An apparatus and method for measuring the speed of sound

Abstract

The present application provides a sound velocity measurement device and method, comprising: a main housing, a laser generator, a laser receiver, a sound generating device, and a signal processor. The signal processor pre-stores a mapping relationship between different sound velocities and calibration times, so as to query the mapping relationship according to the moment or phase when the sound wave signal generated by the sound generating device is collected and the moment or phase when the laser receiver receives the laser signal marked by the sound wave signal in the measurement environment, and obtain the target sound velocity in the measurement environment. By changing the complex physical mapping into a single mapping of "time to sound velocity" or "phase to sound velocity", the present application greatly simplifies the measurement parameter requirements, reduces costs, and realizes the leap of a small-sized measurement device for measuring sound velocity with high precision, and is particularly suitable for measuring sound velocity in other complex environments such as the ocean.

Description

Technical Field

[0001] This application relates to the field of surveying and mapping technology, and particularly to a sound velocity measurement device and method. Background Art

[0002] The sound velocity of seawater is a key parameter in the ocean acoustic detection technology system. The measurement accuracy of seawater sound velocity has an important impact on applications such as seabed topography measurement, underwater navigation and positioning.

[0003] Currently, the measurement of seawater sound velocity mainly includes an indirect measurement method implemented by a Conductivity Temperature Depth (CTD) instrument and a direct measurement method that directly measures the sound velocity through piezoelectric effect or acousto-optic effect, etc. Among them, although the measurement device based on the acousto-optic effect overcomes the problems of circuit delay and crystal oscillator discreteness in the piezoelectric effect, resulting in inaccurate measurement results, due to the acousto-optic effect relying on the acquisition of high-precision acoustic wave flight distance and corresponding flight time, it often requires integrating instruments such as beam splitters, mirrors, frequency oscilloscopes, etc., leading to a complex overall system, a huge volume of the integrated device, and high costs. It is suitable for measuring the standard sound velocity of metering equipment in a laboratory, but it is very difficult to measure the seawater sound velocity in the actual marine working environment. Summary of the Invention

[0004] Based on this, it is necessary to provide a sound velocity measurement device and method for the above technical problems, aiming to solve the technical problem that it is impossible to conveniently measure the high-precision seawater sound velocity in the marine environment in related technologies.

[0005] In a first aspect, this application provides a sound velocity measurement device, including:

[0006] A main housing;

[0007] At least one laser generator for emitting laser signals;

[0008] At least one laser receiver for receiving the laser signals emitted by the laser generator; wherein, the laser generator and the laser receiver are oppositely arranged at both ends of the main housing;

[0009] A sound generating device arranged on the main housing for generating acoustic wave signals to mark the laser signals emitted by the laser generator; and

[0010] A signal processor circuit - connected to the laser generator, the laser receiver, and the sound - generating device; wherein, the signal processor pre - stores a mapping relationship between different sound speeds and calibration times, or a mapping relationship between different sound speeds and calibration phases, so as to query the mapping relationship according to the time or phase when the sound - generating device generates a sound wave signal and the time when the laser receiver receives the laser signal marked by the sound wave signal in the measurement environment, and obtain the target sound speed in the measurement environment.

[0011] As a feasible embodiment of the present application, the signal processor is connected to the laser generator through a first control circuit; the signal processor is connected to the laser generator through a first signal circuit; the signal processor is connected to the sound - generating device through a second control circuit and a second signal circuit.

[0012] As a feasible embodiment of the present application, the laser generator is a pulsed laser generator, and the sound - generating device is an ultrasonic generator.

[0013] As a feasible embodiment of the present application, the laser generator and the laser receiver are relatively and parallelly arranged at both ends of the main housing; the sound - generating device is slidably arranged on the main housing.

[0014] In a second aspect, the present application provides a sound - speed measurement method, which is applied to the signal processor of a sound - speed measurement device. The sound - speed measurement device further includes at least one laser generator for emitting a laser signal, at least one laser receiver for receiving the laser signal emitted by the laser generator, and a sound - generating device for generating a sound wave signal to mark the laser signal emitted by the laser generator; wherein, the signal processor pre - stores a mapping relationship between different sound speeds and calibration times;

[0015] The method includes:

[0016] In the measurement environment, control the laser generator to emit a laser signal so that the laser receiver receives the laser signal;

[0017] In response to the sound - generating device generating a sound wave signal, collect the first time when the sound - generating device generates the sound wave signal;

[0018] In response to the laser receiver receiving the laser signal marked by the sound wave signal, collect the second time when the laser receiver receives the laser signal marked by the sound wave signal;

[0019] According to the first time and the second time, query the mapping relationship to obtain the target sound speed in the measurement environment; or

[0020] In a measurement environment, control the laser generator to emit laser signals at fixed time intervals so that the laser receiver receives the laser signals;

[0021] In response to the laser receiver receiving the laser signal marked by the acoustic wave signal, collect the first phase of the acoustic wave signal generated by the sound - emitting device, and collect the second phase of the laser receiver receiving the laser signal marked by the acoustic wave signal; Collect the second phase of the laser receiver receiving the laser signal marked by the acoustic wave signal;

[0022] According to the first phase and the second phase, query the mapping relationship to obtain the target sound speed in the measurement environment.

[0023] As a feasible embodiment of the present application, the querying the mapping relationship according to the first phase and the second phase to obtain the target sound speed in the measurement environment includes:

[0024] According to the first time difference between the first moment and the second moment, query the mapping relationship to obtain the first target sound speed in the measurement environment; and / or

[0025] In the case where the second moment includes multiple moments, according to the second time differences between the multiple second moments, query the mapping relationship to obtain the second target sound speed in the measurement environment, where the multiple moments respectively correspond to the moments when multiple laser receivers receive the laser signals marked by the acoustic wave signal;

[0026] The querying the mapping relationship according to the first phase and the second phase to obtain the target sound speed in the measurement environment includes:

[0027] According to the first time difference between the first phase and the second phase, query the mapping relationship to obtain the third target sound speed in the measurement environment; and / or

[0028] In the case where the second phase includes multiple phases, according to the second phase differences between the multiple second phases, query the mapping relationship to obtain the fourth target sound speed in the measurement environment, where the multiple phases respectively correspond to the phases when multiple laser receivers receive the laser signals marked by the acoustic wave signal.

[0029] As a feasible embodiment of the present application, the mapping relationship includes a first mapping relationship and a second mapping relationship between the sound speed and the calibration time;

[0030] The querying the mapping relationship according to the first time difference between the first moment and the second moment to obtain the first target sound speed in the measurement environment includes:

[0031] Query the first mapping relationship according to the first time difference between the first moment and the second moment to obtain the first target sound speed in the measurement environment;

[0032] The querying the mapping relationship according to the second time difference between multiple second moments to obtain the second target sound speed in the measurement environment includes:

[0033] Query the second mapping relationship according to the second time difference between multiple second moments to obtain the second target sound speed in the measurement environment;

[0034] and / or

[0035] The mapping relationship includes a third mapping relationship and a fourth mapping relationship between the sound speed and the calibrated phase;

[0036] The querying the mapping relationship according to the first time difference between the first phase and the second phase to obtain the third target sound speed in the measurement environment includes:

[0037] Query the third mapping relationship according to the first phase difference between the first phase and the second phase to obtain the third target sound speed in the measurement environment;

[0038] The querying the mapping relationship according to the second phase difference between multiple second phases to obtain the fourth target sound speed in the measurement environment includes:

[0039] Query the fourth mapping relationship according to the second time difference between multiple second phases to obtain the fourth target sound speed in the measurement environment.

[0040] As a feasible embodiment of the present application, the method further includes:

[0041] When the sound speed difference between the first target sound speed and the second target sound speed meets a preset condition, determine the target sound speed in the measurement environment according to the first target sound speed and the second target sound speed;

[0042] When the phase difference between the first phase and the second phase meets a preset condition, determine the target sound speed in the measurement environment according to the first phase and the second phase.

[0043] As a feasible embodiment of the present application, when the second moment includes multiple moments, the querying the mapping relationship according to the second time difference between multiple second moments to obtain the second target sound speed in the measurement environment includes:

[0044] Query the mapping relationship according to the statistical value of the second time difference between multiple said second moments to obtain the second target sound speed in the measurement environment;

[0045] and / or

[0046] When the second phase includes multiple phases, according to the second phase differences between multiple said second phases, query the mapping relationship to obtain the fourth target sound speed in the measurement environment, including:

[0047] Query the mapping relationship according to the statistical value of the second phase differences between multiple said second phases to obtain the fourth target sound speed in the measurement environment.

