A typical trusted PNT client architecture

Abstract

The present invention relates to the field of trusted PNT technology, and in particular to a typical trusted PNT user-side architecture, including: relying on a PNT information source, an authentication module, an alarm module and a resilience module contained in the architecture, providing a user with trusted PNT information with basic capabilities, protection capabilities, alarm capabilities and resilience capabilities; comparing the timing and longitude and latitude information obtained based on each information source to determine whether each PNT information is qualified, and when it is determined that unqualified PNT information exists, adjusting the acquisition frequency of the PNT information to increase the amount of data acquisition, processing each re-acquired PNT information, determining a final trusted PNT information acquisition method according to the qualified rate of each data, processing the determined abnormal source, determining a trusted PNT information acquisition method in a targeted manner, and integrating the information of each information source in a targeted manner, thereby effectively improving the acquisition efficiency of the PNT information.

Description

Technical Field

[0001] The present invention relates to the field of trusted PNT technology, and in particular to a typical trusted PNT client architecture. Background Art

[0002] As human society enters the era of informatization, digitalization and intelligent development, positioning, navigation and timing (PNT) information is deeply integrated into all walks of life, and space-time information and positioning and navigation services will become important new infrastructure.

[0003] At present, relevant technical research has been carried out on trusted PNT at home and abroad, but it mainly focuses on integrity, anti-interference and other aspects, and no unified opinion has been formed. The current definition of trusted PNT is mainly proposed based on different scenarios and focuses on the characteristics of different industries. It lacks universal and consensus knowledge and understanding. The indicator system also mainly focuses on the needs of their respective business capabilities and has certain industry limitations.

[0004] Chinese Patent Publication No.: CN116600246A discloses a PNT credibility system design and measurement method, including credibility system architecture model design and corresponding credibility measurement method; the credibility system architecture model includes a system three-dimensional architecture model and an engineering architecture model, the system three-dimensional architecture model consists of a cube factor and an outer contour factor, the cube factor consists of three dimensions: a hierarchical factor, a navigation source factor and an influencing factor, the outer contour factor covers the cube factor, specifically, refers to the credibility technology guaranteed by traceability; the engineering architecture model reflects the collaborative work between heterogeneous navigation sources under the PNT credibility system, and the contribution of each navigation source and related technology in the credibility system, and finally proposes a credibility measurement method corresponding to the credibility system architecture model; it can be seen that the above technical solution has the following problems: it does not consider whether each information source is credible, and does not consider the targeted fusion of information of each information source according to the actual information acquisition situation, which affects the accuracy of the acquired PNT information and further affects the efficiency of PNT information acquisition. Summary of the invention

[0005] To this end, the present invention provides a typical trusted PNT user terminal architecture to overcome the problem in the prior art that the determination of whether each information source is trustworthy is not considered, and the information of each information source is not integrated in a targeted manner according to the actual information acquisition situation, which affects the accuracy of the acquired PNT information and further affects the efficiency of obtaining PNT information.

[0006] To achieve the above objectives, the present invention provides a typical trusted PNT client architecture, including:

[0007] A PNT information source for obtaining PNT information, including a GNSS PNT source for obtaining GNSS PNT information, an external source for obtaining external PNT information, and a local source for obtaining local PNT information, wherein the GNSS PNT information includes a navigation message and navigation information;

[0008] an authentication module, comprising a message authentication unit for authenticating the navigation message and a spread spectrum code authentication unit for authenticating the navigation signal, the authentication module being used to send the GNSS PNT information with a failed authentication result to the PNT information source, or to store the GNSS PNT information with a passed authentication result;

[0009] The alarm module is used to obtain several groups of data information based on the PNT information of the received PNT information source and the GNSS PNT information stored in the authentication module, and determine whether the PNT information is qualified according to the comparison results of each group of data information, and when the PNT information is determined to be unqualified, adjust the acquisition frequency of the PNT information, and determine the final acquisition method of the credible PNT information based on the qualified rate of each re-acquired PNT information, including:

[0010] Determine the qualified PNT information as the final credible PNT information;

[0011] or, determining the abnormal source based on the data matching result of the single column data, and adjusting the key length of the electronic message authentication unit to a corresponding value according to the determined abnormal source, performing self-check on the external source or performing self-check on the local source, and controlling the PNT information source to reacquire the PNT information;

[0012] The resilience module is used to fuse the PNT information re-acquired by the alarm module to finally obtain credible PNT information, including: adjusting the weight coefficient for the corresponding abnormal source in the information fusion process to a corresponding value based on the qualified rate.

