Non-Contact Measurement Algorithm of Load Swing Angle for Bridge Crane Based on Contour Detection

The traditional measurement method of the load swing angle for the bridge crane is easily disturbed by the environmental noise, which leads to inaccurate measurement and delayed feedback. In this paper, the computer vision method is used to realize the non-contact measurement of the load swing angle. A rectangular light source is used as a marker and it is detected using an industrial camera. In order to improve the accuracy and real-time performance of the detection, the method of color separation combined with rectangular contour detection is used to quickly identify the marker. Then the swing angle is calculated according to the recognition results by using the camera geometry. It has been demonstrated by experiments that, the algorithm can quickly identify the marker and can accurately calculate the swing angle. In particular, the proposed method has strong independence and anti-interference ability, which is very suitable for bridge crane system.