Application Study On Contouring Manufacture Of Freeform Surface By Serial Milling Robot

Taking the freeform surface's same-thick processing of carrier rocket's cryogenic tank as application background, this paper studies for the manufacturing of freeform surface with large size and complex structure. Based on serial robot's advantages of multi-freedom, large-workspace and flexible-movement, the special serial robot for milling is studied, which also takes robot theory into application. It has great theoretical and practical significance for the promotion of domestic robot industry, the expanding of robot applications and the improvement of the aerospace manufacturing technology.This paper's studies are as follows:First, according to the requirement of large-workspace and high-dexterity, the robot configuration design is finished. According to the DOF required for the manufacture, the joints' configuration is designed based on graphics. Taking account of the characteristics and the environment of the workpiece, two mechanisms are identified based on workspace character and capability of obstacle-avoidance.Second, the kinematics, workspace, singularity and dexterity of the two robots are analyzed. The D-H method is used to solve the kinematics; the Monte-Carlo method and MATLAB programming are used to draw the workspace in views of two-dimension and then three-dimension; the screw theory is used to analyze the singularity; and then the two robots' dexterity are contrasted by solving the condition numbers of them in many random positions. After these analyses, the final robot is chosen.According to processing efficiency and capability of obstacle-avoidance, the trajectory design of continuous path is calculated. For the examples of curved track and line track, series of differential points are obtained by programming, and then the inverse kinematics of these points are calculated. Based on these results, robot models are built, finally, the simulation and animation of the processing are obtained.This paper finishes the configuration design of the milling robot. The calculation and drawing go along with MATLAB programming, the programs are also systemic, which is fundamental for the milling robot's practical application and further study.