A safe and efficient path planning framework for conformal fused filament fabrication using a manipulator arm

Abstract

As opposed to flat or planar extrusion additive manufacturing, the benefits of multi-plane and curved fused deposition of material are conclusive; however, several issues need to be considered and solved when a robotic manipulator is used for the deposition of material. The path and motion planning for printing using robotics need considerations to guarantee adequate results. This work presents the projection of a printing trajectory on a tessellated surface and a Reinforcement Learning strategy that optimizes the angular displacement of joints. The validation of the strategy is presented under simulated conditions inserting different obstacles for a projected zigzag printing pattern on a curved surface. Results show that this approach can choose the optimal inverse kinematic solution to optimize the movement of the main joints of a robot with six degrees of freedom while avoiding different obstacles. The strategy was tested on several actual printings of complex patterns on different curved surfaces using a manipulator arm UR3. Even thought the applicability of lattice manufacturing suggested here, the framework developed and software implemented and validated may be used for any application where a very precise conformal trajectory needs to be followed using a manipulator arm or any multi-axis system saving programming time.