Abstract: An upper body motion measurement system 1 has a plurality of inertia sensor units 2, each of which incorporating an angular velocity sensor 4 and an acceleration sensor 5. The plurality of the inertia sensor units 2 is attached to places that are different from each other on the upper body of a subject P. Based on the detection outputs of the angular velocity sensor 4 and the acceleration sensor 5, the attitude of each of the inertia sensor units 2 is estimated, and the acceleration thereof is further estimated. The angular acceleration of the upper body of the subject P is estimated based on the estimated accelerations of the plurality of the inertia sensor units 2.

Abstract: In order to arrange a heater effectively in a case containing ultrasonic sensors to melt frozen snow attached to the case assuredly to ensure the performance of the ultrasonic sensors, an ultrasonic sensor unit comprises ultrasonic sensors (9, 10), a case (11, 12) for containing the ultrasonic sensors, and a sheet component (20) arranged on an inner side of a bottom (12c) of the case to cover the bottom, and having a heater (22) buried in or mounted on it.

Abstract: In order to arrange a heater effectively in a case containing ultrasonic sensors to melt frozen snow attached to the case assuredly to ensure the performance of the ultrasonic sensors, an ultrasonic sensor unit comprises ultrasonic sensors (9, 10), a case (11, 12) for containing the ultrasonic sensors, and a sheet component (20) arranged on an inner side of a bottom (12c) of the case to cover the bottom, and having a heater (22) buried in or mounted on it.