Linear CCD based novel visual sensor for intelligent spherical tank welding robot

In order to fulfill autonomous climbing and automatic weld seam tracking, a novel visual sensor has been developed for intelligent spherical tank welding robot. Composed of a high-resolution linear CCD, an optical system (including light source, filter, lenses and so on), and an all hardware photoelectrical signal processing circuit, the designed visual sensor could avoid the interference of the arc light during welding and provide the seam track signal precisely in real time. In this paper, the construction and working principle of the linear CCD based visual sensor have been illustrated, then principle of weld seam track detecting has been introduced thoroughly. Equipped with the visual sensor, the spherical tank welding robot could move along the weld seam autonomously, could align the welding torch with weld seam automatically. Therefore, the requirements of multi-layer, multi-pass welding process for spherical tank manufacturing have been met.