A wireless remote control system and method for underwater robot

Abstract

The present invention relates to the field of wireless communication technology, and discloses a wireless remote control system and method for underwater robots. The method obtains multiple images taken by multiple underwater robots through an underwater processor; corrects the original timestamp according to the brightness in the image to obtain a corrected timestamp; synchronizes multiple images according to the corrected timestamp; sends multiple images with corrected timestamps to a relay communication platform; aggregates multiple images with the same corrected timestamp through the relay communication platform to form an image group; determines the ratio of the number of images using FSO links and RF links in the image group according to the weather forecast results and the brightness level of the image group, and sends them to a remote monitoring terminal through the corresponding communication link according to the ratio of the number of images. The present invention solves the technical problems of image synchronization and optimal link transmission according to brightness by setting light according to the set light and dark conversion law underwater.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless communications, and in particular to a wireless remote control system and method for an underwater robot. Background Art

[0002] With the continuous advancement of technology and the continuous expansion of application scenarios, the collaboration of multiple underwater robots and underwater operation devices will play an important role in more fields. For example, in the fields of deep-sea exploration, underwater archaeology, underwater entertainment, etc., the collaboration of multiple underwater robots will bring greater flexibility and efficiency.

[0003] Due to the complex underwater environment, the interference factors such as fish schools and turbulence appear from time to time, the quality of underwater images is poor, and multiple underwater robots have their own clocks, so it is difficult to align the time of the images taken by multiple underwater robots. Moreover, when transmitting images, due to environmental problems underwater and in the atmosphere, the link quality may be affected, causing packet loss, bit errors and other problems.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a wireless remote control system and method for an underwater robot, which solves the technical problems of image synchronization and optimal link transmission according to brightness by setting light according to a set light and dark change rule underwater.

[0006] In a first aspect, an embodiment of the present invention provides a wireless remote control system for an underwater robot, comprising:

[0007] Multiple underwater robots are used to take real-time photos of underwater targets to be measured from multiple angles to obtain multiple images, and to stamp each image with an original time stamp;

[0008] The underwater lamp is within a set distance from the multiple underwater robots and emits light according to a set light-darkness change rule toward the underwater target;

[0009] an underwater processor connected to the plurality of underwater robots, and configured to acquire the plurality of images; correct the original timestamp according to the brightness in the image to obtain a corrected timestamp; align the plurality of images according to the corrected timestamp; and send the plurality of images with the corrected timestamp to a relay communication platform;

[0010] The relay communication platform aggregates multiple images with the same corrected timestamp to form an image group; determines the ratio of the number of images in the image group using a free space optical communication FSO link and a radio frequency communication RF link according to the weather forecast result and the brightness level of the image group, and sends the images to the remote monitoring terminal through the corresponding communication link according to the ratio of the number of images;

[0011] The remote monitoring terminal is used to perform panoramic stitching on the images in the image group to obtain a full view of the underwater target.

[0012] In a second aspect, an embodiment of the present invention provides a wireless remote control method for an underwater robot, which is applied to any wireless remote control system for an underwater robot, and the method comprises:

[0013] Acquire the multiple images through an underwater processor; correct the original timestamp according to the brightness in the image to obtain a corrected timestamp; synchronize the multiple images according to the corrected timestamp; send the multiple images with the corrected timestamp to a relay communication platform; wherein the underwater target is illuminated by light according to a set light and dark change rule;

[0014] Aggregating multiple images with the same corrected timestamp to form an image group through the relay communication platform; determining the ratio of the number of images in the image group using a free space optical communication FSO link and a radio frequency communication RF link according to the weather forecast result and the brightness level of the image group, and sending the images to the remote monitoring terminal through the corresponding communication link according to the ratio of the number of images;

[0015] The images in the image group are panoramically stitched through the remote monitoring terminal to obtain a full view of the underwater target.

[0016] Compared with the prior art, the present invention has the following technical effects:

[0017] 1. By setting the light according to the light and dark change rules, different brightness changes can be reflected in the image, so that the images taken by different underwater robots can be synchronized according to the changes in the brightness.

[0018] 2. Since underwater visibility is very low, the higher the brightness of the image, the higher the clarity and the better it can reflect the appearance of the underwater target. Therefore, the ratio of data transmitted by the FSO link and the RF link is comprehensively adjusted according to the brightness level of the image group and the weather forecast results. This can ensure that images with higher altitudes are transmitted through links with better quality first, reduce the bit error rate, and improve the quality of the final generated image.

