We show that vibrotactile feedback displayed through the steering wheel of a car can reduce the perceptual and cognitive load of the driver, leading to less distraction and fewer navigation errors. To demonstrate the concept, two vibration motors are mounted onto the steering wheel of a driving simulator and driving experiments are performed in virtual environments under two different sensory conditions (auditory alone and auditory and vibrotactile feedback together). The results of our experiments with 12 subjects show that, if passenger auditory noise and distraction exist in the environment, the navigation errors (making a wrong turn or taking a wrong exit) are reduced when vibrotactile feedback is displayed to the users in tandem with the GPS-based voice commands. KEYWORDS INTRODUCTIONThe GPS-based navigation systems are helpful in finding our destination, and becoming a standard feature in today's cars. These systems utilize visual cues and voice commands to guide the driver during navigation. However, excessive visual information on the navigator screen overwhelms the driver. Moreover, conversation of the passengers with each other and the driver, as well as the external noise coming from the road or the environment can easily distract the driver and make the voice commands ineffective. Also, the users of these systems report that the artificial "computer" voice can be annoying. We believe that haptic feedback can decrease the cognitive workload of the driver and reduce the navigation errors. In particular, our aim is to show that the vibrotactile feedback improves the navigation performance of the driver and makes the driving task less exhausting, especially when passenger auditory noise and distraction exist in the environment. The use of haptic feedback in vehicular settings is a relatively new concept and a review of the literature is available in [1,2]. There are studies showing the benefits of vibrotactile feedback in arousing sleepy drivers [2], alerting drivers to approaching danger [3], presenting more detailed navigational information [4], and reducing driver workload when interacting with in-vehicle devices, but we are not aware of any earlier study that aims to integrate vibrotactile feedback into a GPS-based car navigation system to improve the navigation performance of a driver. In [5], vibration motors were attached to the steering wheel of a driving simulator and the recognition rate of the drivers for the vibrotactile stimulus coded in spatio-temporal patterns was measured, but its application to a GPS-based navigation system has not been considered at all. Like any other in-vehicle devices, GPS-based car navigation systems can have a negative effect on safety if they increase the cognitive workload of the driver or distract her/his attention [6, 7 and 8]. It is known that visual and auditory information channels of the today's drivers are already highly occupied. With the availability of GPS-based navigation systems as a standard feature in today's cars, the driver has to concent...

Generating localized haptic feedback on touch displays has been a challenge in recent years. In this study, we introduce a haptic interface using transparent thin-film PVDF actuators to address this issue. The transparency feature allows for mounting the actuators at any location beneath the display, enabling localized haptic feedback as the generated vibration is primarily evident on the mounting area. Two different configurations are designed, simulated and prepared to explore the effectiveness of the proposed approach. The first configuration is used to characterize the haptic interface. Modal and forced-vibration analysis are performed to identify important design characteristics based on human factor considerations. Subsequent 2AFC psychophysics experiments validate the characteristics. In the second configuration, eight actuators are attached to the touch surface in a 2x4 matrix formation and excited at different voltage amplitudes. Human experiments are conducted based on the results from corresponding forced-vibration analysis. The results show that subjects demonstrate an accuracy of 96% in identifying locations with haptic feedback when the actuators are excited with 232 Vpp. Overall, our study demonstrates the effectiveness of the haptic interface equipped with PVDF-type actuators in achieving localized haptic feedback on touch displays.

Generating localized haptic feedback on touch displays has been a challenge in recent years. In this study, we introduce a haptic interface using transparent thin-film PVDF actuators to address this issue. The transparency feature can be used to mount the actuators at any location beneath the display, enabling localized haptic feedback as the generated vibration is primarily evident on the mounting area. Two different configurations are designed, simulated and prepared to explore the effectiveness of the proposed approach. The first configuration is used to characterize the haptic interface. Modal and forced-vibration analyses are performed to identify important design characteristics based on human factors. Subsequent 2AFC psychophysics experiments validate the characteristics. In the second configuration, eight actuators are attached to the touch surface in a 2 × 4 matrix formation and excited at different voltage amplitudes. Human experiments are conducted based on the results from corresponding forced-vibration analysis. The results show that subjects demonstrate an accuracy of 96% in identifying locations with haptic feedback when the actuators are excited with 232 Vpp. Overall, our study demonstrates the effectiveness of the proposed transparent haptic interface equipped with PVDF actuators in achieving localized haptic feedback on touch displays.