CN113678797A - Fishery operation sea-area broadband acoustic signal dolphin acoustic driving method and system - Google Patents
Fishery operation sea-area broadband acoustic signal dolphin acoustic driving method and system Download PDFInfo
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Abstract
The invention relates to a fishery operation sea-area broadband acoustic signal dolphin acoustic dislodging method and a system thereof, which comprises the following steps: obtaining the dolphin response characteristics: acquiring a dolphin sound sensitive frequency range and a dolphin behavior response threshold of a dolphin species; acquiring response characteristics of other fishes: acquiring the sound sensitive frequency range of other fishes and the behavior response threshold of other fishes; and (3) adjusting: adjusting an acoustic dolphin-expelling signal to enable the acoustic signal energy of the acoustic dolphin-expelling signal in the range of the sound sensitive frequency band of other fishes to be smaller than the behavior response threshold of other fishes and the acoustic signal energy in the range of the sound sensitive frequency band of the dolphin to be larger than the behavior response threshold of the dolphin; a transmitting step: and continuously transmitting a plurality of acoustic dolphin driving signals to the underwater.
Description
Technical Field
The invention relates to the field of acoustic dolphin dislodging, in particular to a fishery operation dolphin acoustic dislodging method and system based on broadband acoustic signals.
Background
Small or medium-sized whales, which widely live in all oceans in the world, are distributed in the salt and fresh water near the entrances of inland seas and rivers, and individual species are found in inland rivers. Dolphins are a common whale. Marine fishery fishing is an important protein source for humans, but fishery fishing is often interfered and affected by dolphins. Dolphins seek fish schools and are therefore often mistakenly caught by fishing nets in fishery fishing operations.
In order to protect the teether whale, the existing method for driving away the teether whale, for example, chinese patent is a dolphin acoustic protection device and protection method based on medium-high frequency signals, and patent number CN201711213719.3, it is to transmit acoustic signals to the underwater in the fishing process, the acoustic signals have specific frequency band and waveform form, and play a role in sound wave driving protection for dolphins of widlosse and dolphins of china, but there is no clear conclusion on the application effect of other kinds of dolphins. The signal frequency of the production of this patent is along with covering three frequency points, but is the single-frequency signal, and the coverage bandwidth is narrow, can only have more stable effect of driveing to the mouse dolphin. In addition, in practical application, particularly in fishery fishing, the driving sound signal emitted by the device can obviously influence the fishes, and other fish groups are driven while dolphins are driven, so that normal fishery fishing operation is influenced.
The invention aims to design a fishery operation sea-area broadband acoustic signal dolphin acoustic dislodging method and a system thereof aiming at the problems in the prior art.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a fishery operation dolphin acoustic dislodging method and system based on broadband acoustic signals, and the method and system can effectively solve the problems in the prior art.
The technical scheme of the invention is as follows:
a fishery operation sea-area broadband acoustic signal dolphin acoustic dislodging method comprises the following steps:
obtaining the dolphin response characteristics: acquiring a dolphin sound sensitive frequency range and a dolphin behavior response threshold of a dolphin species;
acquiring response characteristics of other fishes: acquiring the sound sensitive frequency range of other fishes and the behavior response threshold of other fishes;
and (3) adjusting: adjusting an acoustic dolphin-expelling signal to enable the acoustic signal energy of the acoustic dolphin-expelling signal in the range of the sound sensitive frequency band of other fishes to be smaller than the behavior response threshold of other fishes and the acoustic signal energy in the range of the sound sensitive frequency band of the dolphin to be larger than the behavior response threshold of the dolphin;
a transmitting step: and continuously transmitting a plurality of acoustic dolphin driving signals to the underwater.
Further, the acoustic fugu-expelling signal is:
the signal duration is 0.8s-1.2 s;
the energy is 170dB re mu Pa-190dB re mu Pa;
the peak frequency is 26kHz-27kHz, the frequency range of the 10dB bandwidth is 22.5kHz-30.4kHz, and the frequency range of the 20dB bandwidth is 13.8kHz-49.7 kHz.
Further, the acoustic fugu-expelling signal is:
the signal duration is 1 s;
the energy is 180dB re mu Pa;
further, after the adjusting step and before the transmitting step, the method further comprises:
a monitoring step: recording original sonar signals of different types of whales, analyzing the original sonar signals, and establishing a database in which the original sonar signals are associated with the types of the whales; acquiring and recording an acquired sonar signal, analyzing the acquired sonar signal, comparing the acquired sonar signal with the database, judging whether a whale exists in the water area or not, and if so, executing an emission step.