[0019] 3. The present invention provides a novel collaborative scenario of multiple underwater robots, that is, multiple underwater robots take real-time multi-angle photos of underwater targets, and the underwater processor and relay communication platform perform time synchronization and high-quality transmission. The remote monitoring terminal performs panoramic stitching of image groups with the same timestamp to obtain a full picture of the underwater target. Compared with the prior art that can only photograph underwater targets through the patrol of a single underwater robot, the present invention can accurately and timely capture the full picture of the underwater target and the changes in the full picture through multi-robot collaboration.

[0020] 4. This embodiment places underwater lamps underwater and uses a series of calculation methods to simultaneously achieve time alignment of images taken by different underwater robots and high-quality transmission of high-brightness images. The method is simple, effective, and low-cost. It does not require complex image processing algorithms (only brightness is extracted) or satellite timing. The method provided by the present invention can still be implemented when the satellite signal is poor. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 The present invention is a schematic diagram of a wireless remote control system for an underwater robot provided in an embodiment of the present invention.

[0023] Figure 2 The embodiment of the present invention provides a curve for setting the light-dark transformation rule and the brightness statistical value;

[0024] Figure 3 A flowchart of a wireless remote control method for an underwater robot provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0026] Example 1

[0027] This embodiment provides a wireless remote control system for an underwater robot. Figure 1 , including multiple underwater robots, underwater lights, underwater processors, relay communication platforms and remote monitoring terminals. Each component is introduced below.

[0028] Multiple underwater robots are used to take real-time photos of underwater targets to be tested from multiple angles to obtain multiple images, and to stamp each image with an original timestamp. The underwater targets can be organisms or objects, such as reefs and shipwrecks. Each underwater robot has the same structure, including: attitude sensor, depth sensor, central control module, thruster, lighting, switch module, sonar and camera. The central control module has its own real-time clock, and the real-time clocks of different underwater robots are different. The central control module receives images from each sensor, sonar and camera, and sends them to the underwater processor through the switch module. The camera should shoot a series of images in real time toward the underwater target to form an image sequence. The shooting angles of multiple underwater robots are different. When each image is generated, it will be stamped with a timestamp based on the real-time clock of the central control module to which it belongs. For the convenience of description and distinction, the timestamp here is called the original timestamp. It can be seen that the timestamps in the image sequence shot by an underwater robot have a sequence, and the original timestamps of images shot by different underwater robots at the same reference time are likely to be different.

[0029] The underwater lamps and underwater robots are both placed underwater, and the distance between the underwater lamps and the multiple underwater robots is within a set range (for example, 2 meters). If the underwater target is relatively large, multiple underwater lamps can be arranged to ensure that there is an underwater lamp within the set range of each underwater robot. The underwater lamps are facing the underwater target, so that the underwater robot can capture clearer and brighter images. The creativity of this embodiment lies in that the lamps emit light according to a set light and dark conversion rule, the underwater processor is connected to at least one underwater lamp, and synchronously controls the brightness of the light emitted by the lamp according to the set light and dark conversion rule. Among them, the set light and dark conversion rule can be set by oneself, for example, at 10000cd / m 2 ~13000cd / m 2 Increase by 200 to reach 13000cd / m 2 Then decrease by 200 to reach 10000cd / m 2 Then continue to increase, thus forming a gradually brightening and gradually dimming effect. The frequency of lamp brightness change should be greater than or equal to the camera shooting frequency, so that different images are shot at different brightnesses, highlighting the different brightness values ​​in different images.

[0030] The underwater processor is connected to multiple underwater robots to obtain multiple images; that is, multiple underwater robots transmit images to the underwater processor in real time through cables. The underwater processor corrects the original timestamp according to the brightness in the image to obtain a corrected timestamp, which specifically includes the following three steps:

[0031] Step 1: From multiple images, select multiple images to be processed whose original timestamps are within a set time period.

[0032] Assuming there are N underwater robots, the underwater processor receives N image sequences, each of which includes multiple images. The same underwater robot can only take one image at the same time. This embodiment requires synchronization of images in different image sequences, i.e., images taken by different underwater robots.

[0033] Since the light of lamps has a set light-dark change rule, the light-darkness (or brightness) in a short period of time is different, and the real-time clocks of multiple underwater robots are not much different, multiple images of different image sequences within a set period of time (for example, 3s) can be selected as multiple images to be processed for subsequent time synchronization. After these images are synchronized, multiple images to be processed within the next set period of time are synchronized until all images are processed.

