Aerobotix (ABX) worked to develop an automated polishing solution for fighter jet transparency canopies and windshields.
The canopy and windshield sections for the F-35 are constructed by molding a complex shape from a flat sheet of stretched acrylic. The process of forming the canopies creates mark-off and orange peel that cause optical distortions which must be removed before the canopy can be installed on the fighter jet. Removal of the distortion is vital for the pilot to have a clear line of sight.
These labor-intensive processes were initially performed by hand with orbital polishers or polishing blocks. This required 50 or more labor hours per part and put a significant ergonomic strain on operators.
SCRA and GKN tasked ABX with automating this process by replicating the manual procedure with the added repeatability the robot provides. Development began at their robotic polishing laboratory. Through numerous trials and evaluations, ABX was able to narrow down the required force, speed, water, and rouge application to deliver a quality canopy.
ABX utilized a FANUC force sensor to actively adjust the robotic path motion. This kept the force consistent throughout the polishing path and the polishing head normal to the surface. It also allowed the robot to mirror the manual polishing process performed by an operator, with significant improvements. Automating the process prevents the human errors of polishing too much or too forcefully in some areas, which can lead to more optical distortions, and includes a higher control of repeatability. ABX also automated the rouge dispensing to be used in the process.
The polishing cell, coupled with the Automated Paper Changer, gave the customer a completely “lights out” robot solution. This allows canopies to be finished in a 24-hour continuous cycle instead of the 50 manhours throughout the week. The automation of this process will be able to increase throughput for transparency canopies by allowing the robot to run continuously over three shifts. It will also reduce the number of repetitive motion injuries by preventing long hours of manual polishing, as only significant optical defects will require operator intervention.
Automation was able to reduce the process time to about one third of the original time, with required labor being reduced by more than 80%. Keeping these numbers in mind, the estimated cost savings could surpass $150 million over the life of the program.