Further, the specific method for analyzing the original sonar signals is as follows:
carrying out peak value sound pressure level calculation on the original sonar signal, and intercepting data to be analyzed from the original sonar signal if the original sonar signal is greater than a first peak value sound pressure threshold value;
analyzing the frequency spectrum of the data to be analyzed to obtain a signal frequency spectrum, acquiring a peak frequency of the signal frequency spectrum, acquiring a frequency distribution range of a first decibel bandwidth and a frequency distribution range of a second decibel bandwidth from the signal frequency spectrum by taking the peak frequency as a reference, acquiring a frequency bandwidth numerical value of the frequency distribution range of the first decibel bandwidth and defining the frequency bandwidth numerical value as a first characteristic value, acquiring a frequency bandwidth numerical value of the frequency distribution range of the second decibel bandwidth and defining the frequency bandwidth numerical value as a second characteristic value, and defining the peak frequency as a third characteristic value;
and performing time domain energy integration on the data to be analyzed to obtain energy accumulation distribution, counting the time difference T of the energy accumulation distribution in a first energy range, and defining T as a fourth characteristic value.
Further, the first peak sound pressure threshold is 160dB to 180dB, and the step of intercepting the data to be analyzed from the original sonar signal specifically includes: intercepting 70-80 us of data before and after the peak value of the original sonar signal as data to be analyzed;
the obtaining of the frequency distribution range of the first decibel bandwidth and the frequency distribution range of the second decibel bandwidth from the signal spectrum with the peak frequency as a reference specifically includes: acquiring a frequency distribution range of a first decibel bandwidth and a frequency distribution range of a second decibel bandwidth from the signal frequency spectrum by taking the peak frequency as a center, wherein the first decibel bandwidth is a-3 decibel bandwidth, and the second decibel bandwidth is a-10 decibel bandwidth;
the first energy range is 2.5% -97.5%, and the time difference v ^ T of the energy cumulative distribution in the first energy range is counted as: obtaining a time point T at which said cumulative distribution of energy corresponds to 2.5% of the energy1Time point T corresponding to 97.5% of energy of said cumulative distribution of energy2Time difference ═ T2-T1。
Further, the specific method for analyzing the collected sonar signals is the same as the specific method for analyzing the original sonar signals.
Further, the establishing of the database of the correlation between the original sonar signals and the beluga species is specifically as follows: the first characteristic value, the second characteristic value, the third characteristic value and the fourth characteristic value are associated with the whale type, and a database is established; the analysis of the sonar signal acquisition and the comparison with the database specifically comprises the following steps: and analyzing the first characteristic value, the second characteristic value, the third characteristic value and the fourth characteristic value of the collected sonar signals, and comparing the first characteristic value, the second characteristic value, the third characteristic value and the fourth characteristic value with the database to judge whether the whale exists in the water area.
Further provides a fishery operation sea-area broadband acoustic signal dolphin acoustic dislodging system, which comprises the following modules:
dolphin response characteristic acquisition module: the method is used for acquiring the dolphin sound sensitive frequency range and the dolphin behavior response threshold of the dolphin species;
other fish response characteristic acquisition module: the method is used for acquiring the sound sensitive frequency range of other fishes and other fish behavior response thresholds of other fishes;
an adjusting module: the system is used for adjusting the acoustic dolphin-expelling signal, so that the acoustic signal energy of the acoustic dolphin-expelling signal in the range of the sound sensitive frequency band of other fishes is smaller than the behavior response threshold of other fishes, and the acoustic signal energy in the range of the sound sensitive frequency band of the dolphin is larger than the behavior response threshold of the dolphin;
further comprises a signal generating unit, a digital-to-analog converting unit, a power amplifying unit, an underwater acoustic emission transducer and a power supply unit,
the signal generating unit is used as a signal source and used for generating a sound source signal, the working peak frequency of the signal generating unit is more than 20kHz, and the-10 dB bandwidth frequency range and the-20 dB bandwidth frequency range of the working frequency band range of the signal generating unit are more than 10kHz and more than 30 kHz;
the digital-to-analog conversion unit is used for converting the digital signal generated by the signal generation unit into an analog signal;
the power amplification unit is used for regulating and controlling the energy of the sounding source signal and can increase the sound source level to more than 180dBre mu Pa;
the underwater sound emission transducer group is used for converting the analog electric signals into sound waves and radiating the sound waves in water.
Accordingly, the present invention provides the following effects and/or advantages:
the invention makes the acoustic signal energy of the acoustic dolphin-expelling signal in the range of the acoustic sensitive frequency band of other fishes less than the behavioral response threshold of other fishes and more than the behavioral response threshold of dolphin by adjusting the acoustic dolphin-expelling signal; and continuously transmitting a plurality of acoustic dolphin-driving signals underwater. The invention is based on the acoustic driving principle, and drives dolphin out of the fishing operation area by transmitting dolphin sensitive frequency sound waves; based on the difference of sound sensitive frequency bands of different kinds of dolphins, a fishery operation dolphin acoustic driving method with broadband sound signals is provided, so that the problem of sound wave driving of different kinds of dolphins is solved; acquiring the sound sensitive frequency range and the corresponding behavior response threshold of different kinds of dolphins by collecting data or testing experiments in the early stage, and selecting corresponding signal parameters according to a field object to be driven in practical application; scientific and convenient, has strong adaptability, and can be applied to the acoustic dislodging of dolphins in different scenes such as wading engineering, fishery fishing and the like.
