Real-time model based electrical powered wheelchair control

Wang, Hongwu; Salatin, Benjamin; Grindle, Garrett G.; Ding, Dan; Cooper, Rory A.

doi:10.1016/j.medengphy.2009.08.002

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Volume 31, Issue 10 , Pages 1244-1254, December 2009

Real-time model based electrical powered wheelchair control☆

Hongwu Wang
- Human Engineering Research Laboratories, VA Pittsburgh Healthcare System, Pittsburgh, PA 15206, USA
- Department of Rehabilitation Science and Technology, University of Pittsburgh, Pittsburgh, PA 15261 USA
Benjamin Salatin
- Human Engineering Research Laboratories, VA Pittsburgh Healthcare System, Pittsburgh, PA 15206, USA
- Department of Rehabilitation Science and Technology, University of Pittsburgh, Pittsburgh, PA 15261 USA
Garrett G. Grindle
- Human Engineering Research Laboratories, VA Pittsburgh Healthcare System, Pittsburgh, PA 15206, USA
- Department of Rehabilitation Science and Technology, University of Pittsburgh, Pittsburgh, PA 15261 USA
Dan Ding
- Human Engineering Research Laboratories, VA Pittsburgh Healthcare System, Pittsburgh, PA 15206, USA
- Department of Rehabilitation Science and Technology, University of Pittsburgh, Pittsburgh, PA 15261 USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA
Rory A. Cooper
- Human Engineering Research Laboratories, VA Pittsburgh Healthcare System, Pittsburgh, PA 15206, USA
- Department of Rehabilitation Science and Technology, University of Pittsburgh, Pittsburgh, PA 15261 USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Corresponding author at: Human Engineering Research Laboratories (151R-1), VA Pittsburgh Healthcare System, 7180 Highland Dr., Building 4 Room 243e 151R-1, Pittsburgh, PA 15206, United States. Tel.: +1 412 365 4850; fax: +1 412 365 4858.

Received 3 June 2009; received in revised form 3 August 2009; accepted 5 August 2009. published online 07 September 2009.

Abstract

The purpose of this study was to evaluate the effects of three different control methods on driving speed variation and wheel slip of an electric-powered wheelchair (EPW). A kinematic model as well as 3D dynamic model was developed to control the velocity and traction of the wheelchair. A smart wheelchair platform was designed and built with a computerized controller and encoders to record wheel speeds and to detect the slip. A model based, a proportional-integral-derivative (PID) and an open-loop controller were applied with the EPW driving on four different surfaces at three specified speeds. The speed errors, variation, rise time, settling time and slip coefficient were calculated and compared for a speed step-response input. Experimental results showed that model based control performed best on all surfaces across the speeds.

Keywords: Electric-powered wheelchair, 3D dynamic model, Model based control, PID, Medical rehabilitation