Anti-interference underwater guidance system and method based on area array detector

Abstract

The invention relates to an underwater guiding system and method, in particular to an anti-interference underwater guiding system and method based on an area array detector, and solves the technical problems that an existing underwater guiding system is asynchronous in transmitting and receiving, limited in anti-interference effect and difficult to meet application requirements of complex scenes. According to the underwater guidance system provided by the invention, the synchronization unit is adopted to obtain the synchronous square wave signal consistent with the turn-on and turn-off time sequence of the stroboscopic lamp array so as to drive the area array detector to work, so that the receiving and transmitting synchronism between the two underwater platforms can be improved; meanwhile, the frequency of the synchronous square wave signal is improved to two times of frequency by using the frequency multiplication unit, so that the area array detector collects images when each stroboscopic light source is turned on and turned off, and background light and water surface reflection interference can be filtered out by combining with the image processor. In addition, the image processor adopts a background subtraction module and a signal preprocessing module to filter background light interference and water surface reflection interference respectively, so that the relative pose calculation precision can be improved, and the guide precision is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to underwater guiding system and method, specifically relates to an anti-interference underwater guiding system and method based on area array detector. BACKGROUND

[0002] Underwater guiding is used for recycling and docking between two underwater platforms, and the underwater guiding system mainly comprises a plurality of stroboscopic light sources and detection assemblies arranged on the two underwater platforms respectively. When the underwater guiding system works, the plurality of stroboscopic light sources flash according to a preset code, and the detection assemblies calculate the positions and attitudes of the stroboscopic light sources according to the detected light spot images, and obtain the relative pose between the two underwater platforms after solving.

[0003] The plurality of stroboscopic light sources emit light according to a preset frequency, and the detection assemblies receive according to a preset frequency. Since there is no transmitting and receiving synchronization device, although the transmitting and receiving frequencies of the two are matched, it is difficult to achieve accurate alignment, and there is a problem of frequency drift when working for a long time, which leads to asynchronous transmission and reception, reduces the received energy, and reduces the detection distance.

[0004] In addition, there are environmental interference and water surface reflection interference in the underwater guiding scene. The environmental interference mainly includes flicker interference and background light interference. For flicker interference, the stroboscopic light source currently flashes according to a preset code, but it is only effective for occasional flicker interference. However, when used in a pool or shallow sea, more background light interference occurs. When the background light is strong, the signal-to-noise ratio of the light spot formed by the stroboscopic light source in the image detected by the detection assembly is low, it is difficult to extract the light spot centroid, and it is impossible to calculate the relative pose between the two underwater platforms. Water surface reflection interference usually occurs in the application scene where the underwater platform is close to the water surface. The image detected by the detection assembly contains both the real light spot and the water surface reflection light spot. When calculating the light spot centroid, the water surface reflection light spot will cause the light spot centroid position to deviate from the true value, and the calculation error of the relative pose will increase. SUMMARY

[0005] The purpose of the present application is to solve the technical problems that the existing underwater guiding system has limited anti-interference effect and is difficult to meet the application requirements of complex scenes, and to provide an anti-interference underwater guiding system and method based on an area array detector.

[0006] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is:

[0007] An anti-interference underwater guiding system based on an area array detector, characterized in that it comprises a stroboscopic light array arranged on an underwater platform A, and a synchronization unit, a frequency doubling unit, an area array detector and an image processor arranged on an underwater platform B.

[0008] The stroboscopic light array comprises N stroboscopic light sources which are sequentially turned on and off according to a preset light-emitting frequency and light-emitting sequence, wherein N is an integer and N≥3;

[0009] The output end of the synchronization unit is connected with the input end of the frequency multiplication unit, for collecting the light-emitting signal of the stroboscopic light array and performing synchronization processing to obtain a synchronization square wave signal consistent with the stroboscopic light array turning on and off timing;

[0010] The output end of the frequency multiplication unit is connected with the trigger end of the area array detector, for increasing the frequency of the synchronization square wave signal to a frequency multiplication to obtain a trigger signal of the area array detector;

[0011] The output end of the area array detector is connected with the input end of the image processor, for periodically collecting images when the N stroboscopic light sources in the stroboscopic light array are turned on and off under the driving of the trigger signal, obtaining 2N stroboscopic light source images in each collection cycle, and sending to the image processor;

[0012] The image processor is configured to filter out environmental background light in N stroboscopic light source images corresponding to the N stroboscopic light sources being turned on according to N stroboscopic light source images obtained in each collection cycle of the area array detector, obtain N background filtered images, then process and filter out water surface reflection from the N background filtered images, and further calculate a real-time pose of the stroboscopic light array relative to the area array detector, so as to obtain a real-time pose of the underwater platform A relative to the underwater platform B, and complete underwater guidance.

