A ship navigation system integrity monitoring method and device

Abstract

The present invention provides a method and device for monitoring the integrity of a ship navigation system, which belongs to the field of ship navigation technology. The present invention includes the following steps: a ship in operation receives information broadcast by a global navigation satellite system and pulse groups transmitted by a main station and a secondary station in a coastal auxiliary navigation system through a receiver; according to the number of visible satellites and the number of available equipment in the auxiliary navigation system, the received signal pseudorange, carrier phase, and envelope leading edge power are analyzed and calculated respectively; multiple position data are continuously recorded at multiple points, and the integrity status of the ship's navigation positioning is evaluated by the position probability estimate and the corrected horizontal precision attenuation factor, and the navigation scheme is effectively adjusted according to the evaluation results. The present invention fully considers the number of visible satellites, avoids navigation failures caused by insufficient number of visible satellites, and effectively reduces the discontinuity of positioning results and the decrease in signal phase convergence speed caused by the switching of navigation signals of each reference signal source.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of ship navigation technology, and in particular to a ship navigation system integrity monitoring method and device. BACKGROUND

[0002] Ship navigation positioning usually adopts a global navigation satellite system as a main navigation system, and is equipped with a receiver to provide ship navigation data such as heading, speed, position, and relative distance.

[0003] The integrity of a ship navigation system refers to whether, in the use process of the ship navigation system, an error caused by a fault or performance deterioration of a device in the navigation system exceeds a possible acceptable limit value, and whether a timely and effective alarm is provided when the device is unavailable. In order to ensure the reliability of the navigation system, the navigation system needs to be monitored for integrity, and the main purpose is to detect and isolate faults.

[0004] The global navigation satellite system is a commonly used navigation system,

[0005] With the development of the marine industry, the safety of offshore production operations is particularly important. In order to effectively enhance the performance of the global navigation satellite system for ship navigation, modern shipping widely uses the technical means of configuring a combined positioning system with a radio navigation device, such as using a Decca or Loran combined with a global navigation satellite system. However, this combined mode does not fully consider the adverse effects of possible faults or abnormalities of visible navigation satellites on ship navigation performance, and even if the autonomous integrity monitoring technology of a satellite navigation receiver is applied, the situation of insufficient number of visible satellites will cause the failure of the technology. In the navigation process, the combined positioning system often appears false alarms in a normal state, thereby greatly reducing the efficiency of ship operations.

[0006] The prior art has the following deficiencies:

[0007] 1. The adverse effects of possible faults or abnormalities of visible navigation satellites on ship navigation performance are not fully considered, and even if the autonomous integrity monitoring technology of a satellite navigation receiver is applied, the situation of insufficient number of visible satellites will cause the failure of the technology. SUMMARY

[0008] To solve the problems in the prior art, the present application provides a ship navigation system integrity monitoring method and device, which comprises a combined navigation system composed of a global navigation satellite system and a shore-based auxiliary navigation system; a ship in operation simultaneously receives information broadcast by the global navigation satellite system and pulse groups respectively transmitted by main stations and vice stations in a station chain of the shore-based auxiliary navigation system; different strategies are adopted for different numbers of visible satellites and numbers of available main stations and vice stations in the station chain to make integrity alarm judgments: when the sum of the number of visible satellites in the combined navigation system and the total number of available main stations and vice stations in the station chain of the shore-based auxiliary navigation system is less than an integrity threshold, an unusable alarm of the combined navigation system is given; when the sum of the number of available satellites in the combined navigation system and the total number of available main stations and vice stations in the station chain of the shore-based auxiliary navigation system is greater than or equal to the integrity threshold, the integrity of the combined navigation system is judged by the following method: if the number of visible satellites remains greater than or equal to a first preset threshold and unchanged within the time length of transmitting a complete almanac or 1 main frame, the positions displayed by the satellite system are recorded at multiple points for multiple times, residual errors are calculated, satellite system position probability estimates are obtained, and ship navigation system integrity state evaluation is made according to the coordinates of the last point, the position coordinates of the last point displayed by the auxiliary navigation system, the satellite system position probability estimate and the auxiliary navigation system position probability estimate; if the number of visible satellites remains greater than or equal to the first preset threshold and unchanged within the time length of transmitting a complete almanac or 1 main frame, the available main stations and vice stations in the shore-based auxiliary navigation system and the global navigation satellite are used as reference signal sources together; the direction cosine vectors of the reference signal sources to the ship receiving equipment are determined according to the position relationship between each reference signal source and the ship receiving equipment to form a linearization matrix H; the horizontal position accuracy decay factor is corrected according to the linearization matrix H and the correction factor of the ship navigation system; the ship navigation system integrity state evaluation is made according to the pseudo-range, the carrier phase and the corrected horizontal position accuracy decay factor; and it is judged whether to give an alarm according to the integrity state evaluation result. The present application fully considers the number of visible satellites, uses the global satellite navigation system and the auxiliary navigation system, solves the problem of insufficient number of visible navigation satellites for the ship navigation equipment to run the existing receiver integrity detection, greatly reduces the operation cost, and effectively reduces the discontinuity of positioning results and the decrease of signal phase convergence speed caused by the switching of navigation signals of each reference signal source.

[0009] The present application provides a ship navigation system integrity monitoring method, which comprises the following steps:

[0010] The combined navigation system is composed of a global navigation satellite system and a shore-based auxiliary navigation system;

[0011] The ship in operation simultaneously receives information broadcast by the global navigation satellite system and pulse groups respectively transmitted by main stations and vice stations in a station chain of the shore-based auxiliary navigation system;

[0012] Different strategies are adopted for different number of visible satellites and total number of available primary stations and secondary stations in the station chain of the coastal-based navigation system for integrity alarm judgment:

[0013] When the sum of the number of visible satellites in the integrated navigation system and the total number of available primary stations and secondary stations in the station chain of the coastal-based navigation system is less than the integrity threshold, an integrated navigation system unavailable alarm is issued;

[0014] When the sum of the number of available satellites in the integrated navigation system and the total number of available primary stations and secondary stations in the station chain of the coastal-based navigation system is greater than or equal to the integrity threshold, the following method is used to judge the integrity of the integrated navigation system:

[0015] If the number of visible satellites remains greater than or equal to the first preset threshold and does not change within the time of transmitting a complete almanac or 1 primary frame, multiple position data are continuously recorded at multiple points; the position probability estimate is obtained by analyzing the pseudo-range, carrier phase and envelope front power of the received signal; and the integrity state of the ship navigation system is evaluated according to the recorded position data and the position probability estimate;

[0016] If the number of visible satellites remains less than the first preset threshold and changes within the time of transmitting a complete almanac or 1 primary frame, the available primary stations and secondary stations in the coastal-based navigation system and the global navigation satellite are used as reference signal sources together; the linearization matrix H composed of the direction cosine vectors of each reference signal source to the ship receiving device is determined according to the position relationship between each reference signal source and the ship receiving device; the horizontal position accuracy decay factor is corrected according to the linearization matrix H and the correction factor of the ship navigation system; and the integrity state of the ship navigation system is evaluated according to the pseudo-range, carrier phase and corrected horizontal position accuracy decay factor;

[0017] The integrity state evaluation result is used to determine whether to issue an alarm.