[0048] As a feasible embodiment of the present application, the method further includes:

[0049] After adjusting the position of the sound generating device, continue to collect the third moment when the sound generating device generates a sound wave signal and the fourth moment when the laser receiver receives the laser signal marked by the sound wave signal, or, when the laser receiver receives the laser signal marked by the sound wave signal, collect the third phase of the sound wave signal generated by the sound generating device and the fourth phase of the laser signal;

[0050] Determine the fault detection result of the sound speed measurement device according to the first time difference between the first moment and the second moment, and the third time difference between the third moment and the fourth moment; and / or

[0051] Determine the fault detection result of the sound speed measurement device according to the second time differences between multiple said second moments and the fourth time differences between multiple said fourth moments; and / or;

[0052] Determine the fault detection result of the sound speed measurement device according to the first phase difference between the first phase and the second phase and the third phase difference between the third phase and the fourth phase; and / or;

[0053] Determine the fault detection result of the sound speed measurement device according to the second phase differences between multiple said second phases and the fourth phase differences between multiple said fourth phases.

[0054] In a third aspect, the present application further provides a processor, in which a mapping relationship between different sound speeds and calibration times and computer instructions are pre-stored, and the processor is used to execute the computer instructions to perform the sound speed measurement method as described in any one of the above.

[0055] The sound velocity measurement device provided by the embodiment of the present application pre-stores the mapping relationship between different sound velocities and calibration time or phase in a signal processor in advance, and is circuit-connected to a laser generator, a laser receiver, and a sound generating device, so that during measurement, according to the moment when the sound wave signal is generated by the sound generating device and the moment or phase when the laser receiver receives the laser signal marked by the sound wave signal collected, the mapping relationship can be queried, thereby directly obtaining the target sound velocity in the measurement environment. Compared with the measurement device based on the acousto-optic effect composed of a variety of instrument components, the sound velocity measurement device provided by the present application changes from the complex physical mapping of "distance-time to sound velocity" to the single mapping of "time to sound velocity" or "phase to sound velocity", thereby greatly simplifying the measurement parameter requirements, reducing costs, and achieving the leap of a miniaturized measurement device for measuring sound velocity with high precision, especially suitable for measuring sound velocity in other complex environments such as the ocean. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0057] Figure 1 It is a schematic structural diagram of a sound velocity measurement device provided by an embodiment of the present application;

[0058] Figure 2 It is a schematic step flow diagram of a sound velocity measurement method provided by an embodiment of the present application;

[0059] Figure 3 It is a schematic step flow diagram of querying the mapping relationship to obtain the sound velocity provided by an embodiment of the present application;

[0060] Figure 4 It is a schematic step flow diagram of identifying the fault of the sound velocity measurement device provided by an embodiment of the present application;

[0061] Figure 5 It is a schematic step flow diagram of another sound velocity measurement method provided by an embodiment of the present application;

[0062] Figure 6 It is a schematic step flow diagram of another querying the mapping relationship to obtain the sound velocity provided by an embodiment of the present application;

[0063] Figure 7 It is a schematic step flow diagram of another identifying the fault of the sound velocity measurement device provided by an embodiment of the present application;

[0064] Figure 8 It is a schematic structural diagram of a signal processor provided by an embodiment of the present application;

[0065] Attached drawing reference signs:

[0066] Main housing 101;

[0067] First laser generator 1021;

[0068] Second laser generator 1022;

[0069] First laser receiver 1031;

[0070] Second laser receiver 1032;

[0071] Sound generating device 104;

[0072] Signal processor 105. Detailed implementation manners

[0073] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the attached drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present application.

[0074] In the description of the present application, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality of" means two or more, unless otherwise specifically defined.

[0075] In the description of the present application, the term "for example" is used to mean "serving as an example, illustration, or explanation". Any embodiment described as "for example" in the present application is not necessarily construed as being more preferred or having more advantages than other embodiments. In order for any person skilled in the art to implement and use the present invention, the following description is given. In the following description, details are set forth for purposes of explanation. It should be understood that those of ordinary skill in the art can recognize that the present invention can be implemented without the use of these specific details. In other instances, well-known structures and processes are not elaborated in detail so as not to obscure the description of the present invention with unnecessary details. Therefore, the present invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope in accordance with the principles and features disclosed in the present application.

[0076] To facilitate the understanding of the sound velocity measurement device and method provided by the embodiments of the present application, the application background of relevant sound velocity measurement devices and methods will be described accordingly. Specifically, the sound velocity measurement device and method provided by the present application are mainly applicable to the measurement of seawater sound velocity in a marine environment. Among them, seawater sound velocity is a key parameter in the marine acoustic detection technology system, and the measurement accuracy of seawater sound velocity has an important impact on applications such as seabed topography measurement, underwater navigation, and positioning. At present, the relatively common sound velocity measurement devices mainly include an indirect measurement method that measures the conductivity, temperature, and depth of water through a CTD (Conductivity Temperature Depth) instrument and then estimates the seawater sound velocity by inverse calculation using a formula, and a direct measurement method that directly measures the sound velocity by using the piezoelectric effect or the acousto-optic effect, etc. Among them, compared with the problem that the piezoelectric effect is affected by circuit delay and discrete interference of the crystal oscillator, resulting in inaccurate measurement results, the acousto-optic effect is to use the effects such as refraction and interference generated by the generated acoustic wave signal on the optical signal, and collect the time used for the acoustic wave to affect the optical signal after traveling a given distance after being emitted to accurately measure the sound velocity. Among them, since the sound velocity depends on the accurate acoustic wave flight distance and the collection of the corresponding flight time, the measurement device often needs to integrate instruments such as beam splitters, mirrors, frequency oscilloscopes, etc., resulting in a complex overall system, a huge volume of the integrated device, often exceeding 0.5M*0.5M*0.5M, and high costs. Although the sound velocity can be accurately measured, it is mainly used for the measurement of standard sound velocity in an experimental environment. In an actual marine environment, it is often difficult to directly measure the sound velocity in seawater.

[0077] To solve the above problems, greatly simplify the measurement parameter requirements, reduce costs, and thus achieve the effect of high-precision sound velocity measurement with a miniaturized measurement device, the present application provides a sound velocity measurement device with a simple structure and a sound velocity measurement method applicable to the sound velocity measurement device, especially applicable to the measurement of sound velocity in a marine or other complex environment.

[0078] Specifically, please refer to Figure 1 , Figure 1 which is a schematic structural diagram of a sound velocity measurement device provided by the embodiments of the present application, and is described in detail as follows.

[0079] The sound velocity measurement device provided by the present application generally includes:

[0080] A main housing 101;

[0081] At least one laser generator;

[0082] At least one laser receiver;

[0083] A sound emitting device 104 disposed on the main housing; and

[0084] A signal processor 105 that is circuit - connected to the laser generator, the laser receiver, and the sound - generating device.

[0085] Among them, the laser generator is used to emit laser light, and the laser receiver is used to receive the emitted laser light. The laser generators are relatively arranged at both ends of the main housing and can usually be fixedly connected to the main housing. Of course, it is also feasible to arrange the laser generator and the laser receiver in other ways. For example, the laser generator 102 and the laser receiver can also be respectively arranged on the brackets on both sides of the main housing. This application does not limit the installation form of the laser generator and the laser receiver here. Any installation form that can enable the laser receiver to receive the laser signal emitted by the laser generator is within the scope protected by this application.

[0086] In addition, for a better understanding of the implementation scheme where the sound - speed measurement device includes multiple laser generators and laser receivers, in this embodiment, Figure 1 As shown, the sound - speed measurement device including two laser generators and two laser receivers is taken as an example for illustration. Specifically, the laser generators include a first laser generator 1021 and a second laser generator 1022, and the laser receivers include a first laser receiver 1031 and a second laser receiver 1032. Among them, the first laser generator 1021 and the first laser receiver 1031 are relatively arranged so that the first laser receiver 1031 can receive the laser light emitted by the first laser generator 1021, and the second laser generator 1022 and the second laser receiver 1032 are relatively arranged so that the second laser receiver 1032 can receive the laser light emitted by the second laser generator 1022. It can be understood that in the case where the sound - speed measurement device includes more laser generators and laser receivers, it is also required that one laser receiver can receive the signal emitted by another laser transmitter.

[0087] In an optional embodiment, the sound - generating device 104 can be used to generate a sound - wave signal. The propagation path of the sound - wave signal is relatively perpendicular to the path of the laser light emitted by the laser generator. The sound - wave signal can be used to mark the laser signal emitted by the laser generator through the acousto - optic effect. For example, the sound - wave signal can usually change the propagation medium, such as the refractive index of seawater for light, so that the laser receiver can receive the laser signal whose propagation path is interfered and marked by the sound - wave signal. Of course, in addition to the implementation scheme provided above, the laser receiver can also determine whether it has received the laser signal interfered and marked by the sound - wave signal through other methods, such as detecting the phase of the received laser light. This application does not limit this in the embodiments.

