CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to and the benefit of Japanese Patent Application No. 2020-022651 filed on Feb. 13, 2020, the entire disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates mainly to a driving assistance apparatus.

Description of the Related Art

Some vehicles include electronic control units (ECUs) that assist driving by executing some or all of driving operations, such as acceleration, braking, and steering, in place of the driver. Such a vehicle travel state is generally referred to as “automated driving”. In automated driving, a situation where ECUs execute some of the driving operations is called “partially-automated driving” or the like, while a situation where ECUs execute all of the driving operations is called “fully-automated driving” or the like.

The aforementioned automated driving is divided into several control states (which may also be referred to as “levels”) depending on the degree to which the ECUs assist in driving (see “Levels of Automated Driving”, http://www.mlit.go.jp/common/001226541.pdf). Here, when transitioning from one control state to another control state, it may take a significant amount of time to prepare the driver, switch control modes of the ECUs, prepare the settings of other in-vehicle apparatuses involved therewith, and the like, for example. As an example of measures for responding to this issue, Japanese Patent Laid-Open No. 2019-64488 discloses a technique in which when an automated driving mode is canceled (i.e., when transitioning to a manual driving mode), the driving goes through a partially-automated driving mode that provides a relatively low level of driving assistance.

On the other hand, as the content of driving assistance becomes more diverse, individual automobile manufacturers are sometimes dividing such control states into even finer levels, which may complicate the schemes for transitions between control states (e.g., settings for transition conditions and the like). Thus what is needed is a technique useful for improving usability in such vehicles.

SUMMARY OF THE INVENTION

An exemplary object of the present invention is to make it relatively easy to achieve both a diversification of the content of driving assistance and an improvement of the usability of a vehicle.

One of the aspects of the present invention provides an in-vehicle driving assistance apparatus that can execute driving assistance on the basis of any one of a plurality of control modes having mutually-different degrees of driving assistance, the apparatus comprising a receiving unit configured to receive a transition instruction of the control mode, a setting unit configured to set the control mode based on the transition instruction, a determining unit configured to determine whether or not a transition scheme for the control mode indicated by the transition instruction has a pre-registered detail, and a suppressing unit configured to suppress the setting of the control mode by the setting unit when the transition scheme for the control mode indicated by the transition instruction does not have the pre-registered detail.

