Sound velocity measuring device and method

Abstract

The invention provides a sound velocity measuring device and method, and the device comprises a main housing, a laser generator, a laser receiver, a sound production device, and a signal processor, and the signal processor stores the mapping relation between different sound velocities and calibration time in advance. The mapping relation is inquired according to the moment or phase of the acoustic signal generated by the sound production device and the moment or phase of the laser signal marked by the acoustic signal received by the laser receiver in the measurement environment, and the target sound velocity in the measurement environment is obtained. Complex physical mapping is changed into single mapping from time to sound velocity or from phase to sound velocity, the measurement parameter requirement is greatly simplified, the cost is reduced, the spanning property that a miniaturized measurement device measures the sound velocity at high precision is achieved, and the method is particularly suitable for measurement of the sound velocity in other complex environments such as the ocean.

Description

Technical Field

[0001] The present application relates to the field of surveying and mapping technology, and in particular to a device and method for measuring the speed of sound. Background Art

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

[0003] At present, the measurement of seawater sound velocity mainly includes indirect measurement method realized by conductivity temperature depth (CTD) and direct measurement method of directly measuring sound velocity by piezoelectric effect or acousto-optic effect. Among them, although the measurement device based on acousto-optic effect overcomes the problem of inaccurate measurement results caused by circuit delay and discreteness of crystal oscillator existing in piezoelectric effect, the acousto-optic effect relies on high-precision acquisition of sound wave flight distance and corresponding flight time, and often requires integration of spectrometers, reflectors, frequency oscilloscopes and other instruments, resulting in a complex overall system. The integrated equipment is huge in size and expensive, which is suitable for measuring standard sound velocity in the laboratory for metrological equipment, but it is difficult to measure the seawater sound velocity in a real marine working environment. Summary of the invention

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

[0005] In a first aspect, the present application provides a sound velocity measurement device, comprising:

[0006] main housing;

[0007] at least one laser generator, for emitting a laser signal;

[0008] At least one laser receiver, used to receive the laser signal emitted by the laser generator; wherein the laser generator and the laser receiver are arranged at two ends of the main housing opposite to each other;

[0009] a sound generating device disposed on the main housing, used to generate a sound wave signal to mark the laser signal emitted by the laser generator; and

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

[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 pulse 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 arranged relatively parallel to each other at two ends of the main shell; and the sound-generating device is slidably arranged on the main shell.

[0014] In a second aspect, the present application provides a sound velocity measurement method, which is applied to a signal processor of a sound velocity measurement device, wherein the sound velocity measurement device further comprises 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 velocities and calibration times;

[0015] The method comprises:

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

[0017] In response to the sound wave signal generated by the sound-generating device, collecting the first moment when the sound wave signal is generated by the sound-generating device;

[0018] In response to the laser receiver receiving the laser signal marked by the acoustic wave signal, collecting a second moment when the laser receiver receives the laser signal marked by the acoustic wave signal;

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

[0020] In a measurement environment, controlling the laser generator to emit a laser signal at a fixed time interval so that the laser receiver receives the laser signal;

[0021] In response to the laser receiver receiving the laser signal marked by the acoustic wave signal, collecting a first phase of the acoustic wave signal generated by the sound-generating device, and collecting a second phase of the laser signal marked by the acoustic wave signal received by the laser receiver; collecting a second phase of the laser signal marked by the acoustic wave signal received by the laser receiver;

[0022] The mapping relationship is queried according to the first phase and the second phase to obtain the target sound speed in the measurement environment.

[0023] As a feasible embodiment of the present application, 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] querying the mapping relationship according to a first time difference between the first time and the second time to obtain a first target sound speed in the measurement environment; and / or

[0025] In the case where the second moment includes multiple moments, querying 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, wherein the multiple moments respectively correspond to the moments when multiple laser receivers receive the laser signal marked by the sound wave signal;

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

[0027] querying the mapping relationship according to a first time difference between the first phase and the second phase to obtain a third target sound speed under the measurement environment; and / or

[0028] In the case where the second phase includes multiple phases, the mapping relationship is queried according to the second phase difference between the multiple second phases to obtain the fourth target sound speed under the measurement environment, wherein the multiple phases respectively correspond to the phases of the laser signals marked by the sound wave signal received by multiple laser receivers.

[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 time and the second time to obtain the first target sound speed under the measurement environment includes:

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

[0032] The querying the mapping relationship according to the second time difference between the plurality of second time moments to obtain the second target sound speed under the measurement environment comprises:

[0033] querying the second mapping relationship according to the second time difference between the plurality of second time moments to obtain a 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 calibration 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 under the measurement environment includes:

[0037] According to a first phase difference between the first phase and the second phase, query the third mapping relationship to obtain a third target sound speed in the measurement environment;

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

[0039] The fourth mapping relationship is queried according to the second time differences between the plurality of second phases to obtain a fourth target sound speed in the measurement environment.

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

[0041] When a sound speed difference between the first target sound speed and the second target sound speed meets a preset condition, determining a 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, the target sound speed in the measurement environment is determined 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, querying 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 includes:

[0044] According to the statistical value of the second time difference between the plurality of second time moments, query the mapping relationship to obtain the second target sound speed in the measurement environment;

[0045] and / or

[0046] In the case where the second phase includes multiple phases, querying the mapping relationship according to the second phase difference between the multiple second phases to obtain the fourth target sound speed under the measurement environment includes:

[0047] The mapping relationship is queried according to the statistical value of the second phase difference between the plurality of second phases to obtain a 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 the 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 a fault detection result of the sound velocity measurement device according to a first time difference between the first time and the second time, and a third time difference between the third time and the fourth time; and / or

[0051] Determine a fault detection result of the sound velocity measuring device according to a second time difference between a plurality of the second time moments and a fourth time difference between a plurality of the fourth time moments; and / or;

[0052] determining a fault detection result of the sound velocity measuring device according to a first time difference between the first phase and the second phase, and a third phase difference between the third phase and the fourth phase; and / or;

[0053] A fault detection result of the sound velocity measuring device is determined based on a second phase difference between a plurality of the second phases and a fourth phase difference between a plurality of the 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 items.

