Summary
LMSTM Engineering services analyze and optimize the noise, vibration and harshness (NVH) performance of hybrid and electric vehicles. Combining traditional methods with new model- based systems engineering (MBSE) techniques and approaches, LMS Engineering experts can accurately predict NVH and acoustic performance by carefully studying the relationship between the electrical and mechanical design of the powertrain and body structures of hybrid and electric vehicles.
The design of eco-friendly vehicles ranks high on the agenda of global automotive manufacturers and suppliers. With hybrid and electrical automobiles, the goal is to reduce fuel consumption and unwanted emissions.
But these eco-friendly vehicles can strongly impact the noise, vibration and harshness behavior of the vehicle and, therefore, the driver’s comfort. LMS Engineering helps ensure that drivers experience the same driving sensations as with a traditional car with the added comfort of a quiet electric powertrain.
LMS Engineering has developed a unique methodology to combine integrated testing and simulation data for significant productivity gains in product development and verification.
LMS Engineering technical experts help you evaluate the synthesized data to make design refinements for optimal system performance, from short-term physical workarounds to longer-term control-based solutions.
LMS Engineering services optimize NVH and acoustic performance for next-generation vehicles
www.siemens.com/plm/lms-engineering Benefits
• Accurately analyze and optimize the NVH and acoustic performance
• Significantly lower acoustic noise radiated from an electric powertrain
• Understand the vehicle’s body sensitivity to transfer vibration
• Enhanced productivity due to engineering knowledge and technology transfer
• Frontload the co-optimization of control, electrical and mechanical aspects of electric vehicles
Noise optimization for electric vehicles
Acoustic simulation results of radiated noise.
Typical NVH challenges that appear during the design of electric and hybrid electric vehicles are:
Electromagnetic and vibro-acoustic simulation
Electric motors need to be powerful yet able to deliver the right acoustic impression, typically avoiding high- frequency sharpness caused by excitation of structural resonances above one kilohertz (kHz). The type of electric motor that you choose has a significant impact on the noise signature from a mechanical and control strategy point of view.
The casing design of the electric motor is of key importance to the motor noise signature, which typically includes stiff cast structures with resonances above one kHz. LMS Engineering experts can propose and virtually verify design changes that improve the mechanical design, using traditional solutions such as shifting modes or adding damping to the structure. Alternatively, the
excitation of the motor can be reduced by optimizing the current shaping provided by the motor controller.
Also, the importance of quietness and increasing clarity of sound becomes clear, especially when driving at low or constant speeds.
Deciding when and where to add sound, if at all, takes on more importance. LMS Engineering helps customers answer this question with the technologies to objectivize the phenomena and the experience to understand how to successfully apply it to a vehicle.
LMS
Noise optimization for electric vehicles
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42244-A13 8/16 P Low frequency structure-borne noise
Understanding the vehicle body’s sensitivity to transfer vibration remains a challenge. During acceleration, electric vehicles have very different interior sound characteristics compared to traditional combustion engine vehicles. LMS Engineering has carried out projects using transfer path analysis (TPA) and acoustic source quantification (ASQ) to check the structure-borne/
airborne contribution split for different noise phenomena as well as identifying which paths are important.
In-vehicle noise perception
Manufacturers are keen to ensure the vibro-acoustic perception matches the desired dynamic impression of the vehicle. For electric vehicles, that means actively boosting noise content to convey powerfulness and improve the feeling of speed. On the other side, high-frequency sounds produced by electric motors are often perceived as annoying, and manufacturers look to minimize this with objective assessment using metrics or subjective evaluation.
Siemens PLM Software www.siemens.com/plm Americas +1 314 264 8499 Europe +44 (0) 1276 413200 Asia-Pacific +852 2230 3308 Acoustic FRF measurements. Operational measurements.
