Image-based visual seam tracking system for fillet joint

In this paper a compact vision-based seam tracking system is designed for fillet joint. The main consideration in developing this system is its applicability and reliability. Thus programmable logical controller (PLC) is used as the controller and smart camera as the vision sensor. To get reliable image features, laser structured light is used. Besides its hardware structure, the image processing and control algorithm are designed elaboratively. The intercepts of the two lines in the stripe image are selected as the image features to get an approximately uncoupled relationship between the change of image features and the movement of two axes in two directions. New edge detector with fine noise reduction and robust line extraction method are proposed. In addition, the controller is carefully constructed with input filtering and output verification. Finally, a series of experiments were well conducted to verify the performance of the proposed system.