Iterative measurement for precise welding plane detection

This paper proposes the iterative measurement method for precise welding plane detection for automatic welding robots based on the principal component analysis (PCA). The robot has the laser scanner on its wrist and can detect many points on the plane by rotational motion of the wrist. By applying the PCA method to the detected points, the plane equation of the welding plane can be obtained. Since the plane is most accurately detected when the normal vector of the plane is parallel with the central axis of the laser scanner, the manipulator is iteratively controlled to align the central axis parallel with the normal vector. According to the iterative measurement process, the precise plane equation can be obtained. For verifying the proposed method, the experiments with the prototype of the rotational laser scanner are carried out.