SCIENCE CHINA Information Sciences, Volume 61 , Issue 7 : 070224(2018) https://doi.org/10.1007/s11432-017-9435-3

Guaranteeing almost fault-free tracking performance from transient to steady-state: a disturbance observer approach

More info
  • ReceivedNov 9, 2017
  • AcceptedApr 20, 2018
  • PublishedJun 5, 2018


In this paper, we propose an output-feedback fault-tolerant controller (FTC) for a class of uncertain multi-input single-output systems under float and lock-in-place actuator faults.Of particular interest is to recover a fault-free tracking performance of a (pre-defined) nominal closed-loop system, during the entire time period including the transients due to abrupt actuator faults.As a key component, a high-gain disturbance observer (DOB) is employed to rapidly compensate the lumped disturbance, a compressed expression of all the effect of actuator faults (as well as model uncertainty and disturbance) on the system.To implement this high-gain approach, a fixed control allocation (CA) law is presented in order to keep an extended system with a virtual scalar input to remain of minimum phase under any patterns of faults.It is shown via the singular perturbation theory that the proposed FTC, consisting of the high-gain DOB and the CA law, resolves the problem in an approximate but arbitrarily accurate sense.Simulations with the linearized lateral model of Boeing 747 are performed to verify the validity of the proposed FTC scheme.


This work was partly supported by Institute for Information Communications Technology Promotion (IITP) Grant Funded by the Korea Government (MSIP) (Grant No. 2014-0-00065, Resilient Cyber-Physical Systems Research), and partly by National Research Foundation of Korea (NRF) Grant Funded by the Korea Government (MSIP) (Grant No. 2015R1A2A2A01003878).


[1] Belcastro C M, Groff L, Newman R L, et al. Preliminary analysis of aircraft loss of control accidents: worst case precursor combinations and temporal sequencing. In: Proceedings of AIAA Guidance, Navigation, and Control Conference, National Harbor, 2014. 1--32. Google Scholar

[2] Gorman S. Electricity grid in U.S. penetrated by spies. The Wall Street Journal, 2009. http://www.ismlab.usf.edu/isec/files/Electricity-Grid-Spied-04-09-WSJ.pdf. Google Scholar

[3] Zhang Y, Jiang J. Bibliographical review on reconfigurable fault-tolerant control systems. Annu Rev Control, 2008, 32: 229-252 CrossRef Google Scholar

[4] Yu X, Jiang J. A survey of fault-tolerant controllers based on safety-related issues. Annu Rev Control, 2015, 39: 46-57 CrossRef Google Scholar

[5] Li D Y, Li P, Cai W C. Adaptive fault-tolerant control of wind turbines with guaranteed transient performance considering active power control of wind farms. IEEE Trans Ind Electron, 2018, 65: 3275-3285 CrossRef Google Scholar

[6] Chakravarty A, Mahanta C. Actuator fault-tolerant control (FTC) design with post-fault transient improvement for application to aircraft control. Int J Robust Nonlinear Control. 2016, 26: 2049--2074. Google Scholar

[7] Bustan D, Sani S K H, Pariz N. Adaptive fault-tolerant spacecraft attitude control design with transient response control. IEEE/ASME Trans Mech, 2014, 19: 1404-1411 CrossRef Google Scholar

[8] Ohishi K, Ohnishi K, Miyachi K. Torque-speed regulation of DC motor based on load torque estimation method. In: Proceedings of JIEE International Power Electronics Conference, Tokyo, 1983. 1209--1218. Google Scholar

[9] Chen W H, Yang J, Guo L. Disturbance-observer-based control and related methods-an overview. IEEE Trans Ind Electron, 2016, 63: 1083-1095 CrossRef Google Scholar

[10] Sariyildiz E, Ohnishi K. Stability and robustness of disturbance-observer-based motion control systems. IEEE Trans Ind Electron, 2015, 62: 414-422 CrossRef Google Scholar

[11] Li S, Yang J, Chen W H, et al. Disturbance Observer-based Control: Methods and Applications. Boca Raton: CRC Press, 2014. Google Scholar

[12] Shim H, Park G, Joo Y. Yet another tutorial of disturbance observer: robust stabilization and recovery of nominal performance. Control Theory Technol, 2016, 14: 237-249 CrossRef Google Scholar

[13] Xu B, Yuan Y. Two performance enhanced control of flexible-link manipulator with system uncertainty and disturbances. Sci China Inf Sci, 2017, 60: 050202 CrossRef Google Scholar

[14] Back J, Shim H. Adding robustness to nominal output-feedback controllers for uncertain nonlinear systems: a nonlinear version of disturbance observer. Automatica, 2008, 44: 2528-2537 CrossRef Google Scholar

