Remote communication and control of acoustic detectors
View Patent ↗A method of controlling a function of an acoustic detector includes storing a reference power spectrum of a reference acoustic signal, the reference power spectrum being associated with a mode of operation of the acoustic detector; receiving an acoustic sound signal, the acoustic sound signal including a tone and harmonic tones; generating a real-time acoustic power spectrum of the acoustic sound signal responsive to the receiving of the acoustic sound signal; and performing the mode of operation when a comparison of the real-time acoustic power spectrum with the reference acoustic power spectrum indicates that the acoustic sound signal is a control signal.
1. A control system for controlling a function of an acoustic detector, comprising:
a memory that stores a reference power spectrum of a reference acoustic signal, the reference power spectrum being associated with a mode of operation of the acoustic detector;
a receiver including an analog signal conditioning circuit that receives an acoustic sound signal, the acoustic signal includes a tone and harmonic tones, wherein the receiver generates a real-time acoustic power spectrum in response to the receiving of the acoustic sound signal; and
a detector that performs the mode of operation when a comparison of the real-time acoustic power spectrum with the reference power spectrum indicates that the acoustic sound signal is a control signal;
wherein comparing the real-time acoustic power spectrum with the reference power spectrum includes normalizing each of the real-time acoustic power spectrum and the reference power spectrum and calculating a normalized mean squared error between the normalized real-time acoustic power spectrum and the normalized reference power spectrum and comparing the normalized mean squared error to a threshold to indicate that the acoustic sound signal is the control signal.
2. The control system of claim 1 , wherein the receiver comprises a microphone that generates an analog electrical signal representative of the acoustic sound signal within an audible frequency range over a plurality of octaves.
3. The control system of claim 2 , wherein the receiver comprises an analog-to-digital converter that samples the analog signal at regular intervals and converts it to a stream of digital samples.
4. The control system of claim 3 , wherein the receiver comprises a digital filter coupled to the analog-to-digital converter that processes the stream of digital samples from the analog-to-digital converter continuously and in real time using a plurality of fractional octave digital bandpass filters to obtain the real-time acoustic power spectrum of the acoustic sound signal.
5. The control system of claim 1 , wherein a source of the acoustic sound signal is one of a tuned rod, a whistle, or a piezoelectric transducer.
6. The control system of claim 1 , wherein the detector comprises a processor that analyzes a spectrum of the real-time acoustic power spectrum.
7. The control system of claim 1 , wherein the detector performs the one or more modes of operation when the normalized mean squared error is below the threshold.
8. The control system of claim 1 , wherein the acoustic sound signal is one of an unmodulated acoustic signal, a frequency modulated acoustic signal, or an amplitude modulated acoustic signal.
9. A method of controlling a function of an acoustic detector, comprising:
storing a reference power spectrum of a reference acoustic signal, the reference power spectrum being associated with a mode of operation of the acoustic detector;
receiving an acoustic sound signal, the acoustic sound signal including a tone and harmonic tones;
generating a real-time acoustic power spectrum of the acoustic sound signal responsive to the receiving of the acoustic sound signal; and
performing the mode of operation when a comparison of the real-time acoustic power spectrum with the reference power spectrum indicates that the acoustic sound signal is a control signal;
wherein comparing the real-time acoustic power spectrum with the reference power spectrum includes normalizing each of the real-time acoustic power spectrum and the reference power spectrum and calculating a normalized mean squared error between the normalized real-time acoustic power spectrum and the normalized reference power spectrum and comparing the normalized mean squared error to a threshold to indicate that the acoustic sound signal is the control signal.
10. The method of claim 9 , further comprising generating an analog electrical signal representative of the acoustic sound signal responsive to the receiving of the acoustic sound signal, the analog electrical signal representing an audible frequency range over a plurality of octaves.
11. The method of claim 10 , further comprising sampling the analog signal at regular intervals and converting it to a stream of digital samples.
12. The method of claim 11 , further comprising processing the stream of digital samples from the analog-to-digital converter continuously and in real time using a plurality of fractional octave digital bandpass filters to obtain the real-time acoustic power spectrum of the acoustic sound signal.
13. The method of claim 9 , wherein a source of the acoustic sound signal is one of a tuned rod, a whistle, or a piezoelectric transducer.
14. The method of claim 9 , wherein the detector comprises a processor configured for spectral analysis of the real-time acoustic power spectrum.
15. The method of claim 9 , further comprising performing the mode of operation when the normalized mean squared error is below the threshold.
16. The method of claim 9 , wherein the acoustic sound signal is one of an unmodulated acoustic signal, a frequency modulated acoustic signal, or an amplitude modulated acoustic signal.