[0055] The sound speed measuring device provided in the embodiment of the present application stores the mapping relationship between different sound speeds and calibration time or phase in advance in the signal processor, and is connected with the laser generator, the laser receiver and the sound-generating device circuit, so that under measurement, the mapping relationship can be queried according to the time when the sound-generating device generates the sound wave signal obtained by the acquisition and the time or phase when the laser receiver receives the laser signal marked by the sound wave signal, thereby directly obtaining the target sound speed in the measurement environment. Compared with the measurement device based on the acousto-optic effect and relying on a variety of instrument components, the sound speed measuring device provided in the present application changes the complex physical mapping of "distance-time to sound speed" to a single mapping of "time to sound speed" or "phase to sound speed", thereby greatly simplifying the measurement parameter requirements, reducing costs, and realizing the leapfrogging of miniaturized measurement devices to measure sound speed with high precision, which is particularly suitable for measuring sound speed 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 drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0057] Figure 1 A schematic diagram of the structure of a sound velocity measurement device provided in an embodiment of the present application;

[0058] Figure 2 A schematic diagram of the steps of a sound velocity measurement method provided in an embodiment of the present application;

[0059] Figure 3 A flowchart of the steps of querying the mapping relationship to obtain the sound speed provided in an embodiment of the present application;

[0060] Figure 4 A schematic diagram of a process flow for identifying a fault in a sound velocity measurement device provided in an embodiment of the present application;

[0061] Figure 5 A schematic diagram of the steps of another method for measuring the speed of sound provided in an embodiment of the present application;

[0062] Figure 6 A flowchart of another step of querying a mapping relationship to obtain a sound speed provided in an embodiment of the present application;

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

[0064] Figure 8 A schematic diagram of the structure of a signal processor provided in an embodiment of the present application;

[0065] Figure ID:

[0066] main housing 101;

[0067] A first laser generator 1021;

[0068] A second laser generator 1022;

[0069] A first laser receiver 1031;

[0070] A second laser receiver 1032;

[0071] Sound-generating device 104;

[0072] Signal processor 105. DETAILED DESCRIPTION

[0073] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0074] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0075] In the description of the present application, the word "for example" is used to mean "used as an example, illustration or explanation". Any embodiment described as "for example" in the present application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is given to enable any technician in the field to implement and use the present invention. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the present invention can be implemented without using these specific details. In other examples, well-known structures and processes will not be elaborated in detail to avoid obscuring 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 widest scope consistent with the principles and features disclosed in the present application.

[0076] To facilitate understanding of the sound velocity measurement device and method provided in the embodiments of the present application, the application background of the relevant sound velocity measurement device and method is first described accordingly. Specifically, the sound velocity measurement device and sound velocity measurement method provided in the present application are mainly applicable to the measurement of seawater sound velocity in a marine environment, wherein the seawater sound velocity is a key parameter in the marine acoustic detection technology system, and the measurement accuracy of the seawater sound velocity has an important impact on applications such as seabed topography measurement, underwater navigation and positioning. At present, the more commonly used sound velocity measurement devices mainly include an indirect measurement method that measures the conductivity, temperature and depth of the water body through a temperature-salinity-depth meter to estimate the seawater sound velocity through a formula, and a direct measurement method that directly measures the sound velocity by means of a piezoelectric effect or an acousto-optic effect. Among them, compared with the piezoelectric effect, which may be affected by circuit delays and discrete interference of crystal oscillators, resulting in inaccurate measurement results, the acousto-optic effect utilizes the effects of the generated sound wave signal on the light signal, such as refraction and interference, and collects the time taken for the sound wave to affect the light signal after traveling a given distance after being emitted to accurately measure the sound speed. Among them, since the sound speed depends on the accurate sound wave flight distance and the collection of the corresponding flight time, the measuring equipment often needs to integrate instruments such as spectrometers, reflectors, and frequency oscilloscopes, resulting in a complex overall system. The integrated equipment is huge in size, often exceeding 0.5M*0.5M*0.5M, and the cost is high. Although the sound speed can be accurately measured, it is mainly used to measure the standard sound speed in an experimental environment. In the actual marine environment, it is often difficult to measure the sound speed directly in seawater.

[0077] In order to solve the above-mentioned problems, in order to greatly simplify the measurement parameter requirements and reduce costs, thereby achieving the effect of high-precision sound speed measurement by a miniaturized measuring device, the present application provides a sound speed measuring device with a simple structure and a sound speed measuring method suitable for the sound speed measuring device, which is particularly suitable for measuring the sound speed in the ocean or other complex environments.

[0078] For details, please refer to Figure 1 , Figure 1 A structural schematic diagram of a sound velocity measurement device provided in an embodiment of the present application is described in detail as follows.

[0079] The sound velocity measuring device provided in this application generally includes:

[0080] main housing 101;

[0081] at least one laser generator;

[0082] at least one laser receiver;

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

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

[0085] Among them, the laser generator is used to emit laser, and the laser receiver is used to receive the emitted laser. The laser generator is relatively arranged at the two ends of the main shell, and can usually be fixedly connected to the main shell. 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 shell. The present application does not limit the installation form of the laser generator and the laser receiver. Any installation form that can enable the laser receiver to receive the laser signal emitted by the laser generator is within the scope of protection required by this application.

[0086] In addition, in order to better understand the implementation scheme in which the sound velocity measurement device includes multiple laser generators and laser receivers, in this embodiment, Figure 1 As shown, the sound velocity measuring device includes two laser generators and two laser receivers as an example for explanation. Specifically, the laser generator includes a first laser generator 1021 and a second laser generator 1022, and the laser receiver includes a first laser receiver 1031 and a second laser receiver 1032, wherein the first laser generator 1021 and the first laser receiver 1031 are arranged relative to each other so that the first laser receiver 1031 receives the laser emitted by the first laser generator 1021, and the second laser generator 1022 and the second laser receiver 1032 are arranged relative to each other so that the second laser receiver 1032 receives the laser emitted by the second laser generator 1022. It can be understood that, in the case where the sound velocity measuring 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 an acoustic signal, wherein the propagation path of the acoustic signal is relatively perpendicular to the path of the laser emitted by the laser generator, and the acoustic signal can be used to mark the laser signal emitted by the laser generator through the acousto-optic effect. For example, the acoustic signal can usually change the propagation medium, such as the refractive index of seawater to light, so that the laser receiver can receive the laser signal after the propagation path is marked by the acoustic signal. Of course, in addition to the implementation scheme provided above, the laser receiver can also determine whether it has received the laser signal after being marked by the acoustic signal by other means, such as detecting the phase of the received laser. The embodiments of the present application are not limited here.

[0088] In addition, in order to achieve the measurement of sound speed, the signal processor also pre-stores a mapping relationship between different sound speeds and calibration times, or a mapping relationship between different sound speeds and calibration phases, so that in the measurement environment, according to the time when the sound-emitting 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, the mapping relationship can be queried, thereby directly calibrating the target sound speed in the measurement environment.

