Output feedback attitude control of flexible spacecraft under actuator misalignment and input nonlinearities

Umair Javaid, Ziyang Zhen, Sami Shahid, Dauda Sh Ibrahim, Salman Ijaz

Research output: Journal PublicationArticlepeer-review


The attitude tracking control problem of flexible spacecraft subjected to parameter uncertainties, time-dependent external disturbances, actuator input nonlinearity, and input actuator misalignment is investigated in this paper. Explicitly, the proposed strategy addresses the input actuator misalignment and dead-zone issues that increase the controller design difficulties. Initially, a new second-order sliding mode observer (SoSMO) using an extended state approach is developed by adding a correction function to improve observer performance to estimate unwanted system perturbations. Then, a distinct SoSMO-based integral-type sliding mode control (ISMC) structure is designed in a unified manner to guarantee the asymptotic stability of the closed-loop system. Comparative numerical simulations under input actuator misalignment, the dead-zone nonlinearity, external disturbance, and inertia uncertainty are performed to illustrate the effectiveness of the proposed controller.

Original languageEnglish
Pages (from-to)1783-1801
Number of pages19
JournalJVC/Journal of Vibration and Control
Issue number7-8
Publication statusPublished - Apr 2024


  • Attitude control
  • disturbance observer
  • flexible spacecraft
  • integral sliding mode control
  • second-order sliding mode

ASJC Scopus subject areas

  • General Materials Science
  • Automotive Engineering
  • Aerospace Engineering
  • Mechanics of Materials
  • Mechanical Engineering


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