Tuesday, November 25, 2008

Wrote the procedure for gain tuning the inertial referencing circuit.

Calibrated the LVDT for the 10" hydraulic shaker.

Tried to get some shock data from jeff to send to Loral. Couldn't figure out which files to send. I called jeff to ask but he didn't answer

Sent KD-2300 back to Kaman because they didn't fix it the first time.

Friday, November 21, 2008

Company meeting was today.

Tested more WISE isolators.

Helped Scott P. set up a DCS test to test a damper he is going to be using.

Thursday, November 20, 2008

Tested the life unit for World View. We were out of LN so I had to run to Madco to get a small 35L Liquid Nitrogen tank. The results of the test were a little different than the previous test done in August. At higher frequencies, the loss factor dropped lower. Scott P. talked to Connor and Paul about this and they suggested realigning and making sure the setup was exactly the same as last time. They also suggested testing an undamped specimen and comparing to before.
I checked the pictures of the setup from last time and discovered that there was a washer that I was using that wasn't there before. I redid the setup and retested the isolator. The results came out exactly the same.

I also tested about 5 more WISE isolators. I am now lubing the bolts with Braycote and changing them every other isolator.

Tuesday, November 18, 2008

Finished up presentation for Fast GVT progress report.

Retested WISE isolators that had come in slightly under spec. The first one, SN018, retested fine. Upon mounting the second one, SN036, one of the bolts galled which pretty much ruined the isolator. This probably happened because either (1) there was too much junk on the bolt from using it so much (2) the anodized coating wore off because it was used so much, or (3) last time it was mounted the thread was compromised somehow. This is being resolved. It looks like from now on though we will be using a lubricant when fastening the isolators in.

I setup the RR test back on the work plate to do one more room temperature test.

I setup the World View test rig so that I can do the life unit test in the next few days.

Monday, November 17, 2008

Started preparing for the Life Test on the World View Life Unit isolator. Since one of the kaman probe boxes was damaged that was used for WV, I had to get another set and verify that they give nominally the same results. I did and they agree to within about 1 percent.

I tore down the rejection ratio test rig that was in the Espec chamber.

I started preparing slides for the progress report on Wednesday. Brad wants them done by tomorrow early afternoon.

Thursday, November 13, 2008

DCS tested the WISE isolators most of the day.

Discussed RR with Brad and Paul. They suggested gain tuning a little differently to try and get it more accurate. They suggested turning the variable resister in 1/8th of a turn increments and taking an FFT of the differenced velocity when the input to the system was a 40Hz sine wave. Which ever position had the lowest value at 40Hz would be the best gain matched position. I did this and the resulting room temp rejection ratio when gain tuned like this was a bit better than before. Now Brad and Paul want me to retake the 100F and 32F RR measurements.

Wednesday, November 12, 2008

Went to dentist in the morning. Got to work around 9:10 and went directly into a product demonstration. Several representatives from FARO were here to show us three of their laser positioning systems. They were pretty impressive, they had a scanner which could scan an entire environment 360 degrees, a laser tracker that could map out large objects, and a laser arm which was both a probe and a laser scanner, for accurately scanning small to mid size objects.

Tested WISE, got through 5 more isolators.

Showed the diff temp RR test results to Brad, he wanted slighlty better performance at the 120F level. He had me do another test at 100F. They were better but still not quite under -30dB at .5Hz.

Tuesday, November 11, 2008

Retook different temperature rejection ratios. The problem that arose on Friday due to the condensation in the chamber was fixed by reseating all the electrical components. There must have been some bad connection as a result of water. The RR are pretty nice now.

I calibrated the 10" servohydraulic shaker.

Because of a death in Jeff's family, he will be gone all of this week meaning that I will have to do the WISE acceptance testing. I finished testing three of them today. Results look good.

Friday, November 7, 2008

I finished up the DC temperature sensitivity tests for the Measurement Specialties accels. Results look very similar to last time.

Found a connector and cable for the accelerometer for the Fast GVT. I chose a Mini DIN circular 4 pin connector, and a 22 AWG 4 conductor cable from Belden.

I started putting together a B.O.M. for the project.

I had to redo the rejection ratio test at different temperatures because I did not put the electronics in the environmental control chamber before. It was MUCH faster setting it up this time than last time.

Thursdsay, November 6, 2008

Sat in on a talk/discussion with David Smallwood, an expert on shock. Very interesting and insightful.

Ran part of the DC temp sensitivity test for the Measurement Specialties accels.

Started to look up connectors and cables for the MS accels.

Wednesday, November 5, 2008

Started building up a solid model of the interface box for the Fast GVT. Discovered that the display on the laser probe controller can detach and be panel mounted, while the actual controller can be mounted on a Din rail. I had Brad review my initial ideas and he suggested I make it more "idiot proof" and have both connectors from the accel and laser right next to each other so its hard to screw up. He also wants some way to group the pairs of cable that come off the accel/laser inertial sensor.

I also talked to Paul about it. He mentioned using Din-rail mountable terminal blocks to get power to each of the laser controller boxes.

I scoped out some power supplies for the interface box as well. Right now I am considering a 24VDC supply from Digikey prt no. Z2500-ND and two 15VDC supply from Digikey prt no. Z2475-ND.

I cleaned up the different temperature rejection ratio test I had conducted. I also partially re-setup the DC temperature sensitivity test for the 4000 class Measurement Specialties accels because I was not happy with the first test.

Tuesday, November 4, 2008

Got Rejection ratio at 120F, 32 F, and 70 F and plotted results.

Documented settings of laser displacement sensor controller

Sent 2 more accels to White Sands per Tim's request. Also helped him look up some specs for one type of accel they are dealing with.

Started to organize all my data from the past few weeks of work on the Fast GVT in order to get it up on the project server in an orderly manner, and also so I can put the data in a progress report.

Monday, November 3, 2008

Worked on getting the rejection ratio for the Fast GVT at different temperatures. This involved setting the shaker/accel/laser head up inside an environmental chamber. Brad suggested mounting everything on a large rigged mass so that it would be very stiff, thus not causing any modes in the frequency range of interest. I did this but you could still feel the vibrations on the stand, being transmitted to the laser head. This being the case, I mounted the laser head on the side of the inside of the oven. This gave a good RR.

I also talked to Paul J. about the interface box that would house all the circuitry and control boxes. He suggested using a 19" rack, and having Card Racks mounted in these 19" racks that would hold the PCBs. This way you could easily source the needed power to a group of PCBs. He also suggested that we have multiple interface boxes that could be stationed around the plane so you would not need incredibly long cables to run to the accel/laser head.