Ship-shore data lightweight communication system and method based on hybrid compression algorithm

Abstract

The invention discloses a ship-shore data lightweight communication system and method based on a hybrid compression algorithm, and relates to the technical field of ship-shore data communication, and the system comprises a main control processing module which is used for obtaining ship navigation data suitable for lossy compression and ship navigation data suitable for lossless compression; the data compression module is used for obtaining corresponding ship navigation data adopting lossy compression and ship navigation data adopting lossless compression; the wireless transmission module is used for transmitting the ship navigation data subjected to lossy compression and the ship navigation data subjected to lossless compression to the shore end monitoring module through a wireless channel; and the shore end monitoring module is used for correspondingly decompressing the ship navigation data subjected to lossy compression and the ship navigation data subjected to lossless compression. According to the invention, the pressure of network load and equipment power consumption caused by large data transmission between the ship and the shore is solved, and the safety and reliability of ship-shore data communication are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of ship-shore data communication, and in particular to a ship-shore data lightweight communication system and method based on a hybrid compression algorithm. Background Art

[0002] In the field of shipping, with the rapid development of the world economy and global trade, maritime transport, as a basic and service industry of the world economy, provides important support and guarantee for the development of the world economy. At the same time, as humans continue to increase the development and utilization of marine resources, the number of ocean-going transport ships and offshore fishing vessels, exploration ships, water operation ships and other types of ships continues to increase, and water traffic activities are becoming increasingly busy and complex, posing huge challenges to ship supervision and navigation safety. As an indispensable data communication in this field, continuous data communication between ships and shores is the most basic guarantee condition for the safe navigation of ships. Therefore, the development of ship-shore data communication technology is of great significance to the growing shipping mission.

[0003] At present, in the process of data communication between ship and shore, combined with the actual situation of ship navigation, the data that needs to be transmitted include ship navigation data, engine room data, meteorological data, ocean current data, etc., so that the shore platform can continuously monitor and analyze the ship's operating status and play a role in support and ship management. Due to the particularity of ship navigation, data communication between ship and shore can only be achieved by wireless communication. In the process of continuous data transmission and reception, the high network load and equipment power consumption of continuous data collection on ships are very likely to cause serious problems such as information blocking and information loss.

[0004] In order to eliminate the increased pressure on network load and equipment power consumption caused by the huge amount of data interaction during data transmission and reception between ship and shore, technical personnel in this field have been seeking effective compression methods for data communication between ship and shore, so as to reduce the amount of data in the transmission process during continuous data transmission and reception between ship and shore, and ensure the quality and reliability of transmitted data. Summary of the invention

[0005] The purpose of the present invention is to provide a ship-shore data lightweight communication system and method based on a hybrid compression algorithm. The hybrid compression algorithm is used to compress a large amount of original data with a lossy or lossless algorithm according to the differences in data format and compression requirements of each application scenario. The data is decompressed and reconstructed on the shore side according to the same algorithm to achieve "data lightweight". Only the lightweight data is transmitted and received, which solves the pressure of network load and equipment power consumption caused by the transmission of large amounts of data between ship and shore, and ensures the safety and reliability of ship-shore data communication.

[0006] The lightweight ship-shore data communication system based on the hybrid compression algorithm designed by the present invention to achieve one of the above purposes is special in that it includes:

[0007] A main control processing module is used to pre-process the ship navigation data to obtain the pre-processed ship navigation data, and classify the pre-processed ship navigation data based on compression rate limit to obtain the ship navigation data suitable for lossy compression and the ship navigation data suitable for lossless compression;

[0008] A data compression module, used to perform lossy compression on the ship navigation data suitable for lossy compression, and to perform lossless compression on the ship navigation data suitable for lossless compression, so as to obtain corresponding ship navigation data using lossy compression and ship navigation data using lossless compression;

[0009] A wireless transmission module, used for transmitting the ship navigation data using lossy compression and the ship navigation data using lossless compression to the shore monitoring module through a wireless channel;

[0010] The shore monitoring module is used to decompress the ship navigation data using lossy compression and the ship navigation data using lossless compression accordingly.

[0011] Furthermore, the system also includes a ship data acquisition module, which is used to transmit the collected ship navigation data to the main control processing module; the ship navigation data collected by the ship data acquisition module includes: ship engine operating status data, ship position information data, ship engine emission data and ship navigation environment data.

