Autonomous Cars will demand higher levels of NVH refinements

NVH-Expectations from the driver-less cars will be on higher side due to reduced human intervention with the vehicle operation; people may consider their autonomous vehicles (AVs) as a min-house or a small office rolling on road! Interior design, seating, entertainment systems will assure Best in class or beyond them! The same refinement will be demanded for the passenger-comfort!

What will be then challenges before NVH-Engineers ? They will have to put extra efforts to provide the below Enablers:

1. Motor-trains ---with the least tonal sound of electromagnetic & gear- whine and if needed, to be provided with encapsulation

2. Perfect body sealing and heavy acoustic insulation on its panels to reduce all ambient noises coming into the cabin (including that of AVAS, too) while running over the road at mid or high speeds

3. Higher body dynamic stiffness and lower NTFs at the power-train & suspension attachment points; if needed, to be provided with secondary isolation to the motor-train mounting

4. Quiet Tyres along with the optimally softer Suspension- bushes or struts of higher damping & lower dynamic stiffness to minimize the road-noise as well as BSR on rough terrains

5. Tuned mass dampers for the drivelines if found resonating at a particular freq.

6. Drive-shafts horizontal or with angular adjustable roller joints

7. Cooling Fan, AC compressor & blower, Brake Vacuum pump, wiper, etc. need to generate their sound (at the source) within limits not to disturb the passengers of AVs due to their intermittent operations

8. Optimized driving conditions to have jerk-free torque transfer to wheels from the motor assuring much smoother and quieter drive than that of equivalent EVs with human driving

9. On top of all this, Active noise cancellation with the Active suspension control to avoid any low or mid frequency In-cab boom (that can not be avoided by all passive treatments) &/or vibrations or shakes due to rough road impacts. On the other hand, Active Sound Designer &/or Active Vibrations Enhancer of specific frequencies might be needed for a long drive of AVs to make them lively on highways and not boring due to a very quiet atmosphere all the time !

The above list of countermeasures is not exhaustive and the NVH Challenges will go up as the competition of AV-markets become intense! People will like to just enjoy moving faster on the road just as they are watching movies in a theatre or reading a book in a Library !