[0013] Further, the synchronization unit comprises a high-speed photoelectric detector, a direct current elimination circuit, a band-pass filter circuit and a time sequence translation circuit connected in sequence;

[0014] The high-speed photoelectric detector is configured to collect the light-emitting signal of the stroboscopic light array and convert it into a voltage square wave signal;

[0015] The direct current elimination circuit is configured to filter out direct current bias caused by background light, and the band-pass filter circuit is configured to filter out signals lower or higher than the preset light-emitting frequency to obtain a square wave signal;

[0016] The output end of the time sequence translation circuit is connected with the input end of the frequency multiplication unit, for forwardly translating the square wave signal to compensate for the delay caused by the high-speed photoelectric detector, the direct current elimination circuit and the band-pass filter circuit, and obtain a synchronization square wave signal.

[0017] Further, the image processor comprises a background subtraction module, a signal preprocessing module and a guidance operation module connected in sequence;

[0018] The input end of the background subtraction module is connected with the output end of the area array detector, for filtering out environmental background light to obtain a background filtered image;

[0019] The and signal preprocessing module is used for converting the background filtered image into row and signals and column and signals, so as to filter out the water surface reflection light spot, and obtain the row and signals and column and signals of the filtered image.

[0020] The guide operation module is used for calculating the light spot centroid positions of the N frequency flash light sources according to the row and signals and column and signals of the filtered image, so as to obtain the real-time pose of the frequency flash light array relative to the area array detector, and further obtain the real-time pose of the underwater platform A relative to the underwater platform B, and complete the underwater guidance.

[0021] Further, the resolution of the area array detector is 1920*1080.

[0022] The application further provides an anti-interference underwater guidance method based on an area array detector, which adopts the above-mentioned anti-interference underwater guidance system based on an area array detector, and is characterized in that the method comprises the following steps:

[0023] Step 1, the positions of the N frequency flash light sources in the frequency flash light array are numbered respectively to obtain the serial numbers of the N frequency flash light sources, the light-emitting frequency of the frequency flash light array and the light-emitting sequence of the N frequency flash light sources are preset to obtain the preset light-emitting time sequence, and then the N frequency flash light sources of the frequency flash light array are sequentially turned on and turned off according to the preset light-emitting time sequence;

[0024] Step 2, the synchronous unit collects the signals emitted by the frequency flash light array and performs synchronous processing to obtain a synchronous square wave signal consistent with the turning-on and turning-off time sequence of the frequency flash light array, and sends the synchronous square wave signal to the frequency multiplication unit;

[0025] Step 3, the frequency multiplication unit increases the frequency of the synchronous square wave signal to 2 times to obtain a trigger signal, and sends the trigger signal to the area array detector;

[0026] Step 4, the area array detector periodically collects images when the N frequency flash light sources of the frequency flash light array are turned on and turned off under the driving of the trigger signal, 2N frequency flash light source images are obtained in each collection cycle, and the 2N frequency flash light source images are sent to the image processor;

[0027] Step 5, the image processor filters out the ambient background light in the N frequency flash light source images corresponding to the N frequency flash light source images when the frequency flash light source is on, respectively, to obtain N background filtered images; then, the N background filtered images are processed to filter out the water surface reflection, and then the centroid positions of the light spots in the N frequency flash light source images when the frequency flash light source is on are calculated, and the serial numbers of the N frequency flash light sources are obtained according to the centroid positions of the light spots; the real-time pose of the frequency flash light array relative to the area array detector is obtained by using the relative installation position relationship between the N frequency flash light sources, so as to obtain the real-time pose of the underwater platform A relative to the underwater platform B, and the underwater guidance is completed.

[0028] Further, step 2.1, calibrate the delay of the high-speed photoelectric detector, the direct current isolation circuit and the band-pass filter circuit;

[0029] Step 2.2, the high-speed photoelectric detector collects the light-emitting signal of the frequency flash light array and converts it into a voltage square wave signal transmitted to the direct current isolation circuit;

[0030] Step 2.3, the direct current isolation circuit and the band-pass filter circuit filter out the direct current bias, signals lower or higher than the preset light-emitting frequency in the voltage square wave signal in turn, obtain the square wave signal and transmit it to the time sequence translation circuit;

[0031] Step 2.4, the time sequence translation circuit translates the square wave signal forward according to the delay of the high-speed photoelectric detector, the direct current isolation circuit and the band-pass filter circuit, so that the translated square wave signal is consistent with the timing of the frequency flash light array turning on and off, obtains the synchronous square wave signal, and sends it to the frequency multiplication unit.

