Ian Summers

School of Physics
University of Exeter
Exeter
EX4 4QL
UK
i.r.summers@exeter.ac.uk

Overview

I am a physicist with expertise in signal processing. I have been researching in the area of touch perception for over 25 years, starting with work in the 1970s and 1980s on a touch-based hearing aid for the profoundly deaf. More recent work has concentrated on other aspects of communication via the sense of touch, with applications in computer interfaces and virtual environments. I am particularly interested in the relation between mechanical inputs to the skin and the touch sensation they invoke, with a view to understanding how to produce realistic virtual touch sensations.

Issues and Interests

I have recently participated in the EU-funded ENACTIVE project on multi-modal interfaces for enactive learning, and the EU-funded HAPTEX project on virtual representation of objects such as textiles, for which the surface “feel” is particularly significant. Consequently I have considerable experience of working with a multidisciplinary team, and of the issues associated with the virtual representation of textiles.
In the HAPTEX project, we produced a workable system for visual and tactile presentation of virtual textiles. For a first attempt, the HAPTEX system was surprisingly good. However, there is room for improvement in many areas and I am anxious to work on new developments. Unfortunately, the HAPTEX system was not available beyond the end of the project, and so I am looking for the opportunity of building a new, improved system.
Particular issues for a new system include:
o design of an effective force-feedback system that can accurately present the small forces generated by interaction with a textile;
o design of a tactile stimulator that can present distributed stimuli over the fingertips (there is a particular problem of delivering touch stimuli to the thumb and finger when a virtual textile is grasped between them, as there is no space for stimulator hardware against the skin);
o design of tactile rendering software – i.e., working from a software description of a textile, software which can generate touch stimuli “on the fly” to create appropriate tactile sensations during active exploration of a virtual scenario.

Further reading

D Allerkamp, G Böttcher, F-E Wolter, AC Brady, J Qu and IR Summers; ‘A vibrotactile approach to tactile rendering’, The Visual Computer 23 2007: 97-108.
This paper includes design considerations for an array stimulator to produce synthetic tactile sensations. An important point is that the stimulator does not attempt to create a surface topology – instead it attempts to create the appropriate excitations of touch receptors in the skin.
N Magnenat-Thalmann, P Volino, U Bonanni, IR Summers, M Bergamasco, F Salsedo and F-E Wolter; ‘From Physics-based Simulation to the Touching of Textiles: The HAPTEX Project’, The International Journal of Virtual Reality 6 2007: 35-44.
This paper gives an overview of the HAPTEX project, including consideration of hardware and software requirements to deliver a realistic visual and tactile representation of a virtual textile. The heart of the system is a software model of the textile which represents its mechanical behaviour when manipulated.
IR Summers and AC Brady; ‘Psychophysics experiments on a tactile renderer’, Proceedings of Materials & Sensations 2008, Pau, 2008: 39-42.
This paper investigates the different virtual touch sensations that can be generated via a stimulator array on the fingertip. It is possible to discriminate changes in spectral information (relating to surface texture) as well as changes in intensity (relating to overall roughness).

Links

http://newton.ex.ac.uk/research/biomedical/tactile/haptex.html
http://newton.ex.ac.uk/research/biomedical/tactile/
http://haptex.miralab.unige.ch/