CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2020-110607 filed on Jun. 26, 2020, the disclosure of which is incorporated by reference herein.

BACKGROUND

Technical Field

The present disclosure relates to a vehicle periphery monitoring device, a vehicle periphery monitoring method, and a non-transitory storage medium.

Related Art

A video processing system that detects dirt or scratches or the like on a lens by comparing characteristic quantities of images in the same image acquisition range that have been acquired by a plurality of cameras is disclosed, for example, in Japanese Patent Application Publication Laid-Open (JP-A) No. 2019-102929. More specifically, this video processing system divides an image acquisition range of respective images acquired by a plurality of cameras into areas, and calculates the quantity of cumulative edges in each area. If the difference in the respective quantities of cumulative edges is greater than a predetermined threshold value, then it is determined that a foreign object is adhering to a lens.

However, in the video processing system disclosed in JP-A No. 2019-102929, because it is not possible to detect any misalignment of the camera mounting positions, if a composite image is displayed on a display unit inside a vehicle cabin, there is a possibility that incorrect composite images containing positionally misaligned images will be displayed.

SUMMARY

The present disclosure provides a vehicle periphery monitoring device that, in a structure that displays composite images, inhibits composite images that are incorrect because of camera misalignment from being displayed.

A vehicle periphery monitoring device of a first aspect has a rear image acquisition unit that acquires rear images including a first image of a vehicle rear side acquired by a rear camera, a second image of a vehicle rear right-side acquired by a rear right-side camera, and a third image of a vehicle rear left-side acquired by a rear left-side camera, a target position acquisition unit that acquires from a plurality of sensors including the rear camera, the rear right-side camera and the rear left-side camera relative positions of a target present in areas including the vehicle rear side, the vehicle rear right-side, and the vehicle rear left-side relative to its own host vehicle, a target position determination unit that determines whether or not the relative positions of the target acquired by the target position acquisition unit are mutually consistent with each other in the plurality of sensors, and a display processing unit that, in a case in which it is determined by the target position determination unit that the relative positions of the target are mutually consistent with each other, displays a single composite image that is created by combining the first image, the second image, and the third image at a display unit provided in a vehicle cabin, and that, in a case in which it is determined by the target position determination unit that the relative positions of the target are not mutually consistent with each other, displays the first image, the second image, and the third image individually and adjacently to each other on the display unit.

In the vehicle periphery monitoring device according to the first aspect, a rear image acquisition unit acquires a rear image that includes a first image of a vehicle rear side, a second image of a vehicle rear right-side, and a third image of a vehicle rear left-side. Here, the first image is an image acquired by a rear camera. Moreover, the second image is an image acquired by a rear right-side camera, and the third image is an image acquired by a rear left-side camera.

The target position acquisition unit acquires from a plurality of sensors including the rear camera, the rear right-side camera and the rear left-side camera relative positions, relative to its own host vehicle, of a target present in areas including the vehicle rear side, the vehicle rear right-side, and the vehicle rear left-side. In addition, a target position determination unit determines whether or not the relative positions of the target, relative to its own host vehicle, acquired by the target position acquisition unit are mutually consistent with each other in the plurality of sensors. Furthermore, a display processing unit displays the first image, the second image, and the third image on a display unit provided in a vehicle cabin.

Here, in a case in which it is determined by the target position determination unit that the relative positions of the target, relative to its own host vehicle, are mutually consistent in the plurality of sensors, the display processing unit displays at the display unit a single composite image that is created by combining the first image, the second image, and the third image. As a result, a vehicle occupant is able to easily recognize the position of a target traveling at the rear of their own vehicle.

On the other hand, in a case in which it is determined by the target position determination unit that the relative positions of the target, relative to its own host vehicle, are not mutually consistent in the plurality of sensors, the display processing unit displays the first image, the second image, and the third image individually and adjacently to each other on the display unit. In this way, in a case in which the mounting position of any one of the rear camera, the rear right-side camera, or the rear left-side camera becomes out of alignment, by displaying the individual images on the display unit, a composite image containing positionally misaligned images does not get displayed on the display unit.

