Abstract
In this paper, a new pen-based device without special writing plane is proposed. We tried to reproduce handwritten pattern using 3D pen acceleration and angular velocity measured by accelerometers and gyroscopes respectively. Pen positions are calculated with twice integration of pen acceleration considering pen rotation. The condition of the pen rotation is measured by pen angular velocity. In the process of twice integration, small noise and output drift of the sensors cause reproduction error. Pen velocity signals are rectified to remove the reproduction errors. Though coordinate system of reproduced pattern is slanted according to the initial pen slant, reproduced pattern can be transformed to the pattern on horizontal plane using gravitational acceleration. The experimental results show the possibility of a new pen-based interface system without special writing plane.
