A Parallel Kinematic Concept Targeting at More Accurate Assembly of Aircraft Sections

This article is concerned with the kinematics for flexible and precise assembly systems for big and heavy parts, e.g. parts of plane fuselages or wings. The hypothesis of this article is that the common 3-PPPS Tripod (which is a current industrial solution to the problem) may be replaced by a 6-SPS parallel kinematic. In difference to many other parallel kinematic machines, the part which has to be assembled is used itself as the end effector platform in this concept. On the part and on the floor, there is a generic grid of fixation points, which gives the possibility for (re)configuration and adaption to suit particular requirements. This article compares the transmission of drive errors in order to evaluate the transmission of alignment increments. This criterion is used for an optimization that searches for a kinematic configuration that outperforms the Tripod systems. It is shown that there is a considerable number of configurations which are superior to the Tripod system. Based on these insights, it is concluded that there is potential for the improvement of current systems through multi-objective optimization.