VEHICLE CONTROL DEVICE, CONTROL METHOD THEREFOR, AND VEHICLE CONTROL SYSTEM

The present invention is directed to improving compatibility between accuracy and responsiveness for estimation of a movement trajectory of a preceding vehicle. A vehicle control apparatus calculates an approximation equation of an N-th degree function as a movement trajectory of a preceding vehicle from at least two pieces of relative position information in each of a plurality of retrospective ranges set as ranges to which the vehicle control apparatus should date back from newest relative position information in a history of a stored plurality of pieces of relative position information, and calculates a coefficient of a predetermined degree in each approximation equation. In the calculation of the coefficient of the predetermined degree, the vehicle control apparatus uses an approximation equation calculated from the at least two pieces of relative position information acquired when setting the retrospective range to the same range or a narrower range compared to when calculating a coefficient of a relatively low degree when calculating a coefficient of a relatively high degree, and uses an approximation equation calculated from the at least two pieces of relative position information acquired when setting the retrospective range to a narrower range compared to when calculating a coefficient of a lowest degree at least when calculating a coefficient of a highest degree. The vehicle control apparatus outputs an instruction according to the calculated coefficient of each degree to a steering control apparatus of a subject vehicle.