Semi-offline trajectory synchronized algorithm of the cooperative automated fiber placement system

This paper presents an innovative semi-offline trajectory synchronized algorithm for a cooperative AFP (Automated Fiber Placement) system which consists of a 6 degree-of-freedom (DOF) robot, a 6-RSS (Revolute-spherical-spherical) parallel robot, a spindle mounted on the platform to hold the mandrel. The cooperative AFP system is capable of manufacturing more complex composite components which pose high demand for trajectory planning than those by the current APF systems. However, for the cooperative AFP system, there might not be a feasible path for laying up the fiber due to the requirement of free from collisions and singularities in some cases. The semi-offline trajectory synchronized algorithm proposed in this paper can free the planned trajectory from strictly subjecting to the constraints and singularities by adding correction to pre-planned path online. Thus, the fiber can be laid up continuously without interruption. The correction is calculated based on the poses of the multi-robots detected by the photogrammetry sensor. When and how the offsets should be added to the parallel robot under the different circumstances are discussed in this paper. Experimental results demonstrate the successful avoidance of singularities and joint limits during manufacturing process.