CN220491043U - Underwater multi-wavelength parallel line laser array self-scanning imaging system - Google Patents

Abstract

An underwater multi-wavelength parallel line laser array self-scanning imaging system. In the underwater sealed container, a plurality of tile-level high-power semiconductor laser-word line blue-green wave band lasers are adopted and are arranged on a platform capable of being swept within a pitching range of +/-30 degrees, a plurality of mutually parallel word line lasers with different wavelengths are emitted underwater through a light passing window of the watertight container, and an underwater target is scanned and irradiated in a large view field. And covering the laser visual field by using optical imagers with corresponding different working wavelengths, receiving laser images on the underwater target, and processing the laser images by using an imaging analysis processing module to obtain the information of the position, the shape, the distance, the surface state and the like of the underwater target.

Description

Underwater multi-wavelength parallel line laser array self-scanning imaging system

Technical Field

An underwater multi-wavelength parallel line laser array self-scanning imaging system. Laser detection, scanning imaging of underwater targets, detection and imaging of submarine targets or obstacles.

Background

The detection and imaging of underwater targets are important research directions of underwater optics and marine optics disciplines, and are important means and tools for human understanding, developing and utilizing the ocean and protecting the ocean. In underwater operation, navigation or underwater exploration, an underwater environment or a target object needs to be observed to determine an operation scheme, a navigation direction and the like, and if the observation is inaccurate, operation accidents, damage to personnel and equipment facilities and equipment can be caused, so that great losses of personnel and economy are caused.

The traditional detection technique under water is sonar measurement. The sonar uses the acoustic signal to transmit in the water, when the target is reflected, the reflected acoustic wave is received by the receiving transducer, and is converted into the electric signal, and the electric signal is processed to obtain the measurement result. The advantage of sonar is that the acoustic wave travels a longer distance in the water. The method has the defects that the detection resolution of the characteristics of the target is low because the wavelength of the sound wave is long, the characteristics of the shape, the size and the like of the target cannot be determined, and the method cannot work normally in a water area with strong sound background noise.

The laser detection and imaging have the advantages of visual detection target, high imaging resolution, high information content and the like. The main disadvantage of underwater laser imaging is that the transmission distance of the laser in the water is strongly attenuated by the water to light, and the working distance is limited, only in the range of a few meters to tens of meters. Generally, blue-green lasers in the spectral range of the light transmission window of water may be preferred. Laser imaging can be achieved by two-dimensional scanning with a conventional spot laser beam, but is relatively complex. The spot laser beam is the output of a conventional laser, and produces a laser spot on the target. Another so-called one-word line laser product has now developed. A word line laser is a conventional laser with a cylindrical optical element at its output end to convert a spot laser beam into a word line laser beam that produces a laser line in a straight line at the target. A word line laser has formed a mature product line and has found wide application in collimation, measurement, imaging, and the like. Particularly, with the maturation and popularization of laser diodes, i.e. semiconductor lasers, i.e. word line lasers, employing various semiconductor lasers plus miniature columnar optical elements have been quite mature conventional products, which have the advantages of compactness, low cost and easy use, greatly promoting the application of a word line laser in various different situations.

The utility model is a research and development effort aiming at various underwater engineering, detection and imaging of underwater targets, and strong requirements of detection technology and device with higher resolution for targets, which are simpler and more reliable and can meet the requirements of a certain working distance.

Disclosure of Invention

The basic working principle of the underwater multi-wavelength parallel line laser array self-scanning imaging system is that parallel line lasers formed by emitting at least two line lasers with different wavelengths are used for scanning and irradiating an underwater target object simultaneously or respectively, at least two line laser images with different wavelengths on the underwater target object are received by an optical imager corresponding to the different laser wavelengths respectively, and information such as the position, the basic shape, the distance, the surface state of the target object and the like of the underwater target object is obtained through image processing. One example is to use two one-word line lasers with different laser wavelengths to form two different-wavelength one-word line laser images on an underwater target. By a wordline laser is meant a line of a finite length, e.g. several meters to 10 meters, of a laser beam pattern of an output laser over a distance by adding a certain optical element, e.g. a cylindrical optical element, to the output of a conventional laser, instead of a spot of the output beam of the conventional laser. A typical example of the performance of a semiconductor laser-word line laser transmitter is as follows: the working laser wavelength is 450nm, the output power of one word line laser is 1.5W, and the opening angle of one word line laser in one word line direction is 110 degrees. The external dimension of the packaged radiator is only 33X 75mm, and the radiator is powered by a 12-24V battery and can continuously work for a long time. The semiconductor laser-word line laser is a basic component unit in the present application, and the specific detailed structural configuration of the semiconductor laser-word line laser itself is not discussed in the present application.