[0088] In addition, in order to measure the sound speed, a mapping relationship between different sound speeds and calibration times, or a mapping relationship between different sound speeds and calibration phases, is pre-stored in the signal processor, so as to query the mapping relationship according to the time when the acoustic wave signal generated by the sound generating device is collected and the time or phase when the laser receiver receives the laser signal marked by the acoustic wave signal in the measurement environment, thereby directly calibrating the target sound speed in the measurement environment.

[0089] Specifically, in another feasible embodiment of the present application, in order to better control the sound speed measurement device, the signal processor can usually be connected to the laser generator through a first control circuit to control the laser generator to turn on or off, so as to control the emission of laser or stop the emission of laser. The signal processor can also be connected to the laser generator through a first signal circuit to perform specific operations in response to the laser generator receiving a laser signal or a specific laser signal. For example, record the time information when the laser generator receives the laser signal. In addition, the signal processor can also be connected to the sound generating device through a second control circuit and a second signal circuit to record the time information of controlling the sound generating device to generate an acoustic wave signal while controlling the sound generating device to turn on or off, so as to control the generation of an acoustic wave signal or stop generating an acoustic wave signal. Of course, in addition to recording the time information when the laser generator receives the laser signal, the signal processor can also be used to record the phase information of the laser signal marked by the acoustic wave received by the laser receiver and the phase information of the acoustic wave signal generated by the sound generating device for subsequent sound speed measurement.

[0090] In addition, as a further feasible implementation solution of the present application, in order to further improve the accuracy of seawater sound speed measurement, the laser generator can be a pulsed laser generator, and the sound generating device can be an ultrasonic generator. Of course, the above laser generator and sound generating device can also be determined based on actual needs. For example, the laser generator can also be a mode-locked laser for emitting a femtosecond laser optical frequency comb, that is, a pulsed light with a pulse interval fixed at the femtosecond level. The embodiments of the present application do not limit this here.

[0091] In addition, this application provides a simple-structured sound velocity measuring device for measuring the sound velocity. To further improve the stability of the sound velocity measurement by the sound velocity measuring device, as a further feasible implementation solution of this application, the laser generator and the laser receiver can be relatively arranged in parallel at both ends of the main housing. At this time, the sound generating device is slidably arranged on the main housing, so that during the process of the sound generating device being slidably arranged at different positions on the main housing, the laser transmission path between the sound generating device and the laser generator and the laser receiver remains at a fixed distance. That is to say, in the above solution, when the sound generating device slides on the main housing, the distance traveled by the laser signal emitted by the marking laser generator by the generated sound wave signal remains relatively unchanged, and the required time is also unchanged. As a result, the results received by the signal processor, such as time information or phase information, should also be relatively stable. Therefore, in this way, the position of the sound generating device on the main housing can be adjusted to determine whether there may be a fault in the sound velocity measuring device according to the results received by the signal processor, so as to avoid affecting the stability of the sound velocity measurement result due to the use of a faulty sound velocity measuring device.

[0092] The sound velocity measuring device provided in the embodiment of this application pre-stores the mapping relationship between different sound velocities and calibration times or phases in the signal processor in advance, and is circuit-connected to the laser generator, the laser receiver, and the sound generating device, so that during the measurement, according to the moment when the sound generating device generates a sound wave signal and the moment or phase when the laser receiver receives the laser signal marked by the sound wave signal collected, the mapping relationship can be queried, so as to directly obtain the target sound velocity in the measurement environment. Compared with the measuring device based on the acousto-optic effect composed of a variety of instrument components, the sound velocity measuring device provided in this application changes from the complex physical mapping of "distance-time to sound velocity" to the single mapping of "time to sound velocity" or "phase to sound velocity", thus greatly simplifying the measurement requirement parameters, reducing costs, and achieving the leap of a small-sized measuring device for measuring the sound velocity with high precision, especially suitable for measuring the sound velocity in other complex environments such as the ocean.

[0093] On the basis of the above-provided sound velocity measuring device, this application further provides a sound velocity measuring method applied to the signal processor of the sound velocity measuring device. Specifically, this method is described by taking the method of realizing sound velocity measurement through time information as an example. Please refer to Figure 2 , Figure 2 which is a schematic flow chart of the steps of a sound velocity measuring method provided in the embodiment of this application, including steps S210 to S240:

[0094] S210, in the measurement environment, control the laser generator to emit a laser signal so that the laser receiver receives the laser signal.

[0095] In the embodiments of the present application, by placing the sound velocity measurement method in the measurement environment of the ocean and controlling the laser generator to emit a laser signal through the first control circuit mentioned above, the laser receiver on the other side of the sound velocity measurement device can receive the laser signal.

[0096] S220. In response to the sound generating device generating a sound wave signal, collect the first moment when the sound generating device generates the sound wave signal.

[0097] In the embodiments of the present application, the signal processor can also control the sound generating device to generate a sound wave signal through the second control circuit, and at the same time collect and record the first moment when the sound generating device generates the sound wave signal.

[0098] S230. In response to the laser receiver receiving the laser signal marked by the sound wave signal, collect the second moment when the laser receiver receives the laser signal marked by the sound wave signal.

[0099] In the embodiments of the present application, after the sound generating device generates a sound wave signal, when the sound wave propagates on the laser propagation path between the laser generator and the laser receiver, based on the acousto-optic effect, it will interfere with the laser signal emitted by the laser generator, thereby forming a mark on the laser signal. The laser receiver can, after receiving the laser signal marked by the sound wave signal, pass through the first signal circuit to obtain the second moment when the laser receiver receives the laser signal marked by the sound wave signal.

[0100] S240. According to the first moment and the second moment, query the mapping relationship to obtain the target sound velocity in the measurement environment.

[0101] It can be understood that the speed of sound waves can usually be determined by the flight distance / flight time. Among them, the flight distance is the distance that the sound wave propagates to the laser propagation path, and the flight time is usually related to the moment between the sound generating device emitting the sound wave signal and the laser receiver receiving the laser signal marked by the sound wave signal in an ideal state. In fact, due to the delay of the control circuit or other factors, there are often certain errors in the flight distance or flight time, which affects the accuracy of the sound velocity measurement result. Therefore, in order to improve the stability of the measurement result of the sound velocity measurement device, it is often necessary to integrate additional instruments in the system to compensate for the errors. Although it can improve the accuracy of the measurement result, it undoubtedly also increases the cost and size of the system and is not suitable for accurately measuring the sound velocity of seawater in an offshore environment.

[0102] In this application, considering a fixed flight distance and other error factors, by calibrating the time difference between the emission of an acoustic wave signal detected by a signal processor at the standard speed of sound and the reception of a laser signal marked by the acoustic wave signal, establishing a mapping relationship between time and the speed of sound, and storing it, the requirements for measurement parameters can be greatly simplified. The complex physical mapping is transformed into a relatively easy-to-detect and measure single mapping of "time to the speed of sound". Thus, according to the first and second detected times mentioned above, the mapping relationship can be queried to directly calibrate the target speed of sound in the measurement environment.

[0103] In this application, by pre-storing the mapping relationship between different speeds of sound and calibration times in the signal processor and connecting it to the laser generator, laser receiver, and sound-emitting device circuit, the target speed of sound in the measurement environment can be directly obtained by querying the mapping relationship based on the time when the sound-emitting device generates an acoustic wave signal and the time when the laser receiver receives the laser signal marked by the acoustic wave signal collected during the measurement. Compared with the measurement device based on the acousto-optic effect composed of multiple instrument components, this application changes the complex physical mapping of "distance - time to the speed of sound" into a single mapping of "time to the speed of sound", thus greatly simplifying the requirements for measurement parameters, reducing costs, and achieving a leap in the miniaturized measurement device for measuring the speed of sound with high precision, especially suitable for measuring the speed of sound in other complex environments such as the ocean.

[0104] Specifically, it can be understood that the mapping relationship between the speed of sound and the calibration time pre-stored in the signal processor can be understood as the mapping relationship between the speed of sound and the propagation time of the calibrated acoustic wave signal. Therefore, in addition to considering the time difference between the emission of the acoustic wave signal by the sound-emitting device and the reception of the laser signal marked by the acoustic wave signal by the laser receiver as the propagation time of the calibrated acoustic wave signal, in the case where the speed-of-sound measurement device includes multiple laser transmitters and multiple laser receivers, the time difference between the different times when the multiple laser receivers respectively receive the laser signals marked by the acoustic wave signal can also be used as the propagation time of the calibrated acoustic wave signal, and the speed of sound in the measurement environment can also be determined. Specifically, please refer to Figure 3 , Figure 3 which is the flowchart of the steps for querying the mapping relationship to obtain the speed of sound provided by the embodiment of this application.

[0105] S310, according to the first time difference between the first time and the second time, query the mapping relationship to obtain the first target speed of sound in the measurement environment.

