Vehicle position estimation device, vehicle position estimation method, and non-transitory recording medium

1. A vehicle position estimation device comprising a processor configured to:

estimate a vertical position of a vehicle based on an output of a vehicle state detection device detecting a status quantity of the vehicle;

detect actual dividing lines at both left and right sides of the vehicle;

compare a dividing line on a map at the vertical position of the vehicle and an actual dividing line and estimate a horizontal position of the vehicle based on a relative positional relationship between the actual dividing line and the vehicle; and

determine a driving route of the vehicle, wherein

the processor is configured to calculate an amount of change of a horizontal position with respect to the driving route for each of dividing lines of both left and right sides of the driving route in a predetermined range before and after the vertical position of the vehicle based on a map information, and determine a dividing line on the map for comparison based on the amounts of change.

2. The vehicle position estimation device according to claim 1 , wherein if the amount of change for the dividing line of one side of the driving route is less than a predetermined threshold value and the amount of change for the dividing line of the other side of the driving route is equal to or greater than that threshold value, the processor is configured to use the dividing line at the one side on the map for comparison.

3. The vehicle position estimation device according to claim 1 , wherein if a point where the horizontal position of the actual dividing line with respect to the driving route changes is detected, the processor is configured to correct the vertical position of the vehicle based on a relative positional relationship between the point and the vehicle.

4. A vehicle position estimation method including:

estimating a vertical position of a vehicle based on an output of a vehicle state detection device detecting a status quantity of the vehicle;

detecting actual dividing lines at both left and right sides of the vehicle;

comparing a dividing line on a map at the vertical position of the vehicle and an actual dividing line and estimating a horizontal position of the vehicle based on a relative positional relationship between the actual dividing line and the vehicle; and

determining a driving route of the vehicle, wherein

estimating the horizontal position of the vehicle includes calculating an amount of change of a horizontal position with respect to the driving route for each of dividing lines of both left and right sides of the driving route in a predetermined range before and after the vertical position of the vehicle based on a map information, and determining a dividing line on the map for comparison based on the amounts of change.

5. A non-transitory recording medium having recorded thereon a computer program causing a computer to:

estimate a vertical position of a vehicle based on an output of a vehicle state detection device detecting a status quantity of the vehicle;

detect actual dividing lines at both left and right sides of the vehicle;

compare a dividing line on a map at the vertical position of the vehicle and an actual dividing line and estimate a horizontal position of the vehicle based on a relative positional relationship between the actual dividing line and the vehicle; and

determine a driving route of the vehicle, wherein

estimating the horizontal position of the vehicle includes calculating an amount of change of a horizontal position with respect to the driving route for each of dividing lines of both left and right sides of the driving route in a predetermined range before and after the vertical position of the vehicle based on a map information, and determining a dividing line on the map for comparison based on the amounts of change.