A 3D-compensating Algorithm for LNG Shipbuilding Profiles Robot Cutting System

The LNG shipbuilding profiles’ deformation leads to lots of challenges for hi-precision shipbuilding, in order to achieve hi-precision manufacturing for deformed LNG shipbuilding profiles, a 3D-compensating algorithm for shipbuilding profile deformation is developed based on the profile deformation happening principles. The spatial coordinates on edge curve of the profile are measured and collected by a moving 2D laser sensor. Basing on the collected profile edge coordinates, an formula of polynomial curve is defined and fitted by the method of least squares, which takes accumulated chord length as parameters. Giving coordinates on a standard profile, the target coordinates on deformed profile can be calculated, eventually the deformation of the profile is compensated and the hi-precision manufacturing for deformed shipbuilding profile is fulfilled. Furthermore, the compensation algorithm has been implemented with VC++ and MATLAB mixed programming technology, which has been used in a robot flexible cutting system for serial production a famous shipbuilding company. The results show the 3D-deformation of shipbuilding profiles get compensated as expected, it also verified the algorithm is effective and efficient. Keywords-LNG ship; compensation algorithm; profiles cutting; laser measurement; MATLAB