Improvement of a Worker´s Motion Trace System Using a Terrestrial Magnetism Sensor

Guarantee of quality of products is very important for company activities; so many companies consider guaranteeing quality of their products is very important. In guarantee of quality in industrial products, they are not only important that designs, parts and materials but also production process itself. In assembly process, this means that production works is done according with accurate procedure is important. Generally, most assemble processes have steps to confirm results and working quality of former steps. However, there are some cases that it is impossible to confirm quality of former step´s work. For example, in a work to attach and fix a part using some screws, there is certain order to screw some screws to guarantee accuracy to attach the part. However, if the order to screw is not obeyed, this violation cannot be detected by appearance since the screws are enough screws, and the part is fixed. Therefore, we have been developing a worker´s motion trace system by using terrestrial magnetism sensors and acceleration sensors to confirm whether the worker´s motion accords correct assembly procedure. Up to now, our system trace system cannot judge whether worker´s motion is correct or not in 100% accuracy. So we tired to improve a method to judge the worker´s motion. In this paper, we describe this new method based on LOF, and its evaluation.