Vibrotactile rendering for simulating virtual environment in a mobile game

Vibrotactile rendering is a process of computing and generating haptic information in response to a user´s interaction with virtual objects. The crucial procedure in the vibrotactile rendering is to transform the simulated behavior of a virtual object into vibrotactile information according to user´s action. This paper presents a vibrotactile rendering method that expresses the reaction of a car on a road surface in a racing game using vibrotactile information. To this end, we first design a miniaturized vibrotactile rendering system with an eccentric vibration motor and a solenoid actuator, which generates vibrotactile information having a large bandwidth and amplitude. We also construct an interactive racing game as a test bed for the proposed vibration rendering method. We designed voltage input patterns that can be haptically discriminated by human for experiments. The proposed vibrotactile rendering based on these patterns generates control input to vibrotactile actuators to make users realistically feel the sensation of collision, driving on a bump, driving on a hard shoulder. To evaluate the proposed vibrotactile rendering method, nine persons experience two kind of racing games: one is the game with the proposed vibrotactile rendering, and the other is the game without the vibrotactile rendering. After the experiment, participants are asked to compare and appraise those two games based on suggested criteria. The experiment clearly shows the effectiveness and the feasibility of the proposed vibrotactile rendering method, which implies the sufficient applicability of the proposed vibrotactile rendering system to mobile devices