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Research Papers

A Guide to Design Disturbance Observer

[+] Author and Article Information
Emre Sariyildiz

Department of System Design Engineering,
Keio University,
Yokohama, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama,
Kanagawa 223-8522, Japan
e-mail: emre@sum.sd.keio.ac.jp

Kouhei Ohnishi

Department of System Design Engineering,
Keio University,
Yokohama, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama,
Kanagawa 223-8522, Japan
e-mail: ohnishi@sd.keio.ac.jp

1Corresponding author.

Contributed by the Dynamic Systems Division of ASME for publication in the JOURNAL OF DYNAMIC SYSTEMS, MEASUREMENT, AND CONTROL. Manuscript received December 8, 2012; final manuscript received September 19, 2013; published online December 9, 2013. Assoc. Editor: Luis Alvarez.

J. Dyn. Sys., Meas., Control 136(2), 021011 (Dec 09, 2013) (10 pages) Paper No: DS-12-1414; doi: 10.1115/1.4025801 History: Received December 08, 2012; Revised September 19, 2013

The goal of this paper is to clarify the robustness and performance constraints in the design of control systems based on disturbance observer (DOB). Although the bandwidth constraints of a DOB have long been very well-known by experiences and observations, they have not been formulated and clearly reported yet. In this regard, the Bode and Poisson integral formulas are utilized in the robustness analysis so that the bandwidth constraints of a DOB are derived analytically. In this paper, it is shown that the bandwidth of a DOB has upper and lower bounds to obtain a good robustness if the plant has nonminimum phase zero(s) and pole(s), respectively. Besides that the performance of a system can be improved by using a higher order disturbance observer (HODOB); however, the robustness may deteriorate, and the bandwidth constraints become more severe. New analysis and design methods, which provide good robustness and predefined performance criteria, are proposed for the DOB based robust control systems. The validity of the proposals is verified by simulation results.

