Pass-by Noise Testing
The exterior noise nuisance
ISO 362-1:2015 sets out requirements for the measurement of noise emitted by accelerating road vehicles.
Territory specific legislation then imposes maximum overall levels on vehicle types (i.e. cars, buses, trucks etc.) For example, since 1996 within the EU, passenger cars have not been permitted to exceed 74dB(A) using the well-established acceleration test.
EU Regulation No. 540/2014 (introduced in 2016) reduces that limit over 10-years to 68dB(A) by 2026 and new (more representative) test procedures are also being introduced.
Powertrain NVH extraction
Overall noise level provides no diagnostic (source identification) information.
The PASSBY sub-product for PLATO allows the noise map to be presented as Doppler shift corrected order spectra referenced to a rotation shaft in the vehicle.
The example here shows how engine firing (exhaust) and transmission output gear mesh fundamental, rise above background noise during a truck pass-by test; essential information for powertrain development engineers.
No need for radar
PASSBY from AB Dynamics does not require the set-up and use of a radar system on the track to determine vehicle position.
Instead, purpose designed telemetry equipment relays the speed of a vehicle based shaft to the base station.
The vehicle shaft speed is then used with start/finish marker strips on the track to automatically calculate vehicle speed vs. distance through the test zone. This is simple to set-up, cost-effective and infallible.
By taking advantage of PLATO’s set-up database, pass-by testing (with test run averaging to reduce random variations) becomes deskilled, leaving the user (and vehicle driver) to concentrate on their primary tasks.
Order tracks and overall noise level
The result (component order tracks set against overall noise level) is easily interpreted and invaluable for powertrain development engineers.
Clear, precise results
Passby noise results are reported using PLATO’s intuitive test report and stored within PLATO’s results database (SQL) so they can be passed on to the PLATO server when the laptop/tablet PC connects to a network back at base.