Early Evaluation of 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 in run 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: in run 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 describe about early stage implementation and its evaluation of our proposing method. In our implementation, there is a problem on synchronization sensor data and video recorded on braking zone. So we will discuss on this problem. Also, we will show evaluation about a method that detects landing of the ski jumper automatically using acceleration sensor.