A wordline laser produces a wordline laser image line with a meandering and reflected intensity variation on the target surface due to the shape variation of the target surface. Different object surface states, including materials and shapes, also have different reflection responses to different laser wavelengths and polarization states, affecting the relative different reflection intensities between the different laser wavelengths or polarization states. Meanwhile, different water conditions have different transmission characteristics for laser with different wavelengths. A plurality of word line lasers with different wavelengths or polarization states cover mutually overlapped visual fields, namely the same target area, and the information of the fine shape, the distance and the like of the target object can be obtained through the analysis processing of a plurality of received images on the target object, so that the search range, the measurement speed and the precision of submarine topography, underwater building defects and irregular targets can be greatly improved. The included angle between the parallel line lasers is accurately controlled, and distance information to the target object can be obtained according to the separation distance between the parallel line lasers on the target object, so that accurate three-dimensional imaging can be performed on the target object, the underwater detection distance and the capability of resisting various interferences are improved, and the normal working capability under a complex environment is improved. The relevant image processing and analysis is software-dependent and will not be referred to in this application. However, it is one of the basic utility models to perform one-dimensional scanning in the pitch direction by using a plurality of line lasers having different wavelengths or polarization states, and to realize detection of a two-dimensional, mutually overlapping laser scanning field of view and detection field of view having different wavelengths or polarization states.

The application discloses a unique system device for realizing detection and imaging by using two parallel line lasers with different wavelengths, namely two parallel line lasers formed by high-power semiconductor laser and a word line laser, and two corresponding optical imagers for underwater scanning. The two word line lasers adopt watt-level high-power semiconductor laser word line lasers so as to ensure the action distance of underwater detection imaging.

The application discloses an underwater multi-wavelength parallel line laser array self-scanning imaging system, which comprises a pressure-resistant watertight container designed according to the underwater working depth, wherein the pressure-resistant watertight container is internally provided with an optical platform facing the optical light-passing window, and the optical platform can be swept within a pitching range of +/-30 DEG in a pitching direction facing the pressure-resistant watertight optical light-passing window. A plurality of semiconductor laser-word line lasers having different laser wavelengths in the blue-green spectral range are mounted on the optical stage. The installation and adjustment of the plurality of semiconductor laser word line lasers on the optical platform ensure that the word line lasers emitted by the plurality of semiconductor laser word line lasers are in horizontal directions and parallel to each other, the included angle between the parallel word line lasers emitted by the plurality of semiconductor laser word line lasers is adjustable, the distance between parallel lines of the semiconductor laser word line lasers is adjustable, and the horizontal word line lasers emitted by the semiconductor laser word line lasers and the swaying of the horizontal word line lasers in the pitching range cover and detect targets in the corresponding laser view field range through the pressure-resistant sealing optical light-transmitting window. The system also comprises a plurality of optical imagers, wherein the working wavelengths of the optical imagers are respectively matched with the laser wavelengths of the semiconductor laser word line lasers after the corresponding optical filters are adopted on the optical imagers. The system also comprises an imaging analysis processing module which images and analyzes the received semiconductor laser-word line laser reflection echo information, and calculates and obtains the relevant information of the detection target, including the three-dimensional shape, the distance and the surface state thereof. The imaging analysis processing module can be arranged in the pressure-resistant watertight container or on the water surface working platform.

