This is an interesting video from NASA showing the manufacture of what appear to be different composite spacecraft parts including a fuel tank.
The center piece here is an articulated robot mounted on a “seventh” linear axis with a automated fiber placement end effector. The end effector heats the area and applies strips of resin impregnated composite “tape.” The whole process requires a high level of motion control especially with a rotating work piece.
I’m not an expert on the process but it’s easy to have an appreciation for the new manufacturing processes required by high performance composites.
The pair of blue “post” style machines in the beginning of the video appear to be testing for voids in the finished part.