The invention has practical significance for guaranteeing fishermen operation and avoiding dolphin mis-catching. In fishing, dolphins are mistakenly caught by a fishing net as the fish swim into a fishing net laying area. The invention can emit sound waves with sensitive frequency of dolphin hearing in real time in the field, drive dolphin to be outside the fishing operation area, reduce the discovery that dolphin is caught by mistake and realize protection. The invention has practical application cases, successfully realizes dolphin driving in fishing in south China sea fishery, and has very strong application prospect.
According to the method, the variety of the odontocetia can be quickly and effectively judged by acquiring the sonar signals in the water area in the subsequent water area monitoring through establishing the database related to the odontocetia sonar signals and associating the sonar signals with the variety of the odontocetia.
The monitoring method provided by the invention is used for matching the characteristics of the sonar signals of the whales, only acquiring the sonar signals above 160 dB-180 dB, and simultaneously intercepting the data of 70 us-80 us before and after the peak value of the sonar signals, so that the characteristics of the sonar signals of most of the whales can be met, the noise doped in the sonar signals is eliminated, and the data more beneficial to subsequent processing is obtained.
According to the method, the collected acoustic signals are subjected to parameter analysis of time difference, peak frequency, -3dB bandwidth and-10 dB bandwidth, the parameters are stored, a database is built, meanwhile, the variety of the whale is identified by using the parameters of the time difference, the peak frequency, -3dB bandwidth and-10 dB bandwidth, the traditional method for identifying the type of the whale by using images is broken through, the activity of the whale can be detected under different weather and time, the influence of whether the whale is floating on the water surface is avoided, and convenience is provided for field investigation of the whale.
The system provided by the invention has strong technical applicability, and can self-define signal parameters including signal frequency, waveform form and the like through the signal generation unit based on the difference of sound sensitive frequency bands of different dolphin species so as to adapt to the acoustic driving of different dolphin species; according to the invention, through self-adaptive control of the energy and frequency of the transmitted acoustic signal, the energy of the transmitted acoustic signal in the fish hearing sensitive area is smaller than the hearing threshold of the fish, so that the fish can be protected from being influenced, thereby ensuring fishery fishing; all components of the invention are integrated in the case, the structure is simple and portable, the operation is convenient and not complicated, the conversion cost is low, and the invention can be applied to the acoustic driving of dolphins in different scenes; in addition, the invention can also be used as an experimental system for carrying out a dolphin acoustic drive-off experiment to obtain the sound sensitive frequency range and the corresponding behavior response threshold of different kinds of dolphins.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
Drawings
FIG. 1 is a schematic flow chart of the present invention.
Fig. 2 is a power spectrum density level curve of an acoustic fugu signal and a hearing threshold curve of dolphin and other fishes.
Fig. 3 is a time domain waveform diagram of an acoustic fugu driving signal.
FIG. 4 is a schematic flow chart of the monitoring step.
Fig. 5 is a waveform diagram of an original sonar signal.
Fig. 6 is a sonar waveform of the chinese white dolphin in the time domain.
Fig. 7 shows a sonar waveform of eastern asian finless porpoise in the time domain.
Fig. 8 shows the sound pressure levels of the sonar waveforms of the chinese white dolphin and the east asia finless porpoise.
Fig. 9 shows the duration of the sonar waveform of the chinese white dolphin and the east asian finless porpoise.
Fig. 10 is a waveform diagram of data to be analyzed.
Fig. 11 is a frequency domain diagram of fig. 10 after FFT.
Fig. 12 is an energy accumulation diagram obtained by integration of fig. 10.
FIG. 13 shows the frequency domain characteristics of sonar signals from Chinese white dolphin and east Asia finless dolphin.
FIG. 14 is a plot of the peak frequency, -3dB bandwidth and-10 dB bandwidth profiles of FIG. 13.
FIG. 15 is a table of characteristic values of Chinese white dolphin and east Asia finless porphin.
FIG. 16 is a schematic diagram of the composition of a dolphin acoustic dislodging system.
Fig. 17 is a graph of experimental data.
