As an optional embodiment, the fill light in the light filling module 15 may be an infrared fill light to provide supplement light on the chassis of the vehicle at night.
As an optional embodiment, the image capturing module of the speed measuring module 12 may include an infrared light filter to filter out visible light and reduce interference of invalid light.
As an optional implementation, the light filling module 15 is arranged on a side of the line scan camera 14 and in the line scan direction of the line scan camera 14. Thus, the illumination range of the supplement light emitted by the light filling module 15 consistent with the image capturing range of the line scan camera 14, so that the line scan camera 14 can capture a clear image. The line scan direction of the line scan camera 14 refers to the direction along which a plurality of pixels in one row are arranged. For example, the line scan camera 14 has a row of 100 pixels, and the line scan direction of the line scan camera is the direction in which the 100 pixels are arranged.
The light filling module 15 may be single or plural in number, and the number of which depends on actual needs.