[0089] Specifically, as another feasible embodiment of the present application, in order to better realize the control of the sound velocity measuring device, the signal processor can usually be connected to the laser generator through the first control circuit to control the laser generator to turn on or off, thereby controlling the emission of laser, or stopping the emission of laser. The signal processor can also be connected to the laser generator through the first signal circuit to respond to the laser generator receiving the laser signal or a specific laser signal to perform a specific operation, for example, recording the time information of the laser generator receiving the laser signal. In addition, the signal processor can also be connected to the sound-generating device through the second control circuit and the second signal circuit, while realizing the control of the sound-generating device to turn on or off, thereby controlling the generation of the sound wave signal or stopping the generation of the sound wave signal, and realizing the recording of the time information of the sound-generating device generating the sound wave signal. Of course, in addition to recording the time information of the laser generator receiving the laser signal, the signal processor can also be used to record the phase information of the laser receiver receiving the laser signal marked by the sound wave and the phase information of the sound wave signal generated by the sound-generating device for subsequent sound velocity measurement.

[0090] In addition, as a further feasible implementation scheme of the present application, in order to further improve the accuracy of the measurement of the seawater sound velocity, the laser generator can be a pulsed laser generator, and the sound generator can be an ultrasonic generator. Of course, the above laser generator and sound generator 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 are not limited here.

[0091] In addition, considering that the present application provides a sound velocity measuring device with a simple structure for realizing the measurement of sound velocity, and in order to further improve the stability of the sound velocity measuring device in measuring sound velocity, as a further feasible implementation scheme of the present application, the laser generator and the laser receiver can be relatively parallelly arranged at both ends of the main shell, and the sound-generating device is slidably arranged on the main shell, so that the sound-generating device maintains a fixed distance from the laser transmission path between the laser generator and the laser receiver during the process of sliding the sound-generating device at different positions of the main shell. That is to say, in the above scheme, when the sound-generating device slides on the main shell, the distance traveled by the laser signal emitted by the marking laser generator by the emitted sound wave signal remains relatively unchanged, and the required time remains unchanged, so that the result 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 shell can be adjusted to determine whether the sound velocity measuring device has a possible fault according to the result received by the signal processor, thereby avoiding affecting the stability of the sound velocity measurement result due to the use of a faulty sound velocity measuring device.

[0092] The sound speed measuring device provided in the embodiment of the present application stores the mapping relationship between different sound speeds and calibration time or phase in advance in the signal processor, and is connected with the laser generator, the laser receiver and the sound-generating device circuit, so that under measurement, the mapping relationship can be queried according to the time when the sound-generating device generates the sound wave signal obtained by the acquisition and the time or phase when the laser receiver receives the laser signal marked by the sound wave signal, thereby directly obtaining the target sound speed in the measurement environment. Compared with the measurement device based on the acousto-optic effect and relying on a variety of instrument components, the sound speed measuring device provided in the present application changes the complex physical mapping of "distance-time to sound speed" to a single mapping of "time to sound speed" or "phase to sound speed", thereby greatly simplifying the measurement parameter requirements, reducing costs, and realizing the leapfrogging of miniaturized measurement devices to measure sound speed with high precision, which is particularly suitable for measuring sound speed in other complex environments such as the ocean.

[0093] On the basis of the sound velocity measurement device provided above, the present application further provides a sound velocity measurement method applied to a signal processor of the sound velocity measurement device. Specifically, the method is described by taking a method of realizing sound velocity measurement by using time information as an example. Figure 2 , Figure 2 A schematic flow chart of a method for measuring the speed of sound provided in an embodiment of the present application includes steps S210 to S240:

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

[0095] In an embodiment of the present application, by placing the sound speed measurement method in an ocean measurement environment 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 speed measurement device can receive the laser signal.

[0096] S220, in response to the sound-generating device generating a sound wave signal, collecting the first moment when the sound-generating device generates the sound wave signal.

[0097] In the embodiment 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 acoustic wave signal, collecting a second moment when the laser receiver receives the laser signal marked by the acoustic wave signal.

[0099] In an embodiment of the present application, after the sound-emitting device generates a sound wave signal, when the sound wave propagates on the laser propagation path between the laser generator and the laser receiver, it will interfere with the laser signal emitted by the laser generator based on the acousto-optic effect, thereby forming a mark on the laser signal. After receiving the laser signal marked by the sound wave signal, the laser receiver can receive the laser signal marked by the sound wave signal through the first signal circuit at the second moment.

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

[0101] It is understandable that the speed of sound waves can usually be determined by the flight distance / flight time, where 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 time between the sound-emitting device sending the sound wave signal and the laser receiver receiving the laser signal marked by the sound wave signal under ideal conditions. In fact, due to the delay of the control circuit or other factors, there will often be a certain error in the flight distance or flight time, which will affect the accuracy of the sound speed measurement results. Therefore, in order to improve the stability of the measurement results of the sound speed measurement device, it is often necessary to integrate additional instruments into the system to compensate for the errors. Although the accuracy of the measurement results can be improved, it will undoubtedly increase the cost and size of the system, and it is not suitable for accurate sound speed measurement of seawater in a sea environment.

[0102] The present application considers that under the condition of fixed flight distance and other error factors, by calibrating the time difference between the emission of the sound wave signal detected by the signal processor at the standard sound speed and the reception of the laser signal marked by the sound wave signal, and establishing and storing the mapping relationship between time and sound speed, the requirements for measurement parameters can be greatly simplified, and the complex physical mapping can be converted into a single mapping of "time to sound speed" that is relatively detected and easy to measure. Therefore, the mapping relationship can be queried based on the first and second moments detected above to directly calibrate the target sound speed in the measurement environment.

[0103] The present application stores the mapping relationship between different sound speeds and calibration times in advance in the signal processor, and connects it with the laser generator, the laser receiver and the sound-generating device circuit, so that under measurement, the mapping relationship can be queried according to the time when the sound-generating device generates the sound wave signal obtained by the acquisition and the time when the laser receiver receives the laser signal marked by the sound wave signal, thereby directly obtaining the target sound speed in the measurement environment. Compared with the measurement device based on the acousto-optic effect composed of multiple instrument components, the present application transforms the complex physical mapping of "distance-time to sound speed" into a single mapping of "time to sound speed", thereby greatly simplifying the measurement parameter requirements, reducing costs, and realizing the leapfrogging of miniaturized measurement devices to measure sound speed with high precision, which is particularly suitable for measuring sound speed in other complex environments such as the ocean.

[0104] Specifically, it can be understood that the mapping relationship between the sound speed and the calibration time pre-stored in the signal processor can be understood as the mapping relationship between the sound speed and the calibrated sound wave signal propagation time. Therefore, in addition to considering the time difference between the sound-emitting device emitting the sound wave signal and the laser receiver receiving the laser signal marked by the sound wave signal as the calibrated sound wave signal propagation time, in the case where the sound speed 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 signal marked by the sound wave signal can also be used as the calibrated sound wave signal propagation time, which can also realize the determination of the sound speed in the measurement environment. For details, please refer to Figure 3 , Figure 3 A flowchart of the steps of querying a mapping relationship to obtain the speed of sound provided in an embodiment of the present application.

