotor-dynamic applications. One important issue that has not yet been addressed by previous AMB-driveline control studies is the effect of driveline misalignment. Previous research has shown that misalignment causes periodic parametric and forcing actions, which greatly impact both driveline stability and vibration levels. Therefore, in order to ensure closed-loop stability and acceptable performance of any AMB controlled driveline subjected to misalignment, these effects must be accounted for in the control system design. In this paper, a hybrid proportional derivative (PD) feedback/multiharmonic adaptive vibration control (MHAVC) feedforward law is developed for an AMB/U-joint-driveline system, which is subjected to parallel-offset misalignments, imbalance, and load-torque operating conditions. Conceptually, the PD feedback ensures closed-loop stability while the MHAVC feedforward suppresses steady-state vibration. It is found that there is a range of P and D feedback gains that ensures both MHAVC convergence and closed-loop stability robustness with respect to shaft internal damping induced whirl and misalignment effects. Finally, it is analytically and experimentally demonstrated that the hybrid PD-MHAVC law effectively adapts to and suppresses multiharmonic vibration induced by imbalance, misalignment, and load-torque effects at multiple operating speeds without explicit knowledge of the disturbance conditions.

Multi-Harmonic Adaptive Vibration Control of AMB-Driveline Systems With Non-Constant Velocity Flexible Couplings

2003 ◽  
Author(s):  
Hans A. DeSmidt ◽  
K. W. Wang ◽  
Edward C. Smith
Keyword(s):  
Vibration Control ◽  
Constant Velocity ◽  
Closed Loop ◽  
Harmonic Excitation ◽  
Stability And Convergence ◽  
Control Law ◽  
Shaft Speed ◽  
Load Torque ◽  
Adaptive Vibration Control ◽  
Loop Stability

Active Magnetic Bearings (AMB) have been proposed by many researchers and engineers as an alternative to replace traditional contact bearings in rotors and driveshafts. Such active, non-contact bearings do not have frictional wear and can be used to suppress vibration in sub- and supercritical rotor dynamic applications. One important issue that has not yet been addressed in previous AMB driveline control studies is the effect of non-constant velocity (NCV) flexible couplings, such as U-Joint or disk-type couplings. The NCV effects introduce periodic parametric and forcing actions that are functions of shaft speed, driveline misalignment and load-torque. Previous research has found that NCV couplings can greatly impact stability and cause significant harmonic excitation at integer multiples of the shaft speed. Thus, to ensure closed-loop stability and acceptable performance of any AMB-driveline with NCV couplings, these effects must be accounted for in the control law design. In this paper, a hybrid control law consisting of an analog PD feedback controller augmented with a slowly updating, multiple harmonic adaptive vibration control (MHAVC) is developed for a U-joint-driveline system supported by AMBs. The function of the PD controller is to ensure closed-loop stability and convergence of the MHAVC, while the MHAVC suppresses the steady-state vibration. Closed-loop stability, convergence, and performance are investigated over a range of shaft speeds for various misalignment and load-torque levels. It is found that there is an optimal range of P and D feedback gains that ensures both convergence of the MHAVC and maximizes the robust stability of the closed-loop system, with respect to NCV effects. Furthermore, it is demonstrated that the MHAVC can effectively suppress the multi-harmonic vibration induced by shaft imbalance and NCV coupling effects without knowledge of the disturbance input distribution.

The Oil-Free Shaft Line

1988 ◽  
Author(s):  
Bruno Wagner
Keyword(s):  
Vibration Control ◽  
Magnetic Bearing ◽  
Magnetic Bearings ◽  
Active Magnetic Bearing ◽  
Active Magnetic Bearings ◽  
Present Stage ◽  
Shaft Line ◽  
Process Gas ◽  
Gas Seals ◽  
Length Reduction

This paper recalls the principles and main features of the active magnetic bearings and especially the advantages for turbomachines. Oil-free working and vibration control are part of them. Field experiences are described for different shaft line configurations. Step by step we are going to get totally rid of oil with the introduction of active magnetic bearings together with dry gas seals and gearless drive. Future machines will take the benefit of all this field experience. The trend of the design optimization is the active magnetic bearings in the process gas itself, for a length reduction of shafts. But at the present stage, the active magnetic bearing is a proven technology today.

