SIDE COLLISION DETECTION SYSTEM, OCCUPANT RESTRAINT SYSTEM AND VEHICLE

A control device is provided with a first collision determiner for determining a side collision to a vehicle based on velocity in a direction orthogonal to the advancing direction of the vehicle, and a second collision determiner for determining a side collision to the vehicle based on a displacement amount and displacement velocity of an acceleration sensor provided in a door of the vehicle. When the vehicle is traveling at a relatively high velocity, the control device detects a side collision to the vehicle using the determination result of the first collision determiner and the determination result of the second collision determiner. In addition, when the vehicle is traveling at a low velocity or is stopped, the control device detects a side collision to the vehicle using the determination result of the first collision determiner, without using the determination result of the second collision determiner.