MESA Shaker Systems

Multiple-Exciter-Single-Axis Vibration Testing Shakers

MESA tests are specifically required when the unit under test is too heavy or too big and exceeds the capabilities of a single shaker. In a MESA application, multiple shakers provide excitation to the test specimen in a single axis. Different relations like same magnitude and phase for drives, different phase for drives, different magnitude and phase for drives, can be set for this MESA test.

(Please click on an image to enlarge it.)

Spider Hardware System Management
A Spider system can consist of one or more Spider hardware front-ends. The user constructs the system by combining Spider front-ends detected on the same LAN. The software validates and displays hardware attributes of each Spider front-end.

  • Spider-80M MIMO Controller: based on the efficient Spider-80Xi architecture and is dedicated to MIMO/MESA VCS control and MIMO structural testing applications.

Running Test to Extended Frequency Range

Various challenges hinder a successful vibration control test. The most crucial one is the limitation of structural dynamics of the system. The resonances and anti-resonances of the system cause the drive to reach its low or high limit respectively which can cause an issue with the control.

MESA vibration testing

As illustrated from the above FRF signals from a head-expander, as frequency goes high, flexible modes come into the picture. The resonance frequencies from different locations are aligning, while anti-resonance frequency is varying location-wise.

To accommodate the resonance frequency, the corresponding drive will be dropped so as to maintain the control following reference target; while dealing with the anti-resonance, corresponding drive needs to be high which may be over the shaker input voltage limit. To address this issue, the weighted average control strategy could be used. Per localization nature of the anti-resonances, averaging will smooth out the valleys.

In MESA control, a unique algorithm is developed so that the phase from all control input channels are optimally synthesized based on the criteria of minimum energy of drives.

MESA vibration test diagram.png

The phase optimization algorithm along with weighted average control strategy in a MESA test helps combat the limitations to help achieve good control of the programmed test profile. This approach yields the best control performance even in the frequency range with many high resonances and anti-resonances.

Watch MESA Random & MESA Sine Vibration Testing

MESA Random Vibration Control Video

 

MESA Sine Vibration Control Video

Monitoring Through EDM Cloud

All tests in EDM-VCS support status checks through EDM Cloud. With EDM Cloud support, users can set up any VCS test to upload live data or run logs for completed tests to a cloud storage space provided by Crystal Instruments, where data is securely stored in the user’s account.

The EDM Cloud website is located at https://cloud.go-ci.com. Users can access EDM Cloud from anywhere in the world to check the status of past and current tests. A secure login flow ensures the status can only be checked by authorized personnel with proper credentials. Multiple logins for accessing the same Cloud account is available.