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

[0106] In an embodiment of the present application, when the time between the sound wave signal generated by the sound-emitting device collected by the signal processor and the laser signal marked by the sound wave signal is received by the laser receiver under different sound speeds is calibrated in advance in a standard sound speed environment, and a mapping relationship is established based on the sound speed and this moment, the subsequent signal processor can directly query the corresponding sound speed from the mapping relationship (usually in the signal processor It can be in the form of a mapping table) based on the first moment difference between the first moment and the second moment, as the first target sound speed in the measurement environment.

[0107] It should be noted that in a standard sound speed environment, that is, it is necessary to determine the standard sound speed in a calibration environment, and this usually requires a high degree of measurement accuracy for the sound speed during the calibration process, otherwise it will affect the subsequent actual measurement scenario, that is, the measurement of the seawater sound speed in an ocean environment. Therefore, as a further feasible implementation scheme 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 a calibration environment such as a laboratory.

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

[0109] In an embodiment of the present application, when there are multiple laser receivers, that is, each laser receiver has its own corresponding second moment of 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 multiple different laser receivers is relatively fixed. Therefore, the time difference between the multiple second moments obtained can also be collected as a calibration value, so that the mapping relationship can be queried based on the second time difference between the multiple second moments, thereby obtaining the sound speed in the measurement environment.

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

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

[0112] The first mapping relationship is queried according to a first time difference between the first time and the second time to obtain a first target sound speed in the measurement environment.

[0113] The querying the mapping relationship according to the second time difference between the plurality of second time moments to obtain the second target sound speed under the measurement environment comprises:

[0114] The second mapping relationship is queried according to the second time difference between the plurality of second time moments to obtain the second target sound speed in the measurement environment.

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

[0116] Specifically, to facilitate understanding of the above content, please refer to the following Table 1, which provides a mapping table of mapping relationships stored in the signal processor, as follows:

[0117] Serial number Rated 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, which is about 1500m / s. Of course, when it is needed 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 between the calibrated sound speeds used in the calibration process. For example, in Table 1, calibration is performed every 0.1m / s, so that the sound speed measurement device can achieve a sound speed measurement with an accuracy of 0.1m / s. Of course, the specific accuracy can also be determined based on actual needs, for example, it can also be set to 0.05m / s or 0.01m / s, and the embodiments of the present application will not be repeated here. In addition, during the calibration process, the time difference in the mapping relationship may include a single time difference (i.e., a single column form) or multiple time differences (i.e., a multi-column form in Table 1), wherein 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 may be the time difference between the sound wave signal emitted by the sound-emitting device and the laser signal marked by the sound wave signal received by the laser receiver. The second time difference T2 may also be the time difference between the laser signal marked by the sound wave signal received by the first laser receiver and the laser signal marked by the sound wave signal received by the second laser receiver. In addition, there may 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 sound wave signal received by the second laser receiver and the laser signal marked by the sound wave signal received by the third laser receiver, and so on. The embodiments of the present application are not limited here.

[0119] It can be understood that the above-mentioned mapping table is only one possible form of existence. 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, considering that the error information of the circuit delay signal, the actual flight distance of the sound wave signal, etc. of the same sound velocity measurement device in the calibration environment and in the measurement environment is roughly the same, the mapping between the complex physical relationships is converted into a mapping relationship between time and sound velocity in a single dimension, so as to eliminate such errors and achieve the measurement of the sound velocity. However, in the actual measurement environment, a large error may occur due to interference from the external environment. At this time, it is shown that the current sound velocity measurement device is no longer applicable to the measurement in the current environment. Therefore, in the scheme provided in the embodiment of the present application, by establishing a variety of different mapping relationships, it can also be further used to assist in obtaining a more accurate sound velocity of the measurement result. Specifically, it is described in detail as follows.

[0121] In the embodiment of the present application, it can be understood that when the time difference between multiple signals at different sound speeds is calibrated in the mapping table, such as the time difference between the sound wave signal emitted by the sound-emitting device and the laser signal marked by the sound wave signal received by the laser receiver, or the time difference between the laser signal marked by the sound wave signal received by the first laser receiver and 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 time difference between the sound wave signal emitted by the sound-emitting device and the laser signal marked by the sound wave signal received by the laser receiver, or the time difference between the laser signal marked by the sound wave signal received by the first laser receiver and the laser signal marked by the sound wave signal received by the second laser receiver, the corresponding mapping relationship is queried to obtain the first target sound speed and the second target sound speed obtained by the corresponding measurement, in an ideal case, or when the sound speed measuring device is not disturbed by the external environment and affects the sound speed measurement accuracy, the first target sound speed and the second target sound speed should be small, or there should be a tolerable difference. Therefore, by using the above scheme, a simple detection of the main device of the sound speed measuring device can be achieved to determine whether the sound speed measuring device fails and outputs an erroneous sound speed result. This has high practical value in the application scenario of using a small structured sound velocity measurement device to measure the sound velocity, that is, in the process of accurately measuring the sound velocity with a simple structured sound velocity measurement device, the stability of the sound velocity measurement result is ensured through relatively simple judgment conditions, avoiding large deviations in the test results caused by external environmental interference. Specifically, the sound velocity measurement method also includes:

[0122] In a case where a sound speed difference between the first target sound speed and the second target sound speed meets a preset condition, a target sound speed in the measurement environment is determined according to the first target sound speed and the second target sound speed.

[0123] In an embodiment 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 value, it can be considered that the measurement result of the sound speed measuring device is relatively accurate. At this time, the target sound speed in the measurement environment can be determined based on the first target sound speed and the second target sound speed based on actual needs. For example, as a simple feasible implementation scheme, 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 sound speed difference between the first target sound speed and the second target sound speed does not meet the preset conditions, for example, exceeds the preset threshold, it can be considered that the current sound speed measurement device may provide an erroneous sound speed measurement result due to external or internal factors (for example, a change in circuit delay, or a change in the flight distance of the sound wave signal). At this time, in order to ensure the stability of the measurement results, the first target sound speed and the second target sound speed measured by the current sound speed measurement device can be rejected. Moreover, since the sound speed measurement device provided in the present application has a miniaturized structure and low cost, multiple sound speed measurement devices can be carried portablely during the ocean surveying process, so that the seawater sound speed can still be accurately measured by multiple sound speed measurement devices, which has a high practical significance.

[0125] Of course, similar to the above-mentioned scheme of obtaining multiple sound speeds through multiple groups of mapping relationships and judging whether the sound speed measuring device can accurately measure the sound speed through the difference between the multiple sound speeds, it can be seen from the above-mentioned related description that when the laser generator and the laser receiver can be relatively parallelly arranged at both ends of the main shell, and the sound-generating device is slidably arranged in the main shell, the laser transmission path between the laser generator and the laser receiver can still maintain a fixed distance when the sound-generating device is slidably arranged in different positions of the main shell, that is, the time difference between the signals received by the signal processor will not be changed. Therefore, as another feasible embodiment of the present application, please refer to Figure 4 , another step flow diagram of identifying a fault of a sound velocity measuring device is also provided. Specifically, the method is mainly applicable to a sound velocity measuring device in which a laser generator and a laser receiver can be relatively parallelly arranged at two ends of a main housing, and a sound generating device is slidably arranged on the main housing, and specifically 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 the sound wave signal and the fourth moment when the laser receiver receives the laser signal marked by the sound wave signal.