[0018] Preferably, when the number of visible satellites is greater than or equal to the first preset threshold, the global navigation satellite system is available;

[0019] Preferably, when the total number of available primary stations and secondary stations in the station chain of the coastal-based navigation system is greater than or equal to the second preset threshold, the auxiliary navigation system is available.

[0020] Preferably, the integrity threshold is 4, the first preset threshold is 4, and the second preset threshold is 3.

[0021] Preferably, when the number of visible satellites remains greater than or equal to the first preset threshold and unchanged during the transmission of a complete almanac or a main frame, m measurements are made at n points respectively, and the positions of each measurement displayed by the satellite system are recorded. The residuals of the horizontal coordinates are calculated using the following method: and the residual of the vertical axis Calculation:

[0022] , , , ;

[0023] , , , ;

[0024] in,

[0025] is the jth point i The position of the second measurement, i Take 1-m, j Take 1~n;

[0026] v x and v y are the degrees of freedom of the horizontal and vertical axes, respectively. v x = v y = ( i -1) j ;

[0027] The following method is used to obtain the estimated probability of the satellite system position :

[0028]

[0029] According to the coordinates (x, y) of the last point, the position coordinates of the last point displayed by the auxiliary navigation system ( , ), satellite system position probability estimate And the estimated probability of the auxiliary navigation system position Conduct integrity assessments as follows:

[0030] like , then an alarm indicating that the integrated navigation system is unavailable is issued;

[0031] like , then an alarm indicating that the integrated navigation system is unavailable is issued;

[0032] in,

[0033] is a position probability estimation ratio threshold value, is a position coordinate threshold value, which is calculated from a required false alarm rate and a false alarm rate by a probability distribution density function under a current scene according to the following formula:

[0034] P( , ) = false alarm rate;

[0035] P( , ) = false alarm rate;

[0036] P is a probability distribution density function;

[0037] Preferably, the linearization matrix H is obtained by the following method:

[0038] In m reference signal sources, the i-th reference signal source has the following relationship with the user receiving equipment in the plane position:

[0039]

[0040] wherein,

[0041] c is the speed of light;

[0042] is the time for the reference signal source signal to propagate to the user equipment;

[0043] is the clock difference of the reference signal source, which is obtained from the message of the reference signal source;

[0044] is the clock difference of the ship user equipment;

[0045] x, y represent the position coordinates of the ship user equipment;

[0046] , is the position coordinate of the i-th reference signal source, takes 1-m;

[0047] is the distance between the i-th reference signal source and the ship user equipment; The above formula is simplified to obtain the following linearization model:

[0048]

[0049] wherein,

[0050] ,​​​​ denotes the direction cosine of the unit vector pointing from the position of the ship user equipment to the

[0051]

[0052]

[0053] The linearized model is expressed in matrix form: L = HX.

[0054] wherein,

[0055]

[0056]

[0057]

[0058] L denotes the matrix form of the distances between each reference signal source and the ship user equipment;

[0059] Solving X gives the following form:

[0060] X = (H T H) -1 H T L;

[0061] wherein,

[0062] H T is the transpose matrix of H, H -1 is the inverse matrix of H.

[0063] Preferably, is the corrected horizontal position dilution of precision, which is obtained by the following formula:

[0064]

[0065] wherein,

[0066] tr{} is the trace of a matrix;

[0067] is the correction factor of the auxiliary navigation system, which is defined as follows:

[0068] The number of available devices for positioning of the ship navigation system is k, the kth reference signal source of the m reference signal sources is used as a supplementary reference signal source, and the correction factor of the ship navigation system is defined as follows:

[0069] ​​​;

[0070]

[0071] in,

[0072] It is the accuracy value of positioning using a single global satellite navigation system;

[0073] is the accuracy value of the kth available device using a single assisted navigation system for positioning, where k is 1, 2, .., m;

[0074] is the correction factor of the kth reference signal source in the ship navigation system;

[0075] is the correction factor of the ship navigation system, including m reference signal sources.

[0076] Preferably, according to the residual vector r of the pseudorange and the residual vector τ of the carrier phase and the corrected horizontal position dilution of precision factor Conduct integrity status assessment, including:

[0077] like , then an alarm indicating that the integrated navigation system is unavailable is issued;

[0078] in,

[0079] r is the residual vector r of the pseudorange;

[0080] is the false alarm rate related threshold.

[0081] Preferably, the signal strength received by the ship receiving equipment is intercepted by the envelope front power, and converted into the carrier-to-noise ratio CNR according to the requirements of the navigation system used. When CNR≥T p When , an alarm indicating that the combined navigation system is unavailable is issued; different navigation systems have different requirements and need to be converted according to the requirements of the specific system. For example, except for the k reference signal sources of the auxiliary navigation system in m, the others are all reference signal sources of the satellite navigation system.

[0082] T p It is the threshold value related to the missed alarm rate, which is set according to the required statistical distribution relationship of the missed alarm rate.

[0083] Preferably, and T p The probability distribution density function of the required missed alarm rate is determined by the following formula:

[0084] P( ， ) = Missed Alarm Rate

[0085] 1-P( ， ) = false alarm rate

[0086] Preferably, if the kth device does not issue an alarm, the position output by the integrated navigation system is used for navigation, and if the kth device issues an alarm, the k+1th device is judged to exclude the reference signal source that makes the largest reference signal source, k takes 1, 2,..., m.

[0087] Preferably, the reference signal source is taken when the following statistical quantity of the available devices without alarm is taken to be the minimum value:

[0088]

[0089] Wherein,

[0090] is the combination number of the kth available device of the m reference signal sources;

[0091] indicates the kth reference signal source. The present application provides a ship navigation system integrity monitoring device, which uses any one of the above ship navigation system integrity monitoring methods for integrity monitoring, comprising:

[0092] An available device statistics module is configured to count the number of available satellites and the total number of available main stations and auxiliary stations in the station chain of the coastal auxiliary navigation system.

[0093] An integrity state judgment module is configured to adopt different integrity state judgment strategies according to the result of the available device statistics module.

[0094] When the sum of the number of visible satellites in the integrated navigation system and the total number of available main stations and auxiliary stations in the station chain of the coastal auxiliary navigation system is less than the integrity threshold, an alarm is issued that the integrated navigation system is unavailable.