Detailed Description
To facilitate understanding of those skilled in the art, the structure of the present invention will now be described in further detail by way of examples in conjunction with the accompanying drawings:
referring to fig. 1, a fishery operation sea-area broadband acoustic signal dolphin acoustic dislodging method includes the following steps:
s1, obtaining the dolphin response characteristics: acquiring a dolphin sound sensitive frequency range and a dolphin behavior response threshold of a dolphin species;
s2, acquiring response characteristics of other fishes: acquiring the sound sensitive frequency range of other fishes and the behavior response threshold of other fishes;
in this embodiment, the sound sensitive frequency range and the corresponding behavior response threshold of each dolphin species and other fishes are obtained by referring to data or developing a test experiment, so as to determine the frequency range and the response threshold in steps S1-S2. Wherein, the dolphin species sound sensitive frequency band or other fish sound sensitive frequency band range is that the acoustic organ of each dolphin species or other fish can sense the range in the frequency range; the dolphin behavioral response threshold or other fish behavioral response threshold is above a threshold that can be perceived by the auditory organs of the individual dolphin species or other fish. If not within the frequency band, or below the threshold, the dolphin or other fish will not respond to the acoustic signal.
As shown in fig. 2, in the dolphin driven in this embodiment, the auditory response sensitive region may be from 10kHz to 80kHz, and the corresponding response threshold range is about 55dB to 107dB, wherein the most sensitive frequency point of auditory sense is 40kHz, the auditory threshold is 55dB, the auditory response sensitive frequency band of other fishes is mainly below 1kHz, the corresponding auditory threshold is 104dB to 151dB, and the most sensitive frequency point of 300Hz of auditory sense is 104 dB. Namely, the range of the sound sensitive frequency band of the dolphin is 10kHz to 80kHz, the response threshold of the dolphin behavior is 55dB to 107dB, the range of the sound sensitive frequency band of other fishes is below 1kHz, and the response threshold of the behavior of other fishes is 104dB to 151 dB.
S3, adjusting: adjusting an acoustic dolphin-expelling signal to enable the acoustic signal energy of the acoustic dolphin-expelling signal in the range of the sound sensitive frequency band of other fishes to be smaller than the behavior response threshold of other fishes and the acoustic signal energy in the range of the sound sensitive frequency band of the dolphin to be larger than the behavior response threshold of the dolphin; the acoustic fugu-expelling signal is:
the signal duration is 0.8s-1.2 s;
the energy is 170dB re mu Pa-190dB re mu Pa;
the peak frequency is 26kHz-27kHz, the frequency range of the 10dB bandwidth is 22.5kHz-30.4kHz, and the frequency range of the 20dB bandwidth is 13.8kHz-49.7 kHz.
The high-energy frequency spectrum region of the acoustic dolphin driving signal is overlapped with the dolphin sound sensitive frequency band range region, the energy of each frequency point in the region is higher than a dolphin behavior response threshold, and meanwhile, in other fish sound sensitive frequency band regions, the intensity is lower than other fish behavior response thresholds, so that the dolphin is driven without influencing fishes. In the implementation process, the signal adopts a continuous transmission mode and the sound wave transmission source level can be adjusted through the power amplification unit. The acoustic dolphin-driving signal of the embodiment is broadband, can be induced by various dolphins and makes behavior response, and has a wider audience range compared with the fixed-point frequency of the traditional method.
The acoustic dolphin-driving signal is based on an acoustic driving principle, and drives dolphins away from the fishery fishing operation area by transmitting dolphin sensitive frequency sound waves; based on the difference of sound sensitive frequency bands of different kinds of dolphins, a fishery operation dolphin acoustic driving method with broadband sound signals is provided, so that the problem of sound wave driving of different kinds of dolphins is solved; acquiring the sound sensitive frequency range and the corresponding behavior response threshold of different kinds of dolphins by collecting data or testing experiments in the early stage, and selecting corresponding signal parameters according to a field object to be driven in practical application; scientific and convenient, has strong adaptability, and can be applied to the acoustic dislodging of dolphins in different scenes such as wading engineering, fishery fishing and the like.
S4, monitoring: referring to fig. 4, recording original sonar signals of different kinds of whales, analyzing the original sonar signals, and establishing a database in which the original sonar signals are associated with the whale kinds; acquiring and recording collected sonar signals, analyzing the collected sonar signals, comparing the collected sonar signals with the database, judging the type of the whale, judging whether the whale exists in the water area or not, and if so, executing the emission step.
Specifically, the underwater acoustic transducer, the power amplifier and the digital-to-analog conversion unit are adopted in the implementation, the real-time collected acoustic signals can be transmitted to the software part for post-processing, the collection coverage frequency range can reach 200kHz, and the requirement of whale sonar signal collection with different frequencies and different bandwidths can be met. An underwater acoustic transducer is a tool that can perform electric energy-acoustic energy conversion underwater. The electric signal is transmitted to the digital-to-analog conversion unit and converted into an analog signal, the sampling rate is 400kS/s, and the conversion from low, medium and high frequency digital signals to the analog signal can be realized.
