Physical mobile interaction with kinesthetic feedback

As the gestural interface is emerging as one of the key interfaces for mobile computing, the ability of these interfaces to provide physical feedback is becoming more important. Especially in the context of interacting with a virtual world, generating proper feedback is more important when seeking to engage users in a simulated world. However, due to the inherent size problems of mechanical structures and due to power issues, most handheld devices relied on vibrotactile feedback. To resolve this issue, this paper proposes a haptic interface module that can represent realistic kinesthetic feedback for use with hand interfaces. Large-scale but slowly changing force is generated using a linear servomotor to provide general object information, such as the overall shape of an object. On the other hand, subtle haptic feedback generated by a solenoid-magnet pair provides the detailed surface properties of the object. To measure the performance of the proposed system, two experiments are conducted. From the experimental results, it was revealed that the proposed solenoid-magnet pair could generate about 1N of magnetic force. In terms of perception, the device can provide six levels of kinesthetic feedback. As an application, we propose depth-based interaction in which the proposed system is controlled by a depth-measuring unit.