DATS NVH

Refining the noise and vibration of vehicles and rotating machines is central to creating a successful product. It's not just about making less noise, but making the right noise. DATS NVH is an add-on for DATS-core that gives you the depth and power to measure, understand and refine your product.

Waterfall and order analysis

Extensive tacho analysis lets you analyse angular speed. Waterfall and order analysis then pick out the parts of the spectrum that are harmonically related to rotational speed, and waterfall averaging gives you a more consistent view of the problem. Extract orders, convert frequency spectra to order spectra, and take order cuts straight from a waterfall.

Sound quality metrics

1/nth octave analysis is widely used as a first step to reduce data into standard bands that reflect the human response to noise. DATS NVH then adds a large number of sound quality metrics that quantify noise in ways that more accurately reflect how drivers and passengers perceive it, including:

• Loudness to Zwicker (ISO 532B, diffuse and free field, including vehicle-biased versions) and Stevens (ISO 532A), and loudness versus time
• Articulation Index (ANSI S3.5 1969 and vehicle-biased) and AI versus time
• Composite Rating Performance Value, High Frequency Factor, Preferred Speech Interference Level and Spectral Balance

Time-frequency and wavelet analysis

The time-frequency analysis package includes a number of algorithms, including Wigner-Ville, Zhao-Atlas-Marks and Born-Jordan, each giving slightly different emphasis to features of the signal. Wavelet tools cover wavelet transforms, reconstruction, de-noising and filtering, with mother wavelet generation.

Sound Quality Audio Replay (SQAR)

SQAR lets you listen to and analyse audio data. Combine order filters and frequency filters to investigate in detail and try out "what if?" scenarios, then compare the original and modified signals side by side in the playlist. Visualisations include time histories, time-speed curves, order plots, waterfall plots and colour maps, sound quality metrics and a real-time speed readout.

Analysis functions included

• Waterfall analysis: speed signal from tacho, waterfall from tacho signal with phase, waterfall from speed signal, order extraction, frequency-to-order spectrum conversion and order cuts from a waterfall
• Averaging, weighting and octaves: A, B, C and D spectral and time domain weighting, spectrum averaging, spectrum average and RMS in a user-defined bandwidth, waterfall averaging and 1/nth octave band analysis
• Miscellaneous: Nth octave from time, difference dB signals, N10S10 calculation and equalisation order filter
• SQAR filters: order pass, order reject, Butterworth band pass and band reject, and filter attenuation versus speed

DATS NVH works alongside DATS-Acquisition for capture and the DATS Rotating Machinery add-on for torsional vibration and twist analysis. Find out more about automotive testing and NVH with Prosig, or contact our team for advice.