Vehicle control device for maintaining inter-vehicle spacing including during merging

1. A vehicle control device that controls a first vehicle that is an own vehicle so as to maintain inter-vehicle spacing with a preceding vehicle, the vehicle control device comprising:

a target inter-vehicle spacing calculation unit that calculates target inter-vehicle spacing information based on inter-vehicle spacing information with the preceding vehicle and inter-vehicle spacing information with a trailing vehicle, wherein the preceding vehicle is traveling ahead of the first vehicle and the trailing vehicle is traveling behind the first vehicle with respect to a lane,

wherein the target inter-vehicle spacing calculation unit calculates the target inter-vehicle spacing information based on the inter-vehicle spacing information with the trailing vehicle so that the target inter-vehicle spacing information is restored to a previous value at a predetermined change rate, the previous value being the value before a lane change; and

a vehicle control unit that controls speed of the first vehicle so as to maintain the target inter-vehicle spacing information calculated.

2. The vehicle control device according to claim 1 , wherein the inter-vehicle spacing information is an inter-vehicle spacing time or an inter-vehicle spacing distance.

3. The vehicle control device according to claim 2 , wherein when a switching timing is received, the target inter-vehicle spacing calculation unit sets the inter-vehicle spacing information with the preceding vehicle as the target inter-vehicle spacing information.

4. The vehicle control device according to claim 3 , wherein when the inter-vehicle spacing information with the preceding vehicle is within a predetermined range set in advance, the target inter-vehicle spacing calculation unit sets the inter-vehicle spacing information with the preceding vehicle as the target inter-vehicle spacing information, and when the inter-vehicle spacing information with the preceding vehicle is out of the predetermined range, the target inter-vehicle spacing calculation unit sets a value within the predetermined range calculated from the inter-vehicle spacing information with the preceding vehicle as the target inter-vehicle spacing information.

5. The vehicle control device according to claim 4 , wherein the target inter-vehicle spacing calculation unit sets the inter-vehicle spacing information with the preceding vehicle as the target inter-vehicle spacing information when the inter-vehicle spacing information with the trailing vehicle is equal to or less than a value set in advance and the inter-vehicle spacing information with the preceding vehicle is within the predetermined range.

6. The vehicle control device according to claim 3 , wherein the switching timing is timing when, at a time that the first vehicle changes a lane, the preceding vehicle and the trailing vehicle are recognized among vehicles traveling in the lane to which the first vehicle changed.

7. The vehicle control device according to claim 2 , further comprising a target route generation unit that generates a target route including speed and a traveling direction of the first vehicle based on information from an external environment recognition device that recognizes a traffic environment around the first vehicle,

wherein the target inter-vehicle spacing calculation unit is used by the target route generation unit.

8. The vehicle control device according to claim 2 , further comprising:

a preceding vehicle information calculation unit that determines the preceding vehicle and calculates the inter-vehicle spacing information with the preceding vehicle;

a trailing vehicle information calculation unit that determines the trailing vehicle and calculates the inter-vehicle spacing information with the trailing vehicle;

a control parameter calculation unit that calculates a control parameter for controlling the speed of the first vehicle; and

a control parameter output unit that outputs the calculated control parameter to a control target device.

9. The vehicle control device according to claim 1 , wherein the target inter-vehicle spacing calculation unit increases the predetermined change rate as the inter-vehicle spacing information with the trailing vehicle increases.