Systematic evaluation methodology and performance metrics for haptic interfaces

Since haptics technology is being increasingly used in computer games, surgical simulators, rehabilitation therapy, mobile phones etc., there is a need for defining standards for haptic applications. Our study aims at meeting this need by establishing a norm for evaluation of haptic interfaces and by identifying significant benchmark metrics. Towards this end, we have proposed a combined physical and psychophysical experimental methodology. First, the physical performance measures and device characterization techniques were investigated. Testing conditions were described in an illustrative way to obtain a tutorial-like guideline for device characterization. The physical characterization methods were demonstrated on a novel haptic interface for surgical simulation which has been developed in our lab. Second, a wide range of human psychophysical experiments were reviewed. We have unified the psychophysical experiments as a systematic evaluation method which results in novel benchmark metrics for haptic interfaces. Experimental user studies were carried out with three commercial force-feedback devices. The metrics reveal their basic characteristics which are not easily derived from the given specifications. Applicability of the tests to a tactile feedback device was also investigated. The holistic methodology proposed in this work provides objective evaluation criteria allowing users to compare different haptic devices quantitatively, as well as a better understanding of how the limitations of such devices may influence the results of studies involving interaction with humans.