[0012] Furthermore, the preprocessing of the ship navigation data by the main control processing module includes: sorting the ship navigation data collected at intervals according to the time of collection; performing a difference process on the original data of the ship navigation data collected at the current moment and the original data of the ship navigation data collected at the previous moment to obtain the preprocessed ship navigation data, which is specifically described in the following formula:

[0013]

[0014] Among them, t represents the current time, t 0 represents the initial time, f t [x 1 ,x 2 ,…,x n ] represents the original data of the ship navigation data collected at the current time t, f t-1 [x 1 ,x 2 ,…,x n ] represents the original data of the ship navigation data collected at the previous moment of the current moment t, g t [y1 ,y 2 ,…,y n ] represents the preprocessed ship navigation data; judge whether the current time t is the initial time t 0 , if the current time t is the initial time t 0 , the preprocessed ship navigation data is the original data of the ship navigation data collected at the current time t; if the current time t is not the initial time t 0 When , the preprocessed ship navigation data is the difference between the original data of the ship navigation data collected at the current time t and the original data of the ship navigation data collected at the previous time t.

[0015] Furthermore, the main control processing module classifies the ship navigation data by: classifying the pre-processed ship navigation data based on the compression rate limit, and classifying the pre-processed ship navigation data based on the mixed compression rate of the total data. Determine the data volume ratio of lossless compressed ship navigation data and lossy compressed ship navigation data, and the mixed compression ratio of the total data The calculation is done using the following formula:

[0016]

[0017] Where a represents the data volume of ship navigation data using lossless compression, b represents the data volume dynamically adjusted according to the compression ratio, c represents the data volume of ship navigation data using lossy compression, x represents the data compression ratio of ship navigation data using lossless compression, y represents the data compression ratio dynamically adjusted according to the compression ratio, z represents the data compression ratio of ship navigation data using lossy compression, R 0 Indicates the compression rate limit of the total data; according to the importance of the data in the ship navigation data, the ship navigation data is prioritized, and lossless compression is used for the ship navigation data that needs to ensure integrity and accuracy, and lossy compression is used for the ship navigation data that needs to ensure storage and transmission efficiency; based on the priority assessment of the ship navigation data, the data volume and compression rate of the ship navigation data using lossless compression and the ship navigation data using lossless compression are calculated to obtain the mixed compression rate of the initial total data The mixed compression ratio of the initial total data obtained The limit of the total data compression ratio R 0 Compare and judge, when the mixed compression ratio of the initial total data Greater than the total data compression ratio limit R 0 When the mixed compression rate of the total data is 1, the data volume b dynamically adjusted according to the compression rate is adjusted to the data volume a of the ship navigation data using lossless compression, and the data volume a of the ship navigation data using lossless compression is increased. Meet the limit value R of the total data compression ratio 0 , and obtain the data volume of the ship navigation data using lossless compression and the data volume of the ship navigation data using lossy compression.

[0018] As a preferred solution, the data compression module performs lossless compression of ship navigation data, including: initializing a dictionary for storing all characters of ship navigation data and their corresponding code values; reading the first character in the ship navigation data using lossless compression, and setting it as a prefix character; reading the next character in the ship navigation data using lossless compression, and setting it as a suffix character, combining the prefix character and the suffix character to generate a combined character; determining by looking up the combined character in the dictionary, if the combined character exists in the dictionary, setting it as a new prefix character, and continuing to read the next character in the ship navigation data using lossless compression, combining it with the new prefix character to generate a new combined character, if the combined character does not exist in the dictionary, storing the code value corresponding to the combined character, adding the combined character to the dictionary, and setting the next character as the prefix character; reading all characters in the ship navigation data using lossless compression in sequence until all characters and their corresponding code values ​​are contained in the dictionary, and completing the compression of the ship navigation data using lossless compression.

[0019] Furthermore, the data compression module performs lossy compression of the ship navigation data, including: dividing the lossy compressed ship navigation data into several segments according to data features; performing linear fitting on the lossy compressed ship navigation data of the divided several segments, so that the value of the mean square error MSE (a, b) of the fitting line reaches a minimum value, and the value of the mean square error MSE (a, b) of the fitting line is calculated using the following formula:

[0020]

[0021] Among them, a represents the linear regression slope coefficient, b represents the linear regression intercept coefficient, and t i Indicates that the parameter value is y i The time series of the ship navigation data at that time is iteratively updated by using the fitting straight line of the lossy compressed ship navigation data of the segmented segments, as described in the following formula:

[0022]

