Control of Flexible Structures

Project Title: Collaborative Research: High-Speed AFM through Compressed Sensing

Investigator: S. B. Andersson (Boston University) and Lucy Y. Pao

Sponsor: National Science Foundation

Project Duration: September 2012 - August 2016

Project Title: Advanced Controller Design for Tape Head Positioning Servo System

Investigator: Lucy Y. Pao

Sponsor: Information Storage Industry Consortium Tape Program, Sun Microsystems, Inc., and Oracle Corporation

Project Duration: March 2009 - December 2012

Project Title: High-Speed Precision Motion Control for Near-Field Optical Microscopy and Lithography

Investigators: Lucy Y. Pao and Robert R. McLeod

Sponsor: University of Colorado Innovative Seed Grant Program

Project Duration: September 2008 - August 2011

Project Title: Control Architectures and Adaptive Model-Inverse Based Methods for Nonminimum Phase Uncertain Systems, with Applications to Atomic Force Microscopes

Investigators: Lucy Y. Pao and D. Y. Abramovitch

Sponsor: National Science Foundation

Project Duration: July 2007 - June 2012

Project Title: Control of Atomic Force Microscopes to Achieve Faster Sample Measurements

Investigator: Lucy Y. Pao

Sponsor: Agilent Technologies, Inc.

Project Duration: November 2006 - October 2009

Project Title: Time Optimal Repetitive Control Algorithms

Investigators: Lucy Y. Pao and Dale A. Lawrence

Sponsor: Maxtor Corporation

Project Duration: December 2004 - November 2007

Project Title: Projected Phase-Plane Control of Flexible Structures with Applications to Hard Disk Drives

Investigator: Lucy Y. Pao

Sponsor: National Science Foundation

    Grant CMS-0201459
    Program Manager: Dr. Alison Flatau / Dr. Masayoshi Tomizuka / Dr. Mario Rotea / Dr. Eduardo Misawa / Dr. Suhada Jayasuriya

Project Duration: June 15, 2002 - May 31, 2007

Project Title: Control of Tape Systems Accounting for Reel Eccentricities

Investigator: Lucy Y. Pao

Sponsor: Colorado Center for Information Storage . Project is being carried out in conjunction with Quantum Corporation.

Project Duration: March 1, 2004 - February 28, 2006

Project Title: Speed and Tension Control in Tape Systems

Investigator: Lucy Y. Pao

Sponsor: Colorado Center for Information Storage . Project is being carried out in conjunction with Storage Technology Corporation.

Project Duration: March 1, 2001 - October 31, 2003

Project Title: Rapid Slewing of Flexible Components

Investigator: Lucy Y. Pao

Sponsors: Colorado Center for Information Storage and Quantum Corporation

Project Duration: September 1, 2002 - August 31, 2007

Project Title: Precise Control of Elastic Components for Tape Systems

Investigator: Lucy Y. Pao

Sponsors: Colorado Advanced Software Institute and Storage Technology Corporation

Project Duration: August 15, 1998 - August 31, 1999

Project Title: Rapid and Robust Control of Flexible Structures

Investigator: Lucy Y. Pao

Sponsor: National Science Foundation

    Early Faculty CAREER Development Award, Grant CMS-9625086
    Program Manager: Dr. Devendra P. Garg (1996-1998), Dr. Alison Flatau (1998-2001)

Project Duration: June 1, 1996 - November 30, 2001

Awards:

Visiting Miller Professor Fellowship at the University of California at Berkeley, August 2008 - December 2008

Ph.D. Student Brian Rigney was one of four finalists in the 2009 American Control Conference Student Best Paper Competition

CDC Plenary on "Control of Flexible Structures: From Large Space Structures to Disk Drive Read/Write Arms (Thursday, December 14, 2006).