[0013] Furthermore, the abnormal source is obtained by counting the single column data, arranging the data in descending order according to the number of identical data, and determining the information source corresponding to each data except the data with the largest proportion as the abnormal source.

[0014] Further, the message authentication unit is used to receive the navigation message and implement one-way broadcast authentication on the navigation message to obtain a first authentication result, wherein the first authentication result includes pass or fail;

[0015] The spread spectrum code authentication unit is used to receive the navigation signal, encrypt the spread spectrum code of the pseudo-random noise code broadcast by the satellite, replace the original public spread spectrum code chip with the encrypted spread spectrum code chip generated based on the cryptographic algorithm, perform authentication according to the code sequence, and obtain a second authentication result, which includes pass or fail;

[0016] The GNSS PNT information includes navigation, positioning and timing.

[0017] Further, the alarm module sequentially analyzes and obtains several groups of data information based on the external PNT information and local PNT information of the received PNT information source, and a single group of data information includes longitude and latitude coordinates and corresponding acquisition time points;

[0018] The alarm module is used to determine whether the PNT information is qualified according to the comparison results of each group of data information, including:

[0019] If the data of each group is consistent, the PNT information is judged to be qualified;

[0020] If there is inconsistent data, the PNT information is determined to be unqualified, and the acquisition frequency of the PNT information is adjusted according to the proportion of the amount of unmatched data to the total amount of data in each group of data information.

[0021] Furthermore, the alarm module is used to adjust the acquisition frequency of PNT information based on the proportion of data volume, wherein:

[0022] The acquisition frequency of PNT information determined based on the data volume ratio is proportional to the data volume ratio.

[0023] Furthermore, the alarm module is used to determine the pass rate based on each PNT information re-acquired, and determine the acquisition method of the final credible PNT information based on the pass rate, including:

[0024] Calculate the ratio of the number of PNT information determined to be qualified to the total number of PNT information re-acquired, and determine the ratio as the qualified rate;

[0025] If the qualified rate is greater than the preset qualified rate, the PNT information judged as qualified is determined as the final credible PNT information;

[0026] If the qualified rate is less than or equal to the preset qualified rate, the data source of each obtained matching abnormal information is recorded as an abnormal source, and the abnormal source is processed.

[0027] Furthermore, the alarm module is used to process the abnormal source, including:

[0028] If the abnormal source is a GNSS PNT source, the GNSS PNT source is self-checked and the key length of the message authentication unit is adjusted to the corresponding value;

[0029] If the abnormal source is an external source, self-check the external source;

[0030] If the abnormal source is a local source, self-check the local source.

[0031] Furthermore, the toughness module is used to adjust the weight coefficient for the corresponding abnormal source in the information fusion process to a corresponding value based on the qualified rate, wherein:

[0032] The correction range of the weight coefficient for the corresponding abnormal source determined based on the qualified rate is inversely proportional to the qualified rate.

[0033] Further, the alarm module is used to adjust the key length of the electronic message authentication unit to a corresponding value based on the pass rate, wherein:

[0034] The correction range of the key length of the message authentication unit determined based on the pass rate is inversely proportional to the pass rate.

