0
Research Papers

Sliding Mode Control of Mechanical Systems Actuated by Shape Memory Alloy

[+] Author and Article Information
Hashem Ashrafiuon, Vijay Reddy Jala

Depertment of Mechanical Engineering, Villanova Unidersity, Villanova, PA 19085

J. Dyn. Sys., Meas., Control 131(1), 011010 (Dec 08, 2008) (6 pages) doi:10.1115/1.3023121 History: Received November 27, 2007; Revised July 14, 2008; Published December 08, 2008

This paper presents a model-based sliding mode control law for mechanical systems, which use shape memory alloys (SMAs) as actuators. The systems under consideration are assumed to be fully actuated and represented by unconstrained equations of motion. A system model is developed by combining the equations of motion with SMA heat convection, constitutive law, and phase transformation equations, which account for hysteresis. The control law is introduced using asymptotically stable second-order sliding surfaces. Robustness is guaranteed through the inclusion of modeling uncertainties in the controller development. The control law is developed assuming only positions are available for measurement. The unmeasured states, which include velocities and SMA temperatures and stresses, are estimated using an extended Kalman filter based on the nonlinear system model. The control law is applied to a three-link planar robot for position control problem. Simulation and experimental results show good agreement and verify the robustness of the control law despite significant modeling uncertainty.

FIGURES IN THIS ARTICLE
<>
Copyright © 2009 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

A three-link planar robot arm with two SMA actuators and a servomotor

Grahic Jump Location
Figure 2

The SMA actuators comprised of SMA wire and pulley

Grahic Jump Location
Figure 3

Simulation results for position control of the SMA actuated joint angles

Grahic Jump Location
Figure 4

Variations of the two sliding surface during joint position control

Grahic Jump Location
Figure 5

The SMA wire and transformation temperature estimates during joint position control

Grahic Jump Location
Figure 10

Control voltages during heating and cooling

Grahic Jump Location
Figure 9

Comparison between joint position control experimental and simulation results

Grahic Jump Location
Figure 8

Experimental setup for position control of the three-link robot arm with two SMA actuators

Grahic Jump Location
Figure 7

The estimated SMA wire Martensite fractions during joint position control

Grahic Jump Location
Figure 6

The estimated SMA wire stresses during joint position control

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In