Measuring and Comparing Steering Hiss Noise Accurately

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Measuring and Comparing Steering Hiss Noise
Accurately
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The Problem

• Steering Hiss Noise
• is most audible when parking
• varies with steering load
• is difficult to measure consistently in car
• Need for a Standard Test
• easy to use
• repeatable
• easily and clearly comparable
• Standardised for Rig and Vehicle

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The Test

• Steering Turned by hand
• Steering from centre to both full locks and back
  to centre several times
• tests normally not comparable due to variable
  steering rates
• Boost Pressures measured
• simultaneous to in-car/rig noise
• later used as X-Axis and multiple runs averaged
  at same pressure points

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The Analysis

• noise High Pass Filtered to accentuate hiss
  component
• curves correlate well with subjective ratings
• Multiple runs averaged at each pressure point to
  compensate for operator variability
• resulting in stable curves showing hysteresis

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In-vehicle Hiss Noise vs. Pressure
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End