chatter - Control of Chatter using Active Magnetic Bearings...

Info iconThis preview shows pages 1–13. Sign up to view the full content.

View Full Document Right Arrow Icon
UVA UVA UVA Control of Chatter using Active Magnetic Bearings Carl R. Knospe University of Virginia
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
UVA UVA UVA Opportunity u Chatter is a machining process instability that inhibits higher metal removal rates (MRR) and accelerates tool wear. u The higher MRR achievable through chatter control could yield more than a $10 billion increase in US GDP.
Background image of page 2
UVA UVA UVA Advantages for Machining Active magnetic bearings (AMBs) have several advantages for high speed machining: u stiffer spindles and higher speeds u adaptive balancing via feedforward control u increased damping of spindle modes u ability to adapt bearing properties to cutting conditions via gain scheduled control
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
UVA UVA UVA Two Efforts u Design and testing of a 32,000 rpm milling spindle supported by active magnetic bearings (sponsor: Cincinnati Milacron) u Investigation of new concepts for chatter control (sponsor: NSF)
Background image of page 4
UVA UVA UVA AMB Spindle u Design of high speed AMB spindle u System modeling u Experimental investigation of advanced control
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
UVA UVA UVA AMB Spindle u Design of high speed AMB spindle § optimization of rotor / actuator / control § rotor loss experiments & thermal modeling § dynamic analysis, AMB clearances, tolerances u System modeling u Experimental investigation of advanced control
Background image of page 6
UVA UVA UVA AMB Spindle u Design of high speed AMB spindle u System modeling § analytical models of rotor & actuator § component testing of amplifiers & sensors § initial levitation via PID control § system ID and model adjustment u Experimental investigation of advanced control.
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
UVA UVA UVA AMB Spindle u Design of high speed AMB spindle u System modeling u Experimental investigation of advanced control § assembly coding on parallel controller § multivariable control synthesis and reduction § testing of over 30 control algorithms § adaptive balancing
Background image of page 8
UVA UVA UVA AMB Spindle Features u 32,000 rpm, 90 hp, 3 million DN u 3 radial bearings and 1 thrust bearing § 1000 lbf cutting load u Differential optical sensors § 0.25 μ m noise u Parallel processing DSP controller § 7 input, 7 output, 75 states at 12 kHz
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
UVA UVA UVA Modern Control Framework d(t) z(t) y(t) u(t) Rotor-Actuator Controller System ?
Background image of page 10
UVA UVA UVA Multivariable Control u Most AMB systems operate under decentralized PID control. u Greater performance can be achieved by using all available information to coordinate actions.
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
UVA UVA UVA AMB Spindle Modeling § The control designs are heavily dependent on accurate component models.
Background image of page 12
Image of page 13
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 38

chatter - Control of Chatter using Active Magnetic Bearings...

This preview shows document pages 1 - 13. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online