[0106] In an embodiment of the present application, when, in a standard sound speed environment, the time between the acoustic wave signal generated by the sound - generating device collected by the signal processor and the laser signal received by the laser receiver marked by the acoustic wave signal is calibrated at different sound speeds, and after establishing a mapping relationship based on this sound speed and this time, subsequently, the signal processor can directly query the corresponding sound speed from the mapping relationship (usually in the form of a mapping table in the signal processor) according to the first - time difference between the first moment and the second moment, and use it as the first target sound speed in the measurement environment.

[0107] It should be noted that, in the standard sound speed environment, that is, the standard sound speed in the calibration environment needs to be determined. Usually, this requires a relatively high measurement accuracy of the sound speed during the calibration process. Otherwise, it will affect the measurement of the seawater sound speed in the subsequent actual measurement scenario, that is, the ocean environment. Therefore, as a further feasible implementation solution of the present application, the integrated large - scale sound speed measurement device based on the acousto - optic effect provided above can be used to accurately measure the corresponding sound speed in the calibration environment such as a laboratory.

[0108] S320. When the second moment includes multiple moments, query the mapping relationship according to the second - time difference between the multiple second moments to obtain the second target sound speed in the measurement environment.

[0109] In an embodiment of the present application, when there are multiple laser receivers, that is, when each laser receiver has its own corresponding second moment when receiving the laser signal marked by the acoustic wave signal, similarly, it can be considered that the flight distance of the acoustic wave signal between the laser propagation paths corresponding to the multiple different laser receivers is relatively fixed. Therefore, the time difference between the multiple second moments collected can also be used as a calibration value, and then query the mapping relationship according to the second - time difference between the multiple second moments to obtain the sound speed in the measurement environment.

[0110] Similar to the time difference between the acoustic wave signal generated by the sound - generating device collected by the signal processor and the laser signal received by the laser receiver marked by the acoustic wave signal calibrated at different sound speeds mentioned above in the calibration sound speed environment, when multiple second - time differences are used for calibration, it is necessary to calibrate the time difference between the laser signals received by multiple different laser receivers collected by the signal processor at different sound speeds in the calibration sound speed environment. Regarding the calibration process in the calibration sound speed environment, reference can be made to the foregoing step S310, and the embodiments of the present application will not repeat the description. The solution provided by the embodiments of the present application provides an implementation solution for establishing a mapping relationship with the sound speed through two different calibration times, which can meet the needs of users to accurately measure the sound speed of seawater in different scenarios, such as using a single laser generator (laser receiver) or multiple groups of laser generators (laser receivers).

[0111] Of course, it should be noted that considering the distance of the propagation path of the acoustic wave signal from the sound - emitting device to the laser generator and then to the laser receiver, and the distance of the propagation path of the acoustic wave signal between multiple sets of laser generators and laser receivers may be different. That is, at the same sound speed, the calibrated time differences are often different. Therefore, as a further feasible implementation solution of this application, it is necessary to calibrate the above - mentioned two situations separately. That is, the mapping relationship usually can also include a first mapping relationship and a second mapping relationship. At this time, that is, according to the first time difference between the first moment and the second moment, query the mapping relationship to obtain the first target sound speed in the measurement environment, which usually includes:

[0112] According to the first time difference between the first moment and the second moment, query the first mapping relationship to obtain the first target sound speed in the measurement environment.

[0113] The step of querying the mapping relationship according to the second time difference between multiple second moments to obtain the second target sound speed in the measurement environment includes:

[0114] According to the second time difference between multiple second moments, query the second mapping relationship to obtain the second target sound speed in the measurement environment.

[0115] That is, for the previously collected first time difference and second time difference, query different mapping relationships respectively to obtain the sound speed in the measurement environment.

[0116] Specifically, for the convenience of understanding the above content, please refer to Table 1 below. Table 1 provides a mapping table of the mapping relationship stored in the signal processor, which is specifically as follows:

[0117] Serial number Calibrated sound velocity V (m / s) First time difference T1 Second time difference T2 ……… 1 1400.00 t1 t6 … 2 1400.10 t2 t7 … 3 1400.20 t3 t8 … 4 1400.30 t4 t9 … … … … … … n 1600 t5 t10 …

[0118] Among them, the calibrated sound speed is usually the speed of sound propagation in seawater, that is, about 1500 m / s. Of course, when it needs to be used in other scenarios, a similar calibrated sound speed can usually be calibrated. In addition, the measurement accuracy of the sound speed is usually also related to the interval of the calibrated sound speed used in the calibration process. For example, in Table 1, calibration is performed every 0.1 m / s difference, then the sound speed measurement device can achieve a sound speed measurement with an accuracy of 0.1 m / s. Of course, the specific accuracy can also be determined based on actual needs. For example, it can also be set to 0.05 m / s or 0.01 m / s, which will not be elaborated in this embodiment of the present application. In addition, during the calibration process, the time difference in the mapping relationship can include a single one (i.e., in a single-column form), and can also include multiple ones (i.e., the multi-column form existing in Table 1). Among them, different time differences respectively indicate the time difference between different signals received by the signal acquisition unit during the calibration process. For example, the first time difference T1 can be the time difference between the acoustic wave signal emitted by the sound-emitting device and the laser signal marked by the acoustic wave signal received by the laser receiver. The second time difference T2 can also be the time difference between the laser signal marked by the acoustic wave signal received by the first laser receiver and the laser signal marked by the acoustic wave signal received by the second laser receiver. In addition, there can also be a third time difference T3 in the mapping table, which is used to calibrate the time difference between the laser signal marked by the acoustic wave signal received by the second laser receiver and the laser signal marked by the acoustic wave signal received by the third laser receiver, etc., which will not be limited in this embodiment of the present application.

[0119] It can be understood that the above mapping table is only a possible existing form. In fact, the mapping tables calibrated through different calibration processes may be different, and the mapping relationship calibrated by the current sound speed measurement device can only be stored in the signal processor of the current sound speed measurement device and cannot be applied to other sound speed measurement devices.

[0120] In addition, it should be noted that since it is considered that in the calibration environment and in the measurement environment, the error information such as the circuit delay signal and the actual flight distance of the acoustic wave signal of the same sound speed measurement device is roughly the same, the mapping between complex physical relationships is transformed into a mapping relationship from time to sound speed in a single dimension to eliminate such errors and achieve the measurement of the sound speed. However, in the actual measurement environment, large errors may occur due to external environmental interference. At this time, it indicates that the current sound speed measurement device is no longer applicable to the measurement in the current environment. Therefore, in the solution provided in this embodiment of the present application, establishing multiple different mapping relationships can further be used to assist in obtaining a more accurate sound speed measurement result. Specifically, it is described in detail as follows.

[0121] In the embodiments of the present application, it can be understood that when the time differences between multiple signals at different sound speeds are calibrated in the mapping table, for example, the time difference between the acoustic wave signal emitted by the sound generating device and the laser signal marked by the acoustic wave signal received by the laser receiver, or the time difference between the laser signal marked by the acoustic wave signal received by the first laser receiver and the laser signal marked by the acoustic wave signal received by the second laser receiver, etc., at this time, in the measurement environment, when the time difference between the acoustic wave signal emitted by the sound generating device and the laser signal marked by the acoustic wave signal received by the laser receiver, or the time difference between the laser signal marked by the acoustic wave signal received by the first laser receiver and the laser signal marked by the acoustic wave signal received by the second laser receiver are respectively used to query the corresponding mapping relationship to obtain the corresponding first target sound speed and the second target sound speed measured, in an ideal situation, or when the sound speed measurement device is not affected by the external environment and affects the sound speed measurement accuracy, the first target sound speed and the second target sound speed should be relatively small, or there is a tolerable difference. Therefore, by using the above solution, a simple detection of the sound speed measurement device itself can be realized to determine whether the sound speed measurement device fails and outputs an incorrect sound speed result. This has high practical value in the application scenario of using a small-sized structured sound speed measurement device to measure the sound speed, that is, in the process of accurately measuring the sound speed by a sound speed measurement device with a simple structure, through relatively simple judgment conditions, the stability of the sound speed measurement result is ensured, and large deviations in the test results caused by external environmental interference are avoided. Specifically, the sound speed measurement method further includes:

[0122] When the sound speed difference between the first target sound speed and the second target sound speed meets a preset condition, determine the target sound speed in the measurement environment according to the first target sound speed and the second target sound speed.

[0123] In the embodiments of the present application, when the sound speed difference between the first target sound speed and the second target sound speed meets a preset condition, for example, is less than a preset threshold, it can be considered that the measurement result of the sound speed measurement device is relatively accurate. At this time, the target sound speed in the measurement environment can be determined according to the first target sound speed and the second target sound speed based on actual needs. For example, as a simple and feasible implementation solution, the first target sound speed and the second target sound speed can be weighted, such as taking the average value as the target sound speed in the measurement environment.

