EP-3712806-B1 - DRIVING ASSISTANCE APPARATUS

Inventors

• IKUTA, TETSUYA
• Hoshikawa, Yuma

Dates

Publication Date

20260506

Application Date

20200228

Claims (1)

1. A driving assistance apparatus for monitoring a target object comprising: a sonar apparatus (33) configured to detect an object present in a travelling direction of a vehicle as a sonar detected object, to obtain a longitudinal position (Dsx(c)) and a lateral position (Dsy(c)) of said sonar detected object and to set a certainty value (Cv) of said obtained position of said sonar detected object to a value which becomes greater as the strength of a sonar reflected wave generated by reflection of a sonar transmission wave at the sonar detected object increases and which becomes greater as the time period during which the sonar detected object has been continuously detected is longer, said certainty value (Cv) representing the reliability of the obtained position of an object such that the higher the reliability of the position of an object is, the greater the certainty value (Cv) is; a camera (31) configured to detect an object present in said travelling direction as a camera detected object, to obtain a longitudinal position (Dcx(a)) and a lateral position (Dcy(a)) of said camera detected object and to determine an object type of said camera detected object; a radar apparatus (32) configured to detect an object present in said traveling direction as a radar detected object, to obtain a longitudinal position (Drx(b)) and a lateral position (Dry(b)) of said radar detected object; a PCS-ECU (21); and an ICS-ECU (22); wherein: said PCS-ECU (21) is configured to: determine that a candidate object, which is an object that is detected by said camera (31) as said camera detected object and is detected by said radar apparatus (32) as said radar detected object, is a specific object, if an object type of said candidate object is a pedestrian; and transmit, as specific object information to said ICS-ECU (22), information about said specific object, said information including an average longitudinal position (Dax) and an average lateral position (Day) of said specific object, wherein said average longitudinal position (Dax) is an average of said longitudinal position (Dcx(a)) and said longitudinal position (Drx(b)), and said average lateral position (Day) is an average of said lateral position (Dcy(a)) and said lateral position (Dry(b)); and said ICS-ECU (22) is configured to: when a magnitude of said lateral position (Dsy(c)) is less than a lateral distance threshold (Dyth) and said longitudinal position (Dsx(c)) is less than a longitudinal distance threshold Dxth, and when said certainty value (Cv) of said sonar detected object is higher than a predetermined first certainty threshold (Cth1), determine said sonar detected object is a control target object; when said magnitude of said lateral position (Dsy(c)) is less than said lateral distance threshold (Dyth) and said longitudinal position (Dsx(c)) is less than said longitudinal distance threshold Dxth, and when said certainty value (Cv) of said sonar detected object is lower than said predetermined first certainty threshold (Cth1) and is higher than a predetermined second certainty threshold (Cth2) smaller than said predetermined first certainty threshold (Cth1), and when it is determined that said sonar detected object is the same object as said specific object based on a magnitude of a difference (Dsx(c) - Dax) between said longitudinal position (Dsx(c)) and said average longitudinal position (Dax) being smaller than a separation distance threshold (Dsth) and a magnitude of a difference (Dsy(c) - Day) between said lateral position (Dsy(c)) and said average lateral position (Day) being smaller than said separation distance threshold (Dsth), determine said sonar detected object is a control target object; and when it is determined that said sonar detected object is a control target object, execute collision avoidance control in order to avoid a collision between said control target object and said vehicle.

Description

TECHNICAL FIELD The present disclosure relates to a driving assistance (support) apparatus configured to execute collision avoidance control, when an object present in a travelling direction of a vehicle is detected, in order to avoid a collision between the vehicle and the object. BACKGROUND One conventionally known driving assistance apparatus of such a kind which is applied to a vehicle (hereinafter also referred to as the "conventional apparatus") is equipped with an ultrasonic sonar apparatus as an object detection apparatus. In addition, the conventional apparatus executes the collision avoidance control (specifically, control for generating an alert) when an object in the travelling direction of the vehicle is detected by the ultrasonic sonar apparatus. Furthermore, the conventional apparatus estimates the travelling direction of the vehicle by using a navigation device and enhances detection sensitivity of the ultrasonic sonar apparatus to detect an object which is present in the estimated travelling direction (see, for example, Japanese Patent Application Laid-Open (kokai) No. 2015-121960). US 2019/023267 A1 describes a surroundings monitoring apparatus that obtains the position of an object from a captured image of a region in a heading direction of a vehicle, and obtains a position obtainment accuracy. When the distance between the object and the vehicle becomes relatively short, the position obtainment accuracy increases. However, the distance between the object and the vehicle becomes shorter, the position obtainment accuracy may decrease. Therefore, if collision avoidance control is performed for an object selected on the basis of the position obtainment accuracy, there is a possibility that the collision avoidance control is not performed for an object which is most likely to collide with the vehicle. In view of this, the apparatus obtains, for each object, a required deceleration which is the magnitude of acceleration necessary for stoppage at a position before the object, and performs the collision avoidance control for an object which is the largest in the required deceleration. SUMMARY Incidentally, reliability of the position with respect to a vehicle obtained by an object detection apparatus such as an ultrasonic sonar apparatus may vary depending on a type of object in some cases. Hereinafter, a value indicative of the above-described reliability will be referred to as a "detection certainty value," or a "certainty value" for simplification. For example, as for the ultrasonic sonar apparatus, the certainty value concerning a wall of a building detected as an object is generally higher than the certainty value concerning a pedestrian detected as another object. The reason for this is as follows. The ultrasonic sonar apparatus transmits a wave. The transmitted wave are reflected by an object to be a reflection wave. The ultrasonic sonar apparatus receives the reflection wave to detect the object. The strength of the reflection wave from the wall is higher than that of the reflection wave from the pedestrian. Hereinafter, an object which tends to provide the certainty value which is relatively large will be referred to as a "high certainty object," and an object which tends to provide the certainty value which is relatively small will be referred to as a "low certainty object." In addition, an object which needs to be monitored in order to determine whether or not it is necessary to execute the collision avoidance control for that object also referred to as a "monitoring target object." If the driving assistance apparatus treats (regards) the low certainty object, as well as the high certainty object, as the monitoring target object, there is a relatively high possibility that the collision avoidance control is erroneously executed for an object which is not present in the travelling direction of the vehicle in actuality. Namely, there is the possibility that unnecessary collision avoidance control (hereinafter also referred to as "unnecessary control") is executed in this case. Meanwhile, if the driving assistance apparatus treats only the high certainty object as the monitoring target object, there is another relatively high possibility that the collision avoidance control is not executed for an object (in this case, the low certainty object) which is actually present in the travelling direction of the vehicle. However, in the conventional apparatus, it is not considered to appropriately extract the monitoring target object on the basis of the detection certainty value. In view of the forgoing, one object of the present disclosure is to provide a driving assistance apparatus configured to be able to execute the collision avoidance control for not only the high certainty object but also the low certainty object while avoiding occurrence of the unnecessary control. According to the present invention, there is provided a driving assistance apparatus as defined in appended claim 1. Therefor