University of Colorado Faculty Fellowship, 2001-2002

2001 American Control Conference Best Student Paper Award for paper
    M. A. Lau and L. Y. Pao. "Comparison of Input Shaping and Time-Optimal Control of Flexible Structures," Proc. American Control Conf., Arlington, VA, pp. 1485-1490, June 2001.
Colorado Advanced Software Institute Exemplary Project Award, October 2000

University of Colorado Junior Faculty Development Award, July 1997

1996 IFAC World Congress Young Author Prize for paper
NSF Early Faculty CAREER Award, 1996-2001

Recent Publications:

R. A. Braker and L. Y. Pao, "Proximate Time-Optimal Control of a Second-Order Flexible Structure," Proc. IEEE Multi-Conference on Systems and Control, Sydney, Australia, Sep. 2015, in press.

H. Zhong and L. Y. Pao, "H2 Model Matching Feedforward Control for Tape Head Positioning Servo Systems," Proc. American Control Conf., Washington, D.C., pp. 4511-4516, June 2013.

H. Chen, Y. Li, and L. Y. Pao, "Intersample Ripple Resulting from Discrete-Time Feedforward Control," Proc. American Control Conf., Washington, D.C., pp. 4122-4127, June 2013.

Jeffrey A. Butterworth, L. Y. Pao, and D. Y. Abramovitch. "Analysis and Comparison of Three Discrete-Time Feedforward Model-Inverse Control Techniques for Nonminimum-Phase Systems," IFAC J. Mechatronics, 22(5): 577-587, Aug. 2012, available online 12 March 2012.

S. B. Andersson and L. Y. Pao, "Non-Raster Sampling in Atomic Force Microscopy: A Compressed Sensing Approach," Proc. American Control Conf., Montreal, Canada, pp. 2485-2490, June 2012.

H. Zhong, L. Y. Pao, and R. A. de Callafon, "Feedforward Control for Disturbance Rejection: Model Matching and Other Methods," Proc. Chinese Conf. Decision and Control, Taiyuan, China, 6 pages, May 2012.

Jeffrey A. Butterworth, L. Y. Pao, and D. Y. Abramovitch. "A Discrete-Time Single-Parameter Combined Feedforward/Feedback Adaptive-Delay Algorithm with Applications to Piezo-Based Raster Tracking," IEEE Trans. Control Systems Technology, 20(2): 416-423, March 2012.

Jeffrey A. Butterworth, L. Y. Pao, and D. Y. Abramovitch. "Fitting Discrete-Time Models to Frequency Responses for Systems with Transport Deley," Proc. Int. Mech. Eng. Congress & Expo., Denver, CO, Nov. 2011.

M. P. Chaffe and L. Y. Pao. "Iterative Learning Control for Near-Field Scanning Optical Microscope Applications," Proc. IEEE Multi-Conf. Systems and Control, Denver, CO, pp. 1075-1080, Sept. 2011.

Jeffrey A. Butterworth, L. Y. Pao, and D. Y. Abramovitch. "Dual-Adaptive Feedforward Control for Raster Tracking with Applications to AFMs," Proc. IEEE Multi-Conf. Systems and Control, Denver, CO, pp. 1081-1087, Sept. 2011.

H. Zhong and L. Y. Pao. "Combined Feedforward/Feedback Control for Tape Head Track-Following Servo System," Proc. IFAC World Congress, Milan, Italy, pp. 4040-4045, Aug. 2011.

Jeffrey A. Butterworth, L. Y. Pao, and D. Y. Abramovitch. "A Comparison of ILC Architectures for Nanopositioners with Applications to AFM Raster Tracking," Proc. American Control Conf., San Francisco, CA, pp. 2266-2271, June 2011.

Jeffrey A. Butterworth, L. Y. Pao, and D. Y. Abramovitch. "Adaptive Delay in Combined Feedforward/Feedback Control for Raster Tracking in Atomic Force Microscopes," Proc. American Control Conf., Baltimore, MD, pp. 5738-5744, June 2010.

