Over the past a few days I have been assisting Crystal Instrument’s (CI) engineering team on three projects for NASA.
The first project revealed the latest progress Crystal Instruments has made in modal testing. Dr. Peter Avitabile and the CI team hosted a seminar at NASA’s Marshall Space Flight Center (MSFC) in Huntsville, AL. During the seminar, Aakash Mange, one of the CI product managers, demonstrated and explained the new multi-resolution spectrum analysis method that CI developed. It drew interest from many attendees.
The innovative multi-resolution (MR) spectrum analysis method was developed based on patented technology that generates a multi-stage spectrum FFT. This technological approach utilizes CI’s core hardware platform and hardware design:
As shown in the plot below, this technique provides much higher resolution in the low frequency range. Hence the estimation of the modal parameters are much more accurate.
As shown in the table below, the damping parameters are considerably more accurately estimated when MR technology is used:
The second project that CI’s engineers are working on is a unique shutdown system for the Space Environments Complex (SEC) at the NASA Glenn Research Center (GRC), a Neil A. Armstrong Test Facility (NATF).
A vibration test system usually consists of the following elements: a shaker, the power amplifier that drives the shaker, a vibration controller that controls the amplifier, a high channel count data acquisition system, and the unit under test. Sensors and cables that go along with the overall system also deserve to be mentioned. For aerospace applications, the safety of the test is a major concern. When certain events occur, say the vibration level at certain measurement points exceeds the preset limits, the vibration test must be shut down as soon as possible, in a matter of milli-seconds.
CI engineers are working on a unique tracking filter on the Spider-80Xi platform that can shut down a vibration test extremely quickly.
The tracking filter must meet following criteria:
Accurate estimation amplitude at a known fundamental frequency.
Fast response time to obtain such an amplitude estimation.
Very high attenuation at all harmonic frequencies.
Supports up to 512 channels or more.
Ability to define the thresholds in the Time domain, RMS domain or Frequency domain and sends out a shutdown signal accordingly.
Flexibility to define multiple alarms in different domains together to ensure timely protection.
Continuous time recording
The third project CI is working on is the CI-GRS, a rugged acoustic data acquisition system for NASA Neil A. Armstrong Flight Research Center (AFRC) in California.
CI-GRS products are designed for measuring sonic boom signatures from NASA’s X-59 supersonic prototype aircraft. The X-59 is a jet airplane designed to exceed the speed of sound to produce sonic boom events for measurement by the CI-GRS. Up to 100 CI-GRS units will be deployed within a (150 x 100 nautical mile) range throughout a desert environment (other environments will also be tested). A sequence of orchestrated actions from the X-59 jet flying over the CI-GRS units combined with the two-way communication protocol and GPS time synchronization mechanism will allows all CI-GRS units on the ground to begin acquiring sound data at a designated time.
CI-GRS is probably the most sensitive portable acoustic measurement equipment that has ever been developed in the world. The patented dual A/D system from CI ensures a complete set of recorded data without loss on each microphone connected to all 100 CI-GRS units.
Currently, the NASA AFRC team is actively reviewing and testing the second delivery from CI. CI is providing ongoing support for NASA’s testing efforts.
After observing all the current projects that CI is working on for NASA, it is evident to me that NASA is seeking groundbreaking ideas that generate benefits for their testing applications. Our commitment to continuous innovation in hardware design, software implementation, and signal processing algorithms allows CI to produce groundbreaking progress in test and measurement instrument technology every day.