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References

Ohishi, K., Ohnishi, K., and Miyachi, K., 1983, “Torque-Speed Regulation of dc Motor Based on Load Torque Estimation,” Proc. IEEJ IPEC-TOKYO, 2, pp. 1209–1216.
Ohnishi, K., Shibata, M., and Murakami, T., 1996, “Motion Control for Advanced Mechatronics,” IEEE/ASME Trans. Mechatron., 1(1), pp. 56–67. [CrossRef]
Schrijver, E., and Johannes, D. V., 2002, “Disturbance Observers for Rigid Mechanical Systems: Equivalence, Stability, and Design,” ASME J. Dyn. Syst., Meas., Control, 124(4), pp. 539–548. [CrossRef]
Ohishi, K., Miyazaki, T., and Nakamura, Y., 1995, “Two-Degrees-of-Freedom Speed Controller Based on Doubly Coprime Factorization and Speed Observer,” 21st IEEE International Conference on Industrial Electronics, Control, and Instrumentation, Orlando, FL, 1, pp. 602– 608.
Umeno, T., and Hori, Y., 1991, “Robust Speed Control of dc Servomotors Using Modern Two Degrees-Of-Freedom Controller Design,” IEEE Trans. Ind. Electron. Control Instrum., 38(5), pp. 363–368. [CrossRef]
Guo, L., and Tomizuka, M., 1997, “High-Speed and High-Precision Motion Control With an Optimal Hybrid Feed Forward Controller,” IEEE/ASME Trans. Mechatron., 2(2), pp. 110–122. [CrossRef]
Guvenc, B. A., Guvenc, L., and Karaman, S., 2010, “Robust MIMO Disturbance Observer Analysis and Design With Application to Active Car Steering,” Int. J. Robust Nonlinear Control, 20(8), pp. 873–891. [CrossRef]
Chan, S. P., 1991, “A Disturbance Observer for Robot Manipulators With Application to Electronic Components Assembly,” IEEE Trans. Ind. Electron. Control Instrum., 42(5), pp. 487–493. [CrossRef]
Wang, C., and Tomizuka, M., 2004, “Design of Robustly Stable Disturbance Observers Based on Closed Loop Consideration Using H∞ Optimization and its Applications to Motion Control Systems,” American Control Conference (ACC), Boston, MA, 4, pp. 3764–3769.
Sariyildiz, E., and Ohnishi, K., 2013, “Analysis the Robustness of Control Systems Based on Disturbance Observer,” Int. J. Control [CrossRef], 86, pp. 1733–1743.
Yang, W. C., and Tomizuka, M., 1994, “Disturbance Rejection Through an External Model for Non-Minimum Phase Systems,” ASME J. Dyn. Syst., Meas., Control, 116(1), pp. 39–44. [CrossRef]
Jo, N. H., Shim, H., and Son, Y. I., 2010, “Disturbance Observer for Non-minimum Phase Linear Systems,” Int. J. Control, Autom. Syst., 8(5), pp. 994–1002. [CrossRef]
Chen, X., Zhai, G., and Fukuda, T., 2004, “An Approximate Inverse System for Non-Minimum-Phase Systems and Its Application to Disturbance Observer,” Syst. Control Lett., 52(3–4), pp. 193–207. [CrossRef]
Katsura, S., Irie, K., and Ohishi, K., 2008, “Wideband Force Control by Position-Acceleration Integrated Disturbance Observer,” IEEE Trans. Ind. Electron. Control Instrum., 55,(5), pp. 1699–1706. [CrossRef]
Ishikawa, J., and Tomizuka, M., 1998, “Pivot Friction Compensation Using and Accelerometer and a Disturbance Observer for Hard Disk Drives,” IEEE/ASME Trans. Mechatron., 3,(3), pp. 194–201. [CrossRef]
Tsuji, T., Hashimoto, T., Kobayashi, H., Mizuochi, M., and Ohnishi, K., 2009, “A Wide-Range Velocity Measurement Method for Motion Control,” IEEE Trans. Ind. Electron. Control Instrum., 56(2), pp. 510–519. [CrossRef]
Jeon, S., and Tomizuka, M., 2007, “Benefits of Acceleration Measurement in Velocity Estimation and Motion Control,” Control Eng. Practice, 15(3), pp. 325–332. [CrossRef]
Mitsantisuk, C., Ohishi, K., and Katsura, S., 2012, “Estimation of Action/Reaction Forces for the Bilateral Control Using Kalman Filter,” IEEE Trans. Indus. Electron., 59(11), pp. 4383–4393. [CrossRef]
Choi, Y., Yang, K., Chung, W. K., Kim, H. R., and Suh, H., 2003, “On the Robustness and Performance of Disturbance Observers for Second-Order Systems,” IEEE Trans. Autom. Control, 48(2), pp. 315–320. [CrossRef]
Shima, H., and Jo, N. H., 2009, “An Almost Necessary and Sufficient Condition For Robust Stability of Closed-Loop Systems With Disturbance Observer,” Automatica, 45(1), pp. 296–299. [CrossRef]
Sariyildiz, E., and Ohnishi, K., 2013, “Bandwidth Constraints of Disturbance Observer in the Presence of Real Parametric Uncertainties,” Eur. J. Control, 19(3), pp. 199–205. [CrossRef]
Bode, H. W., 1945, Network Analysis and Feedback Amplifier Design, D. Van Nostrand Co., New York.
Stein, G., 2003, “Respect the Unstable,” IEEE Control Syst. Mag., 23(4), pp. 12–25. [CrossRef]
Horowitz, I. M., 1963, Synthesis of Feedback Systems, Academic Press, New York.
Freudenberg, J. S., and Looze, D. P., 1987, “A Sensitivity Tradeoff for Plants With Time Delay,” IEEE Trans. Autom. Control, 32(2), pp. 99–104. [CrossRef]
Freudenberg, J. S., and Looze, D. P., 1985, “Right Half Plane Poles and Zeros and Design Tradeoffs in Feedback Systems,” IEEE Trans. Autom. Control, 30(6), pp. 555–565. [CrossRef]
Skogestad, S., and Postlethwaite, I., 2001, Multivariable Feedback Control:Analysis and Design, 2nd ed., John Wiley & Sons, New York.
Zhou, K., and Doyle, J. C., 1997, Essentials of Robust Control, Prentice-Hall, Upper Saddle River, NJ.
Middleton, R. H., and Goodwin, G. C., 1990, Digital control and estimation. A unified approach, Prentice-Hall, inc., Englewood Cliffs, NJ.
Seron, M. M., Braslavsky, J. H., and Goodwin, G. C., 1997, Fundamental Limitations in Filtering and Control, Springer-Verlag, London.
Sariyildiz, E., and Ohnishi, K., 2013, “A New Solution for the Robust Control Problem of Non-Minimum Phase Systems Using Disturbance Observer,” IEEE International Conference on Mechatronics (ICM), Vicenza, Italy, pp. 46–51.

Figures

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Fig. 1

A block diagram for a two-degrees-of-freedom DOB based robust control system

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Fig. 2

Nyquist plot of inner-loop when a plant has time-delay and DOB is first order

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Fig. 5

Frequency responses of the inner-loop sensitivity and co-sensitivity transfer functions when a 2nd order DOB is used

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Fig. 3

A block diagram of a DOB based robust control system when a plant is unstable

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Fig. 4

Frequency responses of the inner-loop sensitivity and co-sensitivity transfer functions when the bandwidth of DOB is 100 rad/s

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Fig. 7

Frequency responses of the inner-loop sensitivity and co-sensitivity transfer functions when the order of DOB is one

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Fig. 8

Frequency responses of the outer-loop sensitivity and co-sensitivity transfer functions when the order of DOB is two

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Fig. 9

Step responses of the unstable plant when it is controlled by using the proposed robust controller

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Fig. 10

A general frequency response of a sensitivity function

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Fig. 6

Frequency responses of the inner-loop sensitivity and co-sensitivity transfer functions when the order of DOB is one

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