Collision determinig apparatus for a vehicle

A collision determining apparatus for a vehicle includes a first acceleration measuring device (21) which measures an acceleration acting on a vehicle, a movement amount calculating device (24) which calculates an amount of movement of an occupant, a change in movement speed calculating device (23) which calculates a change in movement speed of the occupant, a first collision determining threshold value setting device (25) which sets collision determining threshold values for a correlation between the amount of movement of the occupant and the change in movement speed of the occupant, a first collision determining device which determines whether or not the correlation exceeds the collision determining threshold value, and a first control signal generating device (27,29,32)which generates a control signal which instructs that an occupant protection apparatus be operated slowly in multiple stages or be operated rapidly in multiple stages.