[0095] When the sum of the number of available satellites in the integrated navigation system and the total number of available main stations and auxiliary stations in the station chain of the coastal auxiliary navigation system is greater than or equal to the integrity threshold, the integrity of the integrated navigation system is judged by the following method:

[0096]

[0097] ​If the number of visible satellites remains greater than or equal to the first preset threshold and unchanged within the time duration of transmitting a complete almanac or 1 main frame, the position data is recorded continuously at multiple points for multiple times; the position probability estimate is obtained by analyzing the pseudo-range, carrier phase and envelope front power of the received signal; and the integrity state of the ship navigation system is evaluated according to the recorded position data and the position probability estimate.

[0098] If the number of visible satellites remains less than the first preset threshold and changes within the time duration of transmitting a complete almanac or 1 main frame, the available main station and auxiliary station in the coastal auxiliary navigation system and the global navigation satellite are used as the reference signal source together; the linear matrix H composed of the direction cosine vectors of each reference signal source to the ship receiving device is determined according to the position relationship between each reference signal source and the ship receiving device; the horizontal position accuracy decay factor is corrected according to the linear matrix H and the correction factor of the auxiliary navigation system; and the integrity state of the ship navigation system is evaluated according to the pseudo-range, carrier phase and corrected horizontal position accuracy decay factor.

[0099] The alarm is sent according to the integrity state evaluation result.

[0100] Compared with the prior art, the beneficial effects of the present application are as follows:

[0101] (1) The present application uses a more scientific and reasonable method to adapt the marine navigation equipment to obtain reliable satellite measurement information, and provides a method for monitoring the integrity of the navigation system under different visible navigation satellite quantities. The problem of insufficient visible navigation satellite quantity for the ship navigation equipment to run the existing receiver integrity detection is solved, and the running cost is greatly reduced.

[0102] (2) The present application effectively utilizes the existing equipment on the coast, considers the observation noise of the ship receiving equipment and the navigation signal quality of different reference signal sources, corrects the horizontal position accuracy decay factor, and can effectively reduce the problems of discontinuous positioning results and signal phase convergence speed caused by switching of the navigation signals of each reference signal source. BRIEF DESCRIPTION OF DRAWINGS

[0103] Fig. 1 The ship navigation system integrity monitoring method flow chart of one embodiment of the present application;

[0104] Fig. 2 The ship navigation system integrity state judgment flow chart when the number of visible satellites of one embodiment of the present application remains greater than or equal to the first preset threshold and unchanged within the time duration of transmitting a complete almanac or 1 main frame;

[0105] Fig. 3An embodiment of the present application can be seen from the following: when the number of visible satellites remains less than a first preset threshold and changes in the time duration of transmitting a complete almanac or 1 main frame, the ship navigation system integrity state judgment flow chart. DETAILED DESCRIPTION

[0106] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. Figs. 1-3 The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0107] The present application provides a ship navigation system integrity monitoring method, comprising the following steps:

[0108] The combined navigation system is composed of a global navigation satellite system and a coastal auxiliary navigation system;

[0109] The ship in operation simultaneously receives the information broadcast by the global navigation satellite system and the pulse groups respectively transmitted by the main stations and the vice stations in the station chain of the coastal auxiliary navigation system;

[0110] For different numbers of visible satellites and the numbers of available main stations and vice stations in the station chain, different strategies are adopted for integrity alarm judgment:

[0111] When the sum of the number of visible satellites in the combined navigation system and the total number of available main stations and vice stations in the station chain of the coastal auxiliary navigation system is less than the integrity threshold, an alarm of unavailability of the combined navigation system is issued;

[0112] When the sum of the number of available satellites in the combined navigation system and the total number of available main stations and vice stations in the station chain of the coastal auxiliary navigation system is greater than or equal to the integrity threshold, the integrity of the combined navigation system is judged by the following method:

[0113] If the number of visible satellites remains greater than or equal to the first preset threshold and does not change in the time duration of transmitting a complete almanac or 1 main frame, the position data is recorded continuously at multiple points for multiple times; the position probability estimate value is obtained by analyzing the pseudo-range, carrier phase and envelope front power of the received signal; and the ship navigation system integrity state is evaluated according to the recorded position data and the position probability estimate value;

[0114] If the number of visible satellites remains less than the first preset threshold and changes in the time duration of transmitting a complete almanac or 1 main frame, the available main stations and vice stations in the coastal auxiliary navigation system and the global navigation satellite are used as the reference signal sources together; the linearization matrix H composed of the direction cosine vectors of each reference signal source to the ship receiving equipment is determined according to the position relationship between each reference signal source and the ship receiving equipment; the horizontal position accuracy decay factor is corrected according to the linearization matrix H and the correction factor of the ship navigation system; and the ship navigation system integrity state is evaluated according to the pseudo-range, carrier phase and corrected horizontal position accuracy decay factor;

[0115] According to the integrity state evaluation result, it is judged whether to send an alarm.

[0116] According to one specific embodiment of the present application, when the number of visible satellites is greater than or equal to a first preset threshold, the global navigation satellite system is available.

[0117] According to one specific embodiment of the present application, when the total number of available main stations and vice stations in the station chain of the auxiliary navigation system on the coast is greater than or equal to a second preset threshold, the auxiliary navigation system is available.

[0118] According to one specific embodiment of the present application, the integrity threshold is 4, the first preset threshold is 4, and the second preset threshold is 3. This is because the accuracy of the auxiliary navigation system, such as the station card and the Loran, is about 100 m, which is not in the same order of magnitude as the satellite positioning of 10 m, and cannot be directly calculated by comparing the accuracy. In order to ensure the required accuracy and reliability of navigation at the same time, this method is used for integrity monitoring.

[0119] According to one specific embodiment of the present application, when the number of visible satellites remains greater than or equal to the first preset threshold and does not change within the time length of transmitting a complete almanac or 1 main frame, the position displayed by the satellite system is recorded by measuring m times at n points respectively, and the following methods are used to calculate the residual errors of the horizontal coordinate and the vertical coordinate :

[0120] , , , ;

[0121] , , , ;

[0122] wherein,

[0123] is the position of the jth point measured for the mth time, i takes 1-m, i takes 1-n; j

[0124] v x and v y are the degrees of freedom of the horizontal and vertical axes respectively, v x = v y = ( i -1)· j ; ​

[0125] The following method is used to obtain the estimated probability of the satellite system position :

[0126]

[0127] According to the coordinates (x, y) of the last point, the position coordinates of the last point displayed by the auxiliary navigation system ( , ), satellite system position probability estimate And the estimated probability of the auxiliary navigation system position (The estimated probability of the position of the auxiliary navigation system is directly read from the instrument panel of the system (Loran, Taica) onboard equipment, and the indication range is usually 0.67~0.99. All coordinates are directly read from the on-site equipment.) Perform the following integrity assessment:

[0128] like , then an alarm indicating that the integrated navigation system is unavailable is issued;

[0129] like , then an alarm indicating that the integrated navigation system is unavailable is issued;

