Stringent environmental noise regulations and the green movement in general are driving the demand for much quieter vehicles.
This is directly reflected on the level of permitted pass-by noise and regulated acoustic performance of practically every newly designed vehicle from trucks and cars to motorcycles and recreational vehicles as well as principle components and systems, such as tires and exhaust.
One example of pass-by noise certification is the new ISO 362:2005 process which really puts testing departments through their paces with requirements for additional testing under multiple ‘real world’ conditions. Add this twist to the pressure of reducing time-to-market testing freeze dates and the ever-increasing number of models that must be tested and it is not surprising that testing departments are on a quest for a reliable, productive and scalable solution for pass-by noise certification and pass-by noise engineering like LMS Test.Lab Exterior Pass-by Noise.
A highly adaptable and scalable pass-by noise testing solution, LMS Test.Lab Exterior Pass-by Noise Testing can be tuned to precise testing requirements and expanded as needed. LMS Test.Lab Exterior Pass-by Noise Testing is based on an extremely reliable hardware and software solution, which combines state-of-the-art LMS SCADAS data acquisition and telemetry with the easy-to-use LMS Test.Lab Pass-by Noise module. The test result is fast and accurate data compliant with both international and local standards.
The system is suitable for one or two operators – depending on the preferred test methodology. Either way, intuitive point-and-click interfaces clearly guide the user through the entire pass-by measurement process: from pre-testing to reporting. After a test run, all the data is immediately available for trackside viewing. This instant access makes it possible to decide on the spot whether or not a vehicle or component is compliant.
LMS Test.Lab Exterior Pass-by Noise Testing supports a wide range of standards including ISO 362 and the ISO 362:2005 revision, SAE J366, SAE J986, SAE J1470, F76A US and Trias20. Specific component-related standards for exhaust noise (EEC 93/97, ISO 5130, Trias 20) and tires (Trias20) are supported for more in-depth testing. It is easy to integrate additional standards as they become available.
LMS Test.Lab Exterior Pass-by Noise Testing system can be configured for dedicated user-defined procedures and specific requirements. For more standard usage, LMS offers three typical configurations:
- Track-based exterior pass-by noise where the LMS SCADAS acquisition system is placed near the test track. This method requires minimal vehicle instrumentation.
- In-vehicle exterior pass-by noise where the LMS SCADAS acquisition system is placed in the vehicle to acquire additional measurement channels for more in-depth analyses.
- For advanced engineering tasks, large amounts of data must be captured near the track and on the vehicle. For such tasks, both systems can be combined and synchronized using the built-in LMS SCADAS GPS receivers.
UTAC, a leading company in testing and certification services, deployed LMS Test.Lab in its environmental laboratory for acoustic testing, citing its testing speed, engineering capabilities, precision, and ease of use as key differentiators. UTAC estimates that testing campaigns run with LMS Test.Lab deliver a 30% time gain compared to tests with other tools. Thanks to LMS Test.Lab, UTAC can offer its customers a precise diagnosis of acoustic problems.
Since ever-more demanding noise regulations are imposed on truck manufacturers, Volvo Truck leaves no stone unturned to minimize the exterior noise of the company’s extensive truck range. At the NVH laboratories of Volvo Truck, engineers systematically measure, analyze and optimize exterior truck noise under different vehicle operating conditions using LMS NVH testing systems. During the development of new truck models, Volvo Truck NVH specialists focus on reducing the noise generated by the entire truck driveline, including engine, intake and exhaust, gearbox and transmission.
LMS delivered a fully integrated testing and analysis system to perform pass-by noise certification of newly developed GM vehicles. GM selected LMS for its strong support of the upcoming revision of the ISO 362 standard. GM also valued the LMS system for its efficient execution of exterior noise tests and related troubleshooting analyses. The strong integration of the new system in the extensive installation of LMS systems for noise and vibration engineering at GM will enable its engineers to easily reuse and leverage exterior noise test data throughout the vehicle development process.
Reducing the pass-by noise of trains is an important issue and innovative companies, such as Lucchini of Italy, are developing a range of new low noise wheels to address the problem. But how can the contribution of a new set of wheels to the overall pass-by noise levels be assessed - given the multiple sources contributing to overall noise levels, the couple of seconds it takes for a train to flash by at 220kph, and the Doppler shifts distorting? 
