AI train scanning camera

The camera films the passing train from the side and builds a continuous strip image of it, while a neural network reads the railcar numbers. The recognised number is tied automatically to the weighing record in the database — the operator only has to confirm the result.

Our own team develops it: the strip-imaging algorithm, the train speed estimation and the number recognition are our own code, not a bought-in module.

Slit-scan imagingNumber recognitionArchive > 10 years
Neural network reading a railcar number with confidence scores
How it works

Slit-scan imaging of the train

The camera stays still. One thin vertical strip is taken from the centre of every frame; the strips are glued together into a long panorama of the whole train, as if a scanner had been run along it.

01

Frame by frame

The video is read frame by frame.

02

Train speed

Our own algorithm determines the speed of the train.

03

Strip width

Fractional shift accumulates into whole pixels: the faster the train moves, the wider the strip; at a standstill no strip is taken, so the panorama is not stretched.

04

Stitching and log

The strips accumulate and are stitched into a single image, while a speed log is written for later analysis of the pass.

Video

Filming and building the panorama on a real site

The camera films the passing locomotive and railcars from the side — below is a recording of one pass from one of our sites.

Example scan

A real train scan

This is what one finished pass looks like: drag the scrollbar under the image to pan through the whole train.

Panorama of a passing train captured by the scanning camera
Drag to see the whole train

A real frame from one of our sites — the locomotive and the railcars of the train as one continuous strip.

Recognition

The railcar number is read automatically

The optical reading module finds the digits of the number on the car body or frame and scores the confidence for every character. If the number cannot be read (dirt, stickers, a non-standard font), the operator enters or corrects it by hand and the link to the weighing is kept.

Number digit detection with confidence scores
Video log frame of a railcar on the scales
Camera of the video logging system
System composition

What the kit includes

  • Cameras: a set of 4 to read numbers from both sides of a railcar
  • Optics: at short distances to the car (1.5–2.5 m) panoramic cameras are used
  • Brackets: 4 pcs; the mounting points are set by the design
  • Power and networking: a PoE switch and a line to the outdoor cabinet
  • Outdoor telecom cabinet: UPS, network equipment, camera power supply, weight terminal
  • Indoor telecom cabinet: UPS, a video recorder with a disk — at least 30 days of video archive from 4 cameras
  • Operator workstation: the video module and the optical number reading module
  • Integration: the number is tied to the weighing record and passed to the customer process control system
The camera type and the mounting points are agreed in the design: the distance from the lens to the railcar on the particular site determines the choice of optics and image sensor.

How the whole hardware-and-software system works →