B. P. Rigney, L. Y. Pao, and D. A. Lawrence. " Nonminimum Phase Adaptive Inverse Control for Settle Performance Applications," IFAC J. Mechatronics, 20(1): 35-44, Feb. 2010.

B. P. Rigney, L. Y. Pao, and D. A. Lawrence. "Nonminimum Phase Dynamic Inversion for Settle Time Applications," IEEE Trans. Control Systems Technology, 17(5): 989-1005, Sept. 2009.

H. Zhong and L. Y. Pao. "Regulating Web Tension in Tape Systems with Time-Varying Radii," Proc. American Control Conf., St. Louis, MO, pp. 198-203, June 2009.

B. P. Rigney, L. Y. Pao, and D. A. Lawrence. "Adaptive Inverse Control for Settling Performance Improvements," Proc. American Control Conf., St. Louis, MO, pp. 190-197, June 2009. One of four finalists for the conference-wide Student Best Paper Award.

Jeffrey A. Butterworth, L. Y. Pao, and D. Y. Abramovitch. "A Comparison of Control Architectures for Atomic Force Microscopes," Asian J. Control, 11(2): 175-181, March 2009.

H. Zhong and L. Y. Pao. "Disturbance Rejection in Parameter-Varying Web-Winding Systems," Proc. IFAC World Congress, Seoul, Korea, pp. 9284-9289, July 2008.

B. P. Rigney, L. Y. Pao, and D. A. Lawrence. "Discrete-Time Exact and Approximate Dynamic Inversion for Settle Performance," Proc. IFAC World Congress, Seoul, Korea, pp. 1778-1784, July 2008.

Jeffrey A. Butterworth, L. Y. Pao, and D. Y. Abramovitch. "A Comparison of Control Architectures for Atomic Force Microscopes," invited keynote paper, Proc. IFAC World Congress, Seoul, Korea, pp. 8236-8250, July 2008.

V. Yousefzadeh, A. Babazadeh, B. Ramachandran, E. Alarcon, L. Pao, and D. Maksimovic. "Proximate Time-Optimal Digital Control for Synchronous Buck DC-DC Converters," IEEE Trans. Power Electronics, 23(4): 2018-2026, July 2008.

H. Zhong and L. Y. Pao. "Feedforward Control to Attenuate Tension Error in Time-Varying Systems,"Proc. American Control Conf., Seattle, WA, pp. 533-538, June 2008.

Jeffrey A. Butterworth, L. Y. Pao, and D. Y. Abramovitch. "The Effect of Nonminimum-Phase Zero Locations on the Performance of Feedforward Model-Inverse Control Techniques in Discrete-Time Systems," Proc. American Control Conf., Seattle, WA, pp. 2696-2702, June 2008.

M. D. Baumgart and L. Y. Pao. "Discrete Time-Optimal Command Shaping," Automatica, 43(8): 1403-1409, Aug. 2007.

D. Y. Abramovitch, S. B. Andersson, L. Y. Pao, and G. Schitter. "A Tutorial on the Mechanisms, Dynamics, and Control of Atomic Force Microscopes," Proc. American Control Conf., New York, NY, pp. 3488-3502, July 2007.

L. Y. Pao, Jeffrey A. Butterworth, and D. Y. Abramovitch. "A Combined Feedforward/Feedback Control of Atomic Force Microscopes," Proc. American Control Conf., New York, NY, pp. 3509-3515, July 2007.

V. Yousefzadeh, E. Alarcon, D. Maksimovic, and L. Pao. "Proximate Time-Optimal Digital Control for DC-DC Converters," Proc. IEEE Power Electronics Specialists Conf., Orlando, FL, June 2007.

M. D. Baumgart and L. Y. Pao. "Robust Control of Nonlinear Web-Winding Systems with and without Tension Sensors," ASME J. Dynamic Systems, Measurement, and Control, 129(1): 41-55, Jan. 2007.

