Development of Rail Trajectory Measurement Device for Inspection of Crane Rail

In factories, an overhead crane is ordinarily used to convey heavy loads amounting to dozens of tons. However, the rails of the overhead crane face the risk of being deformed and cracking under heavy loads, and they are a cause of serious accidents. In this paper, a new inspection device is proposed to prevent such serious accidents; the device is called Trajectory Measurement Device (TMD) which can measure the trajectories of crane rail automatically; so far, workers have measured trajectories manually. In the proposed system, the TMD runs along the trajectory path of a crane-rail from one end, and the laser beam of a laser range sensor irradiates the target plate fixed on the TMD from the other end. Then, images of the target plate are captured with a camera, and the rail trajectory can be estimated by tracing the laser point on the target plate via image processing. In a field experiment, the TMD is actually used to measure the trajectory path of a crane rail in a factory, and its measurement accuracy and effectiveness are evaluated.