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This PULSE software measures the exterior noise of a stationary vehicle and extrapolates the acoustic information to simulate the vehicle’s acoustic performance at the measurement positions of the ISO 362 pass-by noise measurement standard. The vehicle runs on a chassis dyno in a semi-anechoic chamber, and sound is measured at multiple microphone positions. Aerodynamic wind noise and tyre noise corrections are added during post-processing.

USE SCENARIOS

• Product development and troubleshooting in a controlled environment
• Testing in small anechoic chambers
• Relating exterior noise to specific vehicle components

Indoor pass-by provides a powerful and repeatable method for automotive manufacturers to troubleshoot exterior vehicle noise in the controlled environment of a hemi-anechoic chamber. With reduced influence of ambient weather conditions and site variations, measurements are more reproducible. And with a stationary vehicle, a greater degree of instrumentation is possible.

Instead of the vehicle passing two stationary microphones placed 7.5 metres from the vehicle centre – as in standard field pass-by noise measurements – indoor pass-by uses a row of microphones placed alongside the test vehicle. By extracting sections of the time history from the appropriate microphones and stitching them together, the software creates a single time history that reproduces the effect of the vehicle passing two microphones. This system allows microphones to be positioned close to the vehicle while still providing correct results, making it useful where space is limited.

CAPABILITIES

• Tyre noise correction for coast down tests
• Simulation of field pass-by measurements according to a range of international standards including ISO 362-2012  –>  ISO 362-2015
• Correction function to simulate Doppler effect
• Comparison of data to field pass-by noise results
• Listening to virtual pass-by time histories

ADDITIONAL CAPABILITIES

• The exterior noise contribution analysis (ECNA) option helps identify the major contributions to exterior noise from specific noise source such as the powertrain, intake/exhaust system, and tyres. Read more in the PD