In this embodiment, the speed of the vehicle is measured, the line frequency for image capturing is determined according to the speed of the vehicle, and images of the chassis of the vehicle are captured at the determined line frequency. In this way, the line frequency of the line scan camera matches with the speed of the vehicle, which eliminates the deformation of images of the vehicle captured by the line scan camera that would be otherwise occurs due to stretch or compression, and thereby improves utility of the images.

FIG. 3 is a schematic structural diagram of a system for acquiring an image of a chassis of a vehicle provided by the second embodiment of the present application. Referring to FIG. 3, the structure of this embodiment is substantially the same as that of the first embodiment, except that in this embodiment the system for acquiring an image of a chassis of a vehicle further includes: a light filling module 15 configured to provide supplementary light for the chassis of the vehicle under the control of the control module 13 to provide sufficient illumination for performing image capturing by the line scan camera 14. For example, the light filling module 15 may fill light for the chassis of the vehicle when the control module 13 controls the line scan camera 14 to perform image capturing on the chassis of the vehicle.

A fill light is mounted in the light filling module 15. The fill light can be manufactured by a high-power LED light source, which makes the fill light have the advantages of small volume, high output power, high luminous efficiency and long service life. In order to ensure electrical safety, the fill light is powered by DC below 50V.