An integrated device for underwater wireless optical communication and imaging detection

Abstract

An integrated device for underwater wireless optical communication and imaging detection includes an imaging detection module and a power module installed in a watertight housing, characterized in that: the device also includes an optical communication module and an optical transceiver antenna installed in the watertight housing, the imaging detection module collects and processes the target image and transmits it to the optical communication module via a communication interface; the optical communication module includes a sending module and a receiving module; the device adopts a duplex communication mode, at the sending end, the sending module processes the video image collected by the imaging detection module into signal light and sends it to the seawater channel via the optical transceiver antenna, and after a certain distance of signal transmission, it reaches the optical transceiver antenna at the receiving end, and is processed by the receiving module and output to the display terminal. The present invention integrates the active lighting of the blue light LED wireless optical communication module and the imaging detection module, and shares the LED and optical emission lens, so that the device has the characteristics of small size, low power consumption and high efficiency.

Description

Technical Field

[0001] The present invention relates to an underwater wireless optical communication and imaging detection integrated device (hereinafter referred to as the device), which solves the problems of signaling, image data collection and transmission during underwater operations, especially deep-sea operations, and provides technical support for real-time monitoring of underwater operations. Background Art

[0002] In recent years, strategic competition in the ocean field has intensified and has become an important global security concern. Therefore, how to carry out underwater operations efficiently, conveniently and reliably has become a hot topic of research in various countries. Due to the complex underwater operation environment, especially the deep-sea operation environment, the lack of light all year round, and the need to consider the mobility of the platform or the operation object, the "cable-type" communication method brings many inconveniences and safety hazards. Therefore, how to establish an effective communication link between the operation platform and the operation ship, and how to efficiently complete the acquisition, image processing and transmission of underwater image data have become the key to improving underwater operations. Many foreign research institutions have successively conducted various experiments on underwater wireless optical communications. In 2010, the Underwater Laboratory of the Woods Hole Institute in the United States announced at the Marine Science Conference that its team had developed an underwater wireless optical communication system based on light-emitting diodes (LED-Light Emitting Diode), which can reach a transmission rate of 10-20Mb / s within a range of 100m. In 2013, the underwater wireless optical communication system AquaOptical II designed by AquaOptical II technicians at Yale University in the United States had a transmission rate of 2.28Mb / s and a communication distance of 50m. In 2017, the LightSpeed ​​U10 underwater wireless optical communication system in the United States can achieve full-duplex communication greater than 1Mbps at a distance of 100m, weighing about 1.7kg. The University of Pisa in Italy has completed a communication distance of 10m and a bandwidth of 10Mbps. In addition, the Institute of Western Optics of the Chinese Academy of Sciences, Zhejiang University, Ocean University of China and Nanjing University of Posts and Telecommunications have also carried out related technical research, but the communication distance is short when the communication rate is greater than 1Mbps, and there are few reports on integrated devices that take into account imaging detection functions. Therefore, in view of the needs of underwater operation data collection and transmission, it is of great engineering value to invent an integrated device for underwater wireless optical communication and imaging detection. Summary of the invention

[0003] In order to solve the above problems, an underwater wireless optical communication and imaging detection integrated device is provided.

[0004] The object of the present invention is achieved in the following manner:

[0005] An underwater wireless optical communication and imaging detection integrated device, comprising an imaging detection module and a power module installed in a watertight housing, the device also comprising an optical communication module and an optical transceiver antenna installed in the watertight housing, the imaging detection module collects and processes the target image and transmits it to the optical communication module via a communication interface; the optical communication module comprises a sending module and a receiving module;

[0006] The device adopts a duplex communication mode. At the transmitting end, the transmitting module processes the video image collected by the imaging detection module into signal light and sends it to the seawater channel via the optical transceiver antenna. After a certain distance of signal transmission, it reaches the optical transceiver antenna at the receiving end and is processed by the receiving module and output to the display terminal.