[0032] Further, step 5 is specifically:

[0033] Step 5.1, take two adjacent frequency flash light source images corresponding to each frequency flash light source in 2N frequency flash light source images as a group and input them into the background subtraction module, respectively; the background subtraction module subtracts the frequency flash light source image when the frequency flash light array is turned on from the frequency flash light source image when the frequency flash light array is turned off, to obtain N background filtered images;

[0034] Step 5.2, and the signal preprocessing module converts N background filtered images into row and signal according to the pixel row, and then draws the row and signal curve from the lowest pixel row; when the row and signal curve appears a row and signal peak value higher than the preset threshold value from bottom to top, and the row and signal first drops below the preset threshold value, the row and signal of the pixel row in the interval where the row and signal is greater than or equal to the preset threshold value is kept, the row and signal of the remaining pixel row is assigned as 0, the row and signal of N filtered images is obtained, and then N filtered images are converted into column and signal according to the pixel column, and the row and signal of N filtered images are obtained, and the column and signal of N filtered images are obtained;

[0035] Step 5.3, the guide operation module calculates the light spot centroid position and the corresponding attitude angle in N filtered images according to the row and signal and the column and signal of N filtered images by using the multi-element detector measurement principle, and obtains the serial number of the corresponding stroboscopic light source according to the light spot centroid position, so as to obtain the attitude of N stroboscopic light sources relative to the area array detector; then, the pose of the stroboscopic lamp array relative to the area array detector is obtained by combining the relative installation position relationship of N stroboscopic light sources, so as to obtain the pose of the underwater platform A relative to the underwater platform B, and the underwater guidance is completed.

[0036] Further, in step 1, the light-emitting frequency of the stroboscopic lamp array is 10Hz, and the lighting duration and the closing duration of each stroboscopic light source are the same.

[0037] Further, in step 5.2, the preset threshold value is 1000.

[0038] Compared with the prior art, the present application has the following beneficial effects:

[0039] 1、The anti-interference underwater guidance system based on an area array detector provided by the present application has the advantages of transceiver synchronization and anti-interference, and can be used for guidance in scenes with large water attenuation, water surface reflection and complex environment;

[0040] 2、The anti-interference underwater guidance system based on an area array detector provided by the present application uses a synchronization unit to obtain a synchronization square wave signal consistent with the lighting and closing timing of the stroboscopic lamp array to drive the area array detector to work, which can improve the synchronization of the transceiver between the two underwater platforms, realize high-precision alignment of the transceiver, and improve the detection distance; at the same time, the frequency of the synchronization square wave signal is increased to 2 times by using a frequency multiplication unit, so that the area array detector can collect images when each stroboscopic light source is lit and turned off, and then combined with an image processor, the background light interference and water surface reflection interference can be filtered out, and the anti-interference performance is improved;

[0041] 3. The anti-interference underwater guiding system based on the area array detector provided by the application, the image processor comprises a background subtraction module and a signal preprocessing module, background light interference and water surface reflection interference can be filtered out, the signal-to-noise ratio is improved, the relative pose calculation accuracy is improved, and the guiding accuracy is improved;

[0042] 4. The anti-interference underwater guiding method based on the area array detector provided by the application, the stroboscopic light source images when the stroboscopic light array is turned on and turned off are subtracted by using the background subtraction module, the environmental background light interference can be removed, and the signal-to-noise ratio is improved;

[0043] 5. The anti-interference underwater guiding method based on the area array detector provided by the application, the real light spot can be identified by using the signal preprocessing module, the water surface reflection interference is removed, the light spot centroid position calculation accuracy is improved, and the guiding accuracy is improved. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 It is a structure schematic view of the anti-interference underwater guiding system based on the area array detector provided by the application;

[0045] Figure 2 It is a preset light-emitting timing schematic view of step 1 of the anti-interference underwater guiding method based on the area array detector provided by the application;

[0046] Figure 3 It is a comparison view of the output timing of the high-speed photoelectric detector, the direct current isolation circuit, the band-pass filter circuit and the timing translation circuit in the synchronization unit in step 2 of the anti-interference underwater guiding method based on the area array detector provided by the application and the preset light-emitting timing;

[0047] Figure 4 It is a comparison view of the trigger signal, the synchronization square wave signal and the preset light-emitting timing in step 3 of the anti-interference underwater guiding method based on the area array detector provided by the application;

[0048] Figure 5 It is an image schematic view obtained after background filtering in step 5.1 of the anti-interference underwater guiding method based on the area array detector provided by the application;

[0049] Figure 6 It is a schematic view of drawing a row and signal curve in step 5.2 of the anti-interference underwater guiding method based on the area array detector provided by the application, wherein (a) is the image obtained after background filtering, and (b) is a row and signal curve view;

[0050] Figure 7 It is a light spot centroid position schematic view obtained in step 5.3 of the anti-interference underwater guiding method based on the area array detector provided by the application;

[0051] The reference signs are explained as follows:

[0052] 1-Strobe light array, 2-Synchronization unit, 3-Frequency multiplication unit, 4-Area array detector, 5-Image processor; 6-High-speed photodetector, 7-DC blocking circuit, 8-Bandpass filter circuit, 9-Timing translation circuit; 10-Background subtraction module, 11-Signal preprocessing module, 12-Guided calculation module. Detailed Implementation

[0053] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides an anti-interference underwater guidance system and method based on a planar array detector, as proposed in this invention. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this invention and are not intended to limit the scope of protection of this invention.

