WO2020012229A1

WO2020012229A1 - Selective active noise cancelling system

Info

Publication number: WO2020012229A1
Application number: PCT/IB2018/055205
Authority: WO
Inventors: Joaquim Leal RANGEL FONSECA; Rui Miguel CORREIA DIAS; Bruno Miguel DA SILVA MONTEIRO; Eduardo Gil FERRAZ SOARES MENDES; Paulo Jorge DA SILVA SANTOS; Jorge Miguel NUNES SANTOS CABRAL; Luis Alexandre MACHADO ROCHA
Original assignee: Universidade do Minho; Bosch Car Multimedia Portugal SA
Current assignee: Universidade do Minho; Bosch Car Multimedia Portugal SA
Priority date: 2018-07-12
Filing date: 2018-07-13
Publication date: 2020-01-16
Anticipated expiration: 2021-01-12

Abstract

The present application describes a selective active noise cancelling system, intending to solve the problem of reducing unwanted sound waves, representing noise, in a selective manner. The system now proposed is comprised by a noise-detection module and a noise-cancelling module. The noise-detection module is comprised by a set of noise sensors responsible to detect specific and pre-defined noise signals. The noise-cancelling module comprises a processor unit configured to execute active cancelling noise algorithms and a set of speakers for redirecting the resulting signal to the user. This approach allows to only configured noise sources are cancelled, leaving the rest of the environment unaltered.

Description

DESCRIPTION

"SELECTIVE ACTIVE NOISE CANCELLING SYSTEM"

Technical field

The present application relates to a selective active noise cancelling system.

Background art

The state of the art already discloses solutions based on audio headsets with integrated active noise cancelling systems (ANC) , which dispose a signal collector near the ears of the user. Those solutions rely on microphone feed forward ANC to tackle the problem and based on the signal it can act on a wider range of frequencies.

Document US 8,391,530 B2 describes a safety helmet, which, besides a protective function, also has communication functions such as for example listening to a sound signal from a loudspeaker. The safety helmet having an electroacoustic transducer for the delivery of a sound signal. That structure working as a headphone is to provide a device with which a background noise which is variable in respect of time can be suppressed, i.e. act as a noise reduction. The device for active background noise suppression further has a signal processing unit adapted to control the electroacoustic transducer in such a way that a background noise at the location of the first microphone, arranged in the region of the ear entrance, is compensated. The helmet has a second microphone for recording a speech signal. It is adjacent to the mouth or in the proximity of the mouth of the wearer. Such a safety helmet accordingly also has the functionality of a headset. Document US 2017/0178616 A1 discloses a noise reducing helmet. Such device includes a shell, an isolation layer disposed in the shell, two receptacles at opposing positions, two loudspeakers disposed in the two receptacles, two microphones disposed in the vicinity of the two loudspeakers, and an ANC module. Said ANC module comprises two channels that are electrically coupled to the two loudspeakers, wherein the error-signal input of each channel is electrically coupled to the microphone in the vicinity of the loudspeaker that, in turn, is electrically coupled to the output of the same channels. The reference-signal input of each channel is electrically coupled to the microphone in the vicinity of the loudspeaker that is electrically coupled to the output of the respective other channel. For each noise reducing signal, the corresponding error-signal is generated from the sound picked-up at the same position where the respective noise reducing signal is reproduced and the reference-signal is generated from the sound picked-up at the position where the respective other noise reducing signal is reproduced.

Summary

The present application describes a selective active noise cancelling system, comprising:

— a noise-detection module, installed in an apparatus generator of a noise to be cancelled; said module comprising a noise sensor unit and a processing unit, wherein the noise sensor unit is comprised by at least one sensor configured to sense at least one noise source; — a noise-cancelling module, installed in a user's device, comprising a processing unit configured to execute active noise cancelling algorithms, and a set of speakers adapted to redirect the output signal of the active noise cancelling algorithm to the user;

wherein the processing unit of the noise-detection module comprises a wireless communication module configured to transmit the data collected from the sensor unit to the processing unit of the noise cancelling module, said data being the input of the active noise cancelling algorithm.

In one embodiment of the system, the data transmission between noise-detection module and noise-cancelling module is performed using a radio communication protocol.

In one embodiment of the system, the output signal of the active noise cancelling algorithm is a reference signal in anti-phase, based on a sum of the noise signals collected by the noise sensor unit.