[0035] Furthermore, the resilience module is used to fuse the PNT information determined to be reacquired by the alarm module;

[0036] The resilience module is used to fuse the PNT information determined and re-acquired by the alarm module, including:

[0037] Determine the current longitude, assign corresponding weight coefficients to the current longitude determined by GNSS PNT information, local PNT information and external PNT information, and sum them up to obtain the current longitude after information fusion;

[0038] Determine the current latitude, assign corresponding weight coefficients to the current latitude determined by GNSS PNT information, local PNT information and external PNT information, and sum them up to obtain the current latitude after information fusion;

[0039] Determine the current time, assign corresponding weight coefficients to the current time determined by GNSS PNT information, local PNT information and external PNT information, and sum them up to obtain the current time after information fusion.

[0040] Compared with the prior art, the beneficial effect of the present invention lies in that it relies on the PNT information source, authentication module, alarm module and resilience module contained in the architecture to provide users with trusted PNT information with basic capabilities, protection capabilities, alarm capabilities and resilience capabilities; compares the timing and longitude and latitude information obtained based on each information source to determine whether each PNT information is qualified, and when it is determined that unqualified PNT information exists, adjusts the frequency of obtaining PNT information to increase the amount of data obtained, processes the re-acquired PNT information, determines the final method of obtaining trusted PNT information according to the qualified rate of each data, processes the determined abnormal source, determines the method of obtaining trusted PNT information in a targeted manner, and integrates the information of each information source in a targeted manner, thereby effectively improving the efficiency of obtaining PNT information.

[0041] Furthermore, it includes several information sources, GNSS PNT sources, external sources and local sources, and comprehensively determines the information determined by each information source to determine the final credible PNT information, which effectively improves the credibility of data acquisition. The acquisition method of the final credible PNT information is determined based on the pass rate. When the pass rate is greater than the preset pass rate, in this case, there is abnormal data due to accidental abnormal interference. At this time, the PNT information determined to be qualified is determined as the final credible PNT information; when it is less than or equal to the preset pass rate, the information source with abnormalities in this case processes each abnormal source in a targeted manner; and after completing the processing of the abnormal source, the fusion method of each data is determined according to the specific data acquisition situation, which effectively improves the reliability of the data and further improves the efficiency of obtaining PNT information. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A block diagram of a typical trusted PNT client architecture of an embodiment of the present invention;

[0043] Figure 2 A logic determination diagram of whether the PNT information is qualified based on the comparison results of each group of data information by the alarm module of the embodiment of the present invention;

[0044] Figure 3 A logical decision diagram of an alarm module according to an embodiment of the present invention for determining a method for obtaining final credible PNT information based on a qualified rate;

[0045] Figure 4 This is a logical decision diagram for the alarm module in an embodiment of the present invention to process an abnormal source. DETAILED DESCRIPTION

[0046] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0047] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0048] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0049] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] See also Figure 1 , Figure 2 , Figure 3 as well as Figure 4 As shown, they are respectively a module block diagram of a typical trusted PNT client architecture of an embodiment of the present invention, a logic decision diagram of the alarm module determining whether the PNT information is qualified based on the comparison results of each group of data information, a logic decision diagram of the alarm module determining the acquisition method of the final trusted PNT information based on the qualified rate, and a logic decision diagram of the alarm module processing the abnormal source; a typical trusted PNT client architecture of an embodiment of the present invention includes:

[0051] A PNT information source for obtaining PNT information, including a GNSS PNT source for obtaining GNSS PNT information, an external source for obtaining external PNT information, and a local source for obtaining local PNT information, wherein the GNSS PNT information includes a navigation message and navigation information;

[0052] an authentication module, comprising a message authentication unit for authenticating the navigation message based on asymmetric cryptography technology and a spread spectrum code authentication unit for authenticating the navigation signal based on a cryptographic algorithm, the authentication module being used to send the GNSS PNT information with a failed authentication result to the PNT information source, or to store the GNSS PNT information with a passed authentication result;

[0053] The alarm module is used to obtain several groups of data information based on the PNT information of the received PNT information source and the GNSS PNT information stored in the authentication module, and determine whether the PNT information is qualified according to the comparison results of each group of data information, and when the PNT information is determined to be unqualified, adjust the acquisition frequency of the PNT information, and determine the final acquisition method of the credible PNT information based on the qualified rate of each re-acquired PNT information, including:

[0054] Determine the qualified PNT information as the final credible PNT information;

[0055] or, determining the abnormal source based on the data matching result of the single column data, and adjusting the key length of the electronic message authentication unit to a corresponding value according to the determined abnormal source, performing self-check on the external source or performing self-check on the local source, and controlling the PNT information source to reacquire the PNT information;

[0056] The resilience module is used to fuse the PNT information re-acquired by the alarm module to finally obtain credible PNT information, including: adjusting the weight coefficient for the corresponding abnormal source in the information fusion process to a corresponding value based on the qualified rate.

[0057] Specifically, the method for obtaining the abnormal source is to perform statistics on a single column of data, which may be a single column of longitude data, a single column of latitude data, or a single column of timing data, and arrange the data in descending order according to the number of identical data, and determine the information source corresponding to each data except the data with the largest proportion as the abnormal source.

[0058] Specifically, it relies on the PNT information source, authentication module, alarm module and resilience module included in the architecture to provide users with trusted PNT information with basic capabilities, protection capabilities, alarm capabilities and resilience capabilities; compares the timing and longitude and latitude information obtained based on each information source to determine whether each PNT information is qualified, and when it is determined that there is unqualified PNT information, adjusts the frequency of obtaining PNT information to increase the amount of data obtained, processes the re-acquired PNT information, determines the final method of obtaining trusted PNT information according to the qualified rate of each data, processes the determined abnormal source, determines the method of obtaining trusted PNT information in a targeted manner, and integrates the information of each information source in a targeted manner, effectively improving the efficiency of obtaining PNT information.

[0059] Specifically, in the further optimization scheme, the resilience module includes an abnormal isolation / recovery unit, a control and backup unit, and an information fusion processing unit. The information fusion processing unit fuses the re-acquired PNT information according to the instructions generated by the alarm information, and finally obtains trusted PNT information.

[0060] The abnormal isolation / recovery unit generates corresponding isolation / recovery instructions according to the alarm information sent by the alarm module, and sends the corresponding instructions to the control and backup unit.

[0061] The control and backup unit first backs up the PNT information that generates the alarm (determined to be unqualified PNT information), and isolates or recovers the alarm PNT information according to the instructions obtained from the abnormal isolation / recovery unit, and sends the recovered PNT information to the alarm module again.

[0062] The information fusion processing unit receives the PNT information that has successfully passed the verification of the alarm module, selects the fusible information source and the corresponding fusion state to fuse the PNT information, and finally obtains the credible PNT information.

[0063] Specifically, the alarm module includes a self-check unit and a cross-check unit. It performs self-check processing according to the unique characteristics of different PNT information sources, and cross-compares the data of different PNT sources to achieve multi-source cross-check. Finally, the verified PNT information and the alarm information found during the self-check and cross-check process are sent to the resilience module for information anomaly isolation, recovery and information fusion processing.

[0064] After the self-checking unit obtains the PNT information, it performs self-checking on the corresponding PNT information according to the characteristics of different PNT sources. The GNSS PNT source can use RAIM / ARAIM and other technologies to achieve the self-checking function. Other external sources and other local sources should also have corresponding self-checking units to achieve self-checking of the corresponding PNT information. Finally, the self-checking abnormal alarm information is sent to the resilience module 4, and the PNT information that passes the self-checking is sent to the cross-checking unit.

[0065] The cross-check unit will integrate the PNT information data that has passed the self-check and perform horizontal comparison processing on the information. Finally, the cross-check abnormal alarm information will be sent to the PNT information that has passed the self-check and sent to the resilience module.

[0066] The alarm module performs self-verification and cross-verification on non-homologous PNT information, and feeds back the alarm result to the resilience module, thereby realizing the alarm capability of the trusted PNT client architecture.

[0067] Specifically, the external sources include odometers, visual sensors, and laser