On-line Detection of Car-Body Running Attitude for Railway Vehicle Based on Photogrammetry

The running attitude of car-body relative to the track will change because of various vibrations during railway vehicle operation. In this paper, a photogrammetric method based on area array camera and line laser is proposed to measure running attitude of car-body. Firstly, the system is installed at any position of the car-body as long as being able to scan the track and all three positions are non-collinear; the middle point of line laser projection on rail surface is selected as the reference point; and the calibration method is proposed to build the space coordinate transformation of the reference point between image coordinate system and vehicle coordinate system. Secondly, the area array camera will shoot the projection of line laser on rail surface, and the coordinate of the reference point in image coordinate system will be converted into the coordinate in vehicle coordinate system during operation. Then, the mathematical model is established to obtain the running attitude of car-body through coordinates transformation of three reference points in the vehicle coordinate system. Finally, the detection system is built and experiments were carried out both on the car-body vibration simulation platform and the real vehicle. The comparative results verify the reliability of measurement system.