Two-Level Control Structure of Magnetic Bearings

1993 ◽  
Vol 5 (5) ◽  
pp. 438-442 ◽  
Author(s):  
Nobuyoshi Taguchi ◽  
◽  
Takakazu Ishimatsu ◽  
Takashi Shimomachi ◽  
◽  
...  
Keyword(s):  
Control System ◽  
Vibration Control ◽  
Control Structure ◽  
Active Vibration Control ◽  
Experimental Results ◽  
Magnetic Bearings ◽  
Active Magnetic Bearings ◽  
Level Control ◽  
Whirling Motion ◽  
Active Vibration

Active magnetic bearings have several advantages over conventional mechanical and fluid bearings. However, when the magnetic bearings are used at high rotational speeds, whirling motions and vibrations synchronized with the rotation of the rotor should be considered. In order to suppress these unfavorable vibrations of rotor which is supported by magnetic bearings, we have developed an active vibration control system with a two-level control structure. Experimental results show that our active bearings system effectively suppresses the whirling motion.

20420 Modeling and Stabilization of levitation and vibration control on active magnetic bearings system with flexible rotor

2015 ◽  
Vol 2015.21 (0) ◽  
pp. _20420-1_-_20420-2_
Author(s):  
Hirokazu Tomono ◽  
Tasuku Kamekawa ◽  
Hiroyuki Fujisaki ◽  
Masamitsu Shiga ◽  
Toru Watanabe ◽  
...  
Keyword(s):  
Vibration Control ◽  
Magnetic Bearings ◽  
Active Magnetic Bearings ◽  
Flexible Rotor

Vibration Control of Spur Geared Rotor Systems With Transmission Errors by Active Magnetic Bearings

2019 ◽  
Author(s):  
Gargi Majumder ◽  
Rajiv Tiwari
Keyword(s):  
Vibration Control ◽  
Transmission Error ◽  
Magnetic Bearings ◽  
Physical Contact ◽  
Vibration Measurement ◽  
Mesh Deformation ◽  
Control Force ◽  
Active Magnetic Bearings ◽  
Full Spectrum ◽  
Gear Mesh

Abstract Dynamic forces between the mating gears are generated due to the mesh deformation, gear eccentricities, transmission error, and gear run-out, which cause excessive vibration and noise. Study and control of these forced vibrations in gear box are vital to prevent any adverse effects on the gears and its supporting structures. Hence, this work presents a novel concept of active vibration control by introducing Active Magnetic Bearings (AMBs) on the shaft of a spur gearbox having conventional bearings as well. The AMB suppresses the response of the system by generating controlled electromagnetic forces based on the gear shaft vibration measurement. The AMB force is applied without any physical contact as opposed to mechanical forces in conventional bearings. A coupled torsional-lateral vibration analysis has been simulated with the effects of mesh deformation, gear eccentricities, transmission error, and gear run-out. The electromagnetic actuator is designed in such a way that a resultant radial control force can be developed with the help of forces in two mutually perpendicular directions. With a feedforward PID controller, the transverse vibration amplitude is observed to be suppressed to a considerable level. The frequency domain analysis is done using a full spectrum, which shows that multiple harmonics of gear mesh frequency is minimized simultaneously.

A New Modeling Technique and Control System Design of a Flexible Rotor Supported by Active Magnetic Bearings for Motion and Vibration Control

2003 ◽  
Author(s):  
Mitsuhiro Ichihara ◽  
Hideo Shida ◽  
Takahito Sagane ◽  
Hiroshi Tajima ◽  
Muneharu Saigou ◽  
...  
Keyword(s):  
Control System ◽  
Vibration Control ◽  
System Design ◽  
Physical Model ◽  
Magnetic Bearings ◽  
Control System Design ◽  
Active Magnetic Bearings ◽  
Flexible Rotor ◽  
Reduced Order ◽  
And Control

This paper proposed a new modeling technique and control system design of a flexible rotor using active magnetic bearings (AMB) for motion and vibration control. The purpose of the research was to pass through a critical speed and achieve high-speed rotation. To achieve this, it is necessary to control both vibration and motion. Even though reduced order physical model [1] that we used before is available technique in expressing vibration, this technique cannot express motion. Thus we propose an extended reduced order physical model [2] that can simultaneously express motion and vibration. Further, by using the model we apply the design of a new controller that combined proportional integral derivative (PID) with linear quadratic (LQ) control to a flexible rotor. The procedure we propose is verified by simulations as being effective for a flexible rotor.

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