A method and system for optimizing the data of the ground speed of a shipborne receiving equipment of Beidou

Abstract

The present application belongs to the field of ship satellite navigation technology, and particularly relates to a Beidou shipborne receiving equipment ground speed data optimization method and system. The method comprises the following steps: firstly, obtaining data received by the Beidou shipborne receiving equipment, and preprocessing RMC statements in the data received by the Beidou shipborne receiving equipment; extracting ground speed data in the preprocessed RMC statements; calculating the sliding average value Mean and dynamic variance value Var of the continuous N ground speed data; finally, presetting a threshold value, comparing the dynamic variance value with the preset threshold value, if the dynamic variance value Var is less than the preset threshold value, outputting the sliding average value Mean of the ground speed data, otherwise directly outputting the ground speed data extracted from the RMC statements. The present application can solve the problem of existing technology that the Beidou shipborne receiving equipment outputs ground speed data with jitter when moving at low speed or being static, which affects the judgment of the ship navigation state by the ship driver in the scenarios of approaching the port and dense waterways.

Description

Technical Field

[0001] This invention belongs to the field of ship satellite navigation technology, and in particular relates to a method and system for optimizing ground speed data of Beidou shipborne receiving equipment. Background Technology

[0002] On March 11, 2020, the International Electrotechnical Commission (IEC) officially released the first international standard for testing BeiDou shipborne receiving equipment, IEC 61108-5-2020, "Marine navigation and radio communication equipment and systems - Global Navigation Satellite System (GNSS) - Part 5: BDS receiving equipment - Performance requirements, test methods and test results". This serves as the basis for classification societies worldwide to grant type approval for BeiDou equipment for shipboard applications. It is a necessary condition for BeiDou to enter the international maritime field and achieve widespread application, and it is also the basis for global satellite navigation marine product manufacturers to design, produce and test.

[0003] The IEC 61108-5-2020 standard requires that the error in the ground speed (SOG, the speed of the antenna position relative to the ground) of BeiDou shipborne receiving equipment should not exceed 2% or 0.2 knots (whichever is greater) of the actual speed. However, in practical applications, the ground speed data output by BeiDou shipborne receiving equipment exhibits jitter when moving at low speeds or stationary, affecting the judgment of the ship's navigation status by the navigator in scenarios such as berthing in port or in densely packed waterways. Summary of the Invention

[0004] The technical problem solved by this invention is to provide a method and system for optimizing the ground speed data of a Beidou shipborne receiving device, so as to solve the problem that the ground speed data output by the Beidou shipborne receiving device at low speed or when stationary is jittery, which affects the judgment of the ship's navigation status by the driver in scenarios such as docking and dense waterways.

[0005] The basic solution provided by this invention is: a method for optimizing the ground speed data of a Beidou shipborne receiving device, comprising:

[0006] S1: Obtain the data received by the Beidou shipborne receiving equipment and preprocess the RMC statements in the data received by the Beidou shipborne receiving equipment;

[0007] S2: Extract ground speed data from the preprocessed RMC statement;

[0008] S3: Calculate the sliding average Mean of N consecutive ground speed data;

[0009] S4: Calculate the dynamic variance Var of N consecutive ground speed data;

[0010] S5: Set a preset threshold value and compare the dynamic variance value with the preset threshold value. If the dynamic variance value Var is less than the preset threshold value, output the sliding average value Mean of the ground speed data; otherwise, directly output the ground speed data extracted from the RMC statement.

[0011] Furthermore, the RMC statement includes positioning time, status indicator bit, latitude, longitude, ground speed, ground true heading, date, magnetic deflection, mode indicator, and navigation status.

[0012] Furthermore, the preprocessing in S1 includes data cleaning, and S1 includes:

[0013] S1-1: Obtain the status indicator bit of the RMC statement and perform a validity check;

[0014] S1-2: If the value of the status indicator bit is A, the data is valid; if the value of the status indicator bit is V, the data is invalid.

[0015] Furthermore, S3 includes:

[0016] S3-1: Construct a FIFO of depth N as a data buffer and store the ground speed data of the Beidou shipborne receiver into the data buffer in sequence;

[0017] S3-2: Construct a cyclic accumulator to accumulate N consecutive new BeiDou shipborne receiver speed data to the ground and remove old BeiDou shipborne receiver speed data output from the data buffer.