[0124] Of course, when the difference in sound speed between the first target sound speed and the second target sound speed does not meet the preset condition, for example, exceeds the preset threshold, it can be considered that the current sound speed measurement device may provide an incorrect sound speed measurement result due to external or internal factors (for example, circuit delay change or change in the flight distance of the acoustic wave signal). At this time, in order to ensure the stability of the measurement result, the first target sound speed and the second target sound speed measured by the current sound speed measurement device can be rejected. And because the sound speed measurement device provided in this application has a small size and low cost, multiple sound speed measurement devices can be easily carried during ocean mapping. Thus, the seawater sound speed can still be accurately measured through multiple sound speed measurement devices, which has high practical significance in actual use.

[0125] Of course, similar to the foregoing solution of obtaining multiple sound speeds through multiple sets of mapping relationships and determining whether the sound speed measurement device can accurately measure the sound speed based on the difference between the multiple sound speeds, it can be known from the foregoing related description that when the laser generator and the laser receiver can be relatively parallelly arranged at both ends of the main housing, and the sound generating device is slidably arranged in the main housing, when the sound generating device is slidably arranged at different positions in the main housing, the laser transmission path between the sound generating device and the laser generator and the laser receiver can still maintain a fixed distance unchanged, that is, the time difference between the signals received by the signal processor will not change. Therefore, as another feasible embodiment of this application, please refer to Figure 4 , another schematic diagram of the step flow for identifying the failure of the sound speed measurement device is also provided. Specifically, this method is mainly applicable to a sound speed measurement device in which the laser generator and the laser receiver can be relatively parallelly arranged at both ends of the main housing, and the sound generating device is slidably arranged in the main housing. Specifically, it includes steps S410 to S430:

[0126] S410, after adjusting the position of the sound generating device, continue to collect the third moment when the sound generating device generates an acoustic wave signal, and the fourth moment when the laser receiver receives the laser signal marked by the acoustic wave signal.

[0127] In the embodiment of this application, after sliding and adjusting the position of the sound generating device, the third moment when the sound generating device generates an acoustic wave signal and the fourth moment when the laser receiver receives the laser signal marked by the acoustic wave signal will be continuously collected.

[0128] S420, determine the failure detection result of the sound speed measurement device according to the first time difference between the first moment and the second moment, and the third time difference between the third moment and the fourth moment.

[0129] In the embodiments of the present application, since the distance of the propagation path between the sound - generating device and the laser generator to the laser receiver will not be changed after the position of the sound - generating device is adjusted by sliding, therefore, the first time difference between the first moment and the second moment during the past acquisition process, and the third time difference between the third moment and the fourth moment acquired after the position is adjusted can be used to determine the fault detection result of the sound - speed measurement device. Specifically, when the first time difference and the third time difference are less than the threshold, it can be considered that the measurement results of the two measurement processes are stable. At this time, it can be determined that the fault detection result of the sound - speed measurement device is no fault, and thus the corresponding sound speed obtained by querying according to the first time difference or the third time difference can be used as the target sound speed in the measurement environment. Of course, when the first time difference and the third time difference are greater than the threshold, it can be considered that there are large differences in the measurement results of the two measurement processes, that is, the sound - speed measurement device may malfunction, thus avoiding using the incorrect sound - speed measurement device to obtain an incorrect sound - speed result.

[0130] S430. Determine the fault detection result of the sound - speed measurement device according to the second time differences between multiple second moments and the fourth time differences between multiple fourth moments.

[0131] In the embodiments of the present application, similarly to the foregoing, since the distance of the propagation path between multiple laser generators and the laser receiver usually will not be changed after the position of the sound - generating device is adjusted by sliding, therefore, the second time differences between multiple second moments during the past acquisition process and the fourth time differences between multiple fourth moments acquired after the position is adjusted can also be used to determine the fault detection result of the sound - speed measurement device. Among them, regarding the identification of the fault detection result of the sound - speed measurement device and the subsequent execution process, this embodiment will not be repeated. Specifically, reference can be made to the description of step S420.

[0132] Of course, in the implementation scheme of calibrating the sound speed using multiple laser beams, that is, when there are multiple laser receivers in the sound - speed measurement device, at this time, the sound speed in the measurement environment can also be obtained by taking the average value or other statistical values of the moments of multiple beams of light received by the laser receivers. That is, when the second moment includes multiple moments, the querying the mapping relationship according to the second time differences between multiple second moments to obtain the second target sound speed in the measurement environment includes:

[0133] Query the mapping relationship according to the statistical value of the second time differences between multiple second moments to obtain the second target sound speed in the measurement environment.

[0134] Among them, the statistical value here can be at least one or a weighted combination of several of the average value, median, and mode to further improve the accuracy of the measured sound speed.

[0135] Of course, in addition to the method of obtaining the sound speed measurement by calibrating the time provided above, as another feasible embodiment of the present application, a method of measuring the sound speed by calibrating the phase is also provided. Specifically, please refer to Figure 5 , Figure 5 which is a schematic flowchart of the steps of another sound speed measurement method provided by the embodiment of the present application, including steps S510 to S530:

[0136] S510, in the measurement environment, control the laser generator to emit laser signals at a fixed time interval, so that the laser receiver receives the laser signals.

[0137] In this embodiment, similar to the Figure 2 shown sound speed measurement method, by placing the sound speed measurement device in the measurement environment of the ocean and controlling the laser generator to emit laser signals at a fixed time interval through the first control circuit mentioned above, the laser receiver on the other side of the sound speed measurement device can receive the laser signals.

[0138] S520, in response to the laser receiver receiving the laser signals marked by the sound wave signals, collect the first phase of the sound wave signals generated by the sound generating device, and collect the second phase of the laser signals received by the laser receiver marked by the sound wave signals.

[0139] In the embodiment of the present application, after controlling the sound generating device to generate sound wave signals through the second control circuit so that the laser receiver receives the laser signals marked by the sound wave signals, the signal processor can also collect and record the first phase of the sound wave signals generated by the sound generating device, and the second phase of the laser signals marked by the received sound wave signals.

[0140] S530, according to the first time and the second time, query the mapping relationship to obtain the target sound speed in the measurement environment.

[0141] It can be understood that the speed of sound waves can usually be determined by flight distance / flight time. Among them, the flight distance is the distance that the sound waves propagate to the laser propagation path, and the flight time is usually also related to the phase difference between the phase of the sound wave signals emitted by the sound generating device and the phase of the laser signals received by the laser receiver marked by the sound wave signals under ideal conditions. In fact, due to the delay of the control circuit or other factors, there are often certain errors in the flight distance or flight time, which affects the accuracy of the sound speed measurement result. Therefore, in order to improve the stability of the measurement result of the sound speed measurement device, it is often necessary to integrate additional instruments in the system to compensate for the errors. Although the accuracy of the measurement result can be improved, it undoubtedly also increases the cost and size of the system, and is not suitable for accurately measuring the sound speed of seawater in the offshore environment.

[0142] In this application, considering a fixed flight distance and other error factors, the phase difference between the phase of the acoustic wave signal generated by the sound - emitting device at the standard speed of sound and the phase of the laser signal received by the laser receiver marked by the acoustic wave signal is calibrated, a mapping relationship between the phase and the speed of sound is established and stored. This can greatly simplify the requirements for measurement parameters, transform the complex physical mapping into a relatively easy - to - detect and measure single mapping of "phase to speed of sound". Thus, according to the detected first phase and second phase, the mapping relationship can be queried to directly calibrate the target speed of sound in the measurement environment.

[0143] In this application, the mapping relationship between different speeds of sound and calibrated phases is pre - stored in the signal processor in advance, and it is circuit - connected to the laser generator, laser receiver, and sound - emitting device. So, under measurement, according to the phase of the acoustic wave signal generated by the sound - emitting device and the phase of the laser signal marked by the acoustic wave signal received by the laser receiver, the mapping relationship can be queried to directly obtain the target speed of sound in the measurement environment. Compared with the measurement device based on the acousto - optic effect composed of multiple instrument components, this application changes the complex physical mapping of "distance - time to speed of sound" into a single mapping of "phase to speed of sound", thus greatly simplifying the parameter requirements for measurement, reducing costs, and achieving a leap in miniaturizing the measurement device to measure the speed of sound with high precision, especially suitable for measuring the speed of sound in other complex environments such as the ocean.

[0144] Specifically, it can be understood that the mapping relationship between the speed of sound and the calibrated phase pre - stored in the signal processor can be understood as the mapping relationship between the speed of sound and the propagation time of the calibrated acoustic wave signal. Therefore, in addition to considering the phase difference between the phase of the acoustic wave signal generated by the sound - emitting device and the phase of the laser signal marked by the acoustic wave signal received by the laser receiver as the propagation time of the calibrated acoustic wave signal, when the speed - of - sound measurement device includes multiple laser transmitters and multiple laser receivers, the phase difference between the different phases of the laser signals received by the multiple laser receivers marked by the acoustic wave signal can also be used as the propagation time of the calibrated acoustic wave signal, and it can also achieve determining the speed of sound in the measurement environment. Specifically, please refer to Figure 6 , Figure 6 which is the flowchart of the steps for querying the mapping relationship to obtain the speed of sound provided by the embodiment of this application.

