Vehicle driving-support apparatus

A vehicle travel support device comprising:

• an electronic control unit comprising a central processing unit, the electronic control unit including:
• an air resistance detection unit configured to acquire an air resistance distribution in left and right directions of a host vehicle;
• a target traveling position determination unit configured to determine a target traveling position of the host vehicle against a preceding vehicle using the air resistance distribution;
• a travel support unit configured to guide the host vehicle to the target traveling position;
• a traveling risk detection unit configured to detect traveling risks at each position around the host vehicle, the traveling risk detection unit comprising:
• a contour calculation unit configured to calculate a fuel efficiency improvement rate contour on which the fuel efficiency improvement rate becomes constant at a predetermined target value of the fuel efficiency improvement rate on a basis of the air resistance distribution;
• and
• a traveling risk calculation unit configured to calculate the traveling risk of the host vehicle at each position on the fuel efficiency improvement rate contour,
• wherein the target traveling position determination unit determines the target traveling position so as to minimize the traveling risk,
• the traveling risk is determined based on an equation wherein the traveling risk=ε1f(w)+ε2g(x)+ε3h(y)+ε4k(z), f(w) is a function indicating contact risk between the preceding vehicle and the host vehicle, g(x) is a function indicating contact risk between an oncoming vehicle and the host vehicle, h(y) is a function indicating contact risk between the host vehicle and a neighboring vehicle, k(z) is a function indicating a deviation risk of the host vehicle out of the traveling lane, and ε1, ε2, ε3, and ε4 are risk weighting parameters,
• the target traveling position determination unit, according to control performance of behavior in left and right direction of the host vehicle, obtains a first position in which an inter-vehicle gap in a traveling direction of the host vehicle and the preceding vehicle is relatively small as the target traveling position when the control performance of the behavior in the left and right directions of the host vehicle is high, and obtains a second position in which the inter-vehicle gap is relatively large as the target traveling position when the control performance of the behavior in the left and right directions of the host vehicle is low, and
• the control performance is determined on a basis of at least one from among a response performance of the host vehicle, an assist performance of the host vehicle, and driving skills of a driver of the host vehicle.