And laying cloth drainage acoustic transducers in a working sea area by using an investigation ship or a field experiment carrying platform. Underwater sound signals, namely sonar, are collected by an underwater acoustic transducer.
Firstly, a database is established, original sonar signals of different types of whales are recorded in a water area through a water-sound transducer, and the signal source of the original sonar signals can be the recorded sonar signals of the different types of whales in advance or the sonar signals of the different types of whales which are recorded in the water area in real time. Through continuously collecting one or more original sonar signals with the length of 1s, threshold setting is carried out on various acoustic parameters of the original sonar signals of different types of whales, the obtained original sonar signals are associated with the whale types, and a database is established.
Then, record the collection sonar signal at corresponding waters through underwater acoustic transducer, through continuous real-time, gather one or more collection sonar signals of 1s length, whether the analysis is gathered sonar signal belongs to the sonar signal that tooth whale sent, if, then each item acoustic parameter of the analysis collection sonar signal, judge whether each item acoustic parameter of gathering the sonar signal falls into the threshold value scope that certain tooth whale kind corresponds in the database, if then can judge out tooth whale kind according to the threshold value scope that corresponds.
And finally, prompting the workers to have the whales in the water area through a display screen and the like, wherein the whales are the types of the whales.
The original sonar signals and the collected sonar signals are one or more acoustic signals with the length of 0.8s-1.2 s. In this embodiment, both the original sonar signals and the collected sonar signals are 1s, and in other embodiments, the time may be 0.8s or 1.2 s. As shown in fig. 5.
The specific method for analyzing the collected sonar signals is the same as the specific method for analyzing the original sonar signals, and only the specific method for analyzing the original sonar signals is specifically described herein, and the specific method for analyzing the collected sonar signals can be analogized in turn.
The specific method for analyzing the original sonar signals comprises the following steps:
s4.1, performing peak value sound pressure level calculation on the original sonar signal, and if the original sonar signal is greater than a first peak value sound pressure threshold value, intercepting 70-80 us of data before and after the original sonar signal corresponding to the peak value as data to be analyzed; the first peak sound pressure threshold value is 160 dB-180 dB.
Specifically, peak sound pressure level calculation is performed on the original sonar signal, and if the original sonar signal is greater than 170dB, 75us of data before and after the original sonar signal corresponding to the peak value is intercepted from the original sonar signal, and 150us of data in total is used as data to be analyzed and stored and used for processing in subsequent steps. This is because underwater sonar signals are many and complicated, and it is necessary to filter out irrelevant signals by setting a threshold value and simply determine whether the sonar signals belong to sonar signals from whales. Referring to fig. 6-9, fig. 6 is a sonar waveform of a chinese white dolphin in the time domain, and fig. 7 is a sonar waveform of a east asian finless dolphin in the time domain, where the abscissa is time and the ordinate is amplitude. Fig. 8 is a sound pressure level of a sonar waveform of the chinese white dolphin and the east asian finless porpoise, and fig. 9 is a time length of the sonar waveform of the chinese white dolphin and the east asian finless porpoise. Through a large amount of sound signal analysis of whale, the applicant finds that the distribution interval of the Chinese white dolphin in the duration is approximately 20.6-57.5 microseconds, the sound pressure level of the Chinese white dolphin is 190.8-198.6dB, and the sound pressure level of the Chinese white dolphin is 163.58-179.5 dB. Because the energy of the acoustic signal emitted by the dolphin attenuates with distance of propagation, an optimal threshold is set at 170dB based on the monitored coverage distance. Therefore, the sonar signal is defined to be more than 170dB, so that the sound waveform of the whale is considered to be contained, and 150us is the most researched value before and after the peak value of the sound waveform. In this embodiment, most of useless waveforms can be filtered out by setting the two parameters to obtain an optimal sonar signal, as shown by a dotted line frame in fig. 5, and the data to be analyzed obtained by interception is shown in fig. 10.
S4.2, analyzing the frequency spectrum of the data to be analyzed to obtain a signal frequency spectrum, obtaining the peak frequency of the signal frequency spectrum, and obtaining the frequency distribution range of a first decibel bandwidth and the frequency distribution range of a second decibel bandwidth from the signal frequency spectrum by taking the peak frequency as a center, wherein the first decibel bandwidth is-3 decibel bandwidth, and the second decibel bandwidth is-10 decibel bandwidth. And acquiring a frequency bandwidth numerical value of the frequency distribution range of the-3 dB bandwidth and defining the frequency bandwidth numerical value as a first characteristic value, acquiring a frequency bandwidth numerical value of the frequency distribution range of the-10 dB bandwidth and defining the frequency bandwidth numerical value as a second characteristic value, and defining the peak frequency as a third characteristic value.
