A vibrotactile transducer and its applications in the study of perception

Vibrotactile signals are ubiquitous in everyday life, occurring both when manipulating objects and operating power tools. To bring haptics to ambient systems (defined as being embedded in everyday objects), the vibrotactile channel presents itself as a perceptually and energetically efficient method of conveying haptic information.;Using the aforementioned actuator, mock cellphones were made for vibrotactile perception experiments. Employing pulsed vibration signals to combat adaptation effects, experiments were performed to study the effect of weight and underlying vibration frequency on perceived strength. Results show that for the same measured acceleration on the device, a heavier box is perceived to vibrate with greater strength. Furthermore, signals with higher underlying frequency are perceived to be weaker for the same measured acceleration. The results obtained from ungrounded, vibrating objects are consistent with previous studies using grounded devices. The findings suggest the need for a systematic correction rule that assists cellphone designers in how to modify the device's vibratory characteristics according to its weight and the operating frequency.;An ambient haptic device is implemented to synthesize haptic cues resulting from an object rolling down and impacting the inside wall of a tubular cavity. When an object rolls or slides, a variety of cues become available for the estimation of its location inside the cavity. These cues are related to the dynamics of an object subjected to the laws of physics such as gravity and friction. Perception experiments were conducted, in which participants attempted to discriminate among three virtual tubes of different lengths after making the virtual ball roll down. The results support the hypothesis that the subjects mastered the laws related to the dynamics of objects under the influence of gravity and used them to perceive the length of the invisible cavities.;Mobile phones are by far the most popular haptic-enabled devices. Yet, they are often equipped with common vibration motors of narrow-bandwidth capability. A voice-coil vibrotactile transducer design has been demonstrated to be high-bandwidth and capable of functioning under the same enclosure-vibration paradigm. The transducer was modeled by converting its mechanical free-body diagram into equivalent electrical circuits. The experimentally obtained transfer function was combined with the function established theoretically to obtain the impedance expression for each parameter.