The Swivel Arms have several sensors and actuators and are controled directly by the PCL.

On the lower right corner of the picture a section of the rotation axis is visible.

One of the vertical cilinders is visible in the left of the picture. Each cilinder has a suction cup (in the bottom of the cilinder), a vacuum device (the small gray box on the horizontal section of the arm) and pression sensor (on the top of the cilinder).

In this picture it can also be seen the air suply to the cilinder, and the wires to the cilinder position sensors.