[15] Back J, Shim H. An inner-loop controller guaranteeing robust transient performance for uncertain MIMO nonlinear systems. IEEE Trans Autom Control, 2009, 54: 1601-1607 CrossRef Google Scholar

[16] Johansen T A, Fossen T I. Control allocation — a survey. Automatica, 2013, 49: 1087-1103 CrossRef Google Scholar

[17] Hoppensteadt F C. Singular perturbations on the infinite interval. Trans Amer Math Soc, 1966, 123: 521-535 CrossRef Google Scholar

[18] Kokotović P, Khalil H K, O'Reilly J. Singular Perturbation Methods in Control: Analysis and Design. Orlando: Academic Press, 1986. Google Scholar

[19] Bhattacharyya S P, Chapellat H, Keel L H. Robust Control: The Parametric Approach. Englewood Cliffs: Prentice Hall, 1995. Google Scholar

[20] Khalil H K. Nonlinear Systems. 3rd ed. Englewood Cliffs: Prentice Hall, 2002. Google Scholar

[21] Tao G, Chen S, Joshi S M. An adaptive actuator failure compensation controller using output feedback. IEEE Trans Autom Control, 2002, 47: 506-511 CrossRef Google Scholar

[22] Gayaka S, Yao B. Accommodation of unknown actuator faults using output feedback-based adaptive robust control. Int J Adapt Control Signal Process, 2011, 25: 965-982 CrossRef Google Scholar

  • Figure 1

    (Color online) Overall configuration of proposed DOB-based FTC consisting of input allocation law 10, baseline controller 22, and DOB 28a.

  • Figure 2

    (Color online) Simulation results when two lock-in-place faults take place. (a) Output $({\rm~rad/s})$: actual output $y(t)$ with (black dash-dotted) and without DOB (red solid), and nominal output $y_{\mathsf{n}}(t)$ (green dashed); (b) tracking error $({\rm~rad/s})$:actual error $r(t)-y(t)$ with (black dash-dotted) and without DOB (red solid), and nominal error $r(t)-y_{\mathsf{n}}(t)$ (green dashed); (c) control input $({\rm~rad})$ with the proposed FTC: $u_1(t)$ (darkest), $u_3(t)$ (intermediate), $u_2(t)$ (brightest); (d) partial state $\zeta$ with the proposed FTC: $\zeta_1(t)$ $({\rm~rad/s})$ (yellow solid), $\zeta_2(t)$ $({\rm~rad})$ (blue dash-dotted), $\zeta_3(t)$ $({\rm~rad/s})$ (brown dashed).

  • Figure 3

    (Color online) Simulation results when two floating faults sequentially occur. (a) Output $({\rm~rad/s})$: actual output $y(t)$ with (black dash-dotted) and without DOB (red solid), and nominal output $y_{\mathsf{n}}(t)$ (green dashed); (b) tracking error $({\rm~rad/s})$: actual error $r(t)-y(t)$ with (black dash-dotted) and without DOB (red solid), and nominal error $r(t)-y_{\mathsf{n}}(t)$ (green dashed); (c) control input $({\rm~rad})$: $u_1(t)$ (darkest), $u_3(t)$ (intermediate), $u_2(t)$ (brightest); (d) partial state $\zeta$: $\zeta_1(t)$ $({\rm~rad/s})$ (yellow solid), $\zeta_2(t)$ $({\rm~rad})$ (blue dash-dotted), $\zeta_3(t)$ $({\rm~rad/s})$ (brown dashed).

  • Figure 4

    (Color online) Simulation results when two lock-in-place faults take place for comparison of the proposed FTC and the adaptive FTC in [22]. (a) Output $({\rm~rad/s})$: actual output $y(t)$ with the proposed FTC (black dash-dotted) and the adaptive FTC in [22](cyan solid); (b) tracking error $({\rm~rad/s})$:actual error $r(t)-y(t)$ with the proposed FTC (black dash-dotted) and the adaptive FTC in [22](cyan solid); (c) control input $({\rm~rad})$ with the adaptive FTC in [22]: $u_1(t)$ (darkest), $u_3(t)$ (intermediate), $u_2(t)$ (brightest); (d) partial state $\zeta$ the adaptive FTC in [22]: $\zeta_1(t)$ $({\rm~rad/s})$ (yellow solid), $\zeta_2(t)$ $({\rm~rad})$ (blue dash-dotted), $\zeta_3(t)$ $({\rm~rad/s})$ (brown dashed).

Copyright 2020  CHINA SCIENCE PUBLISHING & MEDIA LTD.  中国科技出版传媒股份有限公司  版权所有

京ICP备14028887号-23       京公网安备11010102003388号