[0127] In the embodiment of the present application, after the position of the sound-generating device is adjusted by sliding, the third moment when the sound-generating device generates a sound wave signal and the fourth moment when the laser receiver receives a laser signal marked by the sound wave signal will continue to be collected.

[0128] S420, determining a fault detection result of the sound velocity measurement device according to a first time difference between the first time and the second time, and a third time difference between the third time and the fourth time.

[0129] In the embodiment of the present application, since the distance between the sound-generating device and the propagation path from the laser generator to the laser receiver will not be changed after the position of the sound-generating device is adjusted by sliding, the first time difference between the first moment and the second moment in 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 velocity measurement device. Specifically, when the first time difference and the third time 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 that there is no fault, so that the corresponding sound speed can be obtained by querying according to the first time difference or the third time difference 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 value, it can be considered that there is a large difference in the measurement results of the two measurement processes, that is, the sound velocity measurement device may fail, thereby avoiding the use of the wrong sound velocity measurement device to measure the wrong sound velocity result.

[0130] S430, determining a fault detection result of the sound velocity measurement device according to a second time difference between a plurality of the second time moments and a fourth time difference between a plurality of the fourth time moments.

[0131] In the embodiment of the present application, similar to the above, since the distance of the propagation path between the multiple groups of laser generators and laser receivers is usually not changed after the position of the sound-emitting device is adjusted by sliding, the second time difference between multiple second times in the past acquisition process and the fourth time difference between multiple fourth times collected after the position is adjusted can also be used to determine the fault detection result of the sound velocity measurement device. Among them, the present embodiment will not repeat the description of identifying the fault detection result of the sound velocity measurement device and the subsequent execution process, and please refer to the description of step S420 for details.

[0132] Of course, in the implementation scheme of obtaining the sound speed by using multiple laser beams for calibration, that is, when the sound speed measuring device has multiple laser receivers, the sound speed in the measurement environment can also be obtained by taking an average or other statistical value of the moments of the multiple beams of light received by the laser receiver, that is, when the second moment includes multiple moments, the second moment difference between the multiple second moments is queried according to the mapping relationship to obtain the second target sound speed in the measurement environment, including:

[0133] The mapping relationship is queried according to the statistical value of the second time difference between the plurality of second time moments to obtain the second target sound speed in the measurement environment.

[0134] The statistical value here may be at least one of the mean, median, and mode, or a weighted combination of several of them, so as to further improve the accuracy of the measured sound velocity.

[0135] Of course, in addition to the aforementioned method of obtaining the sound velocity measurement by calibrating the time, as another feasible embodiment of the present application, a method of calibrating the phase is also provided to achieve the measurement of the sound velocity. For details, please refer to Figure 5 , Figure 5 A schematic flow chart of another method for measuring the speed of sound provided in an embodiment of the present application includes steps S510 to S530:

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

[0137] In this embodiment, Figure 2 The sound velocity measurement method shown is similar. By placing the sound velocity measurement device in an ocean measurement environment and controlling the laser generator to emit a laser signal at a fixed time interval 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.

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

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

[0140] S530: According to the first moment and the second moment, query the mapping relationship to obtain a target sound speed in the measurement environment.

[0141] It is understandable that the speed of sound waves can usually be determined by the flight distance / flight time, where the flight distance is the distance that the sound wave propagates to the laser propagation path, and the flight time under ideal conditions can usually be related to the phase difference between the phase of the sound wave signal emitted by the sound-emitting device and the phase of the laser signal marked by the sound wave signal received by the laser receiver. In fact, due to the delay of the control circuit or other factors, there will often be a certain error in the flight distance or flight time, which will affect the accuracy of the sound speed measurement results. Therefore, in order to improve the stability of the measurement results of the sound speed measurement device, it is often necessary to integrate additional instruments into the system to compensate for the errors. Although the accuracy of the measurement results can be improved, it will undoubtedly increase the cost and size of the system, and it is not suitable for accurate sound speed measurement of seawater in a sea environment.

[0142] The present application considers that under the condition of fixed flight distance and other error factors, by calibrating the phase difference between the phase of the sound wave signal generated by the sound-emitting device at the standard sound speed and the phase of the laser signal marked by the sound wave signal received by the laser receiver, and establishing and storing a mapping relationship between phase and sound speed, the requirements for measurement parameters can be greatly simplified, and the complex physical mapping can be converted into a single mapping of "phase to sound speed" that is relatively detected and easy to measure. Therefore, the mapping relationship can be queried based on the first phase and the second phase detected above, so as to directly calibrate the target sound speed in the measurement environment.

[0143] The present application stores the mapping relationship between different sound speeds and calibrated phases in advance in the signal processor, and connects it with the laser generator, laser receiver and sound-generating device circuit, so that under measurement, the mapping relationship can be queried according to the phase of the sound wave signal generated by the sound-generating device and the phase of the laser signal marked by the sound wave signal received by the laser receiver, thereby directly obtaining the target sound speed in the measurement environment. Compared with the measurement device based on the acousto-optic effect which relies on a variety of instrument components, the present application transforms the complex physical mapping of "distance-time to sound speed" into a single mapping of "phase to sound speed", thereby greatly simplifying the measurement parameter requirements, reducing costs, and realizing the leapfrogging of miniaturized measurement devices to measure sound speed with high precision, which is particularly suitable for the measurement of sound speed in other complex environments such as the ocean.

[0144] Specifically, it can be understood that the mapping relationship between the sound speed and the calibrated phase pre-stored in the signal processor can be understood as the mapping relationship between the sound speed and the calibrated sound wave signal propagation time. Therefore, in addition to considering the phase difference between the phase of the sound wave signal generated by the sound-emitting device and the phase of the laser signal marked by the sound wave signal received by the laser receiver as the calibrated sound wave signal propagation time, in the case where the sound speed measurement device includes multiple laser transmitters and multiple laser receivers, the phase difference between the different phases of the laser signals marked by the sound wave signal respectively received by the multiple laser receivers can also be used as the calibrated sound wave signal propagation time, which can also realize the determination of the sound speed in the measurement environment. For details, please refer to Figure 6 , Figure 6 A flowchart of the steps of querying a mapping relationship to obtain the speed of sound provided in an embodiment of the present application.