Specifically, the data to be analyzed is subjected to FFT to obtain a frequency domain graph as shown in fig. 11, where the abscissa is frequency and the ordinate is decibel. The frequency point corresponding to the spectral peak is defined as the peak frequency fp, and the spectral energy value P is read. It can be obtained that the peak frequency is 100kHz and a frequency distribution range of-3 db bandwidth and a frequency distribution range of-10 db bandwidth are obtained from the signal spectrum centered at 100 kHz. The decibel bandwidth refers to a bandwidth corresponding to a drop of a corresponding decibel in a spectrogram with a certain point as a reference. In this embodiment, the peak frequency is used as a key point, and is reduced by 3dB and 10dB to obtain bandwidths corresponding to the two dashed lines shown in fig. 11, and a value corresponding to the dashed line is obtained on the X axis, and a range corresponding to the value, that is, a frequency bandwidth value, is obtained to obtain a first eigenvalue, a second eigenvalue, and a third eigenvalue.
S4.3, performing time domain energy integration on the data to be analyzed to obtain energy accumulation distribution, counting time difference T of the energy accumulation distribution in a first energy range, and defining T as a fourth characteristic value.
Specifically, the waveform shown in fig. 10 is integrated, resulting in an energy accumulation map as shown in fig. 12. The energy of the pulse is integrated, assuming that the pulse is x (n), and the energy E is defined as
It can be seen that the graph of the energy accumulation of the sonar signal of the whale initially has a slope close to 0, then the slope rises suddenly and rapidly, and finally the slope approaches 0 again, and the energy is concentrated in the middle part. Duration is defined as E2.5％Corresponding time point T1To E97.5％Corresponding time point T2Time difference between ═ T2-T1. The calculated time difference ∑ T is also an important parameter of the sonar signal of the whale, and is defined as a fourth feature value.
The applicant finds that the four characteristic values are closely related to the sound of the dolphin, and the kinds of dolphin can be distinguished through the four characteristic values. Then, a database is established by associating the first characteristic value, the second characteristic value, the third characteristic value and the fourth characteristic value with the whale species.
Through four eigenvalues, sonar signals can be detected in real time for different water areas, the collected sonar signals are analyzed, and the steps of analysis are similar to the steps S4.1-S4.3, which are not described again. And obtaining four characteristic values of the collected sonar signals, comparing the first characteristic value, the second characteristic value, the third characteristic value and the fourth characteristic value with the database to obtain the type of the whales matched with the characteristic values, judging whether the whales exist in the water area or not, and if so, executing the transmitting step.
S5, a transmitting step: and continuously transmitting a plurality of acoustic dolphin driving signals to the underwater.
In this embodiment, the acoustic dolphin-expelling signal is:
the signal duration is 1s, and in other embodiments, the signal duration may be 0.8s or 1.2 s.
The energy is 180dB re μ Pa, and in other embodiments, the energy may be 170dB re μ Pa or 190dB re μ Pa.
The peak frequency is 26kHz to 27kHz, the bandwidth of 10dB is 7.9kHz, the frequency range is 22.5kHz to 30.4kHz, the bandwidth of 20dB is 7.9kHz, the frequency range is 13.8kHz to 49.7kHz, the peak frequency is 26.7kHz in the embodiment, and the peak frequency can be 26kHz or 27kHz in other embodiments.
Example two
Further provides a fishery operation sea-area broadband acoustic signal dolphin acoustic dislodging system, which comprises the following modules: with reference to figure 16 of the drawings,
dolphin response characteristic acquisition module: the method is used for acquiring the dolphin sound sensitive frequency range and the dolphin behavior response threshold of the dolphin species;
other fish response characteristic acquisition module: the method is used for acquiring the sound sensitive frequency range of other fishes and other fish behavior response thresholds of other fishes;
an adjusting module: the system is used for adjusting the acoustic dolphin-expelling signal, so that the acoustic signal energy of the acoustic dolphin-expelling signal in the range of the sound sensitive frequency band of other fishes is smaller than the behavior response threshold of other fishes, and the acoustic signal energy in the range of the sound sensitive frequency band of the dolphin is larger than the behavior response threshold of the dolphin;
further comprises a signal generating unit, a digital-to-analog converting unit, a power amplifying unit, an underwater acoustic emission transducer and a power supply unit,
the signal generating unit is used as a signal source and used for generating a sound source signal, the working peak frequency of the signal generating unit is more than 20kHz, and the-10 dB bandwidth frequency range and the-20 dB bandwidth frequency range of the working frequency band range of the signal generating unit are more than 10kHz and more than 30 kHz;
the digital-to-analog conversion unit is used for converting the digital signal generated by the signal generation unit into an analog signal;
the power amplification unit is used for regulating and controlling the energy of the sound source signal and can increase the sound source level to more than 180dBre mu Pa.
The underwater sound emission transducer group is used for converting the analog electric signals into sound waves and radiating the sound waves in water.
The working principle of this embodiment is basically the same as that of the first embodiment, and the detailed description thereof is omitted.