[0054] An anti-jamming underwater guidance system based on an array detector, such as Figure 1 As shown, it includes a strobe light array 1 installed on underwater platform A, and a synchronization unit 2, a frequency doubling unit 3, an area array detector 4, and an image processor 5 installed on underwater platform B.

[0055] The strobe light array 1 includes N strobe light sources, which are sequentially turned on and off according to a preset emission frequency and order, where N is an integer and N≥3. In this embodiment, N=4. The output of the synchronization unit 2 is connected to the input of the frequency multiplier unit 3, used to collect the emission signal of the strobe light array 1 and perform synchronization processing to obtain a synchronization square wave signal consistent with the lighting and turning-off sequence of the strobe light array 1. The output of the frequency multiplier unit 3 is connected to the trigger of the area array detector 4, used to increase the frequency of the synchronization square wave signal to twice the frequency, obtaining the trigger signal of the area array detector 4. The output of the area array detector 4 is connected to the input of the image processor 5, used to periodically collect images of the N strobe light sources in the strobe light array 1 when they are lit and turned off under the drive of the trigger signal. Each collection cycle obtains 2N amplitude strobe light source images and sends them to the image processor 5. In this embodiment, the resolution of the area array detector 4 is 1920×1080. The image processor 5 is used to filter out the ambient background light in the corresponding N stroboscopic light source images when the stroboscopic light source is turned off, obtained from the N stroboscopic light source images when the stroboscopic light source is turned on, based on the N stroboscopic light source images obtained in each acquisition cycle of the area array detector 4, to obtain N background filtered images. Then, the N background filtered images are processed to remove water surface reflections, and the real-time pose of the stroboscopic light array 1 relative to the area array detector 4 is calculated, thereby obtaining the real-time pose of the underwater platform A relative to the underwater platform B, and completing the underwater guidance.

[0056] The synchronous unit 2 comprises a high-speed photodetector 6, a direct-current elimination circuit 7, a band-pass filter circuit 8 and a time sequence translation circuit 9 connected in sequence. The high-speed photodetector 6 is used for collecting the light-emitting signal of the stroboscopic light array 1 and converting the light-emitting signal into a voltage square wave signal. The direct-current elimination circuit 7 and the band-pass filter circuit 8 are used for filtering out the direct current bias caused by the background light and the signal lower or higher than the preset light-emitting frequency respectively, so as to obtain a square wave signal. The output end of the time sequence translation circuit 9 is connected with the input end of the frequency multiplication unit 3, which is used for forwardly translating the square wave signal to compensate the delay caused by the high-speed photodetector 6, the direct-current elimination circuit 7 and the band-pass filter circuit 8, so as to obtain a synchronous square wave signal.

[0057] The image processor 5 comprises a background subtraction module 10, a signal preprocessing module 11 and a guidance operation module 12 connected in sequence. The input end of the background subtraction module 10 is connected with the output end of the area array detector 4, which is used for filtering out the environmental background light to obtain a background-filtered image. The signal preprocessing module 11 is used for converting the background-filtered image into a row sum signal and a column sum signal, so as to filter out the water surface reflection spot to obtain the row sum signal and the column sum signal of the filtered image. The guidance operation module 12 is used for calculating the spot centroid position of the N stroboscopic light sources according to the row sum signal and the column sum signal of the filtered image respectively, so as to obtain the real-time pose of the stroboscopic light array 1 relative to the area array detector 4, and further obtain the real-time pose of the underwater platform A relative to the underwater platform B, thereby completing the underwater guidance.

[0058] The anti-interference underwater guidance system based on the area array detector provided in the embodiment is characterized in that: the four stroboscopic light sources of the stroboscopic light array 1 work at a preset frequency, and only one stroboscopic light source is lit at most each time. After the synchronous unit 2 collects the stroboscopic signal, the direct-current elimination, the band-pass filtering and the time sequence translation are performed respectively, so as to obtain a square wave completely synchronized with the light-emitting time sequence of the stroboscopic light array 1. After the frequency multiplication module 3 is multiplied, the square wave is used as a trigger signal to drive the area array detector 4 to collect the signal of the stroboscopic light array 1 in the lit and off states at 2 times the frequency, and then the background subtraction module 10 is used to remove the background noise, so that only the spot is obtained in the image. In the signal preprocessing module 11, the sum signal of each pixel row is calculated in a top-down manner, and when a row sum signal peak higher than a preset threshold value appears, the gray value of each pixel in the remaining pixel row is assigned as 0, that is, the sum signal of the remaining pixel row is 0, and then the sum signal of each pixel column is calculated. By using the row sum signal and the column sum signal, the attitude of each stroboscopic light source is calculated by the guidance operation module 12 according to the multi-element detector measurement principle, and the relative installation position relationship among the stroboscopic light sources is combined, so as to obtain the relative pose between the area array detector 4 and the stroboscopic light array 1, thereby completing the underwater guidance.