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

[0146] In an embodiment of the present application, when the phase difference between the phase of the sound wave signal generated by the sound-emitting device collected by the signal processor and the phase of the laser signal marked by the sound wave signal received by the laser receiver under different sound speeds is calibrated in advance in a standard sound speed environment, and a mapping relationship is established based on the sound speed and this phase difference, the subsequent signal processor can directly query the corresponding sound speed from the mapping relationship (usually in the signal processor in the form of a mapping table) based on the first phase difference between the first phase and the second phase, as the third target sound speed in the measurement environment.

[0147] It should be noted that in a standard sound speed environment, that is, it is necessary to determine the standard sound speed in a calibration environment, and this usually requires a high degree of measurement accuracy for the sound speed during the calibration process, otherwise it will affect the subsequent actual measurement scenario, that is, the measurement of the seawater sound speed in an ocean environment. Therefore, as a further feasible implementation scheme 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 a calibration environment such as a laboratory.

[0148] S620: When the second phase includes a plurality of phases, query the mapping relationship according to a second phase difference between the plurality of second phases to obtain a fourth target sound speed in the measurement environment.

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

[0150] Among them, similar to the aforementioned calibration of the phase difference between the phase of the sound wave signal generated by the sound-emitting device collected by the signal processor at different sound speeds and the phase of the laser signal marked by the sound wave signal received by the laser receiver, when multiple second phase differences are used for calibration, it is necessary to calibrate the phase difference between the laser signals marked by the sound wave signal received by multiple different laser receivers collected by the signal processor at different sound speeds in the calibration sound speed environment, and the calibration process in the calibration sound speed environment is not repeated in the embodiments of the present application. The solution provided in the embodiments of the present application provides an implementation scheme for establishing a mapping relationship with the sound speed through two different calibration phases, which can meet the needs of users in different scenarios, such as using a single laser generator (laser receiver) or multiple groups of laser generators (laser receivers) to accurately measure the sound speed of seawater.

[0151] Of course, it should be noted that the distance of the acoustic wave signal from the sound-emitting device to the propagation path between the laser generator and the laser receiver may be different from the distance of the acoustic wave signal from the propagation path between multiple groups of laser generators to the laser receiver, that is, at the same sound speed, the calibrated phase difference is often different. Therefore, as a further feasible implementation scheme of the present application, it is necessary to calibrate separately for the above two situations, that is, the mapping relationship can generally include a third mapping relationship and a fourth mapping relationship. At this time, that is to say, according to the first phase difference between the first phase and the second phase, the mapping relationship is queried to obtain the third target sound speed under the measurement environment, which generally includes:

[0152] The third mapping relationship is queried according to a first phase difference between the first phase and the second phase to obtain a third target sound speed in the measurement environment.

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

[0154] The fourth mapping relationship is queried according to the second time differences between the plurality of second phases to obtain a fourth target sound speed in the measurement environment.

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

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

[0157]

[0158] Among them, the calibrated sound speed is usually the speed of sound propagation in seawater, which is about 1500m / s. Of course, when it is needed 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 between the calibrated sound speeds used in the calibration process. For example, in Table 1, calibration is performed every 0.1m / s, so that the sound speed measurement device can achieve a sound speed measurement with an accuracy of 0.1m / s. Of course, the specific accuracy can also be determined based on actual needs, for example, it can also be set to 0.05m / s or 0.01m / s, and the embodiments of the present application will not be repeated here. In addition, during the calibration process, the time difference in the mapping relationship may include a single time difference (i.e., a single column form) or multiple time differences (i.e., a multi-column form in Table 1), wherein 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 may be the phase difference between the phase of the sound wave signal emitted by the sound-emitting device and the phase of the laser signal marked by the sound wave signal received by the laser receiver. The second phase difference may also be 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. In addition, there may also be a third phase difference in the mapping table, which is used to calibrate the phase difference between the phase of the laser signal marked by the sound wave signal received by the second laser receiver and the phase of the laser signal marked by the sound wave signal received by the third laser receiver, and so on. The embodiments of the present application are not limited here.

[0159] It can be understood that the above-mentioned mapping table is only one possible form of existence. 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, considering that the error information of the circuit delay signal, the actual flight distance of the sound wave signal, etc. of the same sound velocity measurement device in the calibration environment and in the measurement environment is roughly the same, the mapping between the complex physical relationships is converted into a mapping relationship between time and sound velocity in a single dimension, so as to eliminate such errors and achieve the measurement of the sound velocity. However, in the actual measurement environment, a large error may occur due to interference from the external environment. At this time, it is shown that the current sound velocity measurement device is no longer applicable to the measurement in the current environment. Therefore, in the scheme provided in the embodiment of the present application, by establishing a variety of different mapping relationships, it can also be further used to assist in obtaining a more accurate sound velocity of the measurement result. Specifically, it is described in detail as follows.

[0161] In the embodiment of the present application, it can be understood that when the phase difference between multiple signals at different sound speeds is calibrated in the mapping table, for example, the phase difference between the phase of the sound wave signal emitted by the sound-emitting 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 difference between 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-emitting 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 After respectively querying the corresponding mapping relationship based on the phase difference between the phase of the laser signal marked by the sound wave signal and the phase of the laser signal marked by the sound wave signal received by the second laser receiver 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 disturbed by the external environment and affects the accuracy of the sound speed measurement, the third target sound speed and the fourth target sound speed should be small, or there is a tolerable difference. Therefore, by using the above scheme, a simple detection of the main device of the sound speed measurement device can be achieved to determine whether the sound speed measurement device fails and outputs an erroneous sound speed result. This has a 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 sound speed measurement device with a simple structure, a relatively simple judgment condition is used to ensure the stability of the sound speed measurement result, and avoid large deviations in the test results caused by external environmental interference. Specifically, the sound speed measurement method also includes:

[0162] In a case where a sound speed difference between the third target sound speed and the fourth target sound speed meets a preset condition, the target sound speed under the measurement environment is determined according to the third target sound speed and the fourth target sound speed.

[0163] In an embodiment 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 value, it can be considered that the measurement result of the sound speed measuring device is relatively accurate. At this time, the target sound speed in the measurement environment can be determined based on the third target sound speed and the fourth target sound speed based on actual needs. For example, as a simple feasible implementation scheme, 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 sound speed difference between the third target sound speed and the fourth target sound speed does not meet the preset conditions, for example, exceeds the preset threshold, it can be considered that the current sound speed measurement device may provide an erroneous sound speed measurement result due to external or internal factors (for example, a change in circuit delay, or a change in the flight distance of the sound wave signal). At this time, in order to ensure the stability of the measurement results, the third target sound speed and the fourth target sound speed measured by the current sound speed measurement device can be rejected. Moreover, since the sound speed measurement device provided in the present application has a miniaturized structure and low cost, multiple sound speed measurement devices can be carried portablely during the ocean surveying process, so that the seawater sound speed can still be accurately measured through multiple sound speed measurement devices, which has a high practical significance.