[0034] Step 2: For each of the multiple images to be processed, extract the statistical values ​​of all pixel brightness.

[0035] For example, if the number of pixels in each image is M, then the brightness statistics of all pixels are the average, maximum or minimum brightness values ​​of the M pixels, with the average value being preferred.

[0036] Step 3: According to the brightness statistics and the set light and dark transformation rule, multiple target images to be processed taken at the same time are selected from the multiple images to be processed, and the original timestamps are corrected to obtain the corrected timestamps.

[0037] The brightness statistics of an image reflects the brightness of the light shining on the underwater target when it was taken. When the light changes brightness according to the set light-dark transformation law, the brightness statistics of the images taken by the same underwater robot at the same viewing angle should be different, and in the image sequence, the size change of the brightness statistics should be the same as the set light-dark transformation law. Similarly, the brightness statistics of the image sequences taken by all underwater robots are the same as the set light-dark transformation law. It should be noted that, considering that the exposure, aperture and other parameters of the cameras of different underwater robots may be different, and the shooting angles are different, even the images taken at the same reference moment may have different brightness statistics, but when the camera parameters and angles remain unchanged, the change law of the brightness statistics is the same as the set light-dark transformation law.

[0038] Based on the above analysis, for each of the multiple images to be processed taken by the underwater robot, the curve of the change of the brightness statistics over time is determined. According to the matching of the change curve with the set light and dark transformation law, multiple target images to be processed taken by different underwater robots at the same time are selected from the multiple images to be processed.

[0039] Figure 2It is a curve of the setting light and dark transformation law and the brightness statistical value provided by an embodiment of the present invention. The horizontal axis is time t / s, the left vertical axis is the brightness statistical value, the right vertical axis is the brightness of the light emitted by the lamp, and the unit and scale of the vertical axis are omitted. The discrete brightness statistical values ​​are curve fitted, and translated left and right and up and down, so that the change curve of the brightness statistical value of the underwater robot A / B can be overlapped with the change curve of the brightness of the lamp light, and the images corresponding to the two overlapping brightness statistical values ​​are taken at the same time. For the convenience of description and distinction, multiple images taken by different underwater robots at the same time are called target images to be processed. It should be noted that Figure 2 If the change frequency of the light of the lamp is the same as the shooting frequency, a better overlap effect will be presented. When the shooting frequency is low, the curve of the brightness statistics may not completely overlap with the curve of the lamp brightness. In this case, the similarity of the curves can be calculated in real time during the translation process, for example, the difference in the ordinates of two points at the same horizontal coordinate on the two curves is calculated, and the total coordinate difference of all points is added as the similarity of the two curves. When the similarity is the smallest, the curves are considered to overlap.

[0040] Based on the above description, N images taken at each moment are obtained from N image sequences, which are called target images to be processed. Then, in the first case of correcting the timestamp, the corrected timestamp of each target image to be processed is obtained according to the real-time clock of the underwater processor. The underwater processor controls the light and dark changes of the lamp according to its own real-time clock. Therefore, based on the aforementioned overlapping curve, the corrected timestamp of each target image to be processed is set to the timing time of the lamp (i.e., the time of the horizontal axis), that is, the timing time of the underwater processor. In this case, the shooting time of each underwater robot is synchronized with the lamp, but in fact, the underwater robot also consumes time to transmit to the underwater processor, so the second case is proposed: the center value of the original timestamp of multiple target images to be processed is used as the corrected timestamp of each target image to be processed, that is, the shooting time of each underwater robot is synchronized.

[0041] After obtaining the corrected timestamp of each image, multiple images are timed according to the corrected timestamp, thereby obtaining a group of images marked with the same corrected timestamp, called an image group. Then, the underwater robot sends multiple images with corrected timestamps to the relay communication platform.

[0042] The relay communication platform is usually located on the water surface and connected to the underwater processor through a cable, so as to transmit images through wired transmission to avoid signal attenuation and noise in the underwater environment. The relay communication platform aggregates multiple images with the same corrected timestamp to form an image group, thus obtaining image groups at each moment and forming an image group sequence.

