9,243 research outputs found
Personalising Vibrotactile Displays through Perceptual Sensitivity Adjustment
Haptic displays are commonly limited to transmitting a discrete
set of tactile motives. In this paper, we explore the
transmission of real-valued information through vibrotactile
displays. We simulate spatial continuity with three perceptual
models commonly used to create phantom sensations: the linear,
logarithmic and power model. We show that these generic
models lead to limited decoding precision, and propose a
method for model personalization adjusting to idiosyncratic
and spatial variations in perceptual sensitivity. We evaluate
this approach using two haptic display layouts: circular, worn
around the wrist and the upper arm, and straight, worn along
the forearm. Results of a user study measuring continuous
value decoding precision show that users were able to decode
continuous values with relatively high accuracy (4.4% mean
error), circular layouts performed particularly well, and personalisation
through sensitivity adjustment increased decoding
precision
Evaluation of Haptic Patterns on a Steering Wheel
Infotainment Systems can increase mental workload and divert
visual attention away from looking ahead on the roads.
When these systems give information to the driver, provide
it through the tactile channel on the steering, it wheel might
improve driving behaviour and safety. This paper describes an
investigation into the perceivability of haptic feedback patterns
using an actuated surface on a steering wheel. Six solenoids
were embedded along the rim of the steering wheel creating
three bumps under each palm. Maximally, four of the six
solenoids were actuated simultaneously, resulting in 56 patterns
to test. Participants were asked to keep in the middle
road of the driving simulator as good as possible. Overall
recognition accuracy of the haptic patterns was 81.3%, where
identification rate increased with decreasing number of active
solenoids (up to 92.2% for a single solenoid). There was no
significant increase in lane deviation or steering angle during
haptic pattern presentation. These results suggest that drivers
can reliably distinguish between cutaneous patterns presented
on the steering wheel. Our findings can assist in delivering
non-critical messages to the driver (e.g. driving performance,
incoming text messages, etc.) without decreasing driving performance
or increasing perceived mental workload
Tac-tiles: multimodal pie charts for visually impaired users
Tac-tiles is an accessible interface that allows visually impaired users to browse graphical information using tactile and audio feedback. The system uses a graphics tablet which is augmented with a tangible overlay tile to guide user exploration. Dynamic feedback is provided by a tactile pin-array at the fingertips, and through speech/non-speech audio cues. In designing the system, we seek to preserve the affordances and metaphors of traditional, low-tech teaching media for the blind, and combine this with the benefits of a digital representation. Traditional tangible media allow rapid, non-sequential access to data, promote easy and unambiguous access to resources such as axes and gridlines, allow the use of external memory, and preserve visual conventions, thus promoting collaboration with sighted colleagues. A prototype system was evaluated with visually impaired users, and recommendations for multimodal design were derived
Sensory Integration of Apparent Motion Speed and Vibration Magnitude
Tactile apparent motion can display directional information in an intuitive way. It can for example be used to give directions to visually impaired individuals, or for waypoint navigation while cycling on busy streets, when vision or audition should not be loaded further. However, although humans can detect very short tactile patterns, discriminating between similar motion speeds has been shown to be difficult. Here we develop and investigate a method where the speed of tactile apparent motion around the user & #x0027;s wrist is coupled with vibration magnitude. This redundant coupling is used to produce tactile patterns from slow & amp;weak to fast & amp;strong. We compared the just noticeable difference (JND) of the coupled and the individual variables. The results show that the perception of the coupled variable can be characterised by JND smaller than JNDs of the individual variables. This allowed us to create short tactile pattens (tactons) for display of direction and speed, which can be distinguished significantly better than tactons based on motion alone. Additionally, most subjects were also able to identify the coupled-variable tactons better than the magnitude-based tactons
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