[0018] S3-3: Calculate the average ground speed data of N Beidou shipborne receiving devices based on the output of the cyclic accumulator.

[0019] Furthermore, S4 includes:

[0020] S4-1: Construct a circular register with a depth of N, and store the ground speed data of the Beidou shipborne receiver into the circular register in sequence;

[0021] S4-2: Calculate the difference between the moving average Mean and the N ground speed data in the loop register;

[0022] S4-3: Calculate the sum of squares of the differences and take the average value as the dynamic variance value Var corresponding to the moving average Mean.

[0023] A system for optimizing ground speed data of a Beidou shipborne receiving device includes a data cleaning module, a data extraction unit, a data calculation module, and a data selection unit.

[0024] The output of the data cleaning unit is connected to the data extraction unit. The data cleaning unit is used to clean the RMC statements received by the Beidou shipborne receiving equipment and remove invalid data.

[0025] The output of the data extraction unit is connected to the data calculation module. The data extraction module is used to extract the ground speed data in the RMC statement after the data cleaning unit cleans it, and transmit it to the data calculation module.

[0026] The output of the data calculation module is connected to the data selection unit. The data calculation module is used to calculate the sliding average value Mean and the dynamic variance Var of the ground speed data.

[0027] The data selection unit is used to compare the dynamic variance value with a preset ground speed error threshold. If the variance value is less than the threshold, the average ground speed data is selected for output; if the variance value is greater than the threshold, the ground speed data is selected.

[0028] Furthermore, the data calculation module includes a moving average unit and a dynamic variance unit. The output of the moving average unit is connected to the dynamic variance unit and the data selection unit. The moving average unit is used to calculate the average value of N ground speed data, realize dynamic smoothing filtering of N ground speed data, and provide the average ground speed data to the dynamic variance unit and the data selection unit.

[0029] The output of the dynamic variance unit is a data selection unit. The dynamic variance unit is used to calculate the dynamic variance of N ground speed data, use the dynamic variance value to determine the magnitude of the change in the ground speed data, and provide the dynamic variance value data to the data selection unit.

[0030] The principle and advantages of this invention are as follows: This invention discloses a method for optimizing ground speed data for BeiDou shipborne receiving equipment. It is applicable to the latest international standard for testing BeiDou shipborne receiving equipment, IEC 61108-5-2020, and the BeiDou receiver navigation and positioning data output format standard, BD 410004—2015. Through dynamic smoothing filtering, it reduces the fluctuation of the ground speed output by the BeiDou shipborne receiving equipment. Simultaneously, it utilizes dynamic variance observation of the data to ensure the response speed under rapidly changing conditions. This invention is applicable to BeiDou, GPS, Galileo, or Glenas satellite navigation products that require ground speed data output. Attached Figure Description

[0031] Figure 1 This is a flowchart of an embodiment of the present invention;

[0032] Figure 2 This is a detailed diagram illustrating the format of the RMC statement in an embodiment of the present invention;

[0033] Figure 3 This is an image showing the ground speed data output of the Beidou shipborne receiving device in a stationary state, as described in this embodiment of the invention.

[0034] Figure 4 This is a functional block diagram in an embodiment of the present invention. Detailed Implementation

[0035] The following detailed description illustrates the specific implementation method:

[0036] The implementation examples are basically as follows Figure 1 and Figure 2 As shown: A method for optimizing ground speed data of a Beidou shipborne receiving device, comprising:

[0037] S1: Obtain the RMC statement received by the Beidou shipborne receiving equipment and preprocess the RMC statement received by the Beidou shipborne receiving equipment.

[0038] In this embodiment, the preprocessing includes data cleaning, receiving RMC statements, such as... Figure 2 As shown, the RMC statement includes positioning time, status indicator bit, latitude, longitude, ground speed, ground true heading, date, magnetic deflection, mode indicator, and navigation status.

[0039] Therefore, S1 includes:

[0040] S1-1: Obtain the status indicator bit of the RMC statement and perform a validity check;

[0041] S1-2: If the value of the status indicator bit is A, the data is valid; if the value of the status indicator bit is V, the data is invalid.

[0042] In this embodiment, data cleaning is used for data preprocessing in RMC statements. The purpose of this method is to remove invalid data. The determination of invalid data is based on the status indicator bit of the RMC statement. Specifically, if the value of the status indicator bit is A, the data is valid; if the value of the status indicator bit is V, the data is invalid. In this way, invalid data in RMC data can be effectively removed.

