Abstract
Present day haptic displays have one or a few contact areas, the information being similar over the whole area. The aim of this investigation was to study the relative importance of increasing the number of contact areas and providing spatially distributed information at each contact area. Technical development was “simulated” in experiments with real objects where the information was constrained in ways similar to those in haptic displays. The results suggest clearly that the largest improvement can be expected if spatially distributed information is made available within each contact area. If that is made, an improvement of performance can be expected also with an increased number of contact areas. Increasing only the number of contact areas will not give the same result.
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Notes
The choice of these two options for improvement of haptic displays does not exclude, of course, that there may be other options as well.
All participants were seen before the experiment proper for molding the sheath(s) to suit the shape of their finger(s) participating in the experiment and/or to check if any of those made for earlier participants fitted sufficiently well. Forty-five different sheaths of the 110 needed were used. The sheaths were produced in the following way. A cast of the pad of the distal phalanx of the finger in question was created by placing it in a form with alginate. Two casts of this cast were molded in paraffin. The size of one of them was increased by dipping it in melted paraffin (as when candles are made) in order to make it correspond to the size of the finger plus the sheath. A cast of the larger paraffin cast was made in plaster. In the larger plaster cast polyester plastic was poured and three sheets of 168 g glass-fiber were placed there together with the smaller paraffin cast. After being solidified the sheath was trimmed to form a smooth outer surface. The sheath was kept in place by a thin (1 mm) rubber glove in a size suitable for each participant.
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Acknowledgements
The study was funded by the EU project IST-2000-29580-PURE-FORM. First technician Lars-Erik Larsson produced the sheaths. Three anonymous reviewers of the first version of the paper provided useful suggestions.
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Jansson, G., Monaci, L. Identification of real objects under conditions similar to those in haptic displays: providing spatially distributed information at the contact areas is more important than increasing the number of areas. Virtual Reality 9, 243–249 (2006). https://doi.org/10.1007/s10055-006-0021-y
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DOI: https://doi.org/10.1007/s10055-006-0021-y