In one embodiment of the system, the apparatus generator of noise is a motorcycle.

Yet in another embodiment of the system, the user' s device is a helmet.

In one embodiment of the system, the speakers are earphones.

In another embodiment of the system, the noise source is the engine of the motorcycle. In one embodiment of the system, the noise source is the road surface, due to the vibrations produced in the motorcycle structure through the contact of the tires with said surface.

In one embodiment of the system, the at least one sensor of the noise sensor unit is an accelerometer.

General Description

The present application intends to solve the problem of reducing unwanted sound waves, representing noise, in a selective manner. According to the principles described herein, a selective active noise cancelling (ANC) system is implemented. In particular, the system now proposed is able to act on signals picked up by sensors configured to sense specific and pre-defined sources of noise, and thus important sounds to a user are not cancelled.

It is an object of the present application to provide a selective ANC system based on sensors for noise acquisition, which are directly integrated in the apparatus that generates the noise.

It is another object of the present application to provide a selective ANC system where only configured noise sources are cancelled, leaving the rest of the environment unaltered.

The above objects, features and advantages of the present application will be described in detail in the following description. In accordance with one aspect of the present application, the above and other objects can be accomplished by means of a selective ANC system comprising a noise- detection module and a noise-cancelling module. In one aspect of the present application, the noise-detection module is installed in the apparatus generator of noise, and is responsible to selectively sense the sources of noise to be cancelled, being comprised by a noise sensor unit, comprising at least one sensor that detects specific and pre-defined noise signal, and a processing unit configured to collect said data from all the sensors. The arrangement and number of noise sensors can be adjusted to the requirements of each case, in particular, with respect to the number of noise sources that need to be cancelled. The processing unit of the noise-detection module has an integrated wireless communication unit, through which the data collected is transmitted to the noise-cancelling module. The data link is established using any kind of wireless communication protocol, such as radio, near-field communication or cellular communication.

In another aspect of the present application, the noise cancelling module is integrated in a user's device, and comprises a processing unit, configured to execute ANC algorithms, with an integrated reception block, and a set of speakers. The reception block is configured to receive the data sent by the noise-detection module, which is the input of the ANC algorithm running in the processing unit. The output of this processing stage is the generation of a reference signal that is based on the noise generating conditions of the noises sensed by the noise-detection module. The reference signal represent a waveform that is in anti-phase, based on a sum of the noise signals collected by the noise sensor unit of the noise-detection module. The speakers are used to redirect the generated waveform to the user .

In one aspect of the present application, the system now developed is applied to vehicles, particularly to motorcycles. In this case, the noise-detection module is installed in the motorcycle body structure, where the noise to be cancelled is generated, and the noise-cancelling module is integrated in the helmet of the driver. The noise sensor unit of the noise-detection module is configured to detect any vibrations in the structure body of the motorcycle. In particular, the produced vibrations in the motorcycle structure through the contact of the tires with the surface of the road on which the vehicle is travelling and the engine itself are the main noise sources that the sensors of said unit will capture. The signal is then sent to the noise cancelling module integrated in the helmet for processing and for being redirected to the user by means of earphones.

With the present approach, the set of noise sensors are integrated directly in the apparatus that generates the noise, for example a motorcycle, and not in the helmet used by the driver, which goes against the traditional approaches that relies only on microphones to collect indiscriminate sound waves. Therefore, the technology now developed allows to select which sound waves to cancel, taking in consideration the safety of the driver and his surroundings, by not cancelling significant sounds like the horn of a vehicle, the sound of other vehicles when travelling, people talking, etc. Brief description of drawings

For easier understanding of this application, figures are attached in the annex that represent the forms of implementation which nevertheless are not intended to limit the technique disclosed herein.

Figure 1 illustrates the selective ANC system developed, in which the reference signs represent:

1 - apparatus generator of noise;

2 - noise-detection module;

3 - noise sensor unit;

4 - processing unit of the noise-detection module;

5 - noise-cancelling module;

6 - speakers;

7 - user's device;

10 - processing unit of the noise-cancelling module.

Figure 2 shows an embodiment of the selective ANC system developed, applied to a motorcycle and to the helmet of the respective driver, in which the reference signs represent:

1 - apparatus generator of noise - motorcycle;

2 - noise-detection module;

3 - noise sensor unit;

3.1, 3.2 - noise sensor;

4 - processing unit of the noise-detection module;

5 - noise-cancelling module;

6 - earphones;

6.1 - right channel;

6.2 - left channel;

7 - user's device - helmet;

8 noise sources;

8.1 engine ; 8.2 - road surface;

9 - ANC algorithm;

10 - processing unit of the noise-cancelling module.

