To support the operation of a mobile object.

Photographing parts 1 which are loaded on the right and left of the moving direction of the mobile object and photograph the front side of the moving direction at a prescribed time interval, storage parts 3 storing photographed pictures, a differential detection part 4(1) which coordinate-divides and compares the picture photographed by a right photographing part 1(#a) and the picture photographed by a left photographing part 1(#b) and extracts the same object to be photographed, which is photographed in the different coordinates in both pictures, a first moving direction judgment part 7(#a) which compares the picture photographed by the right photographing part 1(#a) with the picture which is stored just before and judges the moving direction of the object to be photographed, which is extracted by the differential detection part 4(1), a second moving direction judgment part 7(#b) which compares the picture photographed by the left photographing part 1(#b) with the picture stored just before and judge the moving direction of the object to be photographed, which is extracted by the differential detection part 4(1), and a collision judgment part 8 judging whether the mobile object collides with the object to be photographed or not based on the moving direction of the object to be photographed, which is judged by the moving direction judgments part 7, are provided.