Sliding-Mode-Based Observer-Controller Structure for Fault-Resilient Control in DC Servomotors

Suneel Kumar Kommuri, Jagat Jyoti Rath, Kalyana Chakravarthy Veluvolu*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

38 Citations (Scopus)


This paper presents a robust observer-controller scheme for sensor fault-resilient control in dc servomotor drive-based applications (such as antennae control for satellite tracking, radio telescopes, and conveyor belt systems). In contrast to the earlier works on abrupt faults, this paper considers incipient sensor faults and detects using the higher order sliding mode (HOSM) observer, followed by a tracking controller, which maintains the acceptable drive performance. A robust output tracking controller based on fractional integral terminal sliding mode surface with HOSM terms is developed to ensure faster and finite-time convergence of the error trajectory. Moreover, various slopes of incipient faults are considered to analyze the detection delay, and switching strategy reconfigures the system with the estimated speed whenever the residual crosses the threshold. The closed-loop performance in the presence of most common faults (abrupt, incipient, and intermittent) is experimentally validated on a dc motor-based industrial mechatronic drives unit with belt-drive inertial load (which exhibits nonlinear friction, torque variations, and other disturbances).

Original languageEnglish
Article number7962214
Pages (from-to)918-929
Number of pages12
JournalIEEE Transactions on Industrial Electronics
Issue number1
Publication statusPublished - Jan 2018
Externally publishedYes


  • Closed-loop stability
  • dc servomotors
  • fault-tolerant control (FTC)
  • higher order sliding modes (HOSMs)
  • incipient sensor faults

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