Quick search Find article
Quick search
Find article

Frequency-weighted feedforward control for dynamic compensation in ionic polymer–metal composite actuators

Yingfeng Shan and Kam K Leang1

Show affiliations


Ionic polymer–metal composites (IPMCs) are innovative materials that offer combined sensing and actuating ability in lightweight and flexible package. IPMCs have been exploited in robotics and a wide variety of biomedical devices, for example, as sensors for teleoperation, as actuators for positioning in active endoscopy, as fins for propelling aquatic robots, and as an injector for drug delivery. In the actuation mode, one of the main challenges is precise position control. In particular, IPMC actuators exhibit relaxation behavior and nonlinearities; and at relatively high operating frequencies dynamic effects limit accuracy and positioning bandwidth. A frequency-weighted feedforward controller is designed to account for the IPMC's structural dynamics to enable fast positioning. The control method is applied to a custom-made Nafion-based IPMC actuator. The controller takes into account the magnitude of the control input to avoid generating excessively large voltages which can damage the IPMC actuator. To account for unmodeled effects not captured by the dynamics model, a feedback controller is integrated with the feedforward controller. Experimental results show a significant improvement in the tracking performance when feedforward control is used. For instance, the feedforward controller shows over 75% reduction in the tracking error compared to the case without feedforward compensation. Finally, the integrated feedforward and feedback control system reduces the tracking error to less than 10% for tracking an 18-Hz triangle-like trajectory. Some of the advantages of feedforward control as well as its limitations are also discussed.


PACS

07.07.Tw Servo and control equipment; robots

07.05.Dz Control systems

81.05.Qk Reinforced polymers and polymer-based composites

07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing

Subjects

Soft matter, liquids and polymers

Instrumentation and measurement

Condensed matter: structural, mechanical & thermal

Dates

Issue 12 (December 2009)

Received 27 May 2009, in final form 3 September 2009

Published 6 October 2009



  1. Frequency-weighted feedforward control for dynamic compensation in ionic polymer–metal composite actuators

    Yingfeng Shan and Kam K Leang 2009 Smart Mater. Struct. 18 125016

  2. Modeling Intracluster Gas in Triaxial Dark Halos: An Analytic Approach

    Jounghun Lee and Yasushi Suto 2003 ApJ 585 151

  3. Percolation with multiple giant clusters

    E Ben-Naim and P L Krapivsky 2005 J. Phys. A: Math. Gen. 38 L417

  4. Direct evidence for the sliding motion of CDW-the motional narrowing of 87Rb NMR

    K Nomura et al 1986 J. Phys. C: Solid State Phys. 19 L289

  5. The Clustering of Massive Halos

    Andrew R. Wetzel et al. 2007 ApJ 656 139

  6. Size Is Everything: Universal Features of Quasar Microlensing with Extended Sources

    Michael J. Mortonson et al. 2005 ApJ 628 594

  7. Comment on 'Relativistic extension of shape-invariant potentials'

    Antonio S de Castro 2002 J. Phys. A: Math. Gen. 35 6203

  8. Effects of Si-rich oxide layer stoichiometry on the structural and optical properties of Si QD/SiO2 multilayer films

    X J Hao et al 2009 Nanotechnology 20 485703

  9. On modified equations for discretizations of ODEs

    P C Moan 2006 J. Phys. A: Math. Gen. 39 5545

  10. Rapid electron internal transport barrier formation during magnetic shear reversal in fully non-inductive TCV discharges

    M.A. Henderson et al 2005 Nucl. Fusion 45 1642

Related review articles

What's this?
View review articles related to this research to gain an insight into the key trends in this subject area. Related review articles are selected based on PACS/MSC codes, and are no more than three years old.

  1. Nitride and oxide semiconductor nanostructured hydrogen gas sensors
  2. A survey of snake-inspired robot designs

View by subject




Export








Please login to access our web services, or create an account if you don't yet have one.

You must have cookies enabled in your web browser to be able to login.

Username
Password

Forgotten your password? Get a new one here.