[0130] in,

[0131] “ is the position probability estimation ratio threshold, is the position coordinate threshold, which is calculated by the probability distribution density function in the current scene according to the required missed alarm rate and false alarm rate using the following formula;

[0132] P( , ) = missed alarm rate;

[0133] P( , ) = false alarm rate";

[0134] P is the probability distribution density function;

[0135] This doesn't mean the assisted (Loran) navigation system is completely eliminated throughout the entire process; rather, calculations and judgments are performed at the final point. Assisted navigation systems are characterized by high reliability (they have greater anti-interference capabilities than satellite navigation systems, so separate equipment integrity monitoring of the assisted navigation system is unnecessary). However, these systems have low absolute position accuracy (10 meters for satellite positioning, around 100 meters for the assisted navigation system) and a low refresh rate (for example, satellite navigation systems can generate 10 to 100 sets of data per second, while assisted navigation systems typically generate one set every half a minute). This avoids repeated calls to the assisted navigation system, reducing wait times, saving hardware costs, and shortening computation time, thereby improving real-time performance.

[0136] According to a specific embodiment of the present invention, the linearization matrix H is obtained by the following method:

[0137] Among the m reference signal sources, the The relationship between the reference signal source and the user receiving device in the plane is as follows:

[0138]

[0139] in,

[0140] c is the speed of light;

[0141] The time taken for the reference signal source signal to propagate to the user equipment;

[0142] It is the clock difference of the reference signal source, which is obtained from the telegram of the reference signal source; the reference signal source will broadcast telegrams, and the user equipment will automatically store them after receiving them, and then calculate them to obtain positioning.

[0143] Clock deviation for ship user equipment;

[0144] x, y represent the location coordinates of the ship user equipment;

[0145] , For the The position coordinates of the reference signal source, Take 1-m;

[0146] For the The distance between the reference signal source and the ship user equipment;

[0147] Simplifying the above formula, we get the following linearized model: ;

[0148] in,

[0149] 、 Indicates that the position of the ship user equipment points to the The direction cosines of the unit vector of the reference signal source;

[0150] is the distance between the ship user equipment and the reference signal source in the x direction;

[0151] is the distance between the ship user equipment and the reference signal source in the y direction;

[0152] The linearized model is expressed in matrix form: L=HX;

[0153] wherein,

[0154]

[0155]

[0156]

[0157] L represents a matrix form of distances between each reference signal source and the ship user equipment;

[0158] Solving X gives the following form:

[0159] X = (H T H) -1 H T L;

[0160] wherein,

[0161] H T is the transpose matrix of H, H -1 is the inverse matrix of H.

[0162] According to one specific embodiment of the present application, is the corrected horizontal position accuracy attenuation factor, which is obtained by the following formula:

[0163]

[0164] wherein,

[0165] tr{} is the trace of a matrix;

[0166] is the correction factor of the auxiliary navigation system, which is defined by the following way:

[0167] The number of available equipment for positioning of the ship navigation system is k, the kth reference signal source in the m reference signal sources is used as a supplementary reference signal source, and the correction factor of the ship navigation system is defined as follows:

[0168] ;

[0169]

[0170] wherein,

[0171] is the accuracy value of single positioning using the global satellite navigation system;

[0172] is the accuracy value of the kth available equipment of single positioning using the auxiliary navigation system, k = 1, 2,..., m.

[0173] correction factor for the kth reference signal source of the ship navigation system;

[0174] correction factor for the ship navigation system, including m reference signal sources.

[0175] According to one specific embodiment of the present application, the residual vector r of pseudo-range and the residual vector τ of carrier phase, and the corrected horizontal position accuracy attenuation factor performing the integrity state evaluation, specifically including:

[0176] if , an alarm of the combined navigation system being unavailable is sent out;

[0177] wherein,

[0178] r is the residual vector r of pseudo-range;

[0179] is the false alarm rate related threshold value.

[0180] According to one specific embodiment of the present application, the signal strength envelope front power received by the ship receiving device is converted into carrier-to-noise ratio CNR according to the requirement of the navigation system used, when CNR≥T p , an alarm of the combined navigation system being unavailable is sent out; different navigation system requirements are different, and conversion according to the specific system requirement is needed, for example, in addition to the k auxiliary navigation system reference signal sources, the others are satellite navigation system reference signal sources.

[0181] T p is the missed alarm rate related threshold value, which is set according to the statistical distribution relationship of the required missed alarm rate.

[0182] According to one specific embodiment of the present application, and T p The probability density function of the required missed alarm rate is determined by the following formula:

[0183] P( ， ) = missed alarm rate

[0184] 1-P( ， ) = false alarm rate

[0185] According to one specific embodiment of the present application, if the kth device does not send out an alarm, the position output by the combined navigation system is used for navigation, and if the kth device sends out an alarm, the k+1 devices are judged to exclude The maximum reference signal source, k takes 1, 2,..., m.

[0186] According to one specific embodiment of the present application, the reference signal source is taken when the following statistical quantity of the available device without alarm is taken to the minimum value:

[0187]

[0188] Wherein,

[0189] The combination number of the kth available device of the m reference signal sources;

[0190] Indicates the kth reference signal source.

[0191] The present application provides a ship navigation system integrity monitoring device, using any of the above ship navigation system integrity monitoring method for integrity monitoring, comprising:

[0192] The available device statistics module is used for counting the number of available satellites and the total number of available main stations and vice stations in the station chain of the coastal auxiliary navigation system;

[0193] The integrity state judgment module adopts different integrity state judgment strategies according to the results of the available device statistics module:

[0194] When the sum of the number of visible satellites in the integrated navigation system and the total number of available main stations and vice stations in the station chain of the coastal auxiliary navigation system is less than the integrity threshold, an alarm is issued that the integrated navigation system is unavailable;

[0195] When the sum of the number of available satellites in the integrated navigation system and the total number of available main stations and vice stations in the station chain of the coastal auxiliary navigation system is greater than or equal to the integrity threshold, the integrity of the integrated navigation system is judged by the following method:

[0196] If the number of visible satellites remains greater than or equal to the first preset threshold and remains unchanged within the time length of transmitting a complete almanac or 1 main frame, the position data is recorded continuously at multiple points for multiple times; the position probability estimate value is obtained by analyzing the pseudo-range, carrier phase and envelope front power of the received signal; the ship navigation system integrity state evaluation is performed according to the recorded position data and the position probability estimate value;

[0197] ​If the number of visible satellites remains less than the first preset threshold and changes in the time of transmitting a complete almanac or 1 main frame, a horizontal precision attenuation factor is calculated and corrected, and the ship navigation system integrity state is evaluated according to the recorded position data, the position probability estimate and the corrected horizontal precision attenuation factor;

[0198] Whether to issue an alarm is determined according to the integrity state evaluation result.