[0145] S610, according to the first time difference between the first phase and the second phase, query the mapping relationship to obtain the third target speed of sound in the measurement environment.

[0146] In an embodiment of the present application, when, in a standard sound velocity environment, the phase difference between the phase of the acoustic wave signal generated by the sound generating device collected by the signal processor and the phase of the laser signal marked by the acoustic wave signal received by the laser receiver is calibrated at different sound velocities, and after establishing a mapping relationship based on this sound velocity and this phase difference, subsequently, the signal processor can directly query the corresponding sound velocity from the mapping relationship (usually in the form of a mapping table in the signal processor) based on the first phase difference between the first phase and the second phase as the third target sound velocity in the measurement environment.

[0147] It should be noted that, in a standard sound velocity environment, that is, it is necessary to determine the standard sound velocity in the calibration environment, and usually, the measurement accuracy requirement for the sound velocity in the calibration process is relatively high, otherwise it will affect the measurement of the seawater sound velocity in the subsequent actual measurement scenario, that is, the ocean environment. Therefore, as a further feasible implementation solution of the present application, the integrated large-scale sound velocity measurement device based on the acousto-optic effect provided above can be used to accurately measure the corresponding sound velocity in the calibration environment such as a laboratory.

[0148] S620, in the case where the second phase includes multiple phases, query the mapping relationship according to the second phase difference between the multiple second phases to obtain the fourth target sound velocity in the measurement environment.

[0149] In an embodiment of the present application, when there are multiple laser receivers, that is, when each laser receiver has its own corresponding second phase of the laser signal received and marked by the acoustic wave signal, considering that the flight distance of the acoustic wave signal between the laser propagation paths corresponding to the multiple different laser receivers is relatively fixed, therefore, the phase difference between the multiple second phases collected can also be used as a calibration value, and then query the mapping relationship according to the second phase difference between the multiple second phases to obtain the sound velocity in the measurement environment.

[0150] Similar to the calibration of the phase difference between the phase of the acoustic wave signal generated by the sound generating device collected by the signal processor and the phase of the laser signal marked by the acoustic wave signal received by the laser receiver at different sound velocities mentioned above, when using multiple second phase differences for calibration, it is necessary to calibrate the phase difference between the laser signals marked by the acoustic wave signals received by multiple different laser receivers collected by the signal processor at different sound velocities in the calibration sound velocity environment. The calibration process in the calibration sound velocity environment will not be repeated in the embodiments of the present application. The solution provided by the embodiments of the present application provides an implementation solution for establishing a mapping relationship with the sound velocity through two different calibration phases, which can meet the user's accurate measurement of the seawater sound velocity in different scenarios, such as using a single laser generator (laser receiver) or multiple groups of laser generators (laser receivers).

[0151] Of course, it should be noted that considering the distance of the propagation path of the acoustic wave signal from the sound - generating device to the laser generator and then to the laser receiver, it may be different from the distance of the propagation path of the acoustic wave signal between multiple groups of laser generators and laser receivers. That is, at the same sound speed, the calibrated phase differences are often different. Therefore, as a further feasible implementation solution of this application, it is necessary to calibrate separately for the above - mentioned two situations. That is, the mapping relationship usually further includes a third mapping relationship and a fourth mapping relationship. At this time, that is, according to the first phase difference between the first phase and the second phase, query the mapping relationship to obtain the third target sound speed in the measurement environment, which usually includes:

[0152] According to the first phase difference between the first phase and the second phase, query the third mapping relationship to obtain the third target sound speed in the measurement environment.

[0153] The step of querying the mapping relationship according to the second phase difference between multiple second phases to obtain the fourth target sound speed in the measurement environment includes:

[0154] According to the second time difference between multiple second phases, query the fourth mapping relationship to obtain the fourth target sound speed in the measurement environment.

[0155] That is, for the previously collected first phase difference and second phase difference, query different mapping relationships respectively to obtain the sound speed in the measurement environment.

[0156] Specifically, for the convenience of understanding the above content, please refer to Table 2 below. Table 2 provides a mapping table of another mapping relationship stored in the signal processor, which is specifically as follows:

[0157]

[0158] Among them, the calibrated sound speed is usually the speed of sound propagation in seawater, that is, about 1500 m / s. Of course, when it needs to be used in other scenarios, a similar calibrated sound speed can usually be calibrated. In addition, the measurement accuracy of the sound speed is usually also related to the interval of the calibrated sound speed used in the calibration process. For example, in Table 1, calibration is performed every 0.1 m / s difference, then the sound speed measurement device can achieve a sound speed measurement with an accuracy of 0.1 m / s. Of course, the specific accuracy can also be determined based on actual needs. For example, it can also be set to 0.05 m / s or 0.01 m / s, which will not be elaborated in the embodiments of this application. In addition, during the calibration process, the time difference in the mapping relationship can include a single one (i.e., in a single-column form), and can also include multiple ones (i.e., in the multi-column form existing in Table 1). Among them, different phase differences respectively indicate the phase differences between the phases of different signals received by the signal acquisition unit during the calibration process. For example, the first phase difference can be the phase difference between the phase of the acoustic wave signal emitted by the sound-emitting device and the phase of the laser signal marked by the acoustic wave signal received by the laser receiver. The second phase difference can also be the phase difference between the phase of the laser signal marked by the acoustic wave signal received by the first laser receiver and the phase of the laser signal marked by the acoustic wave signal received by the second laser receiver. In addition, a third phase difference can also exist in the mapping table, which is used to calibrate the phase difference between the phase of the laser signal marked by the acoustic wave signal received by the second laser receiver and the phase of the laser signal marked by the acoustic wave signal received by the third laser receiver, etc., which will not be limited in the embodiments of this application.

[0159] It can be understood that the above mapping table is only a possible existing form. In fact, the mapping tables calibrated through different calibration processes may be different, and the mapping relationship calibrated by the current sound speed measurement device can only be stored in the signal processor of the current sound speed measurement device and cannot be applied to other sound speed measurement devices.

[0160] In addition, it should be noted that since it is considered that in the calibration environment and in the measurement environment, the same sound speed measurement device has approximately the same error information such as circuit delay signals and the actual flight distance of acoustic wave signals, the mapping between complex physical relationships is transformed into a mapping relationship from time to sound speed in a single dimension to eliminate such errors and achieve the measurement of the sound speed. However, in the actual measurement environment, large errors may occur due to external environmental interference. At this time, it indicates that the current sound speed measurement device is no longer applicable to the measurement in the current environment. Therefore, in the solution provided by the embodiments of this application, establishing multiple different mapping relationships can further be used to assist in obtaining a more accurate sound speed measurement result. Specifically, it is described in detail as follows.

[0161] In the embodiments of the present application, it can be understood that when the phase differences between multiple signals at different sound speeds are calibrated in the mapping table, for example, the phase difference between the phase of the sound wave signal emitted by the sound generating device and the phase of the laser signal marked by the sound wave signal received by the laser receiver, or the phase difference between the phase of the laser signal marked by the sound wave signal received by the first laser receiver and the phase of the laser signal marked by the sound wave signal received by the second laser receiver, etc., at this time, in the measurement environment, when the phase difference between the phase of the sound wave signal emitted by the sound generating device and the phase of the laser signal marked by the sound wave signal received by the laser receiver, or the phase difference between the phase of the laser signal marked by the sound wave signal received by the first laser receiver and the phase of the laser signal marked by the sound wave signal received by the second laser receiver are used to query the corresponding mapping relationships respectively to obtain the corresponding measured third target sound speed and the fourth target sound speed, in an ideal situation, or when the sound speed measurement device is not affected by the external environment and affects the sound speed measurement accuracy, the third target sound speed and the fourth target sound speed should be relatively small, or there is a tolerable difference. Therefore, by using the above solution, a simple detection of the sound speed measurement device itself can be realized to determine whether the sound speed measurement device fails and outputs an incorrect sound speed result. This has high practical value in the application scenario of using a small structured sound speed measurement device to measure the sound speed, that is, in the process of accurately measuring the sound speed by a simple-structured sound speed measurement device, through relatively simple judgment conditions, the stability of the sound speed measurement result can be ensured, and large deviations in the test result caused by external environment interference can be avoided. Specifically, the sound speed measurement method further includes:

[0162] When the sound speed difference between the third target sound speed and the fourth target sound speed meets a preset condition, determine the target sound speed in the measurement environment according to the third target sound speed and the fourth target sound speed.

