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Wheelchair ergometers are widely used in research, clinical practice, and sports environments. The majority of wheelchair ergometers are roller systems that allow for wheelchair propulsion in the personal wheelchair on one or two (instrumented) rollers. Oftentimes these systems are only statically calibrated. However, wheelchair propulsion is dynamic by nature, requiring a dynamic validation process. The aim of the current project was to present a low-cost portable system for the dynamic metrological verification of wheelchair roller ergometers, based on an instrumented reference wheel. The tangential force on the roller is determined, along with its uncertainty, from the reference wheel properties, and compared with the force measured by the ergometer. Uncertainty of this reference wheel system was found to be lower than the one of the ergometer used, indicating that this novel approach can be used for the metrological verification of ergometers. [ABSTRACT FROM AUTHOR]

Residual vibrations affect machines at the end of commanded motion and can cause a lengthening of the work cycle. The proposed work addresses to the reduction of this undesired phenomenon with an optimization approach based on the Fourier transformation of the motion profile suppressing a band of exciting frequencies around the natural frequencies of the system. Experimental results confirmed a significant improvement, in terms of residual vibrations, with respect to the state of the art of motion profiles specifically designed for residual vibrations reduction. [ABSTRACT FROM AUTHOR]