[0199] Embodiment 1

[0200] According to one specific embodiment of the present application, the ship navigation system integrity monitoring method of the present application is described in detail as follows.

[0201] The present application provides a ship navigation system integrity monitoring method, comprising the following steps:

[0202] The combined navigation system is composed of a global navigation satellite system and a coastal auxiliary navigation system;

[0203] The ship in operation simultaneously receives the information broadcast by the global navigation satellite system and the pulse groups respectively transmitted by the main stations and the vice stations in the station chain of the coastal auxiliary navigation system;

[0204] Different strategies are adopted for different numbers of visible satellites and the numbers of available main stations and vice stations in the station chain to make integrity alarm judgments:

[0205] When the sum of the number of visible satellites in the combined navigation system and the total number of available main stations and vice stations in the station chain of the coastal auxiliary navigation system is less than the integrity threshold, an alarm of unavailability of the combined navigation system is issued;

[0206] When the sum of the number of available satellites in the combined navigation system and the total number of available main stations and vice stations in the station chain of the coastal auxiliary navigation system is greater than or equal to the integrity threshold, the integrity of the combined navigation system is judged by the following method:

[0207] If the number of visible satellites remains greater than or equal to the first preset threshold and does not change in the time of transmitting a complete almanac or 1 main frame, the position data is recorded continuously at multiple points for multiple times; the position probability estimate is obtained by analyzing the pseudo-range, carrier phase and envelope front power of the received signal; and the ship navigation system integrity state is evaluated according to the recorded position data and the position probability estimate.

[0208] If the number of visible satellites remains less than the first preset threshold and changes in the time of transmitting a complete almanac or 1 main frame, the available main stations and secondary stations in the station chain of the coastal auxiliary navigation system and the global navigation satellite system are used as the reference signal source; the linear matrix H composed of the direction cosine vectors from each reference signal source to the ship receiving equipment is determined according to the position relationship between each reference signal source and the ship receiving equipment; the horizontal position accuracy attenuation factor is corrected according to the linear matrix H and the correction factor of the ship navigation system; and the integrity state of the ship navigation system is evaluated according to the pseudo-range, carrier phase and corrected horizontal position accuracy attenuation factor.

[0209] The integrity state evaluation result is used to determine whether to issue an alarm.

[0210] Embodiment 2

[0211] According to one specific embodiment of the present application, the ship navigation system integrity monitoring method of the present application is described in detail as follows: in the embodiment, the integrity threshold is 4, the first preset threshold is 4, the second preset threshold is 3, and the number of visible satellites remains greater than or equal to the first preset threshold and unchanged in the time of transmitting a complete almanac or 1 main frame.

[0212] The present application provides a ship navigation system integrity monitoring method, which comprises the following steps:

[0213] The combined navigation system is composed of the global navigation satellite system and the coastal auxiliary navigation system;

[0214] The ship in operation receives the information broadcast by the global navigation satellite system and the pulse groups respectively transmitted by the main stations and secondary stations in the station chain of the coastal auxiliary navigation system;

[0215] When the number of visible satellites is greater than or equal to the first preset threshold, the global navigation satellite system is available;

[0216] When the total number of available main stations and secondary stations in the station chain of the coastal auxiliary navigation system is greater than or equal to the second preset threshold, the auxiliary navigation system is available;

[0217] Different strategies are used for integrity alarm judgment for different numbers of visible satellites and different numbers of available main stations and secondary stations in the station chain:

[0218] When the sum of the number of visible satellites in the combined navigation system and the total number of available main stations and secondary stations in the station chain of the coastal auxiliary navigation system is less than the integrity threshold, an alarm is issued that the combined navigation system is unavailable;

[0219] When the sum of the number of available satellites in the combined navigation system and the total number of available main stations and secondary stations in the station chain of the coastal auxiliary navigation system is greater than or equal to the integrity threshold, the integrity of the combined navigation system is judged by the following method:

[0220] If the number of visible satellites remains greater than or equal to a first preset threshold and remains unchanged during the transmission of a complete almanac or a main frame, multiple position data are continuously recorded at multiple points; the position probability estimate is obtained based on the pseudorange, carrier phase, and envelope leading edge power of the received signal; and the integrity status of the ship navigation system is assessed based on the recorded position data and the position probability estimate, specifically:

[0221] Continuously record the positions displayed by the satellite system multiple times at multiple points and perform residual calculations;

[0222] Obtaining a probability estimate of the satellite system position;

[0223] Conduct integrity assessment of the ship's navigation system based on the coordinates of the last point, the coordinates of the last point displayed by the auxiliary navigation system, the estimated probability of the satellite system's position, and the estimated probability of the auxiliary navigation system's position;

[0224] Determine whether to issue an alarm based on the integrity status assessment results.

[0225] Example 3

[0226] According to a specific embodiment of the present invention, the integrity monitoring method of the ship navigation system of the present invention is described in detail below. In this embodiment, the integrity threshold is 4, the first preset threshold is 4, and the second preset threshold is 3. It can be seen that the number of satellites remains greater than or equal to the first preset threshold and the number remains unchanged within the duration of transmitting a complete almanac or 1 main frame.

[0227] The present invention provides a method for monitoring the integrity of a ship navigation system, comprising the following steps:

[0228] An integrated navigation system consisting of a global navigation satellite system and a coastal navigation aid system;

[0229] The ship in operation simultaneously receives the information broadcast by the global navigation satellite system and the pulse groups transmitted by the main station and the secondary station in the station chain of the coastal auxiliary navigation system;

[0230] When the number of visible satellites is greater than or equal to a first preset threshold, the global navigation satellite system is available;

[0231] When the total number of available main stations and secondary stations in the station chain of the coastal auxiliary navigation system is greater than or equal to a second preset threshold, the auxiliary navigation system is available;

[0232] Different strategies are used for integrity alarm judgment for different numbers of visible satellites and the number of available primary and secondary stations in the station chain:

[0233] When the number of visible satellites in the integrated navigation system and the total number of available primary and secondary stations in the station chain of the coastal aided navigation system are less than the integrity threshold, an integrated navigation system unavailable alarm is issued;

[0234] When the number of visible satellites in the integrated navigation system and the total number of available primary and secondary stations in the station chain of the coastal aided navigation system are greater than or equal to the integrity threshold, the following method is used to determine the integrity of the integrated navigation system:

[0235] If the number of visible satellites remains greater than or equal to the first preset threshold and unchanged within the time period of transmitting a complete almanac or 1 primary frame, then at n points, m measurements are taken respectively, and the positions of each measurement displayed by the satellite system are recorded. The following method is used to calculate the horizontal residual and the vertical residual :

[0236] , , , ;

[0237] , , , ;

[0238] wherein,

[0239] is the position of the jth point at the mth measurement, i , i , j ,

[0240] v x and v y are the degrees of freedom of the horizontal and vertical axes respectively, v x = v y = ( i -1)· j ;

