LQG Controller

  • Wodek Gawronski
Part of the Mechanical Engineering Series book series (MES)

This chapter presents the tuning process of the LQG controller. Its applications in the antenna industry are discussed in many papers, but scarcely implemented. LQG controllers are implemented at the 34- and 70-m Deep Space Network antennas.

The discussion begins with the short description of the LQG controller, and its tracking version, gives the closed loop equations of a flexible antenna with the LQG controller, and shows the similarity of the PI and LQG controllers. It discusses how to select the LQG weights to obtain the required performance, present the controller tuning steps, and show the limits of the performance. Next, it presents two graphical user interfaces (GUI) to tune the LQG controllers. The GUIs do not require detailed knowledge of the tuning process to obtain excellent closed loop performance. The chapter also discusses the LQG controller in the velocity loop.

Properties of the LQG Controller

The LQG controllers are well established; see, for example, [4, 5, 6], [8],...


Settling Time Controller Gain Wind Gust Flexible Mode Proportional Gain 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. 1.
    Collins, Jr., EG, Haddad WM, Ying SS. (1994). Construction of Low-Authority, Nearly Non-Minimal LQG Compensators for Reduced-Order Control Design. 1994 IEEE American Control Conference, Baltimore, MD.Google Scholar
  2. 2.
    Dutton K, Thompson S, Barraclough B. (1997). The Art of Control Engineering. Addison-Wesley, Harlow.Google Scholar
  3. 3.
    Eisentraeger P, Suess M. (2000). Verification of the Active Deformation Compensation System of the LMT/GMT by End-to-End Simulations. In: Radio Telescopes, Proceedings of SPIE, Vol. 4015.Google Scholar
  4. 4.
    Gawronski W. (1994). Design of a Linear Quadratic Controller for the Deep Space Network Antennas. AIAA J. Guidance, Control, and Dynamics, vol. 17.Google Scholar
  5. 5.
    Gawronski W. (2001). Antenna Control Systems: From PI to H. IEEE Antennas and Propagation Magazine, 43(1).Google Scholar
  6. 6.
    Gawronski W. (2004). Advanced Structural Dynamics and Active Control of Structures, Springer, New York.CrossRefGoogle Scholar
  7. 7.
    Gawronski W. (2007). Servo Performance Parameters of the NASA Deep Space Network Antennas. IEEE Antennas and Propagation Magazine, 49(6).Google Scholar
  8. 8.
    Gawronski W, Mellstrom JA. (1994). Control and Dynamics of the Deep Space Network Antennas. In: Control and Dynamics Systems, ed. Leondes, CT vol. 63, Academic Press, San Diego, CA, pp. 289–412.Google Scholar
  9. 9.
    Gawronski W, Perez-Zapardiel P. (2007). Performance Comparison of the LQG and PI Controllers in Wind Gusts.IPN Progress Report, 42–171. Available at
  10. 10.
    Gawronski W, Racho C, Mellstrom JA. (1995). Application of the LQG and Feedforward Controllers for the DSN Antennas. IEEE Trans. Control Systems Technology, vol. 3.Google Scholar
  11. 11.
    Gawronski W, Souccar K. (2005). Control Systems of the Large Millimeter Telescope. IEEE Antennas and Propagation Magazine, 47(4).Google Scholar
  12. 12.
    Kaercher HJ, Baars JWM. (2000). The Design of the Large Millimeter Telescope/Gran Telescopio Milimetrico (LMT/GTM). In: Radio Telescopes, Proceedings of SPIE, vol. 4015.Google Scholar
  13. 13.
    Li K, Kosmatopoulos EB, Ioannou PA et al. (1998). Control Techniques for a Large Segmented Reflector. Proc. 37 th IEEE Conf. Decision and Control, Tampa, FL.Google Scholar
  14. 14.
    Li K, Kosmatopoulos EB, Ioannou PA et al. (2000). Large Segmented Telescopes: Centralized, Decentralized and Overlapping Control Designs. IEEE Control Systems Mag., 20(5): 59–72.CrossRefGoogle Scholar
  15. 15.
    Maneri E, Gawronski W. (2000). LQG Controller Design Using GUI: Application to Antennas and Radio-Telescopes. ISA Transactions, 39(2): 243–264.CrossRefGoogle Scholar
  16. 16.
    Olberg M, Lindeborg C, Seyf A et al. (1995). A Simple Robust Digital Controller for the Onsala 20-m Radio Telescope. Proc. SPIE, 2479: 257–265.CrossRefGoogle Scholar
  17. 17.
    Whorton M, Angeli G. (2003). Modern Control for the Secondary Mirror of a Giant Segmented Mirror Telescope. Proc. SPIE, Future Giant Telescopes, vol. 4840.Google Scholar

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • Wodek Gawronski
    • 1
  1. 1.Jet Populsion LaboratoryCalifornia Institute of TechnologyPasedenaUSA

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