[0043] S2: Extract ground speed data from the RMC statement;

[0044] S3: Calculate the sliding average Mean of N consecutive ground speed data; S3 includes:

[0045] S3-1: Construct a FIFO of depth N as a data buffer and store the ground speed data of the Beidou shipborne receiver into the data buffer in sequence;

[0046] S3-2: Construct a cyclic accumulator to accumulate N consecutive new BeiDou shipborne receiver speed data to the ground and remove old BeiDou shipborne receiver speed data output from the data buffer.

[0047] S3-3: Calculate the average ground speed data of N Beidou shipborne receiving devices based on the output of the cyclic accumulator.

[0048] S4: Calculate the dynamic variance Var of N consecutive ground speed data points; S4 includes:

[0049] S4-1: Construct a circular register with a depth of N, and store the ground speed data of the Beidou shipborne receiver into the circular register in sequence;

[0050] S4-2: Calculate the difference between the moving average Mean and the N ground speed data in the loop register;

[0051] S4-3: Calculate the sum of squares of the differences and take the average value as the dynamic variance value Var corresponding to the moving average Mean.

[0052] S5: If the dynamic variance value Var is less than the preset threshold, output the sliding average value Mean of the ground speed data; otherwise, directly output the ground speed data extracted from the RMC statement.

[0053] The optimization method adopted in the technical solution of this application is applicable to the latest international standard for testing BeiDou shipborne receiving equipment, IEC 61108-5-2020, and the BeiDou receiver navigation and positioning data output format standard, BD 410004—2015. Currently, BeiDou shipborne receiving equipment exhibits jitter in its output ground speed data when moving at low speeds or stationary. Figure 3 The image shown is the ground speed data output image of a Beidou shipborne device in a stationary state. As shown in the image, when the ship is docked in a port or in a densely packed waterway, the ground speed data exhibits jitter, which can affect the driver's judgment of the ship's navigation status. To address this, this application first calculates the average value of N ground speed data points to achieve dynamic smoothing filtering. This dynamic smoothing filtering reduces the fluctuation of the ground speed output by the Beidou shipborne receiver. Simultaneously, the dynamic variance of the N ground speed data points is calculated, and the dynamic variance value is used to determine the magnitude of the numerical change in the ground speed data. By observing the dynamic variance of the data, it is ensured that this optimization method can obtain the corresponding speed under rapidly changing ground speed data conditions, thus solving the impact caused by the jitter in the ground speed data.

[0054] like Figure 4As shown, in another embodiment of this example, a ground speed data optimization system for a Beidou shipborne receiving device is also included, comprising a data cleaning unit, a data extraction unit, a moving average unit, a dynamic variance unit, and a data selection unit connected in sequence.

[0055] The output of the data cleaning unit is connected to the data extraction unit. The data cleaning unit is used to determine the status indicator bit of the RMC statement. If it is A, the data is valid and the RMC statement is output to the data extraction unit. If it is V, the data is invalid and the latest valid RMC statement is output to the data extraction unit.

[0056] The output of the data extraction unit is connected to the moving average unit, the dynamic variance unit, and the data selection unit. The data extraction unit is used to extract ground speed data from the RMC statement and provide the ground speed data to the moving average unit, the dynamic variance unit, and the data selection unit.

[0057] The output of the moving average unit is connected to the dynamic variance unit and the data selection unit. The moving average unit is used to calculate the average value of N ground speed data, realize dynamic smoothing filtering of N ground speed data, and provide the average ground speed data to the dynamic variance unit and the data selection unit.

[0058] The output of the dynamic variance unit is a data selection unit. The dynamic variance unit is used to calculate the dynamic variance of N ground speed data, use the dynamic variance value to determine the magnitude of the change in the ground speed data, and provide the dynamic variance value data to the data selection unit.

[0059] The data selection unit is used to select the data type of the output end. By comparing the dynamic variance value with the ground speed error threshold value specified by the standard, if it is less than the threshold value, the average ground speed data is selected for output; if it is greater than the threshold value, the ground speed data is selected.