[0007] The optical transceiver antenna is composed of an optical narrowband filter and a transmitting optical lens.

[0008] The sending module includes a signal acquisition and amplification module, a coding and decoding module, a modulation and demodulation module, a blue light LED driving circuit, and a blue light LED luminous board which are connected in sequence; the video image collected by the imaging detection module is transmitted to the signal amplification module, superimposed with the DC bias, and the channel coding and decoding is completed through the coding and decoding module, and then transmitted to the blue light LED driving circuit through the modulation and demodulation module, and the video signal is loaded onto the blue light LED luminous board, and the video signal is sent out in the form of a light beam.

[0009] The light source of the blue light LED luminous panel adopts blue light with a wavelength of 470mm; the LED arrangement adopts an equilateral layout, including 6 high-brightness blue light LEDs arranged in a circular array; each LED is evenly distributed in a circle at an angle of 60 degrees, and the middle area of ​​the 6 LEDs is reserved as a receiver optical lens window.

[0010] The receiving module includes a photoelectric detector, a preamplifier module, a modulation and demodulation module, a coding and decoding module and an equalization processing module connected in sequence; the blue light beam is focused by a large focal length focusing lens of an optical transceiver antenna and irradiated onto the photoelectric detector, and the optical signal is converted into an electrical signal. The signal is sent to the modulation and demodulation module after power amplification and low-pass filtering to complete demodulation, and is decoded by the coding and decoding module, and then output to a display terminal through equalization processing.

[0011] The imaging detection module includes an ICCD camera, an Ethernet interface module, an FPGA and a GPU; the front end of the ICCD camera is transmitted to the FPGA cache at high speed through the Ethernet interface module, the FPGA sends the collected video image to the GPU, the GPU receives the image and transmits it back to the FPGA, the FPGA receives the data and compresses the image and sends the data to the sending module of the optical communication module through Ethernet.

[0012] The FPGA adopts the XILINX XC7K325T3FFG900I chip.

[0013] Compared with the prior art, the present invention integrates the active lighting of the blue light LED wireless optical communication module and the imaging detection module into an integrated design, and shares the LED and optical emission lens, so that the device has the characteristics of small size, low power consumption and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A working scene diagram of the device involved in the present invention;

[0015] Figure 2 A schematic diagram of a deep learning segmentation algorithm according to the present invention;

[0016] Figure 3 This is a working principle diagram of the communication module involved in the present invention;

[0017] Figure 4 The LED light source layout method involved in the present invention;

[0018] Figure 5 This is a working principle diagram of the imaging detection module involved in the present invention. DETAILED DESCRIPTION

[0019] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0020] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same technical meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0021] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form, and it should also be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0022] In the present invention, terms such as "fixed connection", "connected", "connection", etc. should be understood in a broad sense, indicating that it can be fixedly connected, integrally connected or detachably connected; it can be directly connected or indirectly connected through an intermediate medium. Relevant scientific research or technical personnel in this field can determine the specific meanings of the above terms in the present invention according to specific circumstances, and they should not be understood as limiting the present invention.

[0023] An underwater wireless optical communication and imaging detection integrated device, comprising an imaging detection module and a power module installed in a watertight housing, the device also comprising an optical communication module and an optical transceiver antenna installed in the watertight housing, the imaging detection module collects and processes the target image and transmits it to the optical communication module via a communication interface; the optical communication module comprises a sending module and a receiving module;

[0024] The device adopts a duplex communication mode. At the transmitting end, the transmitting module processes the video image collected by the imaging detection module into signal light and sends it to the seawater channel via the optical transceiver antenna. After a certain distance of signal transmission, it reaches the optical transceiver antenna at the receiving end and is processed by the receiving module and output to the display terminal.

