No abstract

With the widespread availability of computers and mobile devices, we use them for daily communication by exchanging visual and verbal/non-verbal media. We obtain various information from multimedia devices, and such devices recently have a touch panel interface to allow a user to intuitively and interactively use them. A touch panel consists of a touchsensitive panel and a graphical display, and accepts user's intuitive touch inputs together with visual and auditory feedback. With the employment of touch actions in such interface devices, tactile feedback will be expected, if we consider the manipulation of a real object. For presenting tactile feedback, some tactile actuators have been introduced recently, however these actuators require the reference from real objects to generate the appropriate tactile sensations, and the input data to be associated with the output tactile sensations should be precisely prepared in the design of such systems. This study introduces a tactile pen to work with a touch screen, together with an algorithm to automatically generate parameters from an object's picture for driving tactile actuators. A tactile presentation system with a visual display is constructed, and the validity of the texture sensations is verified by a user's experiment.

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For the purpose of developing an actuator for wearable-assistive devices, we have devised and produced a weft yarn-type shape memory alloy (SMA) actuator using the resistance feedback control method. This actuator consists of a polyethylene terephthalate (PET) plate and SMA wire woven into the weft pattern. Since the PET plate and SMA wire are constrained in the lateral direction, this actuator can do the bending operation by the actuation of the SMA wire. In this research, the effects of constraint conditions of the PET plate and SMA wire (i.e. the distance between PET plate and SMA wire (D)), and the number of constraining points (N) were investigated with respect to the bending operating characteristics (bending deflection and operating velocity) of the weft yarn-type SMA actuator. The bending deflection of the actuator was seen to increases with the increase of N. However, the bending deflection of the actuator was seen to decreases with the increase of N beyond the maximum value. The variation of deflection is caused by the variation of frictional force due to the variation of N. Furthermore, the bending deflection of the actuator and operating velocity decrease as D increases. This tendency is caused by the increase of the curvature radius of actuator with the increase of D.

No abstract