[0023] Among them, a represents the linear regression slope coefficient, b represents the linear regression intercept coefficient, and a 0 represents the linear regression slope coefficient in the current iteration, b 0 Represents the linear regression intercept coefficient in the current iteration, a * represents the linear regression slope coefficient after iterative update, b * represents the linear regression intercept coefficient after iterative update, It represents the rate of change of the mean square error to the linear regression slope coefficient, It represents the rate of change of the mean square error to the linear regression intercept coefficient; after each iteration, the number of iterations and the value of the mean square error of the fitting line MSE(a,b) are judged respectively. If the number of iterations of the fitting line of the segmented ship navigation data using lossy compression reaches the set number of iterations or the value of the mean square error of the fitting line MSE(a,b) reaches the minimum, the iteration is terminated, and the optimal linear regression slope coefficient a after iterative update of each segment of the ship navigation data using lossy compression is stored. * and the linear regression intercept coefficient b * ; Make each segment of ship navigation data using lossy compression updated through iteration to obtain the optimal linear regression slope coefficient a * and the linear regression intercept coefficient b * Approximately, compression of ship navigation data using lossy compression is accomplished.

[0024] As a preferred solution, the system also includes a data storage module, which is used to back up the ship navigation data by copying the ship navigation data in the main control processing module to the data storage module, thereby preventing the ship navigation data from being damaged and lost due to equipment failure or unexpected power outage; the data storage module is also used to verify the ship navigation data by comparing the ship navigation data in the data storage module with the ship navigation data in the main control processing module, thereby ensuring the quality and reliability of the ship navigation data transmission.

[0025] Furthermore, the shore monitoring module includes a decompression module and a database; the decompression module sequentially reads the code values ​​of the ship navigation data using lossless compression through a dictionary of all characters and their corresponding code values ​​generated by the ship navigation data using lossless compression, searches the dictionary for characters corresponding to the ship navigation data using lossless compression through the code values, and obtains the lossless data of the ship navigation data; the decompression module also divides the ship navigation data using lossy compression into several segments according to data features, and for each segment of the ship navigation data using lossy compression, the optimal linear regression slope coefficient a after iterative update according to the approximate representation * and the linear regression intercept coefficient b * Data reconstruction is performed and data segments are spliced ​​in segmented order to obtain lossy data of ship navigation data; the database parses and stores the decompressed ship navigation data, so that the platform can determine the operating status and position of the ship.

[0026] The lightweight ship-shore data communication method based on the hybrid compression algorithm designed by the present invention to achieve the second purpose above is special in that it includes the following steps:

[0027] Transmit the collected ship navigation data to the main control processing module;

[0028] Preprocessing the ship navigation data to obtain preprocessed ship navigation data, and classifying the preprocessed ship navigation data based on compression rate limits to obtain ship navigation data suitable for lossy compression and ship navigation data suitable for lossless compression;

[0029] Performing lossy compression on the ship navigation data suitable for lossy compression, and performing lossless compression on the ship navigation data suitable for lossless compression, to obtain corresponding ship navigation data using lossy compression and ship navigation data using lossless compression;

[0030] Back up and verify ship navigation data;

[0031] Transmitting the ship navigation data using lossy compression and the ship navigation data using lossless compression to a shore monitoring module through a wireless channel;

[0032] The ship navigation data using lossy compression and the ship navigation data using lossless compression are decompressed accordingly.

[0033] A computing device designed by the present invention to achieve the third objective above includes a processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other via the communication bus;

[0034] The memory is used to store at least one executable instruction, and the executable instruction enables the processor to execute operations corresponding to the above-mentioned ship-shore data lightweight communication method based on the hybrid compression algorithm.

[0035] The present invention has the following beneficial effects:

[0036] (1) The ship-shore data lightweight communication system and method based on the hybrid compression algorithm significantly improves the efficiency and reliability of data transmission between the ship and the shore by preprocessing the ship's navigation data and using a hybrid compression algorithm based on the compression rate limit. Data preprocessing reduces data redundancy, and the hybrid compression algorithm combines LZW lossless compression and piecewise linear fitting lossy compression to effectively reduce the data volume, making it possible to more efficiently utilize bandwidth resources during transmission and reducing the burden of data transmission.

[0037] (2) The ship-shore data lightweight communication system and method based on the hybrid compression algorithm reduces the communication cost and energy consumption by reducing the bandwidth requirements for data transmission. A large amount of ship navigation data is classified based on compression rate restrictions, and the storage volume of the ship navigation data after lossy or lossless compression is significantly reduced, achieving "data lightweight". Only the lightweight data is transmitted, and lossless reconstruction is performed on the shore according to the same model, reducing the actual amount of data that needs to be transmitted, thereby significantly reducing communication costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The module diagram of a lightweight ship-shore data communication system based on a hybrid compression algorithm.