[0025] like Figure 1 As shown, the device mainly includes an optical communication module (duplex), an imaging detection module, an optical transceiver antenna, a power module and a watertight shell. Due to the use of a duplex communication mode, the function and implementation principle of the device (2) are the same as those of the device (1). The device (1) transmits the blue light 470nm signal light to the seawater channel through the optical transceiver antenna through the internal optical communication module, and reaches the optical transceiver antenna of the device (2) after being transmitted through a certain distance of the channel. Then, the signal is received, filtered and amplified by the optical communication module of the device (2), and the task of underwater communication is finally completed. In addition, in addition to transmitting data, the device can actively illuminate the operating object using the LED blue light (signal light) emitted by the device (1), so that it can be imaged on the ICCD detector of the device (1). The device (1) collects, processes and autonomously classifies the target image through the imaging detection module, and transmits the processing result to the operating ship through the optical communication module.

[0026] The optical transceiver antenna is composed of an optical narrowband filter and a transmitting optical lens.

[0027] The sending module includes a signal acquisition and amplification module, a coding and decoding module, a modulation and demodulation module, a blue light LED driving circuit, and a blue light LED luminous board which are connected in sequence; the video image collected by the imaging detection module is transmitted to the signal amplification module, superimposed with the DC bias, and the channel coding and decoding is completed through the coding and decoding module, and then transmitted to the blue light LED driving circuit through the modulation and demodulation module, and the video signal is loaded onto the blue light LED luminous board, and the video signal is sent out in the form of a light beam.

[0028] The signal acquisition and amplification module is mainly composed of an APD high-sensitivity receiving board, which uses S8664-30K or S8664-50K as the optical receiving device to respectively detect weak optical signals with 140MHz bandwidth and 60MHz bandwidth. The APD high-sensitivity receiving board uses the OPA2846 secondary operational amplifier to realize the functions of transimpedance amplification and voltage-controlled high-pass filtering, and uses the TLV3501-SOT to realize the function of the hysteresis comparator.

[0029] The encoding and decoding and modulation and demodulation modules are mainly completed by the FPGA communication mainboard. The mainboard uses the AC6045 core board of the XLINIX Spartan6 series XC6SLS45 FPGA as the PCB carrier of the FPGA. The core board is mounted on the FPGA communication mainboard, which has multiple external interfaces such as RJ45 network port, USB port and RS232 serial port. The communication mainboard is also equipped with a model STM32F100C8T6B single-chip microcomputer, which realizes the function of current monitoring and dynamic dimming. The FPGA communication mainboard uses the RTL8211DG MAC / PHY Ethernet interface chip to realize Ethernet connection.

[0030] The blue LED driving circuit is mainly composed of an LDO linear voltage regulator and a driving unit. The driving unit uses a PMD2001D driver plus a power MOS tube D4184 for OOK driving. The LDO linear voltage regulator unit uses an LTC3780 LDO control chip, which has the functions of dynamic voltage regulation and current stabilization. It can provide a variable voltage from 20V to 4V for the driving channel. At the same time, the driving current is sampled through the precision sampling resistor of the driving circuit to achieve constant current driving under the control of the single-chip microcomputer.

[0031] The blue light LED luminous panel is a blue light LED luminous panel, which is composed of 6 high-brightness blue light CREE XML2 U3 10WLEDs arranged in a circular array. Each LED is evenly distributed in a circle at an angle of 60 degrees, and the middle area of ​​the 6 LEDs is reserved as the receiver optical lens window. The blue light with a wavelength of 470mm is used; the LED arrangement adopts an equilateral layout.

[0032] The receiving module includes a photoelectric detector, a preamplifier module, a modulation and demodulation module, a coding and decoding module and an equalization processing module connected in sequence; since the system is in duplex mode, the preamplifier module, the modulation and demodulation module, the coding and decoding module are all described in the transmitting module, and the equalization processing module is completed by the FPGA core board using an equalization algorithm.

[0033] The blue light beam is focused by the large-focal-length focusing lens of the optical transceiver antenna and irradiated onto the photodetector. The optical signal is converted into an electrical signal. After power amplification and low-pass filtering, the signal is sent to the modulation and demodulation module for demodulation, decoding is completed through the encoding and decoding module, and then output to the display terminal through equalization processing.

