On Automatic Flying Distance Measurement on Ski Jumper´s Motion Monitoring System

We are developing a ski jumper´s motion monitor system employing terrestrial magnetism and acceleration sensors. On this development, we have confirmed that terrestrial magnetism and acceleration sensors are useful to measure ski jumper´s inrun descending speed and taking-off positions using a model of ski jumping ramp. Also, we gathered required measurement by inquiring a ski jumping athlete and his coach. As this result, we confirmed following measurement: inrun descending speed, jumper´s style and posture at jumping point, and slant of body of the jumper when he is flying. We are developing a ski jumper´s motion monitoring system using terrestrial magnetism, acceleration sensors and a video camera. Our system succeeded to monitor of ski jumper´s take-off form as changes of degrees on jumper´s knee and waist by using cheap terrestrial magnetism sensors. By using our system, it is thought that correction of wrong take-off forms can be realized. To discuss certain take-off form is good or not, flying distance by a particular jump is important. However, flying distance is not measured in daily practice with few numbers of jumpers because of various difficulties for to measure it. In this paper, we propose automatic flying distance measurement method using video cameras and terrestrial magnetism and acceleration sensors. We are assuming the proposing system is used for practices.