The underwater multi-wavelength parallel line laser array self-scanning imaging system comprises at least two semiconductor laser-word line lasers and at least two optical imagers with working wavelengths matched with the semiconductor laser-word line lasers respectively, wherein the wavelengths of the at least two semiconductor laser-word line lasers are different, but are in the range of 400nm to 575nm of blue-green spectrum, the laser power of a single semiconductor laser-word line laser emitter is at least more than 0.5W, and the length of a laser-word line of the semiconductor laser-word line laser is adjustable.

The underwater multi-wavelength parallel line laser array self-scanning imaging system comprises at least two semiconductor laser-word line lasers with different wavelengths and at least two optical imagers with working wavelengths matched with the semiconductor laser-word line lasers respectively, wherein the observation fields of the at least two optical imagers are overlapped in a crossing way, the laser field range of the semiconductor laser-word line lasers corresponding to each other is covered, and the coverage can be adjusted according to different underwater imaging distances and tasks.

The underwater multi-wavelength parallel line laser array self-scanning imaging system comprises at least two semiconductor laser-word line lasers with different wavelengths and at least two optical imagers with working wavelengths matched with the semiconductor laser-word line lasers respectively, wherein the outputs of the at least two semiconductor laser-word line lasers have the same or mutually orthogonal polarization states, the at least two optical imagers are provided with polarization optical elements sensitive to the polarization states of laser, and the receiving of the at least two optical imagers is sensitive to the polarization states of the laser. The polarization state of the output of a word line laser and the polarization state of the laser light to which the optical imager is sensitive are adjustable.

If the surface characteristics or shape of the detection target has higher sensitivity to the polarization state of the detection laser light, a word line laser with certain polarization characteristics and an optical imager are adopted, so that more sensitive and fine target detection effect can be obtained.

A wordline output characteristic of a wordline laser itself automatically provides scanning coverage of the laser in one dimension, e.g., in the horizontal direction. As described above, a wordline laser, or including an optical imager, is mounted such that pitching of the optical platform means that a wordline output of a wordline laser transmitter is scanned within ±30° pitch, i.e. swept in a direction perpendicular to a wordline laser, thereby achieving a two-dimensional scan field of view of the detection laser. Pitching sweeping of a wordline laser may also be accomplished by mounting a wordline laser on a torsion pendulum mechanism such as a conventional torsion pendulum motor or a torsion pendulum mirror. Because a word line laser can adopt a semiconductor laser and a micro optical element, the volume is small, the weight is light, the load requirement on a torsion pendulum motor or a torsion pendulum vibrating mirror is low, and the implementation is easy. Another conventional method is to scan the laser beam with a galvanometer. Not tired.

The system technology disclosed by the application has the advantages that the parallel line laser scanning detection of a plurality of different wavelengths is higher in accuracy and higher in accuracy for target detection, more targets and environment information can be acquired, the detection distance is long, the scanning field of view is large, the system is insensitive to acoustic noise, the normal working capacity under a complex environment is strong, and the whole system device is simple and small in structure, low in cost and the like.

Drawings

FIG. 1 is a schematic top view of an underwater multi-wavelength parallel line laser array self-scanning imaging system.

Detailed Description

A specific embodiment of the underwater multi-wavelength parallel line laser array self-scanning imaging system is described below with reference to fig. 1.

The underwater sealed container in the underwater multi-wavelength parallel line laser array self-scanning imaging system is 010, and one end of the underwater sealed container is a sealed light-transmitting window 011. Within the sealed container 010 is an optical mounting platform 014 which is actuated by a drive motor 015 for performing a pendulum stroke within a range of + -30 deg. in pitch. Depending on the requirements of the underwater application, the slew rate in the range of + -30 deg. in the pitch direction is not as demanding, on the order of 1 per second. A first semiconductor laser-word line laser 016 and a second semiconductor laser-word line laser 017 are mounted on the optical stage 014. The minimum output power of the first semiconductor laser-word line laser 016 and the second semiconductor laser-word line laser 017 is greater than 0.5W, and the laser wavelengths are different from each other but are all in the range of 400nm to 575nm of the blue-green spectrum. The laser outputs of the first and second semiconductor laser-word line lasers 016 and 017 are 018 and 019, respectively, forming first and second parallel line laser lines 020 and 021 on the target. For fig. 1, which is a top view, the drawing represents a horizontal plane, so the first and second parallel line laser lines are 020 and 021 in fig. 1. The length of the first and second parallel line laser lines, i.e. 020 and 021 in fig. 1, on a detection target at a distance depends on the so-called opening angle of the first semiconductor laser-word line laser 016 and the second semiconductor laser-word line laser 017. The opening angles of the first semiconductor laser-word line laser 016 and the second semiconductor laser-word line laser 017 themselves can be changed by adjusting the parameters or positions of the optical parts forming one word line in the first semiconductor laser-word line laser 016 and the second semiconductor laser-word line laser 017. A variable-focus optical lens can be additionally arranged at the output end of each of the first semiconductor laser-word line laser 016 and the second semiconductor laser-word line laser 017, so that the lengths of the first parallel line laser line 020 and the second parallel line laser line 021 formed at a certain target distance can be controlled and adjusted. A shorter wordline length results in higher laser brightness but a smaller laser detection field of view.

