Crystal Instruments Multiple Axis Vibration Testing

Multiple-axis vibration testing brings MIMO and MESA control into one modular platform that scales up to 512 channels. MIMO (Multiple-Input Multiple-Output) targets coordinated multi-shaker operation, while MESA (Multi-Exciter Single-Axis) targets multiple exciters driving a large or long test article along a single axis.

On the MIMO side, MIMO Random control is one of the most common multiple-shaker methods, providing precise real-time control that subjects the device under test to true random noise with a precisely shaped spectrum and Gaussian amplitude statistics; a recording option captures time-stream data at the full sample rate on all input channels. MIMO Sine control is another common method, offering precise real-time control with a control dynamic range up to 100 dB, using linear spectrum profiles of magnitude, or magnitude and phase, assigned to multiple control channels. MIMO Shock control provides precise, real-time, multi-channel control and analysis of classical shock waveforms in the time domain, essentially a time-domain waveform replication process that uses an FFT-based algorithm to correct the test system dynamics.

Further MIMO methods include TTH, where short predefined waveforms are output and a closed-loop algorithm matches the control inputs to the specified shape; MIMO SRS, which drives multiple shakers to meet multiple target Required Response Spectra by synthesizing time waveforms from a user-specified SRS reference profile using wavelets such as sine beats and damped sine; and MIMO TWR, which imports a multi-channel time waveform, pre-processes it (for example bandpass filtering) and selects it as the control profile to reproduce field data in the lab.

On the MESA side, MESA Random provides precise real-time multi-exciter single-channel control and analysis, and after control channels are assigned, the remaining inputs can serve as monitoring and time-data recording channels at full sample rate; MESA Sine works the same way. MESA Sine-on-Random is commonly used with large or long units under test, requiring one control profile and using weighted-average control, with modes that provide identical drives, drives with different phases, or drives with different magnitude and phase. Relevant standards include MIL-STD 810, MIL-STD 202, ISO 8568 and IEC 60068-2-27.