Processing of signals from luminaire mounted microphones for enhancing sensor capabilities
The specification and drawings present a use of multiple microphones for increasing acoustic sensing capabilities by processing acoustic signals from the multiple microphones in outdoor luminaire mounted surveillance/sensor systems. For example, various embodiments presented herein describe signal processing means to utilize stereo/multiple microphones in a luminaire (such as an outdoor roadway luminaire) to provide enhanced information regarding the surroundings of the luminaire. The multiple microphone luminaire sensor processing system can provide a more environmentally robust and sensitive approach which can be, for example, resistant to environmental noise such as a wind noise, as well as capable of isolating specific sounds from the surroundings, e.g., in specific directions.
1. A method for using a plurality of microphones in a sensor module of a luminaire, the method comprising: receiving, by a computing module of the sensor module, information comprising a plurality of acoustic output signals from the corresponding plurality of microphones, and any of detection directionality and location for each of the plurality of microphones; processing, by the computing module, using the received information, the plurality of acoustic output signals to: identify a desirable acoustic signal at least in one of the plurality of acoustic output signals using analysis of the received plurality of acoustic output signals, and correlate the acoustic output signals with any of the detection directionalities and locations of the plurality microphones.
2. The method of claim 1 , wherein the processing is performed in a frequency domain using a fast Fourier transform.
3. The method of claim 1 , wherein the processing is performed in a time domain.
4. The method of claim 1 , wherein the processing, before said identifying and correlating, further comprises selecting acoustic output signals from the plurality of acoustic output signals which are above a noise floor level predefined and stored for each of the plurality of microphones.
5. The method of claim 1 , wherein, when at least two of selected acoustic output signals have different sound features, said correlation comprises associating each of the acoustic signals having different sound features, with a corresponding further signal from a further sensor of the luminaire having a same directionality as the corresponding detection directionality of the corresponding microphone.
6. The method of claim 5 , wherein the further sensor is a video camera, and the corresponding further signal is a video signal.
7. The method of claim 1 , wherein, when at least two of selected acoustic output signals have similar sound features but different noise levels, said identifying comprises choosing one of the selected acoustic signal with a minimum noise level.
8. The method of claim 1 , wherein the selected acoustic output signals have sound feature differences in a predefined range and have a similar noise level, a subtraction technique between the corresponding selected acoustic output signals is used to better isolate a specific sound of interest.
9. The method of claim 1 , further comprising: receive, wirelessly or through a wired connection, by the sensor module one or more further acoustic signals from corresponding one or more further microphones outside of the luminaire with information about further microphones' detection directionalities and locations; and further processing, by the computing module, the plurality of acoustic output signals with added one or more further acoustic signals for said identification and correlation.
10. The method of claim 1 , wherein the plurality of microphones are spatially separated and have different detection directionalities.
11. A luminaire comprising a sensor module which comprises: a plurality of microphones; a processor and a memory for storing program logic, the program logic executed by the processor, comprising: logic for receiving information comprising a plurality of acoustic output signals from the corresponding plurality of microphones, and any of detection directionality and location for each of the plurality of microphones; and logic for processing, using the received information, the plurality of acoustic output signals to: identify a desirable acoustic signal at least in one of the plurality of acoustic output signals using analysis of the received plurality of acoustic output signals, and correlate the acoustic output signals with any of the detection directionalities and locations of the plurality microphones.
12. The luminaire of claim 11 , wherein the processing is performed in a frequency domain using a fast Fourier transform.
13. The luminaire of claim 11 , wherein the processing is performed in a time domain.
14. The luminaire of claim 11 , wherein the processing, before said identifying and correlating, further comprises selecting acoustic output signals from the plurality of acoustic output signals which are above a noise floor level predefined and stored for each of the plurality of microphones.
15. The luminaire of claim 11 , wherein, when at least two of selected acoustic output signals have different sound features, said correlation comprises associating each of the acoustic signals having different sound features, with a corresponding further signal from a further sensor of the luminaire having a same directionality as the corresponding detection directionality of the corresponding microphone.
16. The luminaire of claim 15 , wherein the further sensor is a video camera, and the corresponding further signal is a video signal.
17. The luminaire of claim 11 , wherein, when at least two of selected acoustic output signals have similar sound features but different noise levels, said identifying comprises choosing one of the selected acoustic signal with a minimum noise level.
18. The luminaire of claim 11 , wherein the selected acoustic output signals have sound feature differences in a predefined range and have a similar noise level, a subtraction technique between the corresponding selected acoustic output signals is used to better isolate a specific sound of interest.
19. The luminaire of claim 11 , wherein the program logic further comprises: logic for receiving, wirelessly or through a wired connection, by the sensor module one or more further acoustic signals from corresponding one or more further microphones outside of the luminaire with information about further microphones' detection directionalities and locations; and logic for further processing, by the computing module, the plurality of acoustic output signals with added one or more further acoustic signals for said identification and correlation.
20. The luminaire of claim 11 , wherein the plurality of microphones are spatially separated and have different detection directionalities.