[0163] In the embodiments of the present application, when the sound speed difference between the third target sound speed and the fourth target sound speed meets a preset condition, for example, is less than a preset threshold, it can be considered that the measurement result of the sound speed measurement device is relatively accurate. At this time, the target sound speed in the measurement environment can be determined according to the third target sound speed and the fourth target sound speed based on actual needs. For example, as a simple and feasible implementation solution, the third target sound speed and the fourth target sound speed can be weighted, such as taking the average value as the target sound speed in the measurement environment.

[0164] Of course, when the difference in sound speed between the third target sound speed and the fourth target sound speed does not meet the preset condition, for example, exceeds the preset threshold, it can be considered that the current sound speed measurement device may provide an incorrect sound speed measurement result due to external or internal factors (for example, circuit delay change or change in the flight distance of the acoustic wave signal). At this time, to ensure the stability of the measurement result, the third target sound speed and the fourth target sound speed measured by the current sound speed measurement device can be refused to be used. Moreover, since the sound speed measurement device provided in this application has a small size and low cost, multiple sound speed measurement devices can be easily carried during ocean mapping. Therefore, the seawater sound speed can still be accurately measured through multiple sound speed measurement devices, which has high practical significance in actual use.

[0165] Of course, similar to the foregoing solution of obtaining multiple sound speeds through multiple mapping relationships respectively and determining whether the sound speed measurement device can accurately measure the sound speed based on the difference between the multiple sound speeds, it can be known from the foregoing related description that when the laser generator and the laser receiver can be relatively parallelly arranged at both ends of the main housing, and the sound emitting device is slidably arranged in the main housing, when the sound emitting device is slidably arranged at different positions in the main housing, the laser transmission path between the sound emitting device and the laser generator and the laser receiver can still maintain a fixed distance, that is, the time difference between the signals received by the signal processor will not change. Therefore, as another feasible embodiment of this application, please refer to Figure 7 , and another schematic flow chart of steps for identifying a fault of the sound speed measurement device is also provided. Specifically, this method is mainly applicable to a sound speed measurement device in which the laser generator and the laser receiver can be relatively parallelly arranged at both ends of the main housing, and the sound emitting device is slidably arranged in the main housing, and specifically includes steps S710 to S730:

[0166] S710, after adjusting the position of the sound emitting device, when the laser receiver receives the laser signal marked by the acoustic wave signal, continue to collect the third phase of the acoustic wave signal generated by the sound emitting device and the fourth phase of the laser signal.

[0167] In the embodiment of this application, after the position of the sound emitting device is slidably adjusted, the third phase of the acoustic wave signal generated by the sound emitting device and the fourth phase of the laser signal received by the laser receiver will be continuously collected.

[0168] S720, determine the fault detection result of the sound speed measurement device according to the first time difference between the first phase and the second phase, and the third phase difference between the third phase and the fourth phase.

[0169] In the embodiment of the present application, since the distance of the propagation path between the sound generating device and the laser generator to the laser receiver will not be changed after the position of the sound generating device is adjusted by sliding, therefore, the first phase difference between the first phase and the second phase during the past acquisition process, and the third phase difference between the third phase and the fourth phase acquired after the position is adjusted can be used to determine the fault detection result of the sound velocity measurement device. Specifically, when the first phase difference and the third phase difference are less than the threshold value, it can be considered that the measurement results of the two measurement processes are stable. At this time, it can be determined that the fault detection result of the sound velocity measurement device is no fault, so that the corresponding sound velocity queried according to the first phase difference and the third phase difference can be used as the target sound velocity in the measurement environment. Of course, when the first phase difference and the third phase difference are greater than the threshold value, it can be considered that there are large differences in the measurement results of the two measurement processes, that is, the sound velocity measurement device may malfunction, thus avoiding using the wrong sound velocity measurement device to obtain wrong sound velocity results.

[0170] S430. Determine the fault detection result of the sound velocity measurement device according to the second phase difference between the multiple second phases and the fourth phase difference between the multiple fourth phases.

[0171] In the embodiment of the present application, similarly to the foregoing, since the distance of the propagation path between multiple laser generators and the laser receiver generally will not be changed after the position of the sound generating device is adjusted by sliding, therefore, the second phase difference between the multiple second phases during the past acquisition process and the fourth phase difference between the multiple fourth phases acquired after the position is adjusted can also be used to determine the fault detection result of the sound velocity measurement device. Among them, the fault detection result of the sound velocity measurement device and the subsequent execution process are not repeated in this embodiment.

[0172] In addition, in the implementation scheme of calibrating the sound velocity using multiple laser beams, that is, when there are multiple laser receivers in the sound velocity measurement device, at this time, the sound velocity in the measurement environment can also be obtained by taking the average value or other statistical values of the phases of the multiple beams of light received by the laser receivers. That is, when the second phase includes multiple phases, according to the second phase difference between the multiple second phases, query the mapping relationship to obtain the fourth target sound velocity in the measurement environment, including:

[0173] Query the mapping relationship according to the statistical value of the second phase difference between the multiple second phases to obtain the fourth target sound velocity in the measurement environment.

[0174] Among them, the statistical value here can be at least one or a weighted combination of several of the average value, median, and mode to further improve the accuracy of the measured sound velocity.

[0175] It is understandable that the embodiments provided in this application respectively elaborate in detail on the implementation solutions for determining the sound speed through time calibration or through phase calibration. Of course, it should be noted that the above implementation solutions for determining the sound speed through time calibration or through phase calibration can be set separately, and of course, they can also be integrally set in the same sound speed measurement device. That is, the sound speed measurement device can respectively measure the sound speed by the aforementioned time difference and phase difference methods. Similarly, it can further ensure the accuracy of the obtained sound speed based on the sound speed measurement results obtained by the two methods, further improving the usability of the sound speed measurement device.

[0176] To better implement the sound speed measurement method provided in the embodiments of this application, a specific structure of a signal processor is also provided in the embodiments of this application, as Figure 8 shown. The signal processor specifically includes:

[0177] A control unit 810, configured to control the laser generator to emit a laser signal in a measurement environment, so that the laser receiver receives the laser signal.

[0178] A response unit 820, configured to respond to the sound wave signal generated by the sound generating device and collect the first moment when the sound wave signal is generated by the sound generating device;

[0179] The response unit 820 is further configured to respond to the laser signal marked by the sound wave signal received by the laser receiver and collect the second moment when the laser receiver receives the laser signal marked by the sound wave signal;

[0180] A query unit 830, configured to query the mapping relationship according to the first moment and the second moment to obtain the target sound speed in the measurement environment.

[0181] In some embodiments of this application, the query unit 830 is configured to query the mapping relationship according to the first moment difference between the first moment and the second moment to obtain the first target sound speed in the measurement environment; and / or, in the case where the second moment includes multiple moments, query the mapping relationship according to the second moment difference between the multiple second moments to obtain the second target sound speed in the measurement environment, where the multiple moments respectively correspond to the moments when multiple laser receivers receive the laser signals marked by the sound wave signals.

[0182] In some embodiments of this application, the query unit 830 is configured to query the first mapping relationship according to the first moment difference between the first moment and the second moment to obtain the first target sound speed in the measurement environment; and query the second mapping relationship according to the second moment difference between the multiple second moments to obtain the second target sound speed in the measurement environment.

[0183] In some embodiments of the present application, the query unit 830 is configured to determine the target sound speed in the measurement environment according to the first target sound speed and the second target sound speed when the sound speed difference between the first target sound speed and the second target sound speed meets a preset condition.

[0184] In some embodiments of the present application, the query unit 830 is configured to, after adjusting the position of the sound generating device, continue to collect the third moment when the sound generating device generates a sound wave signal, and the fourth moment when the laser receiver receives the laser signal marked by the sound wave signal. According to the first moment difference between the first moment and the second moment, and the third moment difference between the third moment and the fourth moment, determine the fault detection result of the sound speed measurement device; and / or according to the second moment difference between multiple second moments, and the fourth moment difference between multiple fourth moments, determine the fault detection result of the sound speed measurement device.

[0185] In some embodiments of the present application, the control unit 810 is further configured to control the laser generator to emit laser signals at a fixed time interval in the measurement environment, so that the laser receiver receives the laser signals; the response unit 820 is configured to respond to the laser receiver receiving the laser signals marked by the sound wave signals, collect the first phase of the sound wave signals generated by the sound generating device, and collect the second phase of the laser receiver receiving the laser signals marked by the sound wave signals; the query unit 830 is configured to query the mapping relationship according to the first phase and the second phase to obtain the target sound speed in the measurement environment.

[0186] In some embodiments of the present application, the query unit 830 is configured to query the mapping relationship according to the first phase difference between the first phase and the second phase to obtain the third target sound speed in the measurement environment; and / or, when the second phase includes multiple phases, query the mapping relationship according to the second phase difference between multiple second phases to obtain the fourth target sound speed in the measurement environment, where the multiple phases respectively correspond to the phases of the laser receiver receiving the laser signals marked by the sound wave signals.