[0039] Figure 2 The present invention is a schematic diagram of the working process of a lightweight ship-to-shore data communication system based on a hybrid compression algorithm.

[0040] Figure 3 The present invention is a flowchart of a method for lightweight communication of ship-shore data based on a hybrid compression algorithm.

[0041] Figure 4 Schematic diagram of the flow of lossless compression algorithm.

[0042] Figure 5 The figure is a schematic diagram of the structure of a computing device of the present invention. DETAILED DESCRIPTION

[0043] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0044] Figure 1 FIG. 4 shows a module schematic diagram of a ship-to-shore data lightweight communication system based on a hybrid compression algorithm according to an embodiment of the present invention. Figure 1 As shown, the system includes:

[0045] The ship data acquisition module 1 is used to transmit the collected ship navigation data to the main control processing module 2

[0046] The main control processing module 2 is used to pre-process the ship navigation data to obtain the pre-processed ship navigation data, and classify the pre-processed ship navigation data based on the compression rate limit to obtain the ship navigation data suitable for lossy compression and the ship navigation data suitable for lossless compression;

[0047] The data compression module 3 is used to perform lossy compression on the ship navigation data suitable for lossy compression, and to perform lossless compression on the ship navigation data suitable for lossless compression, so as to obtain corresponding ship navigation data using lossy compression and ship navigation data using lossless compression;

[0048] The data storage module 4 is used to back up and verify the ship's navigation data;

[0049] The wireless transmission module 5 is used to transmit the ship navigation data using lossy compression and the ship navigation data using lossless compression to the shore monitoring module through a wireless channel;

[0050] The shore monitoring module 6 is used to decompress the ship navigation data using lossy compression and the ship navigation data using lossless compression accordingly.

[0051] Figure 2 FIG. 4 shows a schematic diagram of the working process of a ship-to-shore data lightweight communication system based on a hybrid compression algorithm according to an embodiment of the present invention. Figure 2 As shown, the system also includes:

[0052] The ship navigation data collected by the ship data collection module 1 includes: ship engine operation status data, ship position information data, ship engine emission data and ship navigation environment data.

[0053] The data storage module 4 is used to back up the ship navigation data by copying the ship navigation data in the main control processing module 2 to the data storage module 4, thereby preventing the ship navigation data from being damaged or lost due to equipment failure or accidental power outage; the data storage module 4 is also used to verify the ship navigation data by comparing the ship navigation data in the data storage module 4 with the ship navigation data in the main control processing module 2, thereby ensuring the quality and reliability of the ship navigation data transmission.

[0054] The shore monitoring module 6 includes a decompression module and a database; the decompression module sequentially reads the code values ​​of the ship navigation data using lossless compression through a dictionary of all characters and their corresponding code values ​​generated by the ship navigation data using lossless compression, searches the dictionary for characters corresponding to the ship navigation data using lossless compression through the code values, and obtains the lossless data of the ship navigation data; the decompression module also extracts the optimal linear regression slope coefficient a after iterative update of each segment of the ship navigation data using lossy compression according to the data features of the ship navigation data using lossy compression. * and the linear regression intercept coefficient b * Data reconstruction is performed and data segments are spliced ​​in segmented order to obtain lossy data of ship navigation data; the database parses and stores the decompressed ship navigation data, so that the platform can determine the operating status and position of the ship.

[0055] Specifically, the preprocessing of the ship navigation data by the main control processing module 2 includes: sorting the ship navigation data collected at intervals according to the time of collection; performing a difference process on the original data of the ship navigation data collected at the current moment and the original data of the ship navigation data collected at the previous moment to obtain the preprocessed ship navigation data, which is specifically described in the following formula:

[0056]

[0057] Among them, t represents the current time, t 0 represents the initial time, f t [x 1 ,x 2 ,…,x n ] represents the original data of the ship navigation data collected at the current time t, f t-1 [x 1 ,x 2 ,…,x n ] represents the original data of the ship navigation data collected at the previous moment of the current moment t, g t [y 1 ,y 2 ,…,y n ] represents the preprocessed ship navigation data; judge whether the current time t is the initial time t 0 , if the current time t is the initial time t 0 , the preprocessed ship navigation data is the original data of the ship navigation data collected at the current time t; if the current time t is not the initial time t 0 When , the preprocessed ship navigation data is the difference between the original data of the ship navigation data collected at the current time t and the original data of the ship navigation data collected at the previous time of the current time t, thereby improving the efficiency of data processing.

