A speed monitoring method in steel pipe of 3PE-coating process based on industrial Charge-coupled Device

In the process of three layer PE coating(3PE-coating), the speed of steel pipe is a key parameter in the control loop of main drive system, which has direct relationship with performance of control system as well as production quality and efficiency. However, due to forward displacement and rotation characteristic of steel pipe, the traditional contact speed measuring methods are no longer useful under this circumstance. Therefore, a speed monitoring method based on industrial Charge-coupled Device (CCD) is proposed, including image acquisition processing, image calibration, image edge detection and speed calculation. Meanwhile, by industrial application, this algorithm proves to be valid, and the result shows that the speed measuring system in steel pipe of 3PE-coating, not only can detect the speed rapidly and accurately, also have robustness within the influence of the electric magnetic disturbance, dust and high frequency noise in the industrial fields.

1. Introduction

As one of the most advanced pipeline coating technology, 3PE-coating has become the development direction of pipeline coating layer [1], [2]. In 3PE-coating process, the speed of steel pipe can directly affect product output, efficiency and quality. Therefore, how to accurately measure its speed, and therefore conducting it into closed loop feedback controller, draws more and more attention.