[0187] In some embodiments of the present application, the query unit 830 is configured to query the third mapping relationship according to the first phase difference between the first phase and the second phase to obtain the third target sound speed in the measurement environment; query the fourth mapping relationship according to the second moment difference between multiple second phases to obtain the fourth target sound speed in the measurement environment.

[0188] In some embodiments of the present application, the query unit 830 is configured to determine the target sound speed in the measurement environment according to the third target sound speed and the fourth target sound speed when the sound speed difference between the third target sound speed and the fourth target sound speed meets a preset condition.

[0189] In some embodiments of the present application, the query unit 830 is configured to collect the third phase of the sound wave signal generated by the sound generating device and the fourth phase of the laser signal after adjusting the position of the sound generating device; determine the fault detection result of the sound speed measuring device according to the first time difference between the first phase and the second phase, and the third phase difference between the third phase and the fourth phase; and / or; determine the fault detection result of the sound speed measuring device according to the second phase differences between multiple second phases and the fourth phase differences between multiple fourth phases.

[0190] For the specific definition of the signal processor, reference can be made to the definition of the sound speed measurement method in the foregoing text, which will not be elaborated herein. Each unit in the foregoing signal processor can be implemented in whole or in part by software, hardware, and their combination. The foregoing modules can be embedded in or independent of the processor in the computer device in the form of hardware, or stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the foregoing modules.

[0191] In some embodiments of the present application, the signal processor may specifically be in the form of a processor. A mapping relationship between different sound speeds and calibration times and computer instructions are pre-stored in the processor. The processor is configured to execute the computer instructions to perform the sound speed measurement method as described in any one of the foregoing, for example, execute the following steps:

[0192] In the measurement environment, control the laser generator to emit a laser signal so that the laser receiver receives the laser signal;

[0193] In response to the sound generating device generating a sound wave signal, collect the first moment when the sound generating device generates the sound wave signal;

[0194] In response to the laser receiver receiving the laser signal marked by the sound wave signal, collect the second moment when the laser receiver receives the laser signal marked by the sound wave signal;

[0195] According to the first moment and the second moment, query the mapping relationship to obtain the target sound speed in the measurement environment.

[0196] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above various methods. Any reference to a memory, storage, information base, or other medium used in the various embodiments provided in this application can include at least one of non-volatile and volatile memories. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0197] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the various technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0198] The above has introduced in detail a sound velocity measurement device and method provided by the embodiments of the present application. Specific examples are used in this article to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. An apparatus for measuring the speed of sound, characterized in that, Including: A main housing; A plurality of laser generators for emitting laser signals; A plurality of laser receivers for receiving the laser signals emitted by the laser generators; wherein, the laser generators and the laser receivers are relatively and parallelly arranged at two ends of the main housing; A sound generating device arranged on the main housing for generating a sound wave signal to mark the laser signal emitted by the laser generator; and A signal processor circuit - connected to the laser generator, the laser receiver, and the sound generating device; wherein, the signal processor pre - stores a mapping relationship between different sound speeds and calibration times, or a mapping relationship between different sound speeds and calibration phases, so as to query the mapping relationship according to the time when the sound generating device generates the sound wave signal and the time or phase when the laser receiver receives the laser signal marked by the sound wave signal in the measurement environment, and obtain the target sound speed in the measurement environment; The mapping relationship includes a calibration relationship between different sound speeds and the time differences between the laser signals marked by the sound wave signal received by a plurality of different laser receivers collected by the signal processor, and / or a calibration relationship between different sound speeds and the phase differences between the laser signals marked by the sound wave signal received by a plurality of different laser receivers collected by the signal processor; The signal processor is used to query the mapping relationship according to the time difference of the times when a plurality of laser receivers receive the laser signals marked by the sound wave signal or according to the phase difference of the phases when a plurality of laser receivers receive the laser signals marked by the sound wave signal, and obtain the target sound speed in the measurement environment.

2. The device according to claim 1, characterized in that, The signal processor is connected to the laser generator through a first control circuit; the signal processor is connected to the laser generator through a first signal circuit; the signal processor is connected to the sound generating device through a second control circuit and a second signal circuit.

3. The device according to claim 1, wherein The laser generator is a pulsed laser generator, and the sound generating device is an ultrasonic generator.

4. The device according to any one of claims 1 to 3, characterized in that The sound generating device is slidably arranged on the main housing.

5. A method for measuring the speed of sound, characterized in that, Applied to a signal processor in a sound speed measuring device, the sound speed measuring device further includes a plurality of laser generators for emitting laser signals, a plurality of laser receivers for receiving the laser signals emitted by the laser generators, and a sound generating device for generating a sound wave signal to mark the laser signal emitted by the laser generator; wherein, the signal processor pre - stores a mapping relationship between different sound speeds and calibration times; the mapping relationship includes a calibration relationship between different sound speeds and the time differences between the laser signals marked by the sound wave signal received by a plurality of different laser receivers collected by the signal processor, and / or a calibration relationship between different sound speeds and the phase differences between the laser signals marked by the sound wave signal received by a plurality of different laser receivers collected by the signal processor; The method includes: In a measurement environment, controlling the laser generator to emit a laser signal so that the laser receiver receives the laser signal; In response to the sound generating device generating a sound wave signal, collecting the first time when the sound generating device generates the sound wave signal; In response to the laser receiver receiving the laser signal marked by the acoustic wave signal, collect the second moment when the laser receiver receives the laser signal marked by the acoustic wave signal; According to the second time difference between multiple said second moments, query the mapping relationship to obtain the second target sound speed in the measurement environment; and / or In the measurement environment, control the laser generator to emit laser signals at a fixed time interval so that the laser receiver receives the laser signals; In response to the laser receiver receiving the laser signal marked by the acoustic wave signal, collect the first phase of the sound wave signal generated by the sound - emitting device and the second phase of the laser signal received by the laser receiver; According to the second phase difference between multiple said second phases, query the mapping relationship to obtain the fourth target sound speed in the measurement environment.

6. The method according to claim 5, wherein The mapping relationship includes a second mapping relationship; The step of according to the second time difference between multiple said second moments, querying the mapping relationship to obtain the second target sound speed in the measurement environment includes: According to the second time difference between multiple said second moments, query the second mapping relationship to obtain the second target sound speed in the measurement environment; and / or The mapping relationship includes a fourth mapping relationship; The step of according to the second phase difference between multiple said second phases, querying the mapping relationship to obtain the fourth target sound speed in the measurement environment includes: According to the second time difference between multiple said second phases, query the fourth mapping relationship to obtain the fourth target sound speed in the measurement environment.

7. The method according to claim 5 or 6, characterized in that, The method further includes: When the sound speed difference between the first target sound speed and the second target sound speed meets a preset condition, determine the target sound speed in the measurement environment according to the first target sound speed and the second target sound speed; the first target sound speed is obtained by querying the mapping relationship according to the first moment and the second moment; and / or When the sound speed difference between the third target sound speed and the fourth target sound speed meets a preset condition, determine the target sound speed in the measurement environment according to the third target sound speed and the fourth target sound speed; the third target sound speed is obtained by querying the mapping relationship according to the first phase and the second phase.

8. The method according to claim 5, characterized in that, The step of according to the second time difference between multiple said second moments, querying the mapping relationship to obtain the second target sound speed in the measurement environment includes: According to the statistical value of the second time difference between multiple said second moments, query the mapping relationship to obtain the second target sound speed in the measurement environment; and / or The step of according to the second phase difference between multiple said second phases, querying the mapping relationship to obtain the fourth target sound speed in the measurement environment includes: According to the statistical value of the second phase difference between multiple said second phases, query the mapping relationship to obtain the fourth target sound speed in the measurement environment.

9. The method according to claim 5, characterized in that, The method further includes: After adjusting the position of the sound generating device, continue to collect the third moment when the sound generating device generates a sound wave signal, and the fourth moment when the laser receiver receives the laser signal marked by the sound wave signal, or, when the laser receiver receives the laser signal marked by the sound wave signal, collect the third phase of the sound wave signal generated by the sound generating device and the fourth phase of the laser signal; Determine the fault detection result of the sound speed measuring device according to the first time difference between the first moment and the second moment, and the third time difference between the third moment and the fourth moment; and / or Determine the fault detection result of the sound speed measuring device according to the second time differences between multiple second moments, and the fourth time differences between multiple fourth moments; and / or; Determine the fault detection result of the sound speed measuring device according to the first time difference between the first phase and the second phase, and the third phase difference between the third phase and the fourth phase; and / or; Determine the fault detection result of the sound speed measuring device according to the second phase differences between multiple second phases, and the fourth phase differences between multiple fourth phases.

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