Patent Document ID: 20150338222
Application ID: 14404412
Patent Flag: 0

Claim One:
1. A vehicle position detection device, comprising: a vehicle information acquisition part configured to acquire vehicle information on a state of an own vehicle; a conditional probability information storage part configured to store conditional probability information for associating each of values to be taken in the vehicle information, a matching conditional probability that the each of the values occurs in a matching state where a position of the vehicle is map-matched to a link, and a free conditional probability that the each of the values occurs in a free state where the position of the vehicle is not map-matched to a link with one another; a probability index calculation part configured to acquire, using the conditional probability information, the matching conditional probability and the free conditional probability corresponding to a value of the vehicle information acquired by the vehicle information acquisition part, to calculate a probability index in the matching state based on the acquired matching conditional probability, and to calculate a probability index in the free state based on the acquired free conditional probability; and a state determination part configured to determine which state is to be selected based on the probability index in the matching state and the probability index in the free state calculated by the probability index calculation part.