[0165] Of course, similar to the above-mentioned scheme of obtaining multiple sound speeds through multiple groups of mapping relationships and judging whether the sound speed measuring device can accurately measure the sound speed through the difference between the multiple sound speeds, it can be seen from the above-mentioned related description that when the laser generator and the laser receiver can be relatively parallelly arranged at both ends of the main shell, and the sound-generating device is slidably arranged in the main shell, the laser transmission path between the laser generator and the laser receiver can still maintain a fixed distance when the sound-generating device is slidably arranged in different positions of the main shell, that is, the time difference between the signals received by the signal processor will not be changed. Therefore, as another feasible embodiment of the present application, please refer to Figure 7 , another step flow diagram of identifying a fault of a sound velocity measuring device is also provided. Specifically, the method is mainly applicable to a sound velocity measuring device in which a laser generator and a laser receiver can be relatively parallelly arranged at two ends of a main housing, and a sound generating device is slidably arranged on the main housing, and specifically includes steps S710 to S730:

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

[0167] In the embodiment of the present application, after the position of the sound-generating device is adjusted by sliding, the third phase of the sound wave signal generated by the sound-generating device and the fourth phase of the laser signal marked by the sound wave signal received by the laser receiver will continue to be collected.

[0168] S720: Determine a fault detection result of the sound velocity measurement device according to a first time difference between the first phase and the second phase and a third phase difference between the third phase and the fourth phase.

[0169] In the embodiment of the present application, since the distance between the sound-generating device and the propagation path from the laser generator to the laser receiver will not be changed after the position of the sound-generating device is adjusted by sliding, the first phase difference between the first phase and the second phase in 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 that there is no fault, so that the corresponding sound speed can be obtained by querying the first phase difference and the third phase difference as the target sound speed 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 is a large difference in the measurement results of the two measurement processes, that is, the sound velocity measurement device may fail, thereby avoiding the use of the wrong sound velocity measurement device to measure the wrong sound velocity result.

[0170] S430, determining a fault detection result of the sound velocity measurement device according to a second phase difference between a plurality of the second phases and a fourth phase difference between a plurality of the fourth phases.

[0171] In the embodiment of the present application, similar to the above, since the distance of the propagation path between the multiple groups of laser generators and laser receivers is usually not changed after the position of the sound-emitting device is adjusted by sliding, the second phase difference between the multiple second phases in the past acquisition process and the fourth phase difference between the multiple fourth phases collected after the position is adjusted can also be used to determine the fault detection result of the sound velocity measurement device, wherein the identification of 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 obtaining the sound speed by using multiple laser beams for calibration, that is, when there are multiple laser receivers in the sound speed measuring device, the sound speed in the measurement environment can also be obtained by taking an average or other statistical value of the phases of the multiple beams of light received by the laser receiver, that is, when the second phase includes multiple phases, the mapping relationship is queried according to the second phase difference between the multiple second phases to obtain the fourth target sound speed in the measurement environment, including:

[0173] The mapping relationship is queried according to the statistical value of the second phase difference between the plurality of second phases to obtain a fourth target sound speed in the measurement environment.

[0174] The statistical value here may be at least one of the mean, median, and mode, or a weighted combination of several of them, so as to further improve the accuracy of the measured sound velocity.

[0175] It can be understood that the embodiments provided in the present application respectively describe in detail the implementation scheme of determining the sound speed by time calibration or by phase calibration. Of course, it should be noted that the above-mentioned implementation schemes of determining the sound speed by time calibration or by phase calibration can be set separately, and of course can also be integrated in the same sound speed measurement device, that is, the sound speed measurement device can respectively realize the measurement of the sound speed by the aforementioned time difference and phase difference methods, and can also further ensure the accuracy of the sound speed obtained based on the sound speed measurement results obtained by the two methods, thereby further improving the usability of the sound speed measurement device.

[0176] In order to better implement the sound velocity measurement method provided in the embodiment of the present application, the embodiment of the present application also provides a specific structure of a signal processor, such as Figure 8 As shown, the signal processor specifically includes:

[0177] The control unit 810 is used 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-generating device generates the sound wave signal;

[0179] The response unit 820 is further configured to, in response to the laser receiver receiving the laser signal marked by the acoustic wave signal, collect a second moment when the laser receiver receives the laser signal marked by the acoustic wave signal;

[0180] The query unit 830 queries 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 the present application, the query unit 830 is used to query the mapping relationship according to the first moment difference between the first moment and the second moment, so as to obtain the first target sound speed under the measurement environment; and / or, when the second moment includes multiple moments, query the mapping relationship according to the second moment difference between multiple second moments, so as to obtain the second target sound speed under the measurement environment, wherein the multiple moments respectively correspond to the moments when multiple laser receivers receive the laser signal marked by the sound wave signal.

[0182] In some embodiments of the present application, the query unit 830 is used to query the first mapping relationship based on the first time difference between the first time and the second time to obtain the first target sound speed under the measurement environment; and query the second mapping relationship based on the second time difference between multiple second times to obtain the second target sound speed under the measurement environment.

[0183] In some embodiments of the present application, the query unit 830 is used 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 used to continue to collect the third moment when the sound-emitting device generates the sound wave signal and the fourth moment when the laser receiver receives the laser signal marked by the sound wave signal after adjusting the position of the sound-emitting device; determine the fault detection result of the sound velocity measurement device 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; and / or determine the fault detection result of the sound velocity measurement device according to the second moment difference between multiple second moments and the fourth moment.

[0185] In some embodiments of the present application, the control unit 810 is also used to control the laser generator to emit a laser signal with a fixed time interval under a measurement environment so that the laser receiver receives the laser signal; the response unit 820 is used to collect the first phase of the sound wave signal generated by the sound-emitting device in response to the laser receiver receiving the laser signal marked by the sound wave signal, and to collect the second phase of the laser signal marked by the sound wave signal received by the laser receiver; the query unit 830 is used to query the mapping relationship based on the first phase and the second phase to obtain the target sound speed under the measurement environment.

[0186] In some embodiments of the present application, the query unit 830 is used to query the mapping relationship based on the first phase difference between the first phase and the second phase to obtain a third target sound speed under the measurement environment; and / or, when the second phase includes multiple phases, query the mapping relationship based on the second phase difference between the multiple second phases to obtain a fourth target sound speed under the measurement environment, wherein the multiple phases respectively correspond to the phases of the laser signal marked by the acoustic wave signal received by multiple laser receivers.

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

[0188] In some embodiments of the present application, the query unit 830 is used 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 used to collect the third phase of the sound wave signal generated by the sound-emitting device and the fourth phase of the laser signal after adjusting the position of the sound-emitting device; determine the fault detection result of the sound speed measurement device based on 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 measurement device based on the second phase difference between multiple second phases and the fourth phase difference between multiple fourth phases.

