Effectiveness of Stability Evaluation by Acceleration and Angular Velocity While Operating Smartphones

The objective of this study was to investigate the effectiveness of evaluating the stability by accelerometer and gyroscope built in smartphone while users were operating smartphones. A total of three smartphones with different sizes were used for the experiment. The swaying caused by the unstable operation of the smartphone was measured as acceleration and angular velocity and components related to stability were extracted. Since the weight of smartphones differed from one type to another, when the difference between the smartphones was evaluated, the acceleration was converted into force. Participants were asked to evaluate the stability during operation and the risk of dropping. The result showed that the force and angular velocity increased as the smartphone size increased. As the hands of the participants became smaller, the acceleration and angular velocity were increased. It was found that the stability during operation was evaluated as uncomfortable as the force and angular velocity became larger. On the other hand, there was no relationship between the risk of dropping and the force and angular velocity. From these results, acceleration and angular velocity appeared to be effective for evaluation of stability while operating smartphones.