Experimental data
By the method provided by the embodiment I, the dolphin sound sensitive frequency range is 10 kHz-80 kHz, the dolphin behavior response threshold is 55dB-107dB, the sound sensitive frequency range of other fishes is below 1kHz, and the behavior response threshold of other fishes is 104dB-151 dB.
Adjusting the acoustic fugu-expelling signal to: the signal duration is 1s, the energy is 180dB re mu Pa, the peak frequency is 26.7kHz, the bandwidth of-10 dB is 7.9kHz, the frequency range is 22.5kHz-30.4kHz, the bandwidth of-20 dB is 7.9kHz, and the frequency range is 13.8kHz-49.7 kHz.
Establishing a database by the method, and referring to fig. 13-14, wherein the database at least comprises China white dolphin and east Asia finless porphin, wherein the peak frequency of the China white dolphin is 31.435k-135.041k, and the average value is 80.461 k; peak frequency 127.29k-140.448k of finless porpoise, mean 133.345 k; the-3 dB bandwidth of the Chinese white dolphin is 8.900kHz-81.281kHz, and the average value is 39.334 kHz; the-3 dB bandwidth of the finless porpoise is 7.795kHz-21.355kHz, and the average value is 11.753 kHz; the-10 dB bandwidth of the Chinese white dolphin is 60.143kHz-158.086kHz, and the average value is 98.467 kHz; the-10 dB bandwidth of the finless porpoise is 15.3-36.6kHz, and the average value is 26.9 kHz. The time difference of the Chinese white dolphin is 20.6-57.5 microseconds, and the time difference of the Jiangtong dolphin is 47.5-115.6 microseconds, which is specifically referred to fig. 15. The acoustic signal characteristics of other kinds of dolphins can be obtained by the method, again without specific expansion. By establishing the database, acquiring sonar signals in different water areas in real time, analyzing four characteristic values of the acquired sonar signals, and comparing the characteristic values with the database, the type of whales can be accurately judged, and whether dolphins exist can be judged.
In the process of fishing in south China sea fishery, when dolphin is detected in the water area, a plurality of acoustic dolphin driving signals are continuously transmitted to the water. Referring to fig. 17, dolphin acoustic drive-out experiments in the water field; (a) the method and the system provided by the application are proved to be effective by emitting the acoustic wave front (b) and emitting the acoustic wave, the dolphin sails away from the experimental ship (c) and disappears in the visual field range, and other fishes do not disappear in the visual field range.
The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the present invention.
Claims (10)
1. A fishery operation sea-area broadband acoustic signal dolphin acoustic driving method is characterized by comprising the following steps: comprises the following steps:
obtaining the dolphin response characteristics: acquiring a dolphin sound sensitive frequency range and a dolphin behavior response threshold of a dolphin species;
acquiring response characteristics of other fishes: acquiring the sound sensitive frequency range of other fishes and the behavior response threshold of other fishes;
and (3) adjusting: adjusting an acoustic dolphin-expelling signal to enable the acoustic signal energy of the acoustic dolphin-expelling signal in the range of the sound sensitive frequency band of other fishes to be smaller than the behavior response threshold of other fishes and the acoustic signal energy in the range of the sound sensitive frequency band of the dolphin to be larger than the behavior response threshold of the dolphin;
a transmitting step: and continuously transmitting a plurality of acoustic dolphin driving signals to the underwater.
2. The fishery operations sea-area broadband acoustic signal dolphin acoustic dislodging method according to claim 1, characterized in that: the acoustic fugu-expelling signal is:
the signal duration is 0.8s-1.2 s;
the energy is 170dB re mu Pa-190dB re mu Pa;
the peak frequency is 26kHz-27kHz, the frequency range of the 10dB bandwidth is 22.5kHz-30.4kHz, and the frequency range of the 20dB bandwidth is 13.8kHz-49.7 kHz.
3. The fishery operations sea-area broadband acoustic signal dolphin acoustic dislodging method according to claim 2, characterized in that: the acoustic fugu-expelling signal is:
the signal duration is 1 s;
the energy is 180dB re μ Pa.
4. The fishery operations sea-area broadband acoustic signal dolphin acoustic dislodging method according to claim 1, characterized in that: after the adjusting step and before the transmitting step, further comprising:
a monitoring step: recording original sonar signals of different types of whales, analyzing the original sonar signals, and establishing a database in which the original sonar signals are associated with the types of the whales; acquiring and recording an acquired sonar signal, analyzing the acquired sonar signal, comparing the acquired sonar signal with the database, judging whether a whale exists in the water area or not, and if so, executing an emission step.