[0058] Specifically, the main control processing module 2 classifies the ship navigation data by: classifying the pre-processed ship navigation data based on the compression rate limit, and classifying the pre-processed ship navigation data based on the mixed compression rate of the total data. Determine the data volume ratio of lossless compressed ship navigation data and lossy compressed ship navigation data, and the mixed compression ratio of the total data The calculation is done using the following formula:

[0059]

[0060] Where a represents the data volume of ship navigation data using lossless compression, b represents the data volume dynamically adjusted according to the compression ratio, c represents the data volume of ship navigation data using lossy compression, x represents the data compression ratio of ship navigation data using lossless compression, y represents the data compression ratio dynamically adjusted according to the compression ratio, z represents the data compression ratio of ship navigation data using lossy compression, R 0 Indicates the compression rate limit of the total data; according to the importance of the data in the ship navigation data, the ship navigation data is prioritized, and lossless compression is used for the ship navigation data that needs to ensure integrity and accuracy, and lossy compression is used for the ship navigation data that needs to ensure storage and transmission efficiency; based on the priority assessment of the ship navigation data, the data volume and compression rate of the ship navigation data using lossless compression and the ship navigation data using lossless compression are calculated to obtain the mixed compression rate of the initial total data The mixed compression ratio of the initial total data obtained The limit of the total data compression ratio R 0 Compare and judge, when the mixed compression ratio of the initial total data Greater than the total data compression ratio limit R 0 When the mixed compression rate of the total data is 1, the data volume b dynamically adjusted according to the compression rate is adjusted to the data volume a of the ship navigation data using lossless compression, and the data volume a of the ship navigation data using lossless compression is increased. Meet the limit value R of the total data compression ratio 0 , and obtain the data volume of the ship navigation data using lossless compression and the data volume of the ship navigation data using lossy compression.

[0061] The data compression module 3 performs lossless compression of the ship navigation data, including: initializing a dictionary for storing all characters of the ship navigation data and their corresponding code values; reading the first character in the ship navigation data using lossless compression, and setting it as a prefix character; reading the next character in the ship navigation data using lossless compression, and setting it as a suffix character, combining the prefix character and the suffix character to generate a combined character; determining by looking up the combined character in the dictionary, if the combined character exists in the dictionary, setting it as a new prefix character, and continuing to read the next character in the ship navigation data using lossless compression, combining it with the new prefix character to generate a new combined character, if the combined character does not exist in the dictionary, storing the code value corresponding to the combined character, adding the combined character to the dictionary, and setting the next character as the prefix character; reading all characters in the ship navigation data using lossless compression in sequence until all characters and their corresponding code values ​​are contained in the dictionary, and completing the compression of the ship navigation data using lossless compression.

[0062] The data compression module 3 performs lossy compression on the ship navigation data, including: dividing the lossy compressed ship navigation data into several segments according to data characteristics; performing linear fitting on the lossy compressed ship navigation data of the divided segments, so that the mean square error value MSE(a, b) of the fitting line reaches the minimum value, and the mean square error value MSE(a, b) of the fitting line is calculated by the following formula:

[0063]

[0064] Among them, a represents the linear regression slope coefficient, b represents the linear regression intercept coefficient, and t i Indicates that the parameter value is y i The time series of the ship navigation data at that time is iteratively updated by using the fitting straight line of the lossy compressed ship navigation data of the segmented segments, as described in the following formula:

[0065]

[0066] Among them, a represents the linear regression slope coefficient, b represents the linear regression intercept coefficient, and a 0 represents the linear regression slope coefficient in the current iteration, b 0 Represents the linear regression intercept coefficient in the current iteration, a * represents the linear regression slope coefficient after iterative update, b * represents the linear regression intercept coefficient after iterative update, It represents the rate of change of the mean square error to the linear regression slope coefficient, It represents the rate of change of the mean square error to the linear regression intercept coefficient; after each iteration, the number of iterations and the value of the mean square error of the fitting line MSE(a,b) are judged respectively. If the number of iterations of the fitting line of the segmented ship navigation data using lossy compression reaches the set number of iterations or the value of the mean square error of the fitting line MSE(a,b) reaches the minimum, the iteration is terminated, and the optimal linear regression slope coefficient a after iterative update of each segment of the ship navigation data using lossy compression is stored. * and the linear regression intercept coefficient b * ; Through multiple iterations of the linear regression slope coefficient a and the linear regression intercept coefficient b, the optimal balance between data compression and reconstruction accuracy is achieved, and at the same time, each segment of ship navigation data using lossy compression is iteratively updated to obtain the optimal linear regression slope coefficient a * and the linear regression intercept coefficient b * Approximate representation, thereby greatly reducing the resources required for data storage and transmission, and completing the compression of ship navigation data using lossy compression.