The scanning of the first and second parallel laser lines 020 and 021 within the pitching range of + -30 degrees means the swinging scanning in the direction vertical to the parallel laser lines, namely in the direction vertical to the drawing plane, so as to form a large laser view field covering the detection target.

The underwater multi-wavelength parallel line laser array self-scanning imaging system further includes first and second two optical imagers 022 and 023 mounted in an underwater sealed container 010. The outputs of the first and second optical imagers 022 and 023 are connected to an imaging analysis processing module 024. The imaging analysis processing module 024 may also include semiconductor laser wordline lasers 016 and 017 and power supply portions for optical imaging 022 and 023. As an example, the first and second optical imagers 022 and 023 may be cameras as on current cell phones, including camera CCD area array chips and miniature camera lenses. The first and second optical imagers 022 and 023 may employ optical lenses of large receiving aperture if higher detection distances are desired. They are conventional and need not be discussed further in this application nor shown in fig. 1. The imaging analysis processing module 024 performs image analysis processing on the image information of the semiconductor laser-word line laser on the detected target, and calculates relevant information of the target, including the three-dimensional shape, the distance and the surface state of the target. The imaging analysis processing module 024 may be mounted within a pressure-tight, watertight container, as shown in fig. 1. It can also be installed on a water surface working platform which is cooperated with the underwater multi-wavelength parallel line laser array self-scanning imaging system. The power supply portions of the semiconductor laser-wordline laser and the optical imager may be mounted in a pressure-resistant watertight container or on a water surface work platform.

The front of the first and second optical imagers 022 and 023 may be cooperatively provided with a filter having a high pass only for the operating wavelength emitted by the corresponding one of the word line lasers and a low pass for the other wavelength, so that the operating wavelengths of the first and second optical imagers are respectively matched with the wavelengths of the first and second one of the word line laser transmitters, so as to ensure that the first and second optical imagers respectively and uniquely receive the image information of the corresponding first and second one of the word line laser wavelengths. One example is that the laser wavelength of the first and second semiconductor laser-word line lasers is 450nm and 550nm respectively, and the first and second optical filters are respectively arranged in front of the first and second optical imagers, wherein the first filter has a transmittance of more than 90% for 450+/-10 nm and a transmittance of less than 10% for other wavelengths; the second filter has a transmittance of more than 90% for 550 + -10 nm and a transmittance of less than 10% for other wavelengths. The filter itself is typically a glass slide coated with a multilayer dielectric film a few millimeters thick, not otherwise shown in fig. 1 as a conventional technique and method, but considered as part of the first and second optical imagers 022 and 023 themselves. When polarization optical elements sensitive to the polarization of laser light are mounted on the first and second optical imagers 022 and 023, the corresponding polarization optical elements are not separately shown in fig. 1 as well.

The receiving fields of the first and second optical imagers 022 and 023 are substantially coincident with the laser fields of the first and second semiconductor laser-word line lasers 016 and 017, and can correspondingly receive the image information of the first and second semiconductor laser-word line lasers 020 and 021 on the detection target in the laser fields according to the difference of the wavelengths of the outputs 018 and 019 of the first and second semiconductor laser-word line lasers 016 and 017 and the difference of polarization characteristics. The image information is processed and analyzed by an image analysis processing module 024 to obtain the related information of the underwater detection target, including three-dimensional shape, distance and surface state thereof. The imaging analysis processing module 024 may be mounted within the pressure-tight watertight container 010 or on a surface work platform, which is not included in fig. 1.