B. P. Rigney, L. Y. Pao, and D. A. Lawrence. "Model Inversion Architectures for Settle Time Applications with Uncertainty," Proc. IEEE Conf. Decision and Control, San Diego, CA, pp. 6518-6524, Dec. 2006.

B. P. Rigney, L. Y. Pao, and D. A. Lawrence. "Settle-Time Performance Comparisons of Approximate Inversion Techniques for LTI Nonminimum Phase Systems," Proc. American Control Conf., Minneapolis, MN, pp. 600-605, June 2006.

C. La-orpacharapan and L. Y. Pao. "Fast and Robust Control of Systems with Multiple Flexible Modes," IEEE/ASME Trans. Mechatronics, 10(5): 521-534, Oct. 2005.

V. Kulkarni, H. Zhong, and L. Y. Pao. "Robust Rejection of Periodic and Almost Periodic Disturbances," Proc. IFAC World Congress, Prague, Czech Republic, July 2005.

M. D. Baumgart and L. Y. Pao. "Time-Optimal Control of Web-Winding Systems with Air Entrainment," IEEE/ASME Trans. Mechatronics, 10(3): 257-262, June 2005.

H. Zhong, V. Kulkarni, and L. Y. Pao. "Adaptive Control for Rejecting Disturbances with Time-Varying Frequencies in Tape Systems," Proc. American Control Conf., Portland, OR, pp. 533-538, June 2005.

  • L. Y. Pao. "Research in Control Systems, Sensor Fusion, and Haptic Interfaces," Acta Automatica Sinica, 31(1): 75-83, Jan. 2005.
  • M. D. Baumgart and L. Y. Pao. "Robust Control of Tape Transport Systems with No Tension Sensor," Proc. IEEE Conf. Decision and Control, Paradise Island, Bahamas, pp. 4342-4349, Dec. 2004.

    C. La-orpacharapan and L. Y. Pao. "Robust Shaped Time-Optimal Servomechanism Control," Proc. Japan-USA Symposium on Flexible Automation, Denver, CO, July 2004.

    C. La-orpacharapan and L. Y. Pao. "Nonlinear Control for Maneuvering Multiple Flexible Mode Systems," Proc. American Control Conf., Boston, MA, pp. 1176-1182, June 2004.

    C. F. Cutforth and L. Y. Pao. "Adaptive Input Shaping Techniques for Maneuvering Flexible Structures," Automatica, 40(4): 685-693, April 2004.

    L. Y. Pao and C. La-orpacharapan. "Shaped Time-Optimal Feedback Controllers for Flexible Structures," ASME J. Dynamic Systems, Measurement, and Control, 126(1): 173-186, Mar. 2004.

    C. La-orpacharapan and L. Y. Pao. "Shaped Phase-Plane Feedback Control for Disk Drive Systems," IEEE Trans. Magnetics, 40(1): 85-96, Jan. 2004.

    M. D. Baumgart and L. Y. Pao. " Robust Lyapunov-Based Feedback Control of Nonlinear Web-Winding Systems," Proc. IEEE Conf. Decision and Control, Maui, HI, pp. 6398-6405, Dec. 2003.

    L. Y. Pao and C. F. Cutforth. "On Frequency-Domain and Time-Domain Input Shaping for Multi-mode Flexible Structures," ASME J. Dynamic Systems, Measurement, and Control, 125(3): 494-497, Sept. 2003.

    C. La-orpacharapan and L. Y. Pao. " Shaped Time-Optimal Control for Disk Drive Systems with Back EMF, Slew Rate Limits, and Different Acceleration and Deceleration Rates," Proc. American Control Conf., Denver, CO, pp. 4788-4795, June 2003.

    C. La-orpacharapan and L. Y. Pao. " Fast Seek Control for Flexible Disk Drive Systems with Back EMF and Inductance," Proc. American Control Conf., Denver, CO, pp. 3077-3082, June 2003.

    M. D. Baumgart and L. Y. Pao. " A Tension Observer for Nonlinear Web-Winding Systems with Air Entrainment," Proc. American Control Conf., Denver, CO, pp. 4149-4154, June 2003.