[0059] The anti-interference underwater guidance system based on the area array detector provided in the embodiment is characterized in that: the four stroboscopic light sources of the stroboscopic light array 1 work at a preset frequency, and only one stroboscopic light source is lit at most each time. After the synchronous unit 2 collects the stroboscopic signal, the direct-current elimination, the band-pass filtering and the time sequence translation are performed respectively, so as to obtain a square wave completely synchronized with the light-emitting time sequence of the stroboscopic light array 1. After the frequency multiplication module 3 is multiplied, the square wave is used as a trigger signal to drive the area array detector 4 to collect the signal of the stroboscopic light array 1 in the lit and off states at 2 times the frequency, and then the background subtraction module 10 is used to remove the background noise, so that only the spot is obtained in the image. In the signal preprocessing module 11, the sum signal of each pixel row is calculated in a top-down manner, and when a row sum signal peak higher than a preset threshold value appears, the gray value of each pixel in the remaining pixel row is assigned as 0, that is, the sum signal of the remaining pixel row is 0, and then the sum signal of each pixel column is calculated. By using the row sum signal and the column sum signal, the attitude of each stroboscopic light source is calculated by the guidance operation module 12 according to the multi-element detector measurement principle, and the relative installation position relationship among the stroboscopic light sources is combined, so as to obtain the relative pose between the area array detector 4 and the stroboscopic light array 1, thereby completing the underwater guidance.

[0060] Step 1, the positions of the N stroboscopic light sources in the stroboscopic light array 1 are numbered respectively to obtain the serial numbers of the N stroboscopic light sources, and the light-emitting frequency of the stroboscopic light array 1 and the light-emitting sequence of four stroboscopic light sources in the stroboscopic light array 1 are preset to obtain the preset light-emitting timing, and then the N stroboscopic light sources in the stroboscopic light array 1 are sequentially turned on and off according to the preset light-emitting timing. In the stroboscopic light array 1, the stroboscopic light source at the upper right corner is No. 1 light, the stroboscopic light source at the lower right corner is No. 2 light, the stroboscopic light source at the lower left corner is No. 3 light, and the stroboscopic light source at the upper left corner is No. 4 light, as shown in Figure 2 , the four stroboscopic light sources are sequentially turned on and off in the order of No. 1 light, No. 2 light, No. 3 light and No. 4 light, and the turning-on time and the turning-off time of each stroboscopic light source are equal, and the overall light-emitting frequency is f, f = 1 / (2T), T is the time length of the turning-on or turning-off of the stroboscopic light source, in this embodiment, T = 0.05s, then f = 10Hz.

[0061] Step 2, the synchronization unit 2 collects the signals emitted by the stroboscopic light array 1 and performs synchronization processing to obtain a synchronization square wave signal consistent with the timing of the stroboscopic light array 1 turning on and off, and sends it to the frequency multiplication unit 3. The output timing of the high-speed photodetector 6, the direct current isolation circuit 7, the band-pass filter circuit 8 and the timing translation circuit 9 is compared with the preset light-emitting timing as shown in Figure 3 Step 2, the synchronization unit 2 collects the signals emitted by the stroboscopic light array 1 and performs synchronization processing to obtain a synchronization square wave signal consistent with the timing of the stroboscopic light array 1 turning on and off, and sends it to the frequency multiplication unit 3. The output timing of the high-speed photodetector 6, the direct current isolation circuit 7, the band-pass filter circuit 8 and the timing translation circuit 9 is compared with the preset light-emitting timing as shown in

[0062] Step 2.1, calibrate the delay of the high-speed photodetector 6, the direct current isolation circuit 7 and the band-pass filter circuit 8 to obtain a delay of 2ms;

[0063] Step 2.2, the high-speed photodetector 6 collects the light-emitting signals of the stroboscopic light array 1 and converts them into voltage square wave signals transmitted to the direct current isolation circuit 7;

[0064] Step 2.3, the direct current isolation circuit 7 and the band-pass filter circuit 8 filter out the direct current bias, signals lower or higher than the preset light-emitting frequency in the voltage square wave signal in turn to obtain a square wave signal and transmit it to the timing translation circuit 9;

[0065] Step 2.4, the timing translation circuit 9 translates the square wave signal forward by 2ms according to the delay of the high-speed photodetector 6, the direct current isolation circuit 7 and the band-pass filter circuit 8, so that the translated square wave signal is consistent with the timing of the stroboscopic light array 1 turning on and off, to obtain a synchronization square wave signal and send it to the frequency multiplication unit 3.

