Robust adaptive voltage-fed permanent magnet step motor control without current measurements

P. Krishnamurthy, F. Khorrami

Research output: Contribution to journalArticlepeer-review


In this paper, a robust adaptive nonlinear dynamic controller is designed to achieve practical stabilization for position tracking error of a voltage-fed permanent-magnet stepper motor. The control design is an output-feedback design that utilizes only rotor position and velocity measurements. Currents are not available for feedback. Adaptations are utilized so that no knowledge of motor parameters is required except for an upper and lower bound on the time constant of the electrical subsystem. Furthermore, these bounds are unnecessary under the assumption of sinusoidal flux distribution. The proposed controller has dynamic order three and is robust to load torques, cogging forces, and other disturbances satisfying certain bounds. The controller also guarantees asymptotic stabilization if the torque disturbances can be neglected and asymptotic set-point regulation in the sinusoidal flux distribution case.

Original languageEnglish (US)
Pages (from-to)415-425
Number of pages11
JournalIEEE Transactions on Control Systems Technology
Issue number3
StatePublished - May 2003


  • AC drives
  • Adaptive control
  • Motor drives
  • Nonlinear control
  • Robustness
  • Stepper motors

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Electrical and Electronic Engineering


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