[0043] The remote monitoring terminal is generally set up far away from the relay communication platform and needs to be wirelessly transmitted with the relay communication platform. This embodiment uses an FSO / RF hybrid communication link to transmit images. Free space optical (FSO) communication has the characteristics of high data rate, spectrum freedom, easy deployment and high confidentiality, but the channel state is easily affected by weather and atmospheric turbulence. The channel state of the radio frequency (RF) link is rarely affected by fog, but is easily affected by rain. Therefore, the FSO / RF hybrid communication link has begun to receive attention and application. The two links share transceivers, and different types of links use different transceiver apertures. In the prior art, the channel quality is generally determined according to the current weather conditions, and then the data transmission ratio on each link is adjusted. This method can make full use of the advantages of dual links, improve system performance, and ensure the reliability and efficiency of communication. On this basis, this embodiment innovatively considers the image quality. The brightness statistics of each image in the image group are averaged. If the average value is greater than the threshold (for example, 200), the brightness level is high, and the images in the image group are generally brighter; otherwise, the brightness level is low. As we all know, images taken in brighter environments are clearer and have higher image quality, which means that the demand for high channel status links is higher, thereby reducing the loss of high-quality images; low-quality images themselves contain a lot of noise, so links with poor channel status can be accepted. Based on this, the relay communication platform determines the ratio of the number of images in the image group using free space optical communication FSO links and radio frequency communication RF links according to the weather forecast results and the brightness level of the image group, and sends them to the remote monitoring terminal through the corresponding communication link according to the ratio of the number of images.

[0044] Specifically, the channel states of the FSO link and the RF link are first determined according to the weather forecast results, for example, by characterizing them through the bit error rate. For example, it is necessary to predict key parameters such as atmospheric turbulence intensity, visibility, cloud thickness, and precipitation probability, which directly affect the communication performance of the FSO and RF links. For the FSO link, the atmospheric conditions have a particularly significant impact on it, because when the optical signal propagates in free space, it will be affected by various factors such as atmospheric turbulence, attenuation, and pointing errors. Compared with the FSO link, the RF link is less affected by atmospheric conditions, but shadow fading and multipath effects still need to be considered. In actual operation, the data quality of the FSO link and the RF link under different weather conditions can be collected to evaluate the impact on the FSO link and the RF link. Finally, the channel states of the FSO link and the RF link under the current weather forecast results, such as indicators such as the bit error rate, are obtained. When the bit error rate is low (lower than the set threshold), the channel state is excellent, and when the bit error rate is high (higher than the set threshold), the channel state is poor.

[0045] Then, the ratio of the number of images is determined according to the channel status. There is a one-to-one correspondence between the channel status and the number of images, see the table below. Links with good channel status bear more image transmission than links with poor channel status. When both links are good or bad, the ratio of the number of images needs to be determined considering factors such as cost, reliability, and availability, which can be specifically set based on the quality of relevant communication equipment and manual experience.

[0046] Table 1 Preliminary image quantity ratio

[0047]

[0048] The above is the ratio of the number of images determined according to the weather forecast results. If the brightness level of the image group is high, the ratio of the number of images using the link with an excellent channel state will be increased. In other words, if the brightness level of an image group is high, the ratio of the number of images with an excellent channel state in the last column of Table 1 will be increased. The increase can be set by yourself. See Table 2. The ratio of the number of images using the link with an excellent channel state will be increased by 0.5. The ratio of the number of images of links with the same excellent or inferior status will not be adjusted. For example, an image group includes 20 images, and the ratio of the number of images of the FSO link to the RF link is 8.5:1.5. Then, 17 images are transmitted through the FSO link, and the remaining 3 images are transmitted through the RF link.

[0049] Table 2 Ratio of image quantity after adjustment

[0050]

[0051] Regardless of the link used to transmit the image, all images carry a correction timestamp; the remote monitoring terminal is used to perform panoramic stitching of the images in the image group (i.e., images with a unified correction timestamp) to obtain a full view of the underwater target.

[0052] Panoramic stitching technology is a technology that stitches multiple images with overlapping parts (these images are obtained from different times, different perspectives and different cameras) into a seamless panorama or high-resolution image, involving multiple steps such as image projection, feature extraction, feature matching, image transformation, image mapping and image fusion. Since the panoramic stitching technology is relatively mature, this embodiment will not describe the panoramic stitching technology in detail. The remote monitoring terminal is used to display the full picture of the underwater target on the interface, and to send control instructions to multiple underwater robots through the relay communication platform, such as instructions to start shooting and instructions to end shooting.