[0066] Step 3, as shown in Figure 4 , the frequency multiplication unit 3 increases the frequency of the synchronization square wave signal to 2 times to obtain a trigger signal and sends it to the area array detector 4.

[0067] Step 4, the area array detector 4 periodically collects the images of the N stroboscopic light sources of the stroboscopic light array 1 in the on and off state under the driving of the trigger signal, and 2N stroboscopic light source images are obtained in each collection cycle and sent to the image processor 5.

[0068] Step 5, the image processor 5 filters out the ambient background light in the corresponding N stroboscopic light source images when the N stroboscopic light sources are on according to the N stroboscopic light source images when the N stroboscopic light sources are off obtained by the area array detector 4 in each collection cycle, respectively, to obtain N background filtered images; then the N background filtered images are processed to filter out the water surface reflection, and then the position of the light spot centroid and the corresponding attitude angle in the N stroboscopic light source images when the stroboscopic light array 1 is on are calculated, and the serial number of the N stroboscopic light sources is obtained according to the position of the light spot centroid, combined with the relative installation position relationship between the N stroboscopic light sources, the real-time pose of the stroboscopic light array 1 relative to the area array detector 4 is obtained, so as to obtain the real-time pose of the underwater platform A relative to the underwater platform B, and complete the underwater guidance. Specifically:

[0069] Step 5.1, input the two adjacent stroboscopic light source images of each stroboscopic light source in the 2N stroboscopic light source images as a group into the background subtraction module 10, as shown in Figure 5 The background subtraction module 10 subtracts the stroboscopic light source images when the stroboscopic light array 1 is off from the stroboscopic light source images when the stroboscopic light array 1 is on, respectively, to obtain N background filtered images.

[0070] Step 5.2, the sum signal pre-processing module 11 converts the N background filtered images into row sum signals according to the pixel rows, as shown in Figure 6 Then, starting from the lowest pixel row, the row sum signal curve is drawn; when the row sum signal curve appears a peak value higher than the preset threshold value from bottom to top, and the row sum signal first drops below the preset threshold value, the sum signal of the pixel row in the interval where the row sum signal is greater than or equal to the preset threshold value is kept, and the sum signal of the remaining pixel row is assigned as 0, to obtain the row sum signal of the N filtered images, and then the N filtered images are converted into column sum signals according to the pixel columns, to obtain the row sum signal and the column sum signal of the N filtered images.

[0071] When detecting the light spot on the water surface, the water surface reflection may cause two light spots in the image. Since the underwater platform generally has small roll, the two light spots in the image are distributed vertically, the upper one is the water surface reflection light spot, and the lower one is the real light spot. According to the vertical distribution characteristics, in step 5.2, starting from the lowest pixel row, the sum signal of each pixel row is calculated, and the row sum signal curve is drawn, and there are two peaks on the curve. According to the preset threshold value, the row sum signal greater than the preset threshold value in the lower peak is kept, so as to filter out the water surface reflection light spot.

[0072] The preset threshold value can be set according to an actual working scene, is generally less than the peak value and the signal, and is greater than the trough and the signal, and in the embodiment, the preset threshold value is 1000.

[0073] Step 5.3, the guiding operation module 12 calculates the positions of the light spot centroids in the N filtered images and the corresponding attitude angles according to the row and signal, column and signal of the N filtered images, using the multi-element detector measurement principle, and obtains the serial numbers of the N filtered images corresponding to the stroboscopic light sources according to the positions of the light spot centroids, as shown in Figure 7 Then, the pose of the stroboscopic lamp array 1 relative to the area array detector 4 is obtained by combining the relative installation position relationship of the N stroboscopic light sources, so as to obtain the pose of the underwater platform A relative to the underwater platform B, and the underwater guiding is completed.

[0074] In step 5.3, considering that the roll angle of the underwater platform is generally small, the serial numbers of the stroboscopic light sources can be obtained according to the positions of the light spot centroids, as shown in Figure 7 The light spot centroid in the upper right corner is No. 1 light, the light spot centroid in the lower right corner is No. 2 light, the light spot centroid in the lower left corner is No. 3 light, and the light spot centroid in the upper left corner is No. 4 light. According to the serial numbers of the N stroboscopic light sources in the stroboscopic lamp array 1 and the relative installation positions, the pose of the stroboscopic lamp array 1 relative to the area array detector 4 can be obtained through geometric relationship. The specific method for obtaining the pose of the underwater platform A relative to the underwater platform B according to the row and signal, column and signal of the N filtered images can be referred to the patent applications CN118882527A and CN118936509A filed by the applicant.

