Dave Aebischer is a senior data analyst for Cintel. Throughout his career, Dave has focused on improving Army weapon system sustainment outcomes and developing new diagnostic technologies for combat equipment applications. He has introduced innovative technologies and techniques for meeting the challenges of sustaining complex weapon systems in combat environments.
Dave recently spoke with Thomas Wilk, editor in chief of Plant Services, about a project he and his team worked on to support the PATRIOT missile defense system program. In part 2 of their conversation, Dave explains how he used a new condition monitoring tool, motion amplification, to further improve the reliability of the tactical power generators by identifying additional defects that other monitoring methods would have missed.
Below is the transcript of the podcast:
PS: I’ve got two more questions for you today. The first one is about the quality assurance aspect. If I understood your presentation correctly, once you implement the fix, you were also using motion amplification technology as a quality assurance tool to ensure the fix was effective, right?
DA: Exactly, and this was a this was a game changer. It’s kind of strange how we came to motion amplification, but sometime after we had arrived at the EMA/ODS conclusion, the treatment, our reputation at Cintel is to take on very complex DoD problems and weapon systems, and we pride ourselves on having this broad tool set that we can apply to any problem.
I heard about motion amplification (MA) in the process when were putting together our tool set to do the original RCA. We didn't choose it at that time, but it was sort of in the back of our heads. And then my coworker and I got interested in learning more about this, so we could have another tool to apply that might just give us more clarity, more speed, more accuracy, more breadth to bring to problems. We had worked with RDI and the MA technology, and they came out and demoed and got us in a good place on it where we understood the technology, and then we kind of parked it, as we didn't have a project for it.
Now turn the clock up a couple years – now we're getting ready to field, now we're going back in to integrate the PAK with all these stock AMMPS generators that we have up at our Letterkenny Army Depot in Pennsylvania to start fielding the units. My boss came and said, “how do we know that this treatment that we did will work on the prototype? will work on the integrated sets? How do we know that will work? How do we know that the process by which we're integrating the manufacturing into the production process is consistent?”
It took me a little bit there to think about that, and then immediately popped in that MA was going to be something that we could use. I talked to RDI and said, “we've got this situation, do you think that would be effective? You think that would be an effective means?” And they said yeah, I think that would be a good use of it. Practically speaking, we could not go through and do an EMA and ODS on every single set that we produced. That would be inefficient, just impractical, so we needed something that was faster, but also spoke in the same terms, the same engineering units, and would be an accurate production means to go in and say as they finish manufacturing, “I can set up the MA and do a quality assurance test.”
Well, little did I know that this would be just a game-changing capability. What we ended up accomplishing with MA was far greater than just ensuring that these treatments were effective and that they were being installed correctly. We purchased the equipment and I went to training and got spun up on how to use MA, and we started with, how do we compare between we know we had this 3x turning speed structural resonance. We knew that the modified sets of the treatment would get rid of that. So we went to the Depot and we just took a lot of data on a lot of different angles, a lot of different recording points, on generators that were both unmodified and ones that were modified and under all conditions.
What I really wanted to do was establish a baseline: what does good look like on this PAK integrated set, and how can I differentiate it between an unmodified set? That took a little bit of time but then we established some signals that were consistent in a recording spot that was more or less right on the top of the generator, right in the middle where we could see a lot of movement on both axes. And what we found is that we could find the 3x in the unmodified sets, and then we modified them and it went away just like we wanted. We had a couple of markers there, one that I've talked about in the presentation that's really been great is the orbit plot, where it combines the X&Y and a nice picture to see what the generator is moving like.
So there we were, with a set of data that then we could go as soon as they were done with putting a PAK on the generator and replacing the stator with the new welds and everything – doing all the stuff that we've been working on for the last three years is collaborative effort. And now we were just turning these out and we would look at them, and we could see in great detail first of all that the production process was consistent, it was repeatable; and the performance of the damping and stiffening treatment was consistent and repeatable.
But then we sort of entered another dimension because we began to find other problems. The MA is very powerful, as I was explaining at the Leading Reliability conference, and the joke with me and the group at the Depot is, it sees everything! Anything that happens in the production process, I'm going to see, so watch out! What we ended up finding was some other defects in the generator – anomalies or latent defects I guess would be the term for it.
Two very critical problems. One was a mechanical looseness issue that you could see it, but you could only analyze it with MA. I don't know any way else you could do with the set of tools that that has available where I could establish phase relationships quickly and see the orbit plot and see the spectrum. We isolated this problem to torque values. Again, this a tool where the Depot could adjust torque values and then I could immediately go in and take another recording within a few minutes, try it again, and in the process maybe took an hour of just isolating down to when we get to this little torque window, then everything goes away and the problem is cured.
So in a matter of a couple of hours of iteration of the test with the torque values and making another recording, we had the problem solved. Then the beauty of that was we had data – visual data – recordings to present to the government, to the OEMs, to say, look this this what we found. And there's just no denying it, you could just see that was the problem. That was so powerful to be able to legitimize ourselves, that we were putting in the rigor and the work, and the and the results were accurate. That was one of many benefits of using the MA for this tool.