[0060] The above are merely embodiments of the present invention. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for optimizing ground speed data of a Beidou shipborne receiving device, characterized in that: include: S1: Obtain the data received by the Beidou shipborne receiving equipment and preprocess the RMC statements in the data received by the Beidou shipborne receiving equipment; S2: Extract ground speed data from the preprocessed RMC statement; S3: Calculate the sliding average Mean of N consecutive ground speed data; S4: Calculate the dynamic variance Var of N consecutive ground speed data; S5: Set a threshold value and compare the dynamic variance value with the preset threshold value. If the dynamic variance value Var is less than the preset threshold value, output the sliding average value Mean of the ground speed data; otherwise, directly output the ground speed data extracted from the RMC statement. S4 includes: S4-1: Construct a circular register with a depth of N, and store the ground speed data of the Beidou shipborne receiver into the circular register in sequence; S4-2: Calculate the difference between the moving average Mean and the N ground speed data in the loop register; S4-3: Calculate the sum of squares of the differences and take the average value as the dynamic variance value Var corresponding to the moving average Mean; S3 includes: S3-1: Construct a FIFO of depth N as a data buffer and store the ground speed data of the Beidou shipborne receiver into the data buffer in sequence; S3-2: Construct a cyclic accumulator to accumulate N consecutive new BeiDou shipborne receiver speed data to the ground and remove old BeiDou shipborne receiver speed data output from the data buffer. S3-3: Calculate the average ground speed data of N Beidou shipborne receiving devices based on the output of the cyclic accumulator.

2. The method for optimizing ground speed data of a Beidou shipborne receiving device according to claim 1, characterized in that: The RMC statement includes positioning time, status indicator bit, latitude, longitude, ground speed, ground true heading, date, magnetic deflection, mode indicator, and navigation status.

3. The method for optimizing ground speed data of a Beidou shipborne receiving device according to claim 2, characterized in that: The preprocessing in S1 includes data cleaning, and S1 includes: S1-1: Obtain the status indicator bit of the RMC statement and perform a validity check; S1-2: If the value of the status indicator bit is A, the data is valid; if the value of the status indicator bit is V, the data is invalid.

4. A system for optimizing ground speed data of a Beidou shipborne receiving device, characterized in that: It includes a data cleaning unit, a data extraction unit, a data calculation module, and a data selection unit; The output of the data cleaning unit is connected to the data extraction unit. The data cleaning unit is used to clean the RMC statements received by the Beidou shipborne receiving equipment and remove invalid data. The output of the data extraction unit is connected to the data calculation module. The data extraction module is used to extract the ground speed data in the RMC statement after the data cleaning unit cleans it, and transmit it to the data calculation module. The output of the data calculation module is connected to the data selection unit. The data calculation module is used to calculate the sliding average (Mean) and dynamic variance (Var) of the ground speed data; specifically: Construct a circular register of depth N and store the ground speed data of the Beidou shipborne receiver into the circular register sequentially; Calculate the difference between the moving average Mean and the N ground speed data in the loop register; Calculate the sum of squares of the differences and take the average value as the dynamic variance value Var corresponding to the moving average Mean; The data selection unit is used to compare the dynamic variance value with a preset ground speed error threshold. If the variance value is less than the threshold, the average ground speed data is selected for output; if the variance value is greater than the threshold, the ground speed data is selected. Construct a FIFO of depth N as a data buffer, and store the ground speed data of the Beidou shipborne receiver into the data buffer in sequence; Construct a cyclic accumulator to accumulate N consecutive new BeiDou shipborne receiver speed data to the ground and remove old BeiDou shipborne receiver speed data output from the data buffer. Calculate the average ground speed data of N Beidou shipborne receiving devices based on the output of the cyclic accumulator.

5. The system for optimizing ground speed data of a Beidou shipborne receiving device according to claim 4, characterized in that: The data calculation module includes a moving average unit and a dynamic variance unit. The output of the moving average unit is connected to the dynamic variance unit and the data selection unit. The moving average unit is used to calculate the average value of N ground speed data, realize dynamic smoothing filtering of N ground speed data, and provide the average ground speed data to the dynamic variance unit and the data selection unit. The output of the dynamic variance unit is a data selection unit. The dynamic variance unit is used to calculate the dynamic variance of N ground speed data, use the dynamic variance value to determine the magnitude of the change in the ground speed data, and provide the dynamic variance value data to the data selection unit.

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