[0075] In the embodiment, the synchronization unit 2 actively identifies the light-emitting timing of the stroboscopic lamp array 1, realizes the high-precision alignment of the receiving and transmitting, and improves the detection distance; the background subtraction module 10 subtracts the images in the two states of lighting and closing, removes the environmental background light interference, and improves the signal-to-noise ratio; at the same time, the in-phase signal preprocessing module 11 identifies the real light spot, removes the water surface reflection interference, improves the calculation accuracy of the position of the light spot centroid, has the advantages of receiving and transmitting synchronization and anti-interference, and can be used for guiding in scenes with large water attenuation, water surface reflection and complex environment.

Claims

1. An anti-jamming underwater guidance system based on an area array detector, characterized in that: The stroboscopic light array (1) is arranged on the underwater platform A, and the synchronous unit (2), the frequency multiplication unit (3), the area array detector (4) and the image processor (5) are arranged on the underwater platform B; The stroboscopic light array (1) comprises N stroboscopic light sources which are sequentially turned on and turned off according to preset light-emitting frequency and light-emitting sequence, wherein N is an integer and N is greater than or equal to 3; The output end of the synchronous unit (2) is connected with the input end of the frequency multiplication unit (3), used for collecting the light-emitting signal of the stroboscopic light array (1) and performing synchronous processing to obtain a synchronous square wave signal consistent with the on-off timing sequence of the stroboscopic light array (1); The output end of the frequency multiplication unit (3) is connected with the trigger end of the area array detector (4), used for increasing the frequency of the synchronous square wave signal to 2 times to obtain a trigger signal of the area array detector (4); The output end of the area array detector (4) is connected with the input end of the image processor (5), used for periodically collecting images when the N stroboscopic light sources are turned on and turned off under the driving of the trigger signal, and obtaining 2N stroboscopic light source images in each collection cycle and sending the images to the image processor (5); The image processor (5) is used for filtering out environmental background light in N stroboscopic light source images corresponding to the time when the N stroboscopic light sources are turned on according to the N stroboscopic light source images obtained in each collection cycle of the area array detector (4), obtaining N background-filtered images, then processing the N background-filtered images to filter out water surface reflection, and further calculating the real-time pose of the stroboscopic light array (1) relative to the area array detector (4) to obtain the real-time pose of the underwater platform A relative to the underwater platform B, thereby completing underwater guidance.

2. The anti-jamming underwater guidance system based on an area array detector according to claim 1, characterized in that: The synchronous unit (2) comprises a high-speed photoelectric detector (6), a direct current elimination circuit (7), a band-pass filter circuit (8) and a timing translation circuit (9) connected in sequence; The high-speed photoelectric detector (6) is used for collecting the light-emitting signal of the stroboscopic light array (1) and converting the light-emitting signal into a voltage square wave signal; The direct current elimination circuit (7) is used for filtering out direct current bias caused by background light, and the band-pass filter circuit (8) is used for filtering out signals lower or higher than the preset light-emitting frequency to obtain a square wave signal; The output end of the timing translation circuit (9) is connected with the input end of the frequency multiplication unit (3), used for forwardly translating the square wave signal to compensate for the delay caused by the high-speed photoelectric detector (6), the direct current elimination circuit (7) and the band-pass filter circuit (8), and obtain a synchronous square wave signal.

3. The anti-jamming underwater guidance system based on an area array detector according to claim 2, characterized in that: The image processor (5) comprises a background subtraction module (10), a sum signal preprocessing module (11) and a guidance calculation module (12) connected in sequence; The input end of the background subtraction module (10) is connected with the output end of the area array detector (4), used for filtering out environmental background light to obtain a background-filtered image; The sum signal preprocessing module (11) is used for converting the background-filtered image into a row sum signal and a column sum signal, thereby filtering out water surface reflection spots to obtain a row sum signal and a column sum signal of the filtered image; The guide operation module (12) is used for calculating the light spot centroid positions of the N stroboscopic light sources respectively according to the rows and signals and the columns and signals of the filtered images, so as to obtain the real-time pose of the stroboscopic lamp array (1) relative to the area array detector (4), and then obtain the real-time pose of the underwater platform A relative to the underwater platform B, and complete the underwater guidance.

4. The anti-jamming underwater guidance system based on an area array detector according to any one of claims 1-3, characterized in that: The resolution of the area array detector (4) is 1920*1080.