[0067] Figure 3FIG. 4 is a flow chart showing a method for lightweight communication of ship-to-shore data based on a hybrid compression algorithm according to an embodiment of the present invention. Figure 3 As shown, the method comprises the following steps:

[0068] Step 1: Transmit the collected ship navigation data to the main control processing module;

[0069] Step 2: preprocessing the ship navigation data to obtain preprocessed ship navigation data, and classifying the preprocessed ship navigation data based on compression rate limit to obtain ship navigation data suitable for lossy compression and ship navigation data suitable for lossless compression;

[0070] Step 3: Lossy compression is performed on the ship navigation data suitable for lossy compression, and lossless compression is performed on the ship navigation data suitable for lossless compression, so as to obtain corresponding ship navigation data using lossy compression and ship navigation data using lossless compression;

[0071] Step 4: Back up and verify the ship's navigation data;

[0072] Step 5: Transmitting the lossy compressed ship navigation data and the lossless compressed ship navigation data to the shore monitoring module through a wireless channel;

[0073] Step 6: Decompress the lossy compressed ship navigation data and the lossless compressed ship navigation data accordingly.

[0074] Figure 4 A schematic diagram of the process of lossless compression algorithm is shown, such as Figure 4 As shown, the algorithm flow includes: inputting ship navigation data that needs to be losslessly compressed; reading the ship navigation data in sequence according to the first-in-first-out data queue management order; using the LZW lossless compression algorithm to losslessly compress the input ship navigation data, and generating a dictionary of all the character strings of the ship navigation data and their corresponding coding values ​​during the compression process; dynamically updating the dictionary according to whether the coding value has been added to the dictionary during the compression process; and outputting a dictionary of all the character strings of the ship navigation data and their corresponding coding values.

[0075] Figure 5 A schematic diagram of the structure of a computing device according to an embodiment of the present invention is shown. The specific embodiment of the present invention does not limit the specific implementation of the computing device.

[0076] like Figure 5 As shown, the computing device may include: a processor, a communication interface, a memory, and a communication bus.

[0077] Wherein: the processor, the communication interface, and the memory communicate with each other via a communication bus.

[0078] Communication interface, used to communicate with other devices such as client or other server network elements.

[0079] The processor is used to execute the program, and specifically can execute the relevant steps in the embodiment of the ship-to-shore communication method in the above-mentioned ship management system.

[0080] Specifically, the program may include program codes including computer operation instructions.

[0081] The processor may be a central processing unit (CPU), or a specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present invention. The one or more processors included in the computing device may be processors of the same type, such as one or more CPUs; or processors of different types, such as one or more CPUs and one or more ASICs.

[0082] The memory is used to store programs. The memory may include a high-speed RAM memory, and may also include a non-volatile memory, such as at least one disk memory.

[0083] The program can be specifically used to enable the processor to execute the ship-to-shore data lightweight communication method based on the hybrid compression algorithm in any of the above-mentioned method embodiments. The specific implementation of each step in the program can refer to the corresponding descriptions in the corresponding steps and units in the above-mentioned ship-to-shore data lightweight communication system and method embodiment based on the hybrid compression algorithm, which will not be repeated here. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process of the above-described equipment and modules can refer to the corresponding process description in the aforementioned method embodiment, which will not be repeated here.

[0084] The algorithm and display provided herein are not inherently related to any particular computer, virtual system or other device. Various general purpose systems can also be used together with the teachings based on this. According to the above description, it is obvious that the structure required for constructing such systems. In addition, the present invention is not directed to any specific programming language either. It should be understood that various programming languages ​​can be utilized to realize the content of the present invention described herein, and the description of the above specific languages ​​is for disclosing the best mode of the present invention.

[0085] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0086] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting the intention that the claimed invention requires more features than those expressly recited in each claim. Rather, as reflected in the claims, inventive aspects lie in less than all of the features of the individual embodiments previously disclosed. Therefore, the claims that follow the detailed description are hereby expressly incorporated into the detailed description, with each claim itself serving as a separate embodiment of the present invention.

