Innovative applications of active noise reduction and sound generation technologies in contemporary electric vehicles

With the rapid development of electric vehicles, automakers are facing increasingly stringent acoustic requirements. Although traditional passive and active damping systems can suppress noise and vibration to a certain extent, they are expensive and cannot fully utilize the existing electric systems in the vehicle. MdynamiX, ​​in cooperation with the University of Applied Sciences Munich, has developed a revolutionary technology that provides automakers with an efficient and economical solution by utilizing existing electric motors to achieve active noise cancellation (ANC) and active sound generation (ASG).

1. Active Sound Generation (ASG)

1. Technical Background and Advantages
Modern electric vehicles are usually equipped with up to 40 electric drive systems, such as window lifts, sliding roofs, electric power steering, etc. However, these electric systems are idle most of the time. MdynamiX has proposed an innovative idea to use these idle electric motors to generate sound and vibration to optimize the acoustic environment inside the car.

The main advantages of this approach include:

Generate diverse sounds: Using existing motors, you can generate nearly any type of sound, including synthesized engine sounds, music, alarm sounds, and more.

Reduced costs: No additional hardware investment is required, thus reducing verification, procurement, installation and warranty costs.

Energy saving and environmental protection: This method has low energy consumption and can be achieved with minimal energy input.

2. Technical Implementation

ASG technology controls the three-phase AC current of the motor and converts it into an equivalent two-phase coordinate system to independently control torque and flux. This method allows fine manipulation of radial and tangential forces to generate the desired sound and vibration.

3. Application Examples

In practical applications, the effects of ASG technology can be demonstrated in the following video. The video shows the technical implementation and effects of the active sound generation project in cooperation between MdynamiX and the University of Applied Sciences Munich.

2. Active Noise Cancellation (ANC)

1. Technical background and advantages

The noise and vibration in electric vehicles mainly come from components such as the electric power steering (EPS) motor. These noises will be transmitted into the car through the body structure, affecting the riding comfort of passengers. ANC technology actively cancels these noises by adapting the phase and amplitude in real time and using the existing electric motor to optimize the acoustic environment in the car.

The main advantages of this approach include:

Significant noise reduction: Can significantly reduce the disturbing noise generated by the electric drive system.

Maintain performance: Does not affect motor performance and is decoupled from the control system.

Cost-effective: No additional hardware investment is required, which reduces costs, and the method has low energy consumption.

2. Technical Implementation

ANC technology adjusts the sound and vibration output of the motor in real time by adapting the filter online to minimize the instantaneous square error at the error sensor. This real-time adjustment allows the system to automatically optimize the noise reduction effect in different noise environments.

3. Application Examples

In the experiment, ANC technology demonstrated its effectiveness by suppressing interference signals with a frequency of 170Hz. For example, by adapting the filter, destructive interference with the target signal can be achieved, significantly reducing the noise in the driver's ears. Watch the MdynamiX DC motor and PMSM motor active noise reduction project in the following video to learn more about the actual application effect of this technology.

3. Experimental Results and Summary

In multiple experiments, ASG and ANC technologies have demonstrated their excellent performance and practical application value. For example, by effectively suppressing 170Hz frequency interference signals, these technologies significantly improved the acoustic environment in the car and improved riding comfort. In addition, these technologies have also demonstrated their effectiveness in actual driving environments, and can significantly improve the vehicle's NVH (noise, vibration and harshness) performance without increasing hardware costs.

The main conclusions include:

- Generate nearly any type of sound using existing motors without investing in additional hardware.

- Active noise reduction technology can significantly reduce the disturbing noise generated by the electric motor and improve the acoustic environment inside the car.

- The application of these technologies does not require additional hardware costs and has low energy consumption, making it a cost-effective solution.

IV. Conclusion

After the introduction of this article, I believe readers have a general understanding of MdynamiX's motor active noise reduction (ANC) and active sound generation (ASG).