[0241] The following method is used to obtain the satellite system position probability estimate :

[0242]

[0243] According to the coordinates (x, y) of the last point, the position coordinates ( , ) of the last point displayed by the aided navigation system, and the satellite system position probability estimate And auxiliary navigation system position probability estimate If the auxiliary navigation system position probability estimate, directly read from the system (Loran, Decca) shipboard equipment instrument panel, the value range is usually in 0.67~0.99. All coordinates are directly read from the field device value) is as follows:

[0244] If , the combined navigation system is not available alarm is issued;

[0245] If , the combined navigation system is not available alarm is issued;

[0246] Wherein,

[0247] “ The position probability estimate ratio threshold, The position coordinate threshold is calculated from the probability distribution density function according to the required false alarm rate and false alarm rate by the following formula under the current scene;

[0248] P( , ) = false alarm rate;

[0249] P( , ) = false alarm rate”;

[0250] P is the probability distribution density function;

[0251] According to the integrity state evaluation results to determine whether to issue an alarm.

[0252] Example 4

[0253] According to a specific embodiment of the present application, the ship navigation system integrity monitoring method of the present application is described in detail below. In this embodiment, the integrity threshold is 4, the first preset threshold is 4, and the second preset threshold is 3. The number of visible satellites remains less than the first preset threshold and changes in number within the time length of transmitting a complete almanac or 1 main frame.

[0254] The present application provides a ship navigation system integrity monitoring method, comprising the following steps:

[0255] The combined navigation system is composed of a global navigation satellite system and a coastal auxiliary navigation system;

[0256] The ship in operation simultaneously receives the information broadcast by the global navigation satellite system and the pulse groups respectively transmitted by the main station and the auxiliary station in the Decca chain of the coastal auxiliary navigation system;

[0257] For different number of visible satellites and number of available main stations and auxiliary stations in the Decca chain, different strategies are adopted for integrity alarm judgment:

[0258] when the sum of the number of visible satellites in the integrated navigation system and the total number of available primary stations and secondary stations in the station chain of the coastal aided navigation system is less than the integrity threshold, issuing an integrated navigation system unavailable alarm;

[0259] when the sum of the number of visible satellites in the integrated navigation system and the total number of available primary stations and secondary stations in the station chain of the coastal aided navigation system is greater than or equal to the integrity threshold, the following method is used to judge the integrity of the integrated navigation system:

[0260] if the number of visible satellites remains less than the first preset threshold and changes within the time length of transmitting a complete almanac or 1 primary frame, the available primary stations and secondary stations in the coastal aided navigation system and the global navigation satellite are used as reference signal sources together;

[0261] determining a linearization matrix H composed of direction cosine vectors of each reference signal source to the ship receiving device according to the positional relationship between each reference signal source and the ship receiving device;

[0262] correcting the horizontal position accuracy decay factor according to the linearization matrix H and the correction factor of the ship navigation system;

[0263] performing ship navigation system integrity state evaluation according to the pseudo-range, carrier phase and corrected horizontal position accuracy decay factor;

[0264] judging whether to issue an alarm according to the integrity state evaluation result.

[0265] Embodiment 5

[0266] According to a specific embodiment of the present application, the ship navigation system integrity monitoring method of the present application is described in detail below. In this embodiment, the integrity threshold is 4, the first preset threshold is 4, and the second preset threshold is 3. The number of visible satellites remains less than the first preset threshold and changes within the time length of transmitting a complete almanac or 1 primary frame.

[0267] The present application provides a ship navigation system integrity monitoring method, comprising the following steps:

[0268] an integrated navigation system composed of a global navigation satellite system and a coastal aided navigation system;

[0269] a ship in operation simultaneously receives information broadcast by the global navigation satellite system and pulse groups respectively transmitted by the primary stations and secondary stations in the station chain of the coastal aided navigation system;

[0270] different strategies are used for integrity alarm judgment for different numbers of visible satellites and numbers of available primary stations and secondary stations in the station chain:

[0271] When the sum of the number of visible satellites in the integrated navigation system and the total number of available primary stations and secondary stations in the station chain of the coastal aided navigation system is less than the integrity threshold, an integrated navigation system unavailable alarm is issued;

[0272] When the sum of the number of available satellites in the integrated navigation system and the total number of available primary stations and secondary stations in the station chain of the coastal aided navigation system is greater than or equal to the integrity threshold, the following method is used to judge the integrity of the integrated navigation system:

[0273] If the number of visible satellites remains less than the first preset threshold and the number changes within the time of transmitting a complete almanac or 1 primary frame, the available primary stations and secondary stations in the coastal aided navigation system and the global navigation satellite are used as reference signal sources together;

[0274] According to the positional relationship between each reference signal source and the ship receiving equipment, a linear matrix H composed of the direction cosine vectors of each reference signal source to the ship receiving equipment is determined;

[0275] According to the linear matrix H and the correction factor of the ship navigation system, the horizontal position accuracy decay factor is corrected;

[0276] According to the pseudo-range, carrier phase and the corrected horizontal position accuracy decay factor, the integrity state of the ship navigation system is evaluated;

[0277] According to the integrity state evaluation result, it is judged whether to issue an alarm;

[0278] Wherein,

[0279] The linear matrix H is obtained by the following method:

[0280] Among the m reference signal sources, the i-th reference signal source and the user receiving equipment have the following relationship in the plane position:

[0281]

[0282] Wherein,

[0283] c is the speed of light;

[0284] is the time taken by the reference signal source signal to propagate to the user equipment;

[0285] is the clock error of the reference signal source, which is obtained from the text of the reference signal source; the reference signal source broadcasts the text, and the user equipment automatically stores the text after receiving it, and then calculates the positioning.

[0286] is the clock error of the ship user equipment;

[0287] ​x, y represent the coordinates of the location of the ship user equipment;

[0288] , is the coordinates of the location of the first reference signal source, is 1-m;

[0289] is the distance between the first reference signal source and the ship user equipment;

[0290] The above formula is simplified to obtain the following linearization model: ;

[0291] wherein,

[0292] , represents the direction cosine of the unit vector from the location of the ship user equipment to the first reference signal source;

[0293] is the distance between the ship user equipment and the reference signal source in the x direction;

[0294] is the distance between the ship user equipment and the reference signal source in the y direction;

[0295] The linearization model is expressed in matrix form: L = HX;

[0296] wherein,

[0297]

[0298]

[0299]

[0300] L represents the matrix form of the distance between each reference signal source and the ship user equipment;

[0301] Solving X obtains the following form:

[0302] X = (H T H) -1 H T L;

[0303] wherein,

[0304] H T is the transpose matrix of H, H -1 is the inverse matrix of H.

