1. Field of the Disclosure
The disclosure relates to a driving assistance apparatus for a vehicle, the driving assistance apparatus executing following control, which is control for causing a host vehicle to follow a preceding vehicle.
2. Description of Related Art
As proposed in Japanese Patent Application Publication No. 2008-2456 (JP 2008-2456 A), a drive mode can be switched between a plurality of modes including a normal mode, an eco-mode, and a sport mode. The drive modes specify output characteristics of an engine relative to accelerator depression amounts. In the eco-mode, the engine output relative to the accelerator depression amount is limited in comparison with the normal mode in order to conserve fuel. In the sport mode, on the other hand, the engine output relative to the accelerator depression amount is set to be slightly larger than in the normal mode so as to improve a responsiveness by which the engine output responds to an accelerator operation. The drive mode is switched by a selection operation performed by a driver (i.e., in accordance with preferences of the driver).
Incidentally, a driving assistance apparatus that causes a host vehicle to travel so as to follow a preceding vehicle travelling in front of the host vehicle may be employed in a vehicle to lighten a driving operation load of the driver. This control for causing the host vehicle to follow the preceding vehicle will be referred to as following control. During the following control, a target acceleration that enables the host vehicle to follow the preceding vehicle is calculated such that a vehicle-to-vehicle distance between the host vehicle and the preceding vehicle is maintained at a distance within a predetermined range, whereupon an engine or a brake apparatus is controlled on the basis of the target acceleration.
In a vehicle having both switchable drive modes and a following control function, however, the drive mode selected by the driver is not reflected during execution of the following control. In other words, the target acceleration calculated during the following control is calculated without taking the drive mode into account, and therefore the following control cannot be implemented in accordance with the preferences of the driver.