    M. A. Lau and L. Y. Pao. "Input Shaping and Time-Optimal Control of Flexible Structures," Automatica, 39(5): 893-900, May 2003.

    C. F. Cutforth and L. Y. Pao. "Control Using Equal Length Shaped Commands to Reduce Vibration," IEEE Trans. Control Systems Technology, 11(1): 62-72, Jan. 2003.

    C. La-orpacharapan and L. Y. Pao. " Shaped Control for Damped Flexible Structures with Friction and Slew Rate Limits," Proc. IEEE Conf. Decision and Control, Las Vegas, NV, pp. 3099-3105, Dec. 2002.

    M. D. Baumgart and L. Y. Pao. " Transient Control of Web-Winding Systems with Air Entrainment," Proc. IFAC Conf. Mechatronic Systems, Berkeley, CA, pp. 17-22, Dec. 2002.

    C. La-orpacharapan and L. Y. Pao. "Shaped Phase-Plane Control for Flexible Structures with Friction," Proc. American Control Conf., Anchorage, AK, pp. 1911-1916, May 2002.

    C. F. Cutforth and L. Y. Pao. "Analysis and Design of an Adaptive Input Shaper for the Control of Flexible Structures," Proc. American Control Conf., Anchorage, AK, pp. 1903-1910, May 2002.

    M. D. Baumgart and L. Y. Pao. " Discrete Time-Optimal Command Shapers and Controls for Multi-Input Multi-Output Systems," Proc. American Control Conf., Anchorage, AK, pp. 2279-2284, May 2002.

    M. A. Lau and L. Y. Pao. "Characteristics of Time-Optimal Commands for Flexible Structures with Limited Fuel Usage," J. Guidance, Control, and Dynamics, 25(2): 222-231, Mar.-Apr. 2002.

    M. A. Lau and L. Y. Pao. " Comparison of Input Shaping and Time-Optimal Control of Flexible Structures," Proc. American Control Conf., Arlington, VA, pp. 1485-1490, June 2001.

    C. La-orpacharapan and L. Y. Pao. " Control of Flexible Structures with a Projected Phase-Plane Approach," Proc. American Control Conf., Arlington, VA, pp. 3817-3823, June 2001.

    M. D. Baumgart and L. Y. Pao. " Cooperative Multi-Input Shaping for Arbitrary Inputs," Proc. American Control Conf., Arlington, VA, pp. 275-280, June 2001.

    C. F. Cutforth and L. Y. Pao. "Command Shaping Control for Vibration Reduction without Lengthening the Command," Proc. AIAA Guidance, Navigation, and Control Conf., Denver, CO, Aug. 2000.

    M. A. Lau and L. Y. Pao. " Time-Optimal Commands with Specified Fuel Usage for Controlling Flexible Structures," Proc. American Control Conf., Chicago, IL, pp. 3058-3063, June 2000.

    L. Y. Pao. " Strategies for Shaping Commands in the Control of Flexible Structures," Proc. Japan/USA/Vietnam Workshop on Research and Education in Systems, Computation, and Control Engineering, Ho Chi Minh City, Vietnam, pp. 309-318, June 2000.

    L. Y. Pao and M. A. Lau. "Robust Input Shaper Control Design for Parameter Variations in Flexible Structures," ASME J. Dynamic Systems, Measurement, and Control, 122(1): 63-70, March 2000.

    C. F. Cutforth and L. Y. Pao. " A Modified Method for Multiple Actuator Input Shaping," Proc. American Control Conf., San Diego, CA, pp. 66-70, June 1999.

    C. F. Cutforth and L. Y. Pao. " An Analysis of Frequency-Domain Input Shaping Designs for Three-Mode Flexible Systems," Proc. American Control Conf., San Diego, CA, pp. 4388-4392, June 1999.

