While the vehicle is passing over the system for acquiring an image of a chassis of a vehicle, the speed measuring module 12 continuously measures the speed of the vehicle. When the speed of the vehicle changes, the speed measuring module 12 measures new speed information. The control module 13 determines new line frequency according to the new speed information, and changes the line frequency of the line scan camera 14 to the new line frequency, such that the image capturing rate matches with the speed of the vehicle, thereby eliminating the image distortion. This process repeats from the start.

When detecting that the vehicle has left the detection area, the second detecting module 17 sends an outgoing signal. In response to the outgoing signal, the speed measuring module 12 stops the speed measurement, the fill light in the light filling module 15 turns off, the line scan camera 14 stops image capturing, and the whole system switches to an inactive state once again.

The embodiment of the system may also be integrated with a license plate recognition module for identifying the license plate of the vehicle.

For convenience of explanation, in this embodiment, a vehicle is taken as the object for example for description.

FIG. 5 is a schematic flowchart of a method for controlling image capturing provided by the third embodiment of the present application. As shown in FIG. 5, this embodiment of the method may include the following operations.

Step 101: measuring the speed of an incoming vehicle.

At step 101, the speed of the vehicle is measured.