5. An anti-jamming underwater guiding method based on an area array detector, using an anti-jamming underwater guiding system based on an area array detector according to any one of claims 1-4, characterized in that, The method comprises the following steps: Step 1, according to the positions of the N stroboscopic light sources in the stroboscopic lamp array (1), the serial numbers of the N stroboscopic light sources are obtained, and the light-emitting frequency of the stroboscopic lamp array (1) and the light-emitting sequence of the N stroboscopic light sources are preset to obtain the preset light-emitting sequence, and then the N stroboscopic light sources of the stroboscopic lamp array (1) are sequentially turned on and off according to the preset light-emitting sequence; Step 2, the synchronization unit (2) collects the signals emitted by the stroboscopic lamp array (1) and performs synchronization processing to obtain a synchronization square wave signal consistent with the stroboscopic lamp array (1) turning on and off sequence, and sends it to the frequency multiplication unit (3); Step 3, the frequency multiplication unit (3) increases the frequency of the synchronization square wave signal to 2 times to obtain a trigger signal, and sends it to the area array detector (4); Step 4, the area array detector (4) periodically collects images when the N stroboscopic light sources in the stroboscopic lamp array (1) are turned on and off under the driving of the trigger signal, and obtains 2N stroboscopic light source images in each collection cycle, and sends them to the image processor (5); Step 5, the image processor (5) filters out the environmental background light in the N stroboscopic light source images corresponding to the N stroboscopic light sources turned on according to the N stroboscopic light source images obtained in each collection cycle of the area array detector (4) when the N stroboscopic light sources are turned off, obtains N background filtered images, then processes and filters out the water surface reflection of the N background filtered images, and then calculates the light spot centroid positions and corresponding attitude angles in the N stroboscopic light source images when the N stroboscopic light sources in the stroboscopic lamp array (1) are turned on, and obtains the serial numbers of the N stroboscopic light sources according to the light spot centroid positions; the relative installation position relationship between the N stroboscopic light sources is used to obtain the real-time pose of the stroboscopic lamp array (1) relative to the area array detector (4), so as to obtain the real-time pose of the underwater platform A relative to the underwater platform B, and complete the underwater guidance.

6. The anti-jamming underwater guidance method based on an area array detector according to claim 5, characterized in that, Step 2 is specifically: Step 2.1, calibrate the delay of the high-speed photoelectric detector (6), the direct current isolation circuit (7) and the band-pass filter circuit (8); Step 2.2, the high-speed photoelectric detector (6) collects the light-emitting signals of the stroboscopic lamp array (1) and converts them into voltage square wave signals transmitted to the direct current isolation circuit (7); Step 2.3, the direct current isolation circuit (7) and the band-pass filter circuit (8) filter out the direct current bias, signals lower or higher than the preset light-emitting frequency in the voltage square wave signal in sequence to obtain a square wave signal and transmit it to the time sequence translation circuit (9); Step 2.4, the timing shift circuit (9) shifts the square wave signal forward according to the delay of the high-speed photoelectric detector (6), the direct current blocking circuit (7) and the band-pass filter circuit (8), so that the shifted square wave signal is consistent with the timing of the strobe light array (1) turning on and off, a synchronous square wave signal is obtained, and is sent to the frequency multiplication unit (3).

7. The anti-jamming underwater guidance method based on an area array detector according to claim 6, characterized in that, Step 5 is specifically: Step 5.1, two adjacent strobe light array (1) turning on and off strobe light source images corresponding to each strobe light source in 2N strobe light source images are input into the background subtraction module (10) as a group, and the background subtraction module (10) subtracts the strobe light source image when the strobe light array (1) turns on from the strobe light source image when the strobe light array (1) turns off, to obtain N background filtered images; Step 5.2, the in-phase signal preprocessing module (11) converts the N background filtered images into row and signal according to the pixel row, and then draws the row and signal curve from the lowest pixel row. When the row and signal curve appears a row and signal peak value higher than the preset threshold value from bottom to top, and the row and signal first drops below the preset threshold value, the sum signal of the pixel row in the interval where the row and signal is greater than or equal to the preset threshold value is kept, and the sum signal of the remaining pixel row is assigned as 0, to obtain the row and signal of the N filtered images. The row and signal of the N filtered images are converted into column and signal according to the pixel column, to obtain the row and signal of the N filtered images. Step 5.3, the guide operation module (12) calculates the spot centroid position and the corresponding attitude angle in the N filtered images according to the row and signal and the column and signal of the N filtered images, and obtains the serial number of the strobe light source corresponding to the N filtered images according to the spot centroid position, so as to obtain the attitude of the N strobe light sources relative to the area array detector (4). Then, the pose of the strobe light array (1) relative to the area array detector (4) is obtained by combining the relative installation position relationship of the N strobe light sources, so as to obtain the pose of the underwater platform A relative to the underwater platform B, and the underwater guidance is completed.

8. The anti-jamming underwater guidance method based on an area array detector according to claim 7, characterized in that: In step 1, the light-emitting frequency of the strobe light array (1) is 10 Hz, and the turning-on time and the turning-off time of each strobe light source are the same.

9. The anti-jamming underwater guidance method based on an area array detector according to claim 8, characterized in that: In step 5.2, the preset threshold value is 1000.

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