Analyses and standard-index assessment of writing motion using haptic pen

In recent times, the decrease in the number of experienced engineers has become a serious problem. One of the solutions for this problem is to develop a training system which robots assist people to acquire the necessary skills. For developing training system, the extraction and quantitative assessment of information on an engineer's motion is required. In particular, force information is important, especially for a contact motion. Thus, quantitative assessment of the force information is necessary. In this study, a "haptic pen" is used to obtain the exerted writing pressures as force information. Next, the most universal motion from among a number of motions of the engineer is selected and the degree of coincidence of the motion with the most universal motion is determined. The concept of "eigen-universality" is introduced to assess motion, which is of the same type and performed by the same person. To quantitatively evaluate the eigen-universality, graph theory and the coefficient of correlation are used. Moreover, using the coefficient of correlation to obtain "universality" helps us to analyze the degree of coincidence between the most general motion and another motion. The validity of the proposed method is confirmed by experiments.