Patent ID: 8823578

Claim:
A driving assist apparatus mounted to an own vehicle, comprising: a transmitter configured to successively transmit a transmission wave having a constant frequency to a surrounding of the own vehicle; a receiver configured to successively receive a reflected wave of the transmission wave; an obstacle presence determination section configured to determine a presence and an absence of an obstacle in the surrounding of the own vehicle based on the reflected wave received by the receiver; a measurement section configured to compare phase of the reflected wave, which is received by the receiver, with phase of a reference signal, which has a frequency synchronized with the frequency of the transmission wave, and thereby measure delay and advance of the phase of the reflected wave with respect to the phase of the reference signal; and a detection section configured to detect the obstacle having a specific relation with the own vehicle, based on the presence of the obstacle determined by the obstacle presence determination section and the the delay and advance of the phase of the reflected wave with respect to the phase of the reference signal as measured by the measurement section.