摘要 |
Two radar devices are installed for adjacent lanes. A memory sequentially stores a received power value at a time when the two radar devices receive the reflected wave from a vehicle at specified time intervals. A calculator calculates, when a vehicle moves in a direction approaching the two radar devices, as a representative value of the received power at a specified time, a weighted average value when weights, which become heavier as an acquisition time of the received power value becomes farther from the specified time, are assigned to a specified number of received power values, whose acquisition time is prior to a specified time, where a priority is given to the received power values whose acquisition time is close to the specified time. A discriminator determines a lane in which the vehicle is traveling according to a result of comparing the sizes of the calculated representative value. |