Surroundings monitoring apparatus
A surroundings monitoring apparatus 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.
1. A surroundings monitoring apparatus comprising:
an onboard camera which is mounted on a vehicle and which obtains a heading direction image by photographing a region in a heading direction of said vehicle;
a controller which is implemented by at least one programmed processor and configured to:
obtain camera detected positions and reliability index values for camera detected objects that are objects contained in said heading direction image, said camera detected positions being relative positions of said camera detected objects in relation to said vehicle determined on the basis of positions of said camera detected objects in said heading direction image, said reliability index values representing reliabilities in obtaining said camera detected positions;
select, as a camera control target candidate, one of said camera detected objects which are likely to collide with said vehicle when said vehicle travels, in such a manner that, when there exists a single object which is the largest in camera required deceleration which is a magnitude of acceleration of said vehicle required for avoiding collision with said camera detected object and is calculated on the basis of said camera detected position, the object which is the largest in said camera required deceleration is selected as said camera control target candidate, and when there exist a plurality of objects which are the largest in said camera required deceleration, from among the plurality of objects which are the largest in said camera required deceleration, an object which is the highest in reliability represented by a reliability correlation value determined in accordance with said reliability index value is selected as said camera control target candidate;
specify said camera control target candidate as a control target object; and
execute a collision avoidance control for decreasing the magnitude of travel speed of said vehicle so as to avoid collision with said control target object,
wherein the reliability index values are obtained per object such that the greater the degree of similarity between a template and a portion of the heading direction image, the greater the value to which the reliability index values are set.
2. The surroundings monitoring apparatus according to claim 1 , wherein
said controller obtains said reliability index value every time a predetermined time elapses, and obtains said reliability correlation value by smoothing a change in said reliability index value with time.
3. The surroundings monitoring apparatus according to claim 1 , wherein when a longitudinal distance which is a distance between said camera detected object and said vehicle in a longitudinal direction of said vehicle is less than a predetermined distance threshold, said controller sets said camera required deceleration for said camera detected object to a predetermined deceleration equal to or greater than the maximum value of said camera required deceleration calculated for said camera detected object when said longitudinal distance is greater than said distance threshold.
4. The surroundings monitoring apparatus according to claim 3 , further comprising:
an object detector includes a radar apparatus in which said transmission wave is a millimeter electromagnetic wave and a sonar apparatus in which said transmission wave is a millimeter acoustic wave;
a reception device, including a plurality of antennas, for receiving a reflection wave generated as a result of said transmission wave being reflected by an object; and wherein
said controller obtains detector detected positions and detector detection reliabilities for detector detected objects that are objects detected on the basis of said reflection wave, said detector detected positions being relative positions of said detector detected objects in relation to said vehicle, said detector detection reliabilities representing reliabilities in obtaining said detector detected positions;
said controller selects, as a detector control target candidate associated with the radar apparatus or the sonar apparatus, one of said detector detected objects which are likely to collide with said vehicle when said vehicle travels, in such a manner that, when there exists a single object which has the maximum reliability, said single object having the maximum reliability is selected as said detector control target candidate, and when there exist a plurality of objects which have the maximum reliability, from among the plurality of objects having the maximum reliability,
an object which is the largest in detector required deceleration which is the magnitude of acceleration of said vehicle required for avoiding collision with said detector detected object and is calculated on the basis of said detector detected position is selected as said detector control target candidate; and
said controller specifies, as said control target object, an object which is selected from among said camera control target candidate and said detector control target candidates and which is the largest in required deceleration to avoid the closest object among said camera required deceleration and said detector required decelerations for those objects.
5. The surroundings monitoring apparatus according to claim 4 , wherein
said controller selects, as said detector control target candidate associated with said radar apparatus, an object from among objects detected by said radar apparatus and selects, as said detector control target candidate associated with said sonar apparatus, an object from among objects detected by said sonar apparatus; and
said controller specifies, as said control target object, an object which is selected from among said camera control target candidate, said detector control target candidate associated with said radar apparatus, and said detector control target candidate associated with said sonar apparatus and which is the largest in required deceleration to avoid the closest object among said camera required deceleration and said detector required decelerations for those objects.
6. The surroundings monitoring apparatus according to claim 1 , further comprising:
an object detector includes a radar apparatus in which said transmission wave is a millimeter electromagnetic wave and a sonar apparatus in which said transmission wave is a millimeter acoustic wave;
a reception device, including a plurality of antennas, for receiving a reflection wave generated as a result of said transmission wave being reflected by an object; and wherein
said controller obtains detector detected positions and detector detection reliabilities for detector detected objects that are objects detected on the basis of said reflection wave, said detector detected positions being relative positions of said detector detected objects in relation to said vehicle, said detector detection reliabilities representing reliabilities in obtaining said detector detected positions;
said controller selects, as a candidate for a detector control target associated with the radar apparatus or the sonar apparatus, one of said detector detected objects which are likely to collide with said vehicle when said vehicle travels, in such a manner that, when there exists a single object which has the maximum reliability, said single object having the maximum reliability is selected as said detector control target candidate, and when there exist a plurality of objects which have the maximum reliability, from among the plurality of objects having the maximum reliability, an object which is the largest in detector required deceleration which is the magnitude of acceleration of said vehicle required for avoiding collision with said detector detected object and is calculated on the basis of said detector detected position is selected as said detector control target candidate; and,
said controller specifies, as said control target object, an object which is selected from among said camera control target candidate and said detector control target candidates and which is the largest in required deceleration to avoid the closest object among said camera required deceleration and said detector required decelerations for those objects,
wherein when the transmission wave is transmitted a plurality of times, the detector detection reliabilities are obtained per object such that the larger number of times of reception of the reflection wave from the object by the reception device, the greater the value to which the detector detection reliabilities are set.
7. The surroundings monitoring apparatus according to claim 6 , wherein
said controller selects, as said detector control target candidate associated with said radar apparatus, an object from among objects detected by said radar apparatus and selects, as said detector control target candidate associated with said sonar apparatus, an object from among objects detected by said sonar apparatus; and
said controller specifies, as said control target object, an object which is selected from among said camera control target candidate, said detector control target candidate associated with said radar apparatus, and said detector control target candidate associated with said sonar apparatus and which is the largest in required deceleration to avoid the closest object among said camera required deceleration and said detector required decelerations for those objects.