Driving assistance apparatus

• US 8,471,909 B2
• Filed: 04/07/2011
• Issued: 06/25/2013
• Est. Priority Date: 04/19/2010
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Ishikawa, Takahiro
• Primary Examiner(s): Perungavoor, Sath V
• Assistant Examiner(s): Xu, Xiaolan
• Application Number:
  US13/081,524
• Publication Number:
  US 20110254956A1
• Time in Patent Office: 810 Days
• Field of Search: 348/148, 345/647, 382/103
• US Class Current: 348/148
• CPC Class Codes: B60W 2420/403 Image sensing, e.g. optical camera
• CPC Class Codes: B60W 40/08 related to drivers or passengers
• CPC Class Codes: B60W 50/14 Means for informing the driver, warning the driver or prompting a driver intervention
• CPC Class Codes: B62D 1/046 Adaptations on rotatable parts of the steering wheel for accommodation of switches

Abstract

In a hand-free driving warning process for a vehicle, when a grip state of a steering wheel is in a hand-free driving state, and the vehicle is in a travel state stipulated previously, a danger degree is derived based on a position of a vehicle compartment where a non-grip hand exists. In deriving the danger degree, when the non-grip hand is in a high danger position, a high level is set; when the non-grip hand exists in a low danger position, a middle level or a low lever is set. In the low level, any warning is not outputted; in the middle level, a warning is outputted in a sound volume smaller than a usual sound volume; and in the high level, a warning is outputted in the usual sound volume or greater.

Claims

1. A driving assistance apparatus for a vehicle, comprising:

a grip state detection section configured to detect a grip state of a steering wheel in a compartment of the vehicle;

an image acquisition section configured to acquire a captured image of the compartment that covers a possible action range of a person who is seated in a driver'"'"'s seat;

a position specification section configured to specify, based on a captured image acquired by the image acquisition section, a position where a non-grip hand exists, the non-grip hand being a hand that is separate from the steering wheel, on condition that (i) the grip state of the steering wheel is in a hand-free state, in which at least either of two hands is separate from the steering wheel as a result of detecting of the grip state detection section, and (ii) a travel state of the vehicle is within a stipulated travel state, which is predetermined;

a danger derivation section configured to derive a danger degree such that the danger degree comes to have a greater value as a degree of a danger against driving of the vehicle becomes higher because the non-grip hand exists in a position specified by the position specification section; and

a warning section configured to execute an output of a warning in a weaker state as the danger degree derived by the danger derivation section comes to have a smaller value,

wherein;

the danger derivation section

classifies a plurality of positions in the compartment in the vehicle based on danger degrees, and

defines previously a low danger position within the positions classified, wherein the danger degree has a value smaller than a reference value when the non-grip hand exists in the low danger position; and

the danger derivation section derives the danger degree such that when the non-grip hand exists in the low danger position, the danger degree has a value smaller as compared with a case that the non-grip hand exists in a high danger position, which is within the positions classified in the compartment and is other than the low danger position.

2. The driving assistance apparatus according to claim 1, wherein

the danger derivation section derives the danger degree such that the danger degree comes to have a smaller value as a non-grip hand existence duration for which the non-grip hand continues to exist in the low danger position becomes shorter.

3. The driving assistance apparatus according to claim 2, wherein

the danger derivation section derives the danger degree such that when the non-grip hand existence duration relative to the low danger position, where the non-grip hand exists, is shorter than a predetermined value, the danger degree has a minimum value.

4. The driving assistance apparatus according to claim 1, wherein

the danger derivation section derives the danger degree such that when the non-grip hand exists in the high danger position, the danger degree comes to have a greater value as a non-grip hand existence duration, for which the non-grip hand continues to exist in the high danger position, becomes longer.

5. The driving assistance apparatus according to claim 1, wherein

the danger derivation section derives the danger degree such that when the non-grip hand exists in the high danger position, the danger degree comes to have a greater value as the high danger position is farther away from the driver'"'"'s seat.

6. The driving assistance apparatus according to claim 1, wherein:

the high danger position is a position, where a target object manipulated by the non-grip hand exists; and

the danger derivation section derives the danger degree such that when the non-grip hand exists in the high danger position, the danger degree comes to have a greater value as a duration, for which the non-grip hand manipulates the target object in the high danger position and then grips the steering wheel, is estimated to become longer.

7. The driving assistance apparatus according to claim 1, wherein:

the high danger position is a position where a target object manipulated by the non-grip hand exists; and

the danger derivation section derives the danger degree such that when the non-grip hand exists in the high danger position, the danger degree comes to have a greater value as a duration, for which the driver moves a sight line away from a heading direction of the vehicle when manipulating the target object in the high danger position, is estimated to become longer.

8. The driving assistance apparatus according to claim 1, wherein

the position specification section

determines whether a position where the non-grip hand exists is the low danger position, and

defines a high danger position, which is within the positions classified in the compartment and is determined not to be the low danger position.

9. The driving assistance apparatus according to claim 1, wherein

The danger derivation section defines as the low danger position, at least one of (i) an armrest provided in the vehicle, (ii) a window frame in the vehicle, and (iii) a driver'"'"'s upper thigh.

10. The driving assistance apparatus according to claim 1, wherein

the warning section prohibits an output of a warning when the danger degree derived by the danger derivation section is equal to or less than a predetermined value.

11. The driving assistance apparatus according to claim 1, wherein

the stipulated travel state includes a travel state where the hand-free state during driving of the vehicle is evitable.

12. A program product, stored in a non-transitory computer readable storage medium, comprising instructions for execution by a computer, the instructions including a computer-implemented method in a driving assistance apparatus for a vehicle for deriving a danger degree to warn against driving manipulation of the vehicle, the driving assistance apparatus including:

a grip state detection section configured to detect a grip state of a steering wheel in a compartment of the vehicle; and

an image acquisition section configured to acquire a captured image of the compartment that covers a possible action range of a person who is seated in a driver'"'"'s seat,

the instructions for implementing the steps of;

specifying, based on a captured image acquired by the image acquisition section, a position where a non-grip hand exists, the non-grip hand being a hand that is separate from the steering wheel, on condition that (i) the grip state of the steering wheel is in a hand-free state, in which at least either of two hands is separate from the steering wheel as a result of detecting of the grip state detection section, and (ii) a travel state of the vehicle is within a stipulated travel state, which is predetermined;

deriving a danger degree such that the danger degree comes to have a greater value as a degree of a danger against driving of the vehicle becomes higher because the non-grip hand exists in the position specified; and

executing an output of a warning in a weaker state as the danger degree derived comes to have a smaller value, wherein

in the deriving step,

a plurality of positions are classified in the compartment in the vehicle based on danger degrees, and

a low danger position is defined previously within the classified positions, wherein the danger degree has a value smaller than a reference value when the non-grip hand exists in the low danger position; and

in the deriving step,

the danger degree is derived such that when the non-grip hand exists in the low danger position, the danger degree has a smaller value as compared with a case that the non-grip hand exists in a high danger position, which is within the positions classified in the compartment and is other than the low danger position.