To solve the problem wherein, in a conventional device for diagnosing any failure of a vehicle, the occupant restraining property for preventing an occupant from being thrown away or jumped out due to the collision or the overturn of the vehicle in collision or overturn of the vehicle can not be enhanced.
A device for determining overturn of a vehicle includes a roll angular velocity sensor 15 for detecting the roll angular velocity of a vehicle, a roll angle calculation unit 22 for calculating the roll angle from the value of the roll angular velocity detected by the roll angular velocity sensor 15, a map of a function with one coordinate axis indicating the roll angle and the other indicating the roll angular velocity, and a determination unit 12 to determine that the vehicle is possibly overturned when the overturn limit line is set on the map, and the roll angle calculated by the roll angle calculation unit 22 and the value of the roll angular velocity detected by the roll angular velocity sensor 15 exceed the overturn limit line when viewed from the origin of the map.
Shiro Fujitani
Tatsuya Sawada