[0034] The imaging detection module includes an ICCD camera, an Ethernet interface module, an FPGA and a GPU; the front end of the ICCD camera is transmitted to the FPGA cache at high speed through the Ethernet interface module, the FPGA sends the collected video image to the GPU, the GPU receives the image and transmits it back to the FPGA, the FPGA receives the data and compresses the image and sends the data to the sending module of the optical communication module through Ethernet.

[0035] The FPGA adopts the XILINX XC7K325T3FFG900I chip.

[0036] like Figure 3 , 4 As shown in the figure, the main feature of the optical communication module is that the communication wavelength adopts the 470nm blue light of the "underwater window", the LED arrangement adopts the "equilateral" layout, and each LED has the same power. At the transmitting end, the signal source is transmitted to the signal amplification circuit, superimposed with the DC bias, and the channel encoding and decoding work is completed through the encoding and decoding module, and then transmitted to the blue light LED driving circuit through the modulation and demodulation module, and the video signal is loaded onto the high-frequency blue light LED light-emitting board. The video signal is sent out in the form of a light beam, and is collimated by a small focal length focusing lens to reduce the divergence angle of the light source. At the receiving end, the blue light beam is focused by a large focal length focusing lens and irradiated on the photodetector at the focal length of the focusing lens, thereby converting the optical signal into an electrical signal. The signal is sent to the modulation and demodulation module after power amplification and low-pass filtering to complete the demodulation; then the decoding is completed by the encoding and decoding module, and then output to the terminal through post-equalization and other processing.

[0037] like Figure 5As shown in the figure, the main feature of the image processing module is that its architecture adopts the Jetson TX2 series GPU, which has 256 embedded CUDA cores, and the computing power converted into is greater than 1.0 TFLOPS. The interconnection between GPU and FPGA adopts the standard PCI-Express bus, and the bus topology is 4 Lanes, 5.0Gbps / Lane. The camera adopts an image-enhanced ICCD, and the response spectrum is in the visible light band. The front end of the camera is transmitted to the FPGA cache at high speed through the Ethernet conversion module. The FPGA adopts the XILINXXC7K325T3FFG900I chip. Considering the problem that the high-speed signal clock may be out of sync, the FPGA interface control circuit uses FIFO-based dynamic phase correction to ensure high clock synchronization and send the collected video image to the GPU. After receiving the image, the GPU transmits it back to the FPGA. After receiving the data, the FPGA uses H.265 for image compression and sends the data to the communication module through Ethernet. At the same time, the deep learning algorithm is used to complete the classification of the operation object. The main feature of the deep learning algorithm is that the detection network is divided into two parts: component detection and overall object detection. The two parts of detection are integrated into one network. Considering the real-time performance, the device uses SSD network. SSD uses the auxiliary means of anchorbox in FASTER for training, and removes the time-consuming RPN stage. To ensure accuracy, multi-layer featuremap is used for simultaneous prediction. For the target category description in the actual underwater operation scene, multi-view transformation, occlusion, illumination, deformation, background interference, intra-class variability and inter-class similarity have become visual problems in image understanding, and are also the difficulties in high-precision target recognition in the scene. The object segmentation is performed based on the improved deep learning network YOLOv3 as the main detection network method, such as Figure 2 The specific implementation steps include: data preparation, network design, network training (including network structure adjustment, debugging, optimization), model optimization and other stages.

[0038] The main features of the optical transceiver antenna are an optical narrowband filter with a central wavelength of 470nm (half-height width of 10nm) and a transmitting optical lens.

