Road noise development needs to cover every step from design, calibration to mass production, involving multiple departments working together (NVH, electronics, products…)
Step 1: Vehicle acoustic environment confirmation
- Confirm the number of speakers supported by the real car entertainment system and the speaker position.
- Confirm the frequency response curves of the low, medium and high frequency speakers. Ensure that the low frequency response frequency covers the road noise band of interest.
- Confirm the NVH performance of the real vehicle, obtain the original vehicle noise signal data, and perform signal preprocessing and analysis.
Step 2: RNC system layout review
- Determining the arrangement of the MIC locations required by the RNC system requires the MIC to efficiently capture the area of the interior noise.
- Taking the chassis simulation data of the vehicle body as a reference, the vibration sensor is arranged at the corresponding position of the body suspension.
- Arrange the RNC controller.
- Arrange the wiring harness.
Step 3: RNC FRF collection
- The transfer function in the RNC controller is activated by the acquisition tool.
- The RNC controls the car speaker to play the swept sound and simultaneously collects data through the MIC.
- The collected data is uploaded to the host computer and the data is analyzed and calculated using the conversion tool.
- Obtain the transfer function data of the system and input it to the algorithm.
Step 4: Algorithm integration
- The RNC algorithm and the transfer function are simulated on the PC side.
- The noise reduction effect was evaluated by PC software.
- Debug the code and integrate it into the target RNC controller.
- Inspect if the real vehicle algorithm works normally.
Step 5: Compound road condition calibration
- Calibration of road noise data for Idle, POT, WOT, Cruise, Coast Down.
- The parameter table is integrated according to the calibration results.
- The curing of the algorithm.
Step 6: Noise reduction performance evaluation
- Jury testing of the noise reduction effect.
- Compare the in-vehicle seat position noise data with the RNC algorithm on and off.
- Check if the noise reduction effect meets the target setting.
Step 7: Consistency evaluation
- The integrated RNC controller is ported to other models of the same vehicle.
- The noise reduction effect of the vehicle is confirmed according to the noise reduction performance evaluation specification.
- Check consistency.
