CONTACT OBJECT DETECTION APPARATUS AND NON-TRANSITORY RECORDING MEDIUM

A contact object detection apparatus includes an on-road static object detector, a sonar sensor, a position estimator, a corrector, and a contact object determination unit. The on-road static object detector detects an on-road static object from an image of an environment behind a vehicle to calculate a position of the object. When the object is no longer detectable, the position estimator estimates a current position of the object based on the last position detected by the on-road static object detector, traveling speed data, and steering angle data, to calculate an angle between a center axis of the sonar sensor and the estimated current position. The corrector corrects a decrease in a sensor output value of the sonar sensor based on the calculated angle. The contact object determination unit determines whether the object has a possibility of contact with the vehicle, based on the corrected sensor output value.