Fractional Order Visual Servo Control for Fillet Seam Tracking

During the welding manufacturing of a container, the fillet seam's position relative to welding torch varies dramatically due to the seam change or movement. Thus decoupling visual model and fractional order PIλDμcontroller are designed to solve the problem of distortion in the welding process of the fillet weld. Firstly, a visual system with laser structured light is developed to measure the deviation between the torch and welding seam in horizontal and vertical directions. Secondly, the intersection point coordinates of two laser stripes are selected as the image characteristics of initial welding point of the fillet weld and the tracking control. Then, a decoupling visual detection model is presented to gain approximately uncoupled relationship between the image feature and the movement of adjustment mechanism. Furthermore, the fractional-order PIλDμcontroller is designed so that the adjustment range and the control ability is better than the traditional PID controller.