[0053] Compared with the prior art, the present invention has the following technical effects:

[0054] 1. By setting the light according to the light and dark change rules, different brightness changes can be reflected in the image, so that the images taken by different underwater robots can be synchronized according to the changes in the brightness.

[0055] 2. Since underwater visibility is very low, the higher the brightness of the image, the higher the clarity and the better it can reflect the appearance of the underwater target. Therefore, the ratio of data transmitted by the FSO link and the RF link is comprehensively adjusted according to the brightness level of the image group and the weather forecast results. This can ensure that images with higher altitudes are transmitted through links with better quality first, reduce the bit error rate, and improve the quality of the final generated image.

[0056] 3. The present invention provides a novel collaborative scenario of multiple underwater robots, that is, multiple underwater robots take real-time multi-angle photos of underwater targets, and the underwater processor and relay communication platform perform time synchronization and high-quality transmission. The remote monitoring terminal performs panoramic stitching of image groups with the same timestamp to obtain a full picture of the underwater target. Compared with the prior art that can only photograph underwater targets through the patrol of a single underwater robot, the present invention can accurately and timely capture the full picture of the underwater target and the changes in the full picture through multi-robot collaboration.

[0057] 4. This embodiment places underwater lamps underwater and uses a series of calculation methods to simultaneously achieve time alignment of images taken by different underwater robots and high-quality transmission of high-brightness images. The method is simple, effective, and low-cost. It does not require complex image processing algorithms (only brightness is extracted) or satellite timing. The method provided by the present invention can still be implemented when the satellite signal is poor.

[0058] Example 2

[0059] This embodiment defines the structure of the relay communication platform on the basis of the above embodiment. Specifically, the relay communication platform includes a depth meter and an automatic cable retracting and releasing mechanism.

[0060] Among them, the depth meter is used to measure the underwater depth of the relay communication platform; if the underwater depth exceeds the set value (for example, 0.5 meters), it may affect the performance and reliability of the relay communication platform, and it is necessary to surface. The automatic cable retracting mechanism is controlled to release the cable, one end of the cable is fixed on the automatic cable retracting mechanism, and the other end is fixed on the underwater robot. Therefore, when releasing the cable, the relay communication platform can get rid of the downward pulling force of the underwater robot. The released cable should not be too long to avoid cable entanglement.

[0061] After completing the shooting mission, the relay communication platform retracted the cable, allowing multiple underwater robots to surface.

[0062] The automatic cable retracting and releasing mechanism consists of a controllable motor and a cable wound thereon, and the cable is retracted and released by controlling the rotation of the motor.

[0063] Example 3

[0064] This embodiment provides a wireless remote control method for an underwater robot, which is applied to the wireless remote control system for an underwater robot provided in the above embodiments. Figure 3 , the method includes the following operations:

[0065] S110, acquiring the multiple images through an underwater processor; correcting the original timestamp according to the brightness in the image to obtain a corrected timestamp; synchronizing the multiple images according to the corrected timestamp; sending the multiple images with the corrected timestamp to a relay communication platform; wherein the underwater target is illuminated by light according to a set light and dark change rule.

[0066] S120, aggregating multiple images with the same corrected timestamp to form an image group through the relay communication platform; determining the ratio of the number of images in the image group using a free space optical communication FSO link and a radio frequency communication RF link according to the weather forecast result and the brightness level of the image group, and sending the images to the remote monitoring terminal through the corresponding communication link according to the ratio of the number of images.

[0067] S130. Perform panoramic stitching of the images in the image group through the remote monitoring terminal to obtain a full view of the underwater target.

[0068] The underwater processor, relay communication platform and remote monitoring terminal in this embodiment can execute the steps / processes in the aforementioned embodiments and have corresponding technical effects, which will not be repeated here.

[0069] It should be noted that the terms used in the present invention are only for describing specific embodiments, rather than limiting the scope of the present application. As shown in the present specification, unless the context clearly indicates an exception, the words "one", "a", "a kind of" and / or "the" do not specifically refer to the singular, but may also include the plural. The terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method or device. In the absence of further restrictions, the elements defined by the sentence "include one..." do not exclude the presence of other identical elements in the process, method or device including the elements.

[0070] It should also be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention.