    L. Y. Pao and M. A. Lau. "The Expected Residual Vibration of Traditional and Hybrid Input Shaping Designs," J. Guidance, Control, and Dynamics, 22(1): 162-165, Jan.-Feb. 1999.

    L. Y. Pao. "Multi-Input Shaping Design for Vibration Reduction," Automatica, 35(1): 81-89, Jan. 1999.

    L. Y. Pao and M. A. Lau. "An Analysis of the Expected Residual Vibration of Input Shaping Designs," Proc. AIAA Guidance, Navigation, and Control Conf., Boston, MA, pp. 354-364, Aug. 1998.

    L. Y. Pao and M. A. Lau. " Input Shaping Designs to Account for Uncertainty in Both Frequency and Damping in Flexible Structures," Proc. American Control Conf., Philadelphia, PA, pp. 3070-3071, June 1998.

    L. Y. Pao and C. F. Cutforth. " An Analysis and Comparison of Frequency-Domain and Time-Domain Input Shaping," Proc. American Control Conf., Philadelphia, PA, pp. 3072-3074, June 1998.

    L. Y. Pao and W. E. Singhose. "Robust Minimum Time Control of Flexible Structures," Automatica, 34(2): 229-236, Feb. 1998.

    L. Y. Pao. "An Analysis of the Frequency, Damping, and Total Insensitivities of Input Shaping Designs," AIAA J. Guidance, Control, and Dynamics, 20(5): 909-915, Sept.-Oct. 1997.

    L. Y. Pao and W. E. Singhose. "Verifying Robust Time-Optimal Commands for Multi-Mode Flexible Spacecraft," AIAA J. Guidance, Control, and Dynamics, 20(4): 831-833, July-Aug. 1997.

    L. Y. Pao, T. N. Chang, and E. Hou. "Input Shaper Designs for Minimizing the Expected Level of Residual Vibration in Flexible Structures," Proc. American Control Conf., Albuquerque, NM, pp. 3542-3546, June 1997.

    W. E. Singhose and L. Y. Pao. "A Comparison of Input Shaping and Time-Optimal Flexible-Body Control," Control Engineering Practice, 5(4): 456-467, Apr. 1997.

    W. E. Singhose, L. Y. Pao, and W. P. Seering. "Slewing Multimode Flexible Spacecraft with Zero Derivative Robustness Constraints," AIAA J. Guidance, Control, and Dynamics, 20(1): 204-206, Jan.-Feb. 1997.

    W. E. Singhose and L. Y. Pao. "Comparison of Input Shaping Techniques for Speed-Critical Multi-Mode Flexible Systems," Proc. IEEE Conf. on Control Applications, Dearborn, MI, pp. 379-384, Sept. 1996.

    N. C. Singer, L. Y. Pao, W. E. Singhose, and W. P. Seering. ``An Efficient Algorithm for the Generation of Multiple-Mode Input Shaping Sequences," Proc. IEEE Conf. on Control Applications, Dearborn, MI, pp. 373-378, Sept. 1996.

    W. E. Singhose, L. Y. Pao, and W. P. Seering. "Time-Optimal Rest-to-Rest Slewing of Multi-Mode Flexible Spacecraft Using ZVD Robustness Constraints," Proc. AIAA Guidance, Navigation, and Control Conf., San Diego, CA, July 1996.

    L. Y. Pao. "An Analysis of the Total Insensitivity of Input Shaping Designs," Proc. AIAA Guidance, Navigation, and Control Conf., San Diego, CA, July 1996.

    L. Y. Pao and W. E. Singhose. "Unity-Magnitude Input Shapers and Their Relation to Time-Optimal Control," Proc. IFAC World Congress, Vol. A (Robotics, Components, and Instruments), San Francisco, CA, pp. 385-390, July 1996.

    L. Y. Pao. "Input Shaping Design for Flexible Systems with Multiple Actuators," Proc. IFAC World Congress, Vol. P (Aerospace and Transportation Systems), San Francisco, CA, pp. 267-272, July 1996.