[0039] The main function of the power module is to stabilize, reduce noise and transform the battery power supply. Voltage stabilization means that when the external voltage has abnormal conditions such as lightning surge, electrostatic shock, grid voltage change, voltage drop, power supply harmonics exceeding the standard, the voltage provided by the power module should remain unchanged. Noise reduction means that the power module should be able to effectively suppress the common mode noise and differential mode noise coupled from the external power supply to prevent the external high-frequency noise from coupling into the device and causing interference to the device. The power module is mainly composed of abnormal state monitoring circuit, energy storage capacitor and noise filtering capacitor array. Specifically, the high-voltage power supply board HO1-P601-2C adjustable linear high-voltage output module is used, and the output voltage range is 0-600V. The high-voltage power supply board also provides a positive and negative 5V bias voltage to the OPA2846 precision operational amplifier on the APD high-sensitivity receiving board.

[0040] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0041] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. An underwater wireless optical communication and imaging detection integrated device, comprising an imaging detection module and a power supply module installed in a watertight housing, characterized in that: The device also includes an optical communication module and an optical transceiver antenna installed in the watertight housing. The imaging detection module collects and processes the target image and transmits it to the optical communication module via the communication interface; the optical communication module includes a sending module and a receiving module; The device adopts a duplex communication mode. At the transmitting end, the transmitting module processes the video image collected by the imaging detection module into signal light and then sends it to the seawater channel through the optical transceiver antenna. After a certain distance of signal transmission, it reaches the optical transceiver antenna at the receiving end, and is processed by the receiving module and output to the display terminal. The sending module includes a signal acquisition and amplification module, a coding module, a modulation and demodulation module, a blue light LED driving circuit, and a blue light LED light-emitting board connected in sequence; the video image collected by the imaging detection module is transmitted to the signal amplification module, superimposed with the DC bias, and the channel coding and decoding is completed by the coding and decoding module, and then transmitted to the blue light LED driving circuit through the modulation and demodulation module, and the video signal is loaded onto the blue light LED light-emitting board, and the video signal is sent out in the form of a light beam; The blue LED driving circuit is mainly composed of an LDO linear voltage regulator and a driving unit. The driving unit uses a PMD2001D driver and a power MOS tube D4184 for OOK driving. The signal acquisition and amplification module is mainly composed of an APD high-sensitivity receiving board, and uses S8664-30K or S8664-50K as an optical receiving device to respectively realize 140MHz bandwidth and 60MHz bandwidth weak optical signal detection; The light source of the blue light LED luminous panel adopts blue light with a wavelength of 470mm; the LED arrangement adopts an equilateral layout, including 6 high-brightness blue light LEDs arranged in a circular array; each LED is evenly distributed in a circle at an angle of 60 degrees, and the middle area of ​​the 6 LEDs is reserved as a receiver optical lens window.

2. The underwater wireless optical communication and imaging detection integrated device according to claim 1, characterized in that: The optical transceiver antenna is composed of an optical narrowband filter and a transmitting optical lens.

3. The underwater wireless optical communication and imaging detection integrated device according to claim 1, characterized in that: The receiving module includes a photoelectric detector, a preamplifier module, a modulation and demodulation module, a coding and decoding module and an equalization processing module connected in sequence; the blue light beam is focused by a large focal length focusing lens of an optical transceiver antenna and irradiated onto the photoelectric detector, and the optical signal is converted into an electrical signal. The signal is sent to the modulation and demodulation module after power amplification and low-pass filtering to complete demodulation, and is decoded by the coding and decoding module, and then output to a display terminal through equalization processing.

4. The underwater wireless optical communication and imaging detection integrated device according to claim 1, characterized in that: The imaging detection module includes an ICCD camera, an Ethernet interface module, an FPGA and a GPU; the front end of the ICCD camera is transmitted to the FPGA cache at high speed through the Ethernet interface module, the FPGA sends the collected video image to the GPU, the GPU receives the image and transmits it back to the FPGA, the FPGA receives the data and compresses the image and sends the data to the sending module of the optical communication module through Ethernet.

5. The underwater wireless optical communication and imaging detection integrated device according to claim 1, characterized in that: The FPGA adopts the XILINX XC7K325T3FFG900I chip.

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