5. The fishery operations sea-area broadband acoustic signal dolphin acoustic dislodging method according to claim 4, characterized in that:
the specific method for analyzing the original sonar signals comprises the following steps:
carrying out peak value sound pressure level calculation on the original sonar signal, and intercepting data to be analyzed from the original sonar signal if the original sonar signal is greater than a first peak value sound pressure threshold value;
analyzing the frequency spectrum of the data to be analyzed to obtain a signal frequency spectrum, acquiring a peak frequency of the signal frequency spectrum, acquiring a frequency distribution range of a first decibel bandwidth and a frequency distribution range of a second decibel bandwidth from the signal frequency spectrum by taking the peak frequency as a reference, acquiring a frequency bandwidth numerical value of the frequency distribution range of the first decibel bandwidth and defining the frequency bandwidth numerical value as a first characteristic value, acquiring a frequency bandwidth numerical value of the frequency distribution range of the second decibel bandwidth and defining the frequency bandwidth numerical value as a second characteristic value, and defining the peak frequency as a third characteristic value;
and performing time domain energy integration on the data to be analyzed to obtain energy accumulation distribution, counting the time difference T of the energy accumulation distribution in a first energy range, and defining T as a fourth characteristic value.
6. The fishery operations sea-area broadband acoustic signal dolphin acoustic dislodging method according to claim 5, characterized in that:
the first peak sound pressure threshold value is 160 dB-180 dB, and the step of intercepting the data to be analyzed from the original sonar signal specifically comprises the following steps: intercepting 70-80 us of data before and after the peak value of the original sonar signal as data to be analyzed;
the obtaining of the frequency distribution range of the first decibel bandwidth and the frequency distribution range of the second decibel bandwidth from the signal spectrum with the peak frequency as a reference specifically includes: acquiring a frequency distribution range of a first decibel bandwidth and a frequency distribution range of a second decibel bandwidth from the signal frequency spectrum by taking the peak frequency as a center, wherein the first decibel bandwidth is a-3 decibel bandwidth, and the second decibel bandwidth is a-10 decibel bandwidth;
the first energy range is 2.5% -97.5%, and the time difference v ^ T of the energy cumulative distribution in the first energy range is counted as: obtaining a time point T at which said cumulative distribution of energy corresponds to 2.5% of the energy1Time point T corresponding to 97.5% of energy of said cumulative distribution of energy2Time difference ═ T2-T1。
7. The fishery operations sea-fish acoustic method of wide frequency acoustic signal dolphin according to claim 5 or 6, wherein: the specific method for analyzing the collected sonar signals is the same as the specific method for analyzing the original sonar signals.
8. The fishery operations sea-area broadband acoustic signal dolphin acoustic dislodging method according to claim 7, characterized in that: the establishing of the database of the correlation between the original sonar signals and the whale species specifically comprises the following steps: the first characteristic value, the second characteristic value, the third characteristic value and the fourth characteristic value are associated with the whale type, and a database is established; the analysis of the sonar signal acquisition and the comparison with the database specifically comprises the following steps: and analyzing the first characteristic value, the second characteristic value, the third characteristic value and the fourth characteristic value of the collected sonar signals, and comparing the first characteristic value, the second characteristic value, the third characteristic value and the fourth characteristic value with the database to judge whether the whale exists in the water area.
9. A fishery operation sea area broadband acoustic signal dolphin acoustic driving-away system is characterized in that: the system comprises the following modules:
dolphin response characteristic acquisition module: the method is used for acquiring the dolphin sound sensitive frequency range and the dolphin behavior response threshold of the dolphin species;
other fish response characteristic acquisition module: the method is used for acquiring the sound sensitive frequency range of other fishes and other fish behavior response thresholds of other fishes;
an adjusting module: the method is used for adjusting the acoustic dolphin-expelling signal, so that the acoustic signal energy of the acoustic dolphin-expelling signal in the range of the acoustic sensitive frequency band of other fishes is smaller than the behavioral response threshold of other fishes, and the acoustic signal energy in the range of the acoustic sensitive frequency band of the dolphin is larger than the behavioral response threshold of the dolphin.
10. The fishery operations sea-area broadband acoustic signal dolphin acoustic dislodging system of claim 9, wherein: further comprises a signal generating unit, a digital-to-analog converting unit, a power amplifying unit, an underwater acoustic emission transducer and a power supply unit,
the signal generating unit is used as a signal source and used for generating a sound source signal, the working peak frequency of the signal generating unit is more than 20kHz, and the-10 dB bandwidth frequency range and the-20 dB bandwidth frequency range of the working frequency band range of the signal generating unit are more than 10kHz and more than 30 kHz;
the digital-to-analog conversion unit is used for converting the digital signal generated by the signal generation unit into an analog signal;
the power amplification unit is used for regulating and controlling the energy of the sounding source signal and can increase the sound source level to more than 180dBre mu Pa;
the underwater sound emission transducer group is used for converting the analog electric signals into sound waves and radiating the sound waves in water.
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