Non-cooperative target extraction in complex industrial environment based on image segmentation

In complex industrial scenes, it is difficult to acquire high-precision non-cooperative target pose under monocular visual servo control. This paper presents a new method of target extraction and high-precision edge fitting for the wheel of the sintering trolley in steel production, which fuses multiple target extraction algorithms adapting to the working environment of the target. Firstly, based on obvious difference between the pixels of the target image and the non-target image in the gray histogram, these pixels were classified and then segmented in intraclass, removing interference factors and remaining the target image. Then, multiple segmentation results were merged and a final target image was obtained after small connected regions were eliminated. In the edge fitting stage, the edge fitting method with best-circumscribed rectangle was proposed to accurately fit the circular target edge. Finally, PnP algorithm was adopted for pose measurement of the target. The experimental results showed that the average estimation error of pose angle <italic>γ</italic> with respect to the <italic>z</italic>-axis rotation was 0.234 6°, the average measurement error of pose angle α with respect to the <italic>x</italic>-axis rotation was 0.170 3°, and the average measurement error of pose angle <italic>β</italic> with respect to the <italic>y</italic>-axis rotation was 0.227 5°. The proposed method has practical application value.