2017 年 83 巻 856 号 p. 17-00346
This paper analyzes metal-mold polishing by human hands. The metal-mold polishing generally requires long experiences about polishing works. Although experienced persons have many excellent skills, it is a little difficult to evidently teach them to beginners in words because most skills are considered to depend on their physical and intuitive memories. Thus we attempt to bring out the characteristic skills about metal-mold polishing by human hands. This paper mainly discusses the difference of polishing skills between experienced persons and beginners. First, a new data acquisition tool is developed to obtain polishing data, which is designed similar to old tools used by experienced persons. The tool basically consists of a small grasping spatula, a grindstone chip, a force sensor, and a 3D motion sensor. Second, basic data acquired from the developed tool are explained, and the estimation method about some kinds of data is proposed, which are not directly obtained from the sensors attached to the tool. Third, the characteristics between experienced persons and beginners are carefully compared from the view of the tool angle, the polishing velocity, the pressing force, and the mean power of polishing. Then, we focus on the phase trajectories between the polishing position and velocity, and the resistant forces appeared in forward and backward polishing. In order to understand the interesting phenomena about the phase trajectories and resistant forces, a simple dynamical model is newly assumed, and the model evidently explains the phenomena. Finally, the main results and future works are summarized.