Patent ID: 7541917

Claim:
An obstacle discrimination device for discriminating among a pedestrian, a lightweight obstacle lighter than the pedestrian and a heavyweight obstacle heavier than the pedestrian in a collision of a vehicle, the obstacle discrimination device comprising: a first detection unit; a second detection unit which is more resistant to an impact due to the collision than the first detection unit, wherein the first detection unit is mounted at a low-stiffness member of the vehicle, the low-stiffness member being readily deformed to buffer the impact in the collision, the second detection unit is mounted at a high-stiffness member of the vehicle, the high-stiffness member being more resistant to a deformation than the low-stiffness member, and the high-stiffness member includes two front side members of the vehicle; and an obstacle discrimination ECU performing at least one of a discrimination for determining whether or not an obstacle colliding with the vehicle is the lightweight obstacle and a discrimination for determining whether or not the obstacle is the heavyweight obstacle based on detection signals of the first detection unit, and performing the discrimination for determining whether or not the obstacle is the heavyweight obstacle based on detection signals of the second detection unit, the obstacle discrimination ECU sending instructions corresponding to discrimination results to a pedestrian protection device of the vehicle, wherein the obstacle discrimination ECU determines that the obstacle colliding with the vehicle is the heavyweight obstacle when an output value of the second detection unit is larger than a first threshold value, and does not activate a passenger protection airbag when the output value of the second detection unit is larger than the first threshold value but is smaller than a second threshold value that is larger than the first threshold value, and the obstacle discrimination ECU activates the passenger protection airbag to be deployed when the output value of the second detection unit is larger than the second threshold value.