Description of embodiments

Now, embodiments of the present application will be described with reference to the annexed drawings. However, they are not intended to limit the scope of this application.

In one embodiment, the selective ANC system is comprised by a noise-detection module (2), installed in the apparatus generator of the noise (1) to be cancelled and a noise cancelling module (5) integrated in a user's device (7) . In one embodiment of the selective ANC system, the apparatus generator of noise (1) is a motorcycle, and the user's device (7) is the helmet of the driver. Therefore, in this particular embodiment, the noise-detection module (2) is installed in the motorcycle (1) body structure and the noise cancelling module (5) is integrated in the helmet (7) .

In one embodiment, the noise-detection module (2) is comprised by a noise sensor unit (3) comprised by at least two noise sensors (3.1, 3.2) configured to detect the produced vibrations (8.1) through the contact of the tires with the surface of the road and to detect the sound produced by the engine (8.2) of the motorcycle (1) . In one embodiment, the noise sensor (3.1, 3.2) is an accelerometer. The noise-detection module (2) also comprises a processor unit (4), configured to collect the data from the sensors (3.1, 3.2) of the noise sensor unit (3), prior to sending it to the noise-cancelling module (5) integrated in the helmet (7), by means of an integrated wireless communication unit. In one embodiment, the communication between both modules (2, 5) is performed via a radio communication protocol.

In another embodiment, the noise-cancelling module (5) comprises a reception unit, a set of speakers (6) and a processor unit (10) configured to execute an ANC algorithm (9) . In one embodiment, the speakers (6) are earphones. By means of this processing stage, a reference signal based on the noise generating conditions of the noise sources (8) sensed by the noise-detection module (2) is generated. This reference signal represents a waveform that is in anti-phase, based on a sum of the noise signals collected by the sensors (3.1, 3.2) of the noise-detection module (2) . To output the generated waveform, a pair of earphones (6) inside the helmet (7) redirects the sound to the ears - right channel (6.1) and left channel (6.2) - of the driver, which will attenuate or cancel the overall noise generated in the motorcycle (1) .

This description is of course not in any way restricted to the forms of implementation presented herein and any person with an average knowledge of the area can provide many possibilities for modification thereof without departing from the general idea as defined by the claims. The forms of implementation described above can obviously be combined with each other. The following claims further define the forms of implementation.

Claims

1. Selective active noise cancelling system, comprising:

— a noise-detection module (2), installed in an apparatus generator of a noise to be cancelled; said module (2) comprising a noise sensor unit (3) and a processing unit (4) , wherein the noise sensor unit (3) is comprised by at least one sensor configured to sense at least one noise source (8);

— a noise-cancelling module (5), installed in a user's device (7), comprising a processing unit (10) configured to execute active noise cancelling algorithms (9), and a set of speakers (6) adapted to redirect the output signal of the active noise cancelling algorithm (9) to the user; wherein the processing unit (4) of the noise- detection module (2) comprises a wireless communication module configured to transmit the data collected from the sensor unit (3) to the processing unit (10) of the noise-cancelling module (5), said data being the input of the active noise cancelling algorithm ( 9 ) .

2 . System according to claim 1, wherein the data transmission between noise-detection module (2) and noise-cancelling module (5) is performed using a radio communication protocol.

3 . System according to any of the previous claims, wherein the output signal of the active noise cancelling algorithm (9) is a reference signal in anti-phase, based on a sum of the noise signals collected by the noise sensor unit (3) .

4 . System according to any of the previous claims, wherein the apparatus generator of noise (1) is a motorcycle.

5 . System according to claim 4, wherein the user's device

(7) is a helmet.

6. System according to claim 5, wherein the speakers (6) are earphones.

7 . System according to claim 4, wherein the noise source

(8) is the engine (8.1) of the motorcycle (1) .

8. System according to claim 4 or claim 7, wherein the noise source (8) is the road surface (8.2) due to the vibrations produced in the motorcycle (1) structure through the contact of the tires with said surface.

9 . System according to any of the claims 4 to 8, wherein the at least one sensor of the noise sensor unit (3) is an accelerometer.