[0190] For the specific definition of the signal processor, please refer to the definition of the sound velocity measurement method above, which will not be repeated here. Each unit in the above-mentioned signal processor can be implemented in whole or in part by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory in the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0191] In some embodiments of the present application, the signal processor may be in the form of 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 items, for example, performing the following steps:

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

[0193] In response to the sound wave signal generated by the sound-generating device, collecting the first moment when the sound wave signal is generated by the sound-generating device;

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

[0195] According to the first moment and the second moment, the mapping relationship is queried 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 above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and 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-mentioned methods. Any reference to memory, storage, information library or other media used in the embodiments provided in this application may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0197] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0198] The above is a detailed introduction to a sound velocity measurement device and method provided in the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. 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 method and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A sound velocity measuring device, characterized in that: include: main housing; at least one laser generator, for emitting a laser signal; At least one laser receiver, used to receive the laser signal emitted by the laser generator; wherein the laser generator and the laser receiver are arranged at two ends of the main housing opposite to each other; a sound generating device disposed on the main housing, used for generating a sound wave signal to mark the laser signal emitted by the laser generator; and A signal processor connected to the laser generator, the laser receiver and the sound-generating device circuit; wherein the signal processor pre-stores a mapping relationship between different sound velocities and calibration times, or a mapping relationship between different sound velocities and calibration phases, so as to obtain the target sound velocity in the measurement environment by querying the mapping relationship according to the moment when the sound-generating device generates the sound wave signal and the moment or phase when the laser receiver receives the laser signal marked by the sound wave signal.

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

3. The device according to claim 1, characterized in that The laser generator is a pulse 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 laser generator and the laser receiver are arranged relatively and parallelly at two ends of the main shell; the sound generating device is slidably arranged on the main shell.

5. A method for measuring the speed of sound, characterized in that: A signal processor applied to a sound velocity measuring device, wherein the sound velocity measuring device further comprises 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 velocities and calibration times; The method comprises: 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 wave signal generated by the sound-generating device, collecting the first moment when the sound wave signal is generated by the sound-generating device; In response to the laser receiver receiving the laser signal marked by the acoustic wave signal, collecting a second moment when the laser receiver receives the laser signal marked by the acoustic wave signal; According to the first moment and the second moment, query the mapping relationship to obtain the target sound speed in the measurement environment; and / or In a measurement environment, controlling the laser generator to emit a laser signal at a fixed time interval so that the laser receiver receives the laser signal; In response to the laser receiver receiving the laser signal marked by the acoustic wave signal, collecting a first phase of the acoustic wave signal generated by the sound-generating device, and collecting a second phase of the laser signal marked by the acoustic wave signal received by the laser receiver; The mapping relationship is queried according to the first phase and the second phase to obtain the target sound speed in the measurement environment.

6. The method according to claim 5, characterized in that The querying the mapping relationship according to the first moment and the second moment to obtain the target sound speed under the measurement environment includes: According to a first time difference between the first time and the second time, query the mapping relationship to obtain a first target sound speed in the measurement environment; and / or In the case where the second moment includes multiple moments, querying 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, wherein the multiple moments respectively correspond to the moments when multiple laser receivers receive the laser signal marked by the sound wave signal; The querying the mapping relationship according to the first phase and the second phase to obtain the target sound speed under the measurement environment includes: querying the mapping relationship according to a first phase difference between the first phase and the second phase to obtain a third target sound speed under the measurement environment; and / or In the case where the second phase includes multiple phases, the mapping relationship is queried according to the second phase difference between the multiple second phases to obtain the fourth target sound speed under the measurement environment, wherein the multiple phases respectively correspond to the phases of the laser signals marked by the sound wave signal received by multiple laser receivers.

7. The method according to claim 6, characterized in that The mapping relationship includes a first mapping relationship and a second mapping relationship between the sound speed and the calibration time; The querying the mapping relationship according to the first time difference between the first time and the second time to obtain the first target sound speed under the measurement environment includes: According to a first time difference between the first time and the second time, query the first mapping relationship to obtain a first target sound speed in the measurement environment; The querying the mapping relationship according to the second time difference between the plurality of second time moments to obtain the second target sound speed under the measurement environment comprises: querying the second mapping relationship according to the second time difference between the plurality of second time moments to obtain a second target sound speed in the measurement environment; and / or The mapping relationship includes a third mapping relationship and a fourth mapping relationship between the sound speed and the calibration phase; The querying the mapping relationship according to the first phase difference between the first phase and the second phase to obtain the third target sound speed under the measurement environment includes: According to a first phase difference between the first phase and the second phase, query the third mapping relationship to obtain a third target sound speed in the measurement environment; The querying the mapping relationship according to the second phase difference between the plurality of second phases to obtain a fourth target sound speed under the measurement environment includes: The fourth mapping relationship is queried according to the second time differences between the plurality of second phases to obtain a fourth target sound speed in the measurement environment.

8. The method according to claim 6 or 7, characterized in that: The method further comprises: When a sound speed difference between the first target sound speed and the second target sound speed meets a preset condition, determining a target sound speed in the measurement environment according to the first target sound speed and the second target sound speed; and / or In a case where a sound speed difference between the third target sound speed and the fourth target sound speed meets a preset condition, the target sound speed under the measurement environment is determined according to the third target sound speed and the fourth target sound speed.

9. The method according to claim 5, characterized in that In the case where the second moment includes multiple moments, querying the mapping relationship according to the second moment difference between the multiple second moments to obtain the second target sound speed under the measurement environment includes: According to the statistical value of the second time difference between the plurality of second time moments, query the mapping relationship to obtain the second target sound speed in the measurement environment; and / or In the case where the second phase includes multiple phases, querying the mapping relationship according to the second phase difference between the multiple second phases to obtain the fourth target sound speed under the measurement environment includes: The mapping relationship is queried according to the statistical value of the second phase difference between the plurality of second phases to obtain a fourth target sound speed in the measurement environment.

10. The method according to claim 5, characterized in that The method further comprises: After adjusting the position of the sound-generating device, continue to collect the third moment when the sound-generating device generates the 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 a fault detection result of the sound velocity measurement device according to a first time difference between the first time and the second time, and a third time difference between the third time and the fourth time; and / or Determine a fault detection result of the sound velocity measuring device according to a second time difference between a plurality of the second time moments and a fourth time difference between a plurality of the fourth time moments; and / or; determining a fault detection result of the sound velocity measuring device according to a first time difference between the first phase and the second phase, and a third phase difference between the third phase and the fourth phase; and / or; A fault detection result of the sound velocity measuring device is determined based on a second phase difference between a plurality of the second phases and a fourth phase difference between a plurality of the fourth phases.

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