[0305] wherein, The modified horizontal position accuracy degradation factor is obtained by the following formula:

[0306]

[0307] wherein,

[0308] tr{} is a trace of a matrix;

[0309] The modified factor of the auxiliary navigation system is defined by the following manner:

[0310] The number of available devices for positioning of the ship navigation system is k, the kth reference signal source in the m reference signal sources is used as a supplementary reference signal source, and the modified factor of the ship navigation system is defined as follows:

[0311]

[0312]

[0313] wherein,

[0314] is a precision value of single global satellite navigation system positioning;

[0315] is a precision value of the kth available device of single auxiliary navigation system positioning, k is 1, 2,..., m;

[0316] is a modified factor of the kth reference signal source in the ship navigation system;

[0317] is a modified factor of the ship navigation system, including the m reference signal sources.

[0318] wherein, the integrity state assessment is performed according to the residual error vector r of the pseudo-range and the residual error vector τ of the carrier phase and the modified horizontal position accuracy degradation factor The integrity state assessment specifically includes:

[0319] If , an alarm of the combined navigation system being unavailable is issued;

[0320] wherein,

[0321] r is the residual error vector r of the pseudo-range;

[0322] is a false alarm rate related threshold value.

[0323] wherein, the signal strength received by the ship receiving device is intercepted envelope front power, which is converted into a carrier-to-noise ratio CNR according to the requirements of the navigation system used, and when CNR≥T​p When , an alarm indicating that the combined navigation system is unavailable is issued; different navigation systems have different requirements and need to be converted according to the requirements of the specific system. For example, except for the reference signal sources of the k auxiliary navigation systems in m, the others are all reference signal sources of the satellite navigation system.

[0324] T p It is the threshold value related to the missed alarm rate, which is set according to the required statistical distribution relationship of the missed alarm rate.

[0325] in, and T p The probability distribution density function of the required missed alarm rate is determined by the following formula:

[0326] P( ， ) = Missed Alarm Rate

[0327] 1-P( ， ) = false alarm rate

[0328] If the kth device does not issue an alarm, the position output by the integrated navigation system is used for navigation. If the kth device issues an alarm, the k+1 devices are judged to eliminate the The largest reference signal source, k is 1, 2, ..., m.

[0329] The navigation positioning is performed by taking the reference signal source when the following statistics are at their minimum value among the available devices without alarms:

[0330]

[0331] in,

[0332] is the number of combinations of the kth available device for m reference signal sources;

[0333] Indicates the A reference signal source.

[0334] Example 6

[0335] According to a specific embodiment of the present invention, the integrity monitoring device for a ship navigation system of the present invention is described in detail below.

[0336] The present invention provides a ship navigation system integrity monitoring device, which uses any of the above-mentioned ship navigation system integrity monitoring methods to perform integrity monitoring, including:

[0337] Available equipment statistics module, used to count the number of available satellites and the total number of available main and secondary stations in the coastal auxiliary navigation system station chain;

[0338] The integrity state judging module adopts different integrity state judging strategies according to the available device statistics module result:

[0339] When the sum of the number of visible satellites in the combined navigation system and the total number of available main stations and vice stations in the station chain of the coastal auxiliary navigation system is less than the integrity threshold, an alarm is issued that the combined navigation system is unavailable;

[0340] When the sum of the number of available satellites in the combined navigation system and the total number of available main stations and vice stations in the station chain of the coastal auxiliary navigation system is greater than or equal to the integrity threshold, the following method is used to judge the integrity of the combined navigation system:

[0341] If the number of visible satellites remains greater than or equal to the first preset threshold and does not change within the time duration of transmitting a complete almanac or 1 main frame, the position data is recorded continuously at multiple points for multiple times; the position probability estimate value is obtained by analyzing the pseudo-range, carrier phase and envelope front power of the received signal; and the integrity state of the ship navigation system is evaluated according to the recorded position data and the position probability estimate value;

[0342] If the number of visible satellites remains less than the first preset threshold and changes within the time duration of transmitting a complete almanac or 1 main frame, the available main stations and vice stations in the coastal auxiliary navigation system and the global navigation satellite are used as reference signal sources together; the linearization matrix H composed of the direction cosine vectors of each reference signal source to the ship receiving device is determined according to the position relationship between each reference signal source and the ship receiving device; the horizontal position accuracy decay factor is corrected according to the linearization matrix H and the correction factor of the ship navigation system; and the integrity state of the ship navigation system is evaluated according to the pseudo-range, carrier phase and corrected horizontal position accuracy decay factor;

[0343] Whether to issue an alarm is determined according to the integrity state evaluation result.

[0344] The above only describes the preferred embodiments of the present application and is not used to limit the present application. Various modifications and changes can be made by those skilled in the art based on the spirit and principles of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application is included in the protection scope of the present application.

Claims

1. A method for monitoring the integrity of a ship navigation system, characterized in that: The steps include: An integrated navigation system consisting of a global navigation satellite system and a coastal navigation aid system; The ship in operation simultaneously receives the information broadcast by the global navigation satellite system and the pulse groups transmitted by the main station and the secondary station in the station chain of the coastal auxiliary navigation system; Different strategies are used for integrity alarm judgment for different numbers of visible satellites and the number of available primary and secondary stations in the station chain: When the sum of the number of visible satellites in the integrated navigation system and the total number of available primary and secondary stations in the coastal auxiliary navigation system chain is less than the integrity threshold, an integrated navigation system unavailable alarm is issued; When the sum of the number of available satellites in the integrated navigation system and the total number of available primary and secondary stations in the coastal auxiliary navigation system chain is greater than or equal to the integrity threshold, the integrity of the integrated navigation system is determined using the following method: If the number of visible satellites remains greater than or equal to a first preset threshold and remains unchanged during the transmission of a complete almanac or a main frame, the positions displayed by the satellite system are recorded multiple times at multiple points continuously to perform residual calculations; Obtaining a probability estimate of the satellite system position; Conduct integrity assessment of the ship's navigation system based on the coordinates of the last point, the coordinates of the last point displayed by the auxiliary navigation system, the estimated probability of the satellite system's position, and the estimated probability of the auxiliary navigation system's position; If the number of visible satellites remains less than a first preset threshold value during the transmission of a complete almanac or a main frame and the number changes, the available primary and secondary stations in the coastal auxiliary navigation system and the global navigation satellites are used as reference signal sources; Determine the linearization matrix H composed of the direction cosine vectors from each reference signal source to the ship receiving device according to the positional relationship between each reference signal source and the ship receiving device; Correct the horizontal position dilution of precision factor according to the linearization matrix H and the correction factor of the ship navigation system; Conduct integrity assessment of the ship's navigation system based on pseudorange, carrier phase and corrected horizontal position dilution of precision factor; Determine whether to issue an alarm based on the integrity status assessment results.

2. The method for monitoring the integrity of a ship navigation system according to claim 1, wherein: When the number of visible satellites is greater than or equal to a first preset threshold, the global navigation satellite system is available; when the total number of available main stations and secondary stations in the station chain of the coastal auxiliary navigation system is greater than or equal to a second preset threshold, the auxiliary navigation system is available.

