Advanced Acoustic Simulator “AAS”

With the recent spread of electric vehicles and the realization of automatic driving, quietness in the cabin,
which leads to comfort, is becoming more and more important. Under such circumstances, our originally developed acoustic evaluation system, AAS (Advanced Acoustic Simulator), has been used by automakers to set development targets in their efforts to develop cabin acoustics and to demonstrate its great effectiveness in comparative evaluations with benchmark (*1) vehicles. In addition to faithfully reproducing the sound inside the vehicle during driving recorded using 3D acoustic technology, it also has a function to reproduce actual sound based on CAE (*2) analysis data to predict sound changes when modifications are made to soundproofing materials. In addition to sound, the system can also link video and vibration for more realistic evaluation.

*1 Comparison
*2 Computer Aided Engineering (computer-aided simulation technology)

Helps shorten development time.
Instant comparison between benchmark vehicles.

However, this method has problems such as the results being affected by weather conditions and driver habits, and the evaluator forgetting the sound due to time lag caused by changing vehicles, etc. With AAS, the pre-recorded cabin sound can be reproduced instantly indoors, making it possible for all evaluators to evaluate the vehicle under exactly the same sound conditions. AAS can instantly reproduce pre-recorded cabin sounds indoors, making it possible for all evaluators to evaluate the vehicle under exactly the same sound and conditions. In this way, the AAS enables instantaneous comparisons between benchmark vehicles, contributing to shorter development times. In addition, MHI has a cloud-based database of cabin sounds for various segments of vehicles (from compact types to luxury cars and electric vehicles), and is gradually expanding its vehicle lineup.

Target value setting with a high degree of certainty.
Confirmation not only by “numerical” values but also by actual “room sound”.

AAS is equipped with a function (equalizing function) that reproduces the cabin sound when changes are made to the position, material, thickness, etc. of the soundproofing material in the actual vehicle to a level equivalent to the actual cabin sound, based on CAE analysis. Generally, quietness targets are set based on “numerical values,” but even if the target “numerical value” is achieved based on data, there is often a slight difference from the quietness actually felt by the “ear” when the driver actually rides in the car, By using the AAS equalization function, the target quietness can be confirmed not only by “numerical values” but also by the actual cabin sound heard by the “ear”. This makes it possible to set targets with a high degree of certainty.

New lineup of compact types for easy installation and mobility.

The compact type AAS, newly developed in 2022, maintains the sound reproduction performance of the fullspec conventional model, but has been made small enough to be transported by a 4-ton truck by eliminating the large curved surface monitor and seat vibration device. The compact type requires only 10 m2 of space for installation, a space saving of more than 70% compared to the conventional model. By installing this compact type at each site where automotive acoustic development is conducted, it will be possible for the person in charge to check and evaluate the interior sound between benchmark vehicles without having to travel between sites in Japan and overseas for test drives and other events.

For more information, please refer toTOKAI Lab Technical Service Document (PDF).