External force estimation of a piezo-actuated compliant mechanism based on a fractional order hysteresis model

Zhiwei Zhu, Suet To, Yangmin Li, Wu Le Zhu, Leixiang Bian

Research output: Journal article publicationJournal articleAcademic researchpeer-review

14 Citations (Scopus)


Sensing of external forces applied on piezo-actuated compliant mechanisms plays a key role in state monitoring, process control and feedback strategy design in a variety of fields, including micro-/nanopositioning, micro-/nanomanipulation, and micro-/nanomanufacturing. In this paper, a force estimation strategy is proposed by comparing the practically measured displacement with the estimated free one without external forces, when subjecting to any given actuation voltages. To have an accurate prediction of the free displacement relating to the actuation voltage, an improved fractional order model is proposed. With this model, the system response is decomposed into a basic linear component and a nonlinear hysteresis component, and the extracted hysteresis is then described by an ordinary fractional order differential model using a modified voltage signal as the model input, which extracts a linear time-delay component from the original voltage. Comparative study with other two differential type hysteresis models are experimentally conducted on a piezo-actuated bridge-type compliant mechanism, demonstrating well the effectiveness and superiority of the proposed model for both system response modeling and external force estimation.

Original languageEnglish
Pages (from-to)296-306
Number of pages11
JournalMechanical Systems and Signal Processing
Publication statusPublished - 15 Sep 2018


  • Compliant mechanism
  • External force estimation
  • Fractional order model
  • Hysteresis nonlinearity
  • Piezoelectric actuator

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Signal Processing
  • Civil and Structural Engineering
  • Aerospace Engineering
  • Mechanical Engineering
  • Computer Science Applications

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