3. The method for monitoring the integrity of a ship navigation system according to claim 2, wherein: The integrity threshold is 4, the first preset threshold is 4, and the second preset threshold is 3.

4. The method for monitoring the integrity of a ship navigation system according to claim 3, wherein: When the number of visible satellites remains greater than or equal to the first preset threshold value and remains unchanged during the transmission of a complete almanac or a main frame, measure m times at n points respectively, record the position of each measurement displayed by the satellite system, and use the following method to calculate the residual of the horizontal coordinate and the residual of the vertical axis Calculation: ， ， ， ； ， ， ， ； in, is the jth point i The position of the second measurement, i Take 1-m, j Take 1~n; v x and v y are the degrees of freedom of the horizontal and vertical axes, respectively. v x = v y = ( i -1) j ; The following method is used to obtain the estimated probability of the satellite system position : According to the coordinates (x, y) of the last point, the position coordinates of the last point displayed by the auxiliary navigation system ( , ), satellite system position probability estimate And the estimated probability of the auxiliary navigation system position Conduct integrity assessments as follows: like , then an alarm indicating that the integrated navigation system is unavailable is issued; like , then an alarm indicating that the integrated navigation system is unavailable is issued; in, T a is the position probability estimation ratio threshold, is the position coordinate threshold, which is calculated by the probability distribution density function in the current scene according to the required missed alarm rate and false alarm rate using the following formula; P( , ) = missed alarm rate; 1-P( , ) = false alarm rate; P is the probability distribution density function.

5. The method for monitoring the integrity of a ship navigation system according to claim 3, wherein: The linearization matrix H is obtained as follows: Among the m reference signal sources, the The relationship between the reference signal source and the user receiving device in the plane is as follows: in, c is the speed of light; The time taken for the reference signal source signal to propagate to the user equipment; is the clock error of the reference signal source, which is obtained from the message of the reference signal source; Clock deviation for ship user equipment; x, y represent the location coordinates of the ship user equipment; , For the The position coordinates of the reference signal source, Take 1-m; For the The distance between the reference signal source and the ship user equipment; Simplifying the above formula, we get the following linearized model: ; in, 、 Indicates that the position of the ship user equipment points to the The direction cosines of the unit vector of the reference signal source; is the distance between the ship user equipment and the reference signal source in the x direction; is the distance between the ship user equipment and the reference signal source in the y direction; The linearized model is expressed in matrix form: L=HX; in, L represents the matrix form of the distance between each reference signal source and the ship user equipment; Then solving X yields the following form: X=(H T H) -1 H T L; in, H T is the transposed matrix of H, H -1 is the inverse matrix of H.

6. The method for monitoring the integrity of a ship navigation system according to claim 5, characterized in that: is the corrected horizontal position dilution of precision factor, which is obtained by the following formula: in, tr{} is the trace of the matrix; is the correction factor for the ship's navigation system, defined as follows: The number of available devices for positioning in the ship navigation system is k, and the kth reference signal source among the m reference signal sources is used as a supplementary reference signal source. The correction factor of the ship navigation system is The definition is as follows: ； in, It is the accuracy value of positioning using a single global satellite navigation system; is the accuracy value of the kth available device using a single assisted navigation system for positioning, where k is 1, 2, .., m; is the correction factor of the kth reference signal source in the ship navigation system; is the correction factor of the ship navigation system, including m reference signal sources.

7. The method for monitoring the integrity of a ship navigation system according to claim 6, wherein: According to the residual vector r of pseudorange and the residual vector τ of carrier phase and the corrected horizontal position precision reduction factor Conduct integrity status assessment, including: like , then an alarm indicating that the integrated navigation system is unavailable is issued; in, r is the residual vector r of the pseudorange; is the false alarm rate related threshold.

8. The method for monitoring the integrity of a ship navigation system according to claim 7, wherein: The signal strength received by the ship receiving equipment is intercepted and the envelope front power is converted into the carrier-to-noise ratio CNR according to the requirements of the navigation system used. When CNR≥T p When the integrated navigation system is unavailable, an alarm is issued; T p It is the threshold value related to the missed alarm rate, which is set according to the required statistical distribution relationship of the missed alarm rate.

9. The method for monitoring the integrity of a ship navigation system according to claim 8, wherein: If the kth device does not issue an alarm, the position output by the integrated navigation system is used for navigation. If the kth device issues an alarm, the k+1 devices are judged to eliminate the The largest reference signal source, k is 1, 2, ..., m.

10. The method for monitoring the integrity of a ship navigation system according to claim 9, wherein: The reference signal source when the following statistics are at their minimum value among the available devices without alarms is used for navigation and positioning: in, is the number of combinations of the kth available device for m reference signal sources; Indicates the A reference signal source.

11. A ship navigation system integrity monitoring device, characterized in that: Integrity monitoring is performed using the ship navigation system integrity monitoring method according to any one of claims 1 to 10, comprising: Available equipment statistics module, used to count the number of available satellites and the total number of available main and secondary stations in the coastal auxiliary navigation system station chain; The integrity status judgment module adopts different integrity status judgment strategies based on the results of the available equipment statistics module: When the sum of the number of visible satellites in the integrated navigation system and the total number of available main and secondary stations in the station chain of the coastal auxiliary navigation system is less than the integrity threshold, an integrated navigation system unavailable alarm is issued; When the sum of the number of available satellites in the integrated navigation system and the total number of available primary and secondary stations in the coastal auxiliary navigation system chain is greater than or equal to the integrity threshold, the integrity of the integrated navigation system is determined using the following method: If the number of visible satellites remains greater than or equal to a first preset threshold and remains unchanged during the transmission of a complete almanac or a main frame, the positions displayed by the satellite system are recorded multiple times at multiple points continuously to perform residual calculations; Obtaining a probability estimate of the satellite system position; Conduct integrity assessment of the ship's navigation system based on the coordinates of the last point, the coordinates of the last point displayed by the auxiliary navigation system, the estimated probability of the satellite system's position, and the estimated probability of the auxiliary navigation system's position; If the number of visible satellites remains less than a first preset threshold value during the transmission of a complete almanac or a main frame and the number changes, the available primary and secondary stations in the coastal auxiliary navigation system and the global navigation satellites are used as reference signal sources; Determine the linearization matrix H composed of the direction cosine vectors from each reference signal source to the ship receiving device according to the positional relationship between each reference signal source and the ship receiving device; Correct the horizontal position dilution of precision factor according to the linearization matrix H and the correction factor of the auxiliary navigation system; Conduct integrity assessment of the ship's navigation system based on pseudorange, carrier phase and corrected horizontal position dilution of precision factor; Determine whether to issue an alarm based on the integrity status assessment results.

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