The underwater multi-wavelength parallel line laser array self-scanning imaging system described in fig. 1 is a system capable of independently carrying out laser detection imaging on a detection target under water. Obviously, according to the technology disclosed above, the underwater multi-wavelength parallel line laser array self-scanning imaging system which is installed on other underwater vehicles, underwater robots and other platforms can be easily realized.

Claims (4)

1. The underwater multi-wavelength parallel line laser array self-scanning imaging system is characterized in that: the pressure-resistant watertight container is designed according to the underwater working depth and is provided with a pressure-resistant sealing optical light-passing window, an optical platform facing the optical light-passing window is arranged in the pressure-resistant watertight container, and the optical platform can be swept within a pitching range of +/-30 degrees in a pitching direction facing the pressure-resistant sealing optical light-passing window; a plurality of semiconductor laser word line lasers with different laser wavelengths in the blue-green spectrum range are arranged on the optical platform; the installation and adjustment of the plurality of semiconductor laser-word line lasers on the optical platform ensure that the word line lasers emitted by the plurality of semiconductor laser-word line lasers are in horizontal directions and parallel to each other, the included angle between the parallel word line lasers emitted by the plurality of semiconductor laser-word line lasers is adjustable, the interval between parallel lines of the semiconductor laser-word line lasers is adjustable, the horizontal word line lasers emitted by the semiconductor laser-word line lasers and the swaying of the horizontal word line lasers in the pitching range cover and detect targets in the corresponding laser view field range through the pressure-resistant sealing optical light-passing window; the semiconductor laser comprises a plurality of semiconductor laser word line lasers, a plurality of optical imagers, a plurality of light filters and a plurality of light filters, wherein the optical imagers are respectively matched with the laser wavelengths of the semiconductor laser word line lasers after the corresponding light filters are adopted on the optical imagers; the imaging analysis processing module is used for imaging and analyzing the received semiconductor laser-word line laser reflection echo information and calculating to obtain the related information of the detection target, including three-dimensional shape, distance and surface state of the detection target; the imaging analysis processing module can be arranged in the pressure-resistant watertight container or on the water surface working platform.

2. The underwater multi-wavelength parallel line laser array self-scanning imaging system of claim 1, characterized in that: the semiconductor laser comprises at least two semiconductor laser word line lasers and at least two optical imagers with working wavelengths respectively matched with the semiconductor laser word line lasers, wherein the wavelengths of the at least two semiconductor laser word line lasers are different and are all in the range of 400nm to 575nm of blue-green spectrum, the laser power of a single semiconductor laser word line laser emitter is at least more than 0.5W, and the length of a laser word line of the semiconductor laser word line laser is adjustable.

3. The underwater multi-wavelength parallel line laser array self-scanning imaging system of claim 1, characterized in that: the device comprises at least two semiconductor laser word line lasers with different wavelengths and at least two optical imagers with working wavelengths respectively matched with the semiconductor laser word line lasers, wherein the observation fields of the at least two optical imagers are overlapped in a crossing way, the laser field ranges of the semiconductor laser word line lasers corresponding to the at least two optical imagers are covered, and the coverage can be adjusted according to different underwater imaging distances and tasks.

4. The underwater multi-wavelength parallel line laser array self-scanning imaging system of claim 1, characterized in that: the semiconductor laser word line laser comprises at least two semiconductor laser word line lasers with different wavelengths and at least two optical imagers with working wavelengths matched with the semiconductor laser word line lasers respectively, wherein the outputs of the at least two semiconductor laser word line lasers have identical or mutually orthogonal polarization states, the at least two optical imagers are provided with polarization optical elements sensitive to the polarization states of the laser, and the reception of the at least two optical imagers is sensitive to the polarization states of the laser; the polarization state of the output of a word line laser and the polarization state of the laser light to which the optical imager is sensitive are adjustable.