Claims

1. A ship-shore data lightweight communication system based on a hybrid compression algorithm, characterized in that: include: A main control processing module is used to pre-process the ship navigation data to obtain the pre-processed ship navigation data, and classify the pre-processed ship navigation data based on compression rate limit to obtain the ship navigation data suitable for lossy compression and the ship navigation data suitable for lossless compression; A data compression module, used to perform lossy compression on the ship navigation data suitable for lossy compression, and to perform lossless compression on the ship navigation data suitable for lossless compression, so as to obtain corresponding ship navigation data using lossy compression and ship navigation data using lossless compression; A wireless transmission module, used for transmitting the ship navigation data using lossy compression and the ship navigation data using lossless compression to the shore monitoring module through a wireless channel; The shore monitoring module is used to decompress the ship navigation data using lossy compression and the ship navigation data using lossless compression accordingly.

2. The ship-shore data lightweight communication system based on hybrid compression algorithm according to claim 1 is characterized in that: It also includes a ship data acquisition module, which is used to transmit the collected ship navigation data to the main control processing module; The ship navigation data collected by the ship data collection module includes: ship engine operation status data, ship position information data, ship engine emission data and ship navigation environment data.

3. The ship-shore data lightweight communication system based on hybrid compression algorithm according to claim 1 is characterized in that: The preprocessing of the ship navigation data by the main control processing module includes: sorting the ship navigation data collected at intervals according to the time of collection; performing a difference process between the original data of the ship navigation data collected at the current time and the original data of the ship navigation data collected at the previous time to obtain the preprocessed ship navigation data, which is specifically described in the following formula: Among them, t represents the current time, t0 represents the initial time, and f t [x1, x2, …, x n ] represents the original data of the ship navigation data collected at the current time t, f t-1 [x1, x2, …, x n ] represents the original data of the ship navigation data collected at the previous moment of the current moment t, g t [y1, y2, …, y n ] represents the preprocessed ship navigation data; it is determined whether the current moment t is the initial time t0. If the current moment t is the initial time t0, the preprocessed ship navigation data is the original data of the ship navigation data collected at the current moment t; if the current moment t is not the initial time t0, the preprocessed ship navigation data is the difference between the original data of the ship navigation data collected at the current moment t and the original data of the ship navigation data collected at the moment before the current moment t.

4. The ship-shore data lightweight communication system based on hybrid compression algorithm according to claim 1 is characterized in that: The main control processing module classifies the ship navigation data by: classifying the pre-processed ship navigation data based on the compression rate limit, Determine the data volume ratio of lossless compressed ship navigation data and lossy compressed ship navigation data, and the mixed compression ratio of the total data The calculation is done using the following formula: Wherein, a represents the data volume of ship navigation data using lossless compression, b represents the data volume dynamically adjusted according to the compression ratio, c represents the data volume of ship navigation data using lossy compression, x represents the data compression ratio of ship navigation data using lossless compression, y represents the data compression ratio dynamically adjusted according to the compression ratio, z represents the data compression ratio of ship navigation data using lossy compression, and R0 represents the compression ratio limit of the total data; according to the importance of the data in the ship navigation data, the priority of the ship navigation data is evaluated, and the ship navigation data that needs to ensure integrity and accuracy adopts lossless compression, and the ship navigation data that needs to ensure storage and transmission efficiency adopts lossy compression; based on the priority evaluation of the ship navigation data, the data volume and compression ratio of the ship navigation data using lossless compression and the ship navigation data using lossless compression are calculated to obtain the mixed compression ratio of the initial total data. The mixed compression ratio of the initial total data obtained Compare with the limit value R0 of the total data compression rate to determine when the initial total data mixed compression rate When the total data compression rate is greater than the limit value R0, the mixed compression rate of the total data is increased by adjusting the data volume b dynamically adjusted according to the compression rate to the data volume a of the ship navigation data using lossless compression, and increasing the data volume a of the ship navigation data using lossless compression. The limit value R0 of the total data compression rate is met, and the data volume of the ship navigation data using lossless compression and the data volume of the ship navigation data using lossy compression are obtained.

5. The ship-shore data lightweight communication system based on hybrid compression algorithm according to claim 1 is characterized in that: The data compression module performs lossless compression on ship navigation data, including: initializing a dictionary for storing all characters of ship navigation data and their corresponding code values; reading the first character in the ship navigation data using lossless compression, and setting it as a prefix character; reading the next character in the ship navigation data using lossless compression, and setting it as a suffix character, combining the prefix character and the suffix character to generate a combined character; determining by searching the combined character in the dictionary, if the combined character exists in the dictionary, setting it as a new prefix character, and continuing to read the next character in the ship navigation data using lossless compression, combining it with the new prefix character to generate a new combined character, if the combined character does not exist in the dictionary, storing the code value corresponding to the combined character, adding the combined character to the dictionary, and setting the next character as the prefix character; reading all characters in the ship navigation data using lossless compression in sequence until all characters and their corresponding code values ​​are included in the dictionary, and completing the compression of the ship navigation data using lossless compression.

