Control of a high speed machining spindle via μ-synthesis

Knospe, Carl R.; Fittro, Roger; Stephens, Lyndon Scott

doi:10.1109/cca.1997.627779

Cited by 14 publications

(7 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since optimal controllers are tailored for the plant model, this robustness to uncertainties is a prerequisite for successful implementation and gives the method a great potential to industrial application (Steinbuch, Norg, 1998). The method has already been applied successfully to the control of flexible structures in CD-players, tooling machines and magnetic bearings by scientists , Van den Braembussche, 1998, Knospe et al, 1997and Schönhoff et al , 2000c. The optimization aim for SOFIA's attitude control was the minimization of the "compliance" of the attitude measured by the gyro to a virtual torque like disturbance entering at the torque drives location.…”

Section: Attitude Controller Designmentioning

confidence: 97%

End-to-end simulation of the image stability for the airborne telescope SOFIA

et al. 2000

View full text Add to dashboard Cite

To provide astronomers access to infrared wavelength unavailable from the ground the airborne telescope SOFIA is in development. This paper focuses on the image stability of the telescope, its modelling and simulation. The operation ot the telescope under the harsh environmental conditions in the aircraft makes the prediction of the image stability during the design process necessary. For this purpose an integrated mathematical simulation model, which includes the optics. the structural dynamics and the control loops has been constructed. Because of the high relevance of the structural dvnamics for image stability and control design. special attention is paid to the Import and reduction of the finite element model of the telescopes mechanical structure. Different control approaches are considered for the attitude control and the compensation of the impact of the structural flexibility on the image motion. Additionally the secondary mirror servo-mechanism is utilized to optimize the image stability. Simulation results are shown.

show abstract

Section: Attitude Controller Designmentioning

confidence: 97%

End-to-end simulation of the image stability for the airborne telescope SOFIA

et al. 2000

View full text Add to dashboard Cite

show abstract

“…The first is a 32000 rpm prototype magnetic bearing spindle, shown in Fig. 3, designed and constructed in cooperation with Cincinnati Milacron (Stephens, 1995;Knospe, Fittro, & Stephens, 1997;Fittro, 1998;Fittro & Knospe, 1999;Fittro, Knospe, & Stephens, 2003 motor rotor, and thrust disk). Inside the rotor shaft is a 14.2 mm (0.56 in) diameter drawbar.…”

Section: Control Of a High Speed Spindlementioning

confidence: 99%

Active magnetic bearings for machining applications

Knospe

2007

Control Engineering Practice

102

View full text Add to dashboard Cite

High-speed machining offers substantial economic benefits due to increased metal cutting productivity. Critical to realizing this technology's promise are the intertwined challenges of spindle dynamic stiffness and cutting process stability. Active magnetic bearings enable greater spindle dynamic stiffness through higher attainable bearing surface speeds, and also provide a means for enhancing cutting process stability. Herein, experimental results from two test rigs are presented illustrating the potential of magnetic bearings for the active suppression of machining chatter. Application challenges and controller design issues are examined in detail. r

show abstract

“…The linearized expression for the electro-magnetic force around a nominal operating point is given as f = k i i + k x g, where k i and k x are the unknown current and displacement coefficients. These coefficients can be determined experimentally and different procedures are discussed in [8] and [9]. Estimation of these coefficients is often referred to as identification of AMB systems in the literature.…”

Section: Introductionmentioning

confidence: 99%

Subspace identification and robust control of an AMB system

Balini

Houtzager

Witte

et al. 2010

Proceedings of the 2010 American Control Conference

View full text Add to dashboard Cite

Active magnetic bearing (AMB) systems are nonlinear, multi-variable and inherently unstable. Conventionally, LTI models are obtained either from first principles or identification experiments and then used to design/synthesize feedback controllers. In general, identification algorithms are focused on obtaining the current and displacement coefficients for a linearized AMB model, which in-turn is based on first principles modeling. In recent years, it is shown that predictor-based subspace identification algorithms (PBSID) give consistent estimates of the parameters even in the presence of feedback. In view of this, we apply the PBSIDopt method to obtain a linear model of an experimental AMB system. Further, a robust controller against uncertainties in a reduced order model (neglecting flexible dynamics) is synthesized.

show abstract

Control of a high speed machining spindle via μ-synthesis

Cited by 14 publications

References 1 publication

End-to-end simulation of the image stability for the airborne telescope SOFIA

End-to-end simulation of the image stability for the airborne telescope SOFIA

Active magnetic bearings for machining applications

Subspace identification and robust control of an AMB system

Contact Info

Product

Resources

About