Note that the term ‘composite image’ referred to here is an image that is created by performing image processing on each of the first image, the second image, and the third image such that the first image, the second image, and the third image are combined together into a single seamless image.

A vehicle periphery monitoring device of a second aspect is characterized in that, in the first aspect, the target position acquisition unit acquires the relative positions of the target from three or more sensors including the rear camera, the rear right-side camera and the rear left-side camera.

In the vehicle periphery monitoring device of the second aspect, by acquiring the relative positions of the target relative to a host vehicle from three or more sensors, the detection accuracy when detecting the relative positions of the target can be improved compared to a structure in which the relative positions of the target relative to a host vehicle are acquired from two or fewer sensors.

A vehicle periphery monitoring device of a third aspect is characterized in that, in the second aspect, there is further provided an enhanced display unit that provides an enhanced display of a target approaching the host vehicle in an image displayed on the display unit.

In the vehicle periphery monitoring device of the third aspect, by providing an enhanced display of a target approaching their vehicle, it is possible to draw the attention of a vehicle occupant to the target.

A vehicle periphery monitoring device of a fourth aspect is characterized in that, in the third aspect, in a case in which only the relative position of the target detected by just one sensor among the three or more sensors is not consistent in the target information determination unit, the enhanced display unit provides an enhanced display on the display unit based on a relative positions of the target acquired from the remaining sensors after the information from the one sensor has been excluded.

In the vehicle periphery monitoring device of the fourth aspect, by providing an enhanced display based on a relative positions of the target acquired from the remaining sensors, it is possible to provide an enhanced display at the correct position of the target. In other words, because there is a possibility that the mounting position of a sensor having a relative position of the target that is not consistent with those of the other sensors has become misaligned, it is possible to inhibit an enhanced display being provided at an incorrect position due to information from the misaligned sensor being included.

A vehicle periphery monitoring device of a fifth aspect is characterized in that, in the third aspect, in a case in which the relative positions of the target detected by all of the sensors among the three or more sensors are all c in the target position determination unit, the enhanced display unit provides an enhanced display based on the relative position of the target acquired from the sensor having a relative position of the target that is detected as being closest to the host vehicle.

In the vehicle periphery monitoring device of the fifth aspect, by providing an enhanced display based on the relative position of the target acquired from the sensor having a detected relative position of the target that is the closest to the host vehicle, information having a high degree of urgency can be conveyed to a vehicle occupant.

A vehicle periphery monitoring device of a sixth aspect is characterized in that, in the fourth aspect, in a case in which only the relative position of the target detected by any one sensor among the rear camera, the rear right-side camera and the rear left-side camera is not consistent with the other relative positions in the target position determination unit, warning content is displayed on the display unit superimposed on the rear image acquired by the one sensor.

In the vehicle periphery monitoring device of the sixth aspect, by displaying warning content superimposed on the rear image acquired by the sensor having a mounting position has a possibility of being misaligned, it is possible to alert a vehicle occupant as to this possibility.

A vehicle periphery monitoring device of a seventh aspect is characterized in that, in the fifth aspect, in a case in which the relative positions of the target detected by the rear camera, the rear right-side camera and the rear left-side camera are all mutually different from each other in the target position determination unit, warning content is displayed superimposed on all of the images of the first image, the second image, and the third image which correspond to those sensors that have detected the target.

In the vehicle periphery monitoring device of the seventh aspect, because warning content is displayed superimposed on a plurality of images, it is possible to encourage a vehicle occupant to make a vehicle inspection or the like.

A vehicle periphery monitoring device of an eighth aspect is characterized in that, in any one of the first through seventh aspects, the target position acquisition unit acquires the relative positions of the target from the sensors that include radar units that are provided in corner portions of a vehicle body rear portion and detect obstacles at the rear of the vehicle.

In the vehicle periphery monitoring device of the eighth aspect, by detecting a relative position of a target using obstacle detection radar, there is no need to install dedicated sensors so that an increase in the number of components is inhibited.

As has been described above, according to the vehicle periphery monitoring device according to the present disclosure, it is possible, in a structure that displays composite images, to inhibit composite images that are incorrect because of camera misalignment from being displayed.