Claims

1. A wireless remote control system for an underwater robot, characterized in that: include: Multiple underwater robots are used to take real-time photos of underwater targets to be measured from multiple angles to obtain multiple images, and to stamp each image with an original time stamp; The underwater lamp is within a set distance from the multiple underwater robots and emits light according to a set light-darkness change rule toward the underwater target; An underwater processor connected to the multiple underwater robots, and configured to obtain the multiple images; and to correct the original timestamp according to the brightness in the image to obtain a corrected timestamp; synchronizing the plurality of images according to the corrected timestamp; sending multiple images with corrected time stamps to a relay communication platform; The relay communication platform aggregates multiple images with the same corrected timestamp to form an image group; determines the ratio of the number of images in the image group using a free space optical communication FSO link and a radio frequency communication RF link according to the weather forecast result and the brightness level of the image group, and sends the images to the remote monitoring terminal through the corresponding communication link according to the ratio of the number of images; The remote monitoring terminal is used to perform panoramic stitching on the images in the image group to obtain a full view of the underwater target.

2. The system according to claim 1, characterized in that The step of correcting the original timestamp according to the brightness in the image to obtain a corrected timestamp includes: Selecting, from the plurality of images, a plurality of images to be processed whose original timestamps are within a set time period; For each of the plurality of images to be processed, extracting statistical values ​​of brightness of all pixels; According to the brightness statistics and the set light-dark transformation rule, a plurality of target images to be processed taken at the same time are selected from the plurality of images to be processed, and the original timestamps are corrected to obtain corrected timestamps.

3. The system according to claim 2, characterized in that The statistical value includes an average value, a maximum value or a minimum value; According to the brightness statistics and the set light-dark transformation rule, a plurality of target images to be processed taken at the same time are selected from the plurality of images to be processed, including: For each of the multiple images to be processed taken by the underwater robot, determine a curve of brightness statistics changing over time; According to the matching of the variation curve and the set light-dark transformation rule, a plurality of target images to be processed taken by different underwater robots at the same time are selected from the plurality of images to be processed.

4. The system according to claim 3, characterized in that The step of correcting the original timestamp to obtain a corrected timestamp includes: Obtaining a corrected timestamp of each target image to be processed according to the real-time clock of the underwater processor; or, The central value of the original timestamps of the multiple target images to be processed is used as the corrected timestamp of each target image to be processed.

5. The system according to claim 4, characterized in that The brightness level includes high and low; The determining, according to the weather forecast result and the brightness level of the image group, the ratio of the number of images using the free space optical communication FSO link and the radio frequency communication RF link in the image group includes: Determine the channel status of the FSO link and the RF link according to the weather forecast result, and determine the image quantity ratio according to the channel status; the channel status includes good and bad; If the brightness level of the image group is high, the proportion of the number of images using the link with the best channel status is increased.

6. The system according to claim 5, characterized in that The underwater robot comprises: a posture sensor, a depth sensor, a central control module, a thruster, a lighting lamp, a switch module, a sonar and a camera.

7. The system according to any one of claims 1 to 6, characterized in that: The relay communication platform includes a depth gauge and an automatic cable retracting and releasing mechanism; The depth meter is used to measure the underwater depth of the relay communication platform; If the underwater depth exceeds a set value, the relay communication platform controls the automatic cable retracting and releasing mechanism to release the cable; one end of the cable is fixed on the automatic cable retracting and releasing mechanism, and the other end is fixed on the underwater robot.

8. The system according to any one of claims 1 to 6, characterized in that: The remote monitoring terminal is used to display the overall picture of the underwater target on an interface, and to send control instructions to multiple underwater robots through the relay communication platform.

9. A wireless remote control method for an underwater robot, applied to the wireless remote control system for an underwater robot according to any one of claims 1 to 8, characterized in that: The method comprises: Acquire the multiple images through an underwater processor; correct the original timestamp according to the brightness in the image to obtain a corrected timestamp; synchronize the multiple images according to the corrected timestamp; send the multiple images with the corrected timestamp to a relay communication platform; wherein the underwater target is illuminated by light according to a set light and dark change rule; Aggregating multiple images with the same corrected timestamp to form an image group through the relay communication platform; determining the ratio of the number of images in the image group using a free space optical communication FSO link and a radio frequency communication RF link according to the weather forecast result and the brightness level of the image group, and sending the images to the remote monitoring terminal through the corresponding communication link according to the ratio of the number of images; The images in the image group are panoramically stitched through the remote monitoring terminal to obtain a full view of the underwater target.

Images