Silencions ANC Solution

Silencions s|ANC|

The Silencions ANC solution is new generation of active systems for noise cancelation. Based on the knowledge and experience of an interdisciplinary team of scientists and engineers in the fields of acoustics, algorithmics and mechatronics, an innovative system was developed based on machine learning for the harsh environmental conditions.

how does the Silencions S|ANC| system work?

THE POWER OF ANC

The use of machine learning and artificial intelligence make this solution unique and stands out with its unique features, such as:

the use of machine learning technology,
high efficiency, including higher frequencies,
robust design for harsh environmental conditions.

Active Noise Control Solution software

The Silencions system for active noise reduction is improved by using machine learning algorithms. Developed system involves the creation of a solution based on machine learning algorithms for the task of sound wave prediction. A significant advantage of the developed solution is the signal delay reduction by the analog-digital processing system. Initial 200 ms delay has been significantly reduced to a few ms, both through hardware and the developed software component.

Significant work also focused on development of an algorithm accumulating training sets. The designed solution works in two modes, learning and operation with ANC active. Both solutions are based on FxLMS type adaptive filters.

Data collected can be used to optimize the system in many ways. One of them is to use the data to predict the weights of adaptive filters by a neural network. This allows to avoid the long time of the system convergence to optimal weights in the case of sudden changes in the signal course.

Active Noise Control Solution hardware

The device housing was designed specifically for the developed board as shown in Fig. 1. This forced a complete redesign of the electronics housing for any demanding operational needs. Prototypes of individual elements and entire details were manufactured in accordance with the rapid prototyping methodology and were largely based on the use of additive technologies, including 3D printing method LPBF.

Fig. 2 shows final construction with all assembly elements. Tests showed compliance with IP34 and IK06 standards, which allowed for the commencement of certification. These tests were carried out with a positive result, confirming that the system housing meets the requirements of the IK06 standard, which indicates its impact resistance, and the internal protection standard. A certificate no. LT/606.3/2023 was issued confirming IP34 and IK06 compliance of the housing.

*Fig. 1 Assembly drawing of the housing made of 316L.*

*Fig.* *2 Photo of the final housing construction with the electronics installed.*

Test setup and experimental results

A prototype environment in the form of a ventilation duct was built for testing the system and algorithms as shown in Fig. 3. Such a prototype allowed for conducting research in controlled conditions with an approximate known sound propagation path.

Two sound sources were installed in the ventilation duct, and each of them fulfills a specific function. One speaker simulates a noise sound source, while the other speaker acts as an ANC source. The speakers used in the prototype are characterized by a wide frequency response (38Hz-18kHz) and were equipped with housings.

*Fig. 3 Prototype diagram of the ventilation duct, with noise source, ANC speaker, reference and error microphone.*

*Fig. 4 Comparison of active noise cancellation system efficiency for in-channel systems without active ANC (blue line) and with active ANC (red line).*

The developed solution for duct system applications was tested. Fig. 4 shows the effectiveness of the system without (blue line) and with active noise control system (red line) in the amplitude-frequency characteristic in the range up to 1250 Hz. The measurement was performed at the duct outlet location in close vicinity to error sensor.

In the case of measurements recorded for the system without the ANC system, the graph shows a significant reduction in the sound pressure level for the measured signal after the ANC system was activated. In the case of the first dominant frequency, the reduction was about 13.2 dB. For the second dominant frequency the obtained reduction was about 8 dB.

IP protection

As part of the developed strategy, it was decided to file a patent application. Single file covers two embodiments. Within the application, the examples were carefully described and documented through supporting technical diagrams. Patent application was submitted, this procedure was initiated in order to obtain legal protection for the developed innovative technology.

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We have been monitoring, diagnosing and solving noise and vibration problems for years. We create acoustic adaptations for special tasks.