6. The ship-shore data lightweight communication system based on hybrid compression algorithm according to claim 1 is characterized in that: The data compression module performs lossy compression on the ship navigation data, including: dividing the lossy compressed ship navigation data into several segments according to data features; performing linear fitting on the lossy compressed ship navigation data of the divided segments, so that the mean square error value MSE(a, b) of the fitting line reaches the minimum value, and the mean square error value MSE(a, b) of the fitting line is calculated by the following formula: Among them, a represents the linear regression slope coefficient, b represents the linear regression intercept coefficient, and t i Indicates that the parameter value is y i The time series of the ship navigation data at that time is iteratively updated by using the fitting straight line of the lossy compressed ship navigation data of the segmented segments, as described in the following formula: Among them, a represents the linear regression slope coefficient, b represents the linear regression intercept coefficient, a0 represents the linear regression slope coefficient in the current iteration, b0 represents the linear regression intercept coefficient in the current iteration, a * represents the linear regression slope coefficient after iterative update, b * represents the linear regression intercept coefficient after iterative update, It represents the rate of change of the mean square error to the linear regression slope coefficient, It represents the rate of change of the mean square error to the linear regression intercept coefficient; after each iteration, the number of iterations and the value of the mean square error of the fitting line MSE(a,b) are judged respectively. If the number of iterations of the fitting line of the segmented ship navigation data using lossy compression reaches the set number of iterations or the value of the mean square error of the fitting line MSE(a,b) reaches the minimum, the iteration is terminated, and the optimal linear regression slope coefficient a after iterative update of each segment of the ship navigation data using lossy compression is stored. * and the linear regression intercept coefficient b * ; Make each segment of ship navigation data using lossy compression updated through iteration to obtain the optimal linear regression slope coefficient a * and the linear regression intercept coefficient b * Approximately, compression of ship navigation data using lossy compression is accomplished.

7. The ship-shore data lightweight communication system based on hybrid compression algorithm according to claim 1 is characterized in that: It also includes a data storage module, which is used to back up the ship navigation data by copying the ship navigation data in the main control processing module to the data storage module, thereby preventing the ship navigation data from being damaged and lost due to equipment failure or accidental power failure; the data storage module is also used to verify the ship navigation data by comparing the ship navigation data in the data storage module with the ship navigation data in the main control processing module, thereby ensuring the quality and reliability of the ship navigation data transmission.

8. The ship-shore data lightweight communication system based on hybrid compression algorithm according to claim 1 is characterized by: The shore monitoring module includes a decompression module and a database; the decompression module sequentially reads the code values ​​of the ship navigation data using lossless compression through a dictionary of all characters and their corresponding code values ​​generated by the ship navigation data using lossless compression, searches for characters corresponding to the ship navigation data using lossless compression in the dictionary through the code values, and obtains lossless data of the ship navigation data; the decompression module also extracts the optimal linear regression slope coefficient a after iterative update of each segment of the ship navigation data using lossy compression according to the data features of the ship navigation data using lossy compression. * and the linear regression intercept coefficient b * Data reconstruction is performed and data segments are spliced ​​in segmented order to obtain lossy data of ship navigation data; the database parses and stores the decompressed ship navigation data, so that the platform can determine the operating status and position of the ship.

9. A lightweight ship-shore data communication method based on a hybrid compression algorithm, characterized in that: The steps include: Transmit the collected ship navigation data to the main control processing module; Preprocessing the ship navigation data to obtain preprocessed ship navigation data, and classifying the preprocessed ship navigation data based on compression rate limits to obtain ship navigation data suitable for lossy compression and ship navigation data suitable for lossless compression; Performing lossy compression on the ship navigation data suitable for lossy compression, and performing lossless compression on the ship navigation data suitable for lossless compression, to obtain corresponding ship navigation data using lossy compression and ship navigation data using lossless compression; Back up and verify ship navigation data; Transmitting the ship navigation data using lossy compression and the ship navigation data using lossless compression to a shore monitoring module through a wireless channel; The ship navigation data using lossy compression and the ship navigation data using lossless compression are decompressed accordingly.

10. A computing device comprising a processor, a memory, a communication interface and a communication bus, characterized in that: The processor, the memory and the communication interface communicate with each other via the communication bus; The memory is used to store at least one executable instruction, and the executable instruction enables the processor to perform operations corresponding to the ship-shore data lightweight communication method based on a hybrid compression algorithm as described in claim 9.

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