Vehicle location detection device and vehicle location detection method

A vehicle location detection device which is mounted in a vehicle and detects a location of another vehicle near the vehicle, said vehicle location detection device comprising:

• an obstacle information storage unit configured to store obstacle information indicating a geographical location of an obstacle which is likely to block propagation of a vehicle sound;
• a sound pressure information storage unit configured to store vehicle sound pressure information indicating a sound pressure of a vehicle sound at a sound source location;
• a diffraction information storage unit configured to store diffraction information indicating a relationship between a positional relationship and an attenuation amount of a sound pressure, the positional relationship being a relationship among a sound source, a diffraction point, and an observation point of a sound when the sound is diffracted and propagated;
• a sound pressure detecting unit configured to detect a sound pressure of a vehicle sound which has reached the vehicle;
• a direction specifying unit configured to specify a direction from which the vehicle sound has reached;
• a vehicle location detecting unit configured to detect a vehicle location which is a location of the vehicle;
• a diffraction location specifying unit configured to refer to the obstacle information stored in said obstacle information storage unit, and specify a location of an obstacle in the direction specified by said direction specifying unit, based on the vehicle location detected by said vehicle location detecting unit;
• a sound source location specifying unit configured to calculate an attenuation amount of the sound pressure of the vehicle sound by subtracting the sound pressure detected by said sound pressure detecting unit from the sound pressure indicated by the vehicle sound pressure information stored in said sound pressure information storage unit, and specify a location where the other vehicle emitting the vehicle sound is predicted to be present, by specifying a sound source location of a sound diffracted by the obstacle which is specified by said diffraction location specifying unit and serves as a diffraction point, based on the calculated attenuation amount, a rule indicating an attenuation amount dependent on a propagation distance of the sound, and the relationship indicated by the diffraction information stored in said diffraction information storage unit;
• and
• a presentation unit configured to present the location specified by said sound source location specifying unit.