VIBRATION CONTROL SOFTWARE
ENGINEERING DATA MANAGEMENT (EDM) BY CRYSTAL INSTRUMENTS
The Crystal Instruments vibration control system (VCS) software is designed for a wide range of vibration and shock testing customers. Customizable report templates allow the user to generate reports in XML, OpenOffice, PDF or Microsoft Word with a single click. With the Application Programming Interface (API), Crystal Instruments’ controller can be directly accessed from LabVIEW, Matlab or other customized software. Spider front-ends run on Linux, iOS, and Windows operating systems. The same software suites support from as few as two inputs up to 256 input channels with multiple drive output capability. Software solutions for vibration control include:
- Random Vibration Control
- Sine-on-Ransom (SoR)
- Random-on-Random (RoR)
- Sine Oscillator
- Shock Response Spectrum (SRS) Synthesis
- Classical Shock Control
- Total Harmonic Distortion (THD) Measurement for Sine
- Transient Time History
- Time Waveform Replication (TWR)
- Highly Accelerated Life-Testing/Stress-Screening (HALT/HASS)
- Multi-shaker Control
- Kurtosis Control
- Swept Sine Control
- Resonance Search Track & Dwell (RSTD)
- Multi Sine Control
- Transient Random
- Fatigue Damage Spectrum
- Waveform Editor
Random Vibration Control
Random Vibration Control provides precise multi-channel control in real time. The device under test is subjected to true random noise with a precisely shaped spectrum with either Gaussian or non-Gaussian amplitude statistics. With a control dynamic range up to 90 dB, up to 512 channels can be enabled for Control, Notching, Monitoring and time data recording. The recording option records time-stream data at the full sample rate on all input channels. A unique hardware/firmware/software design featuring spectral overlapping provides a fast loop time of less than 15 ms in a typical test.
Sine on Random Control
Up to 12 independently sweeping controlled sine tones may be added to the broadband random signal. Each sine tone has its own sweeping schedule and range. Tones can be turned on and off manually or by a predefined schedule.
Random on Random Control
Up to 12 independent (stationary or sweeping) random narrow-band signals may be superimposed on the broadband random signal. Each narrow-band has its own sweeping schedule and range. They can be turned on and off by a predefined schedule or manually.
Kurtosis control can provide a more damaging non-Gaussian random control time history. A unique patent pending technology can generate a non-Gaussian control time history while precisely maintaining its spectrum shape.
Multi-Resolution Function for Random Vibration Control
EDM provides the multi-resolution feature that applies the selected resolution in the high-frequency range and 8 times of the resolution in the low-frequency range. The cutoff frequency, which divides the low and high-frequency range, is calculated by the software. A few adjacent frequencies can also be selected by the user to avoid system resonance or anti-resonance.
Swept Sine Control
Swept Sine Vibration Control provides precise multi-channel control in real time. It provides a spectrally pure undistorted sine wave and a control dynamic range of up to 100 dB. As many as 256 channels can be enabled for Control, Notching, Monitoring and time-data recording. The recording option records a time-stream at the full sample rate on all input channels. A unique hardware design and spectral overlapping provides a fast loop time of less than 10 ms.
Resonance Search and Tracked Dwell (RSTD) Control
The resonance search function determines resonant frequencies from the peaks of a transmissibility signal. Dwell type (Fixed dwell, Tracked dwell, Phase tracked dwell) may be specified manually (with a list of resonance frequencies) or automatically executed after a resonance search is done. Under real-time control, the tracked dwell entry tracks each resonant frequency as it shifts with time, temperature or damage.
Total Harmonic Distortion (THD) Measurement for Sine
This option adds the ability to compute Total Harmonic Distortion (THD) of the control and Input signals. THD plots can be generated while the drive signal either steps through multiple discrete frequencies or sweeps a sine over a predefined range.
Classical Shock Control
Classical Shock Control provides precise, real-time, multi-channel control and analysis of a transient motion in the time domain. Classical pulse shapes include half-sine, haversine, terminal-peak sawtooth, initial-peak saw tooth, triangle, rectangle, and trapezoid. The recording option records time stream data at the full sample rate for all input channels. Shock response spectrum (SRS) analysis can be applied to any input signal; optionally control of the DUT’s SRS may be executed. Applicable Test Standards include MIL-STD-810F, MIL-STD-202F, ISO 9568 and IEC 60068 (plus user-defined specifications).
Transient Time History Control (TTH)
Targeting seismic simulation applications, TTH controls shaker motion to match any user defined transient waveform. Time waveforms can be imported to EDM in various formats. Scaling, editing, digital re-sampling, high-pass or low-pass filtering and compensation will tailor the waveform so that it may be duplicated on a particular shaker. Compensation appropriately modifies the acceleration waveform so that it does not exceed the shaker stroke available.
Shock Response Spectrum (SRS) Synthesis & Control
The SRS synthesis and control package provides the means to control the measured SRS of the DUT to match a target SRS, the Required Response Spectrum (RRS). The necessary drive time history is synthesized from damped-sine or sine-beat wavelets. Damped Sine Parameters include frequency, amplitude, critical damping factor, and delay. Waveforms may be automatically synthesized from a user-specified SRS reference profile. The Transient Control option allows control using imported transient files. High frequency waveforms, Alarm and Abort tolerances may be applied to any active channel to provide an extra degree of safety for delicate test articles.
Time Waveform Replication
Time Waveform Replication (TWR) provides precise, real-time, multi-channel control for long duration waveform duplication. TWR includes the Waveform Editor, a flexible importing and editing tools for long waveform signals. The Recording option records time stream data at the full sample rate on all input channels.
Profile Definition: Any existing signal is treated as a profile and is imported and defined as a control.
Profile Editing: Waveforms with any sampling rates are digitally resampled, re-scaled, filtered, and different compensation techniques may be applied to edit the profile using the EDM – Waveform Editor tool. Options for cropping, appending and inserting parts of a waveform are also provided
Sine Oscillator is a diagnostic tool providing manual control of the sine output while the system displays various time signals and frequency spectra. Random excitation can be enabled as a checkup function. When the close-loop option is enabled, the Sine Oscillator is essentially a limited sine controller with augmented manual control functions.
Multi-shaker Control for Sine or Random
This option enables the system to output two drive signals simultaneously, to control two shakers. The phase difference between each drive and the control signal is calculated and taken into account during real-time operation. This option supports two shaker systems mounted either in push-pull or parallel-drive configurations.
Multi-Sine control enables multiple sine tones sweeping simultaneously and ensures that multiple resonant frequencies of the structure can be excited. With multiple sine tone excitation, the required time duration of sine testing can be reduced significantly. Independent tracking filters are applied to each tone separately.
Transient Random Control
Transient Random control applies a chain of pulses with random nature to the shaker. The target profile power spectrum is defined in a same way as Random control, with the addition of defining transient pulse interval. Application includes simulation gunfire or road simulation.
Fatigue Damage Spectrum in Random
Fatigue Damage Spectrum (FDS) allows users to compare the potential damage caused by different Random and swept Sine profiles. In a similar fashion to Multi-Sine Control, FDS provides a way to reduce testing times by calculating the quickest path to destruction or damage. Testing times are accelerated by focusing random or swept Sine energy, depending on the FDS calculation, to where it will induce the most fatigue.
HALT/HASS control developed by Crystal Instruments, has Voltage/IEPE input channels, temperature measurement channels, and humidity channels. Output channels can generate various waveform signals to drive an electro-dynamic shaker, a water pressure shaker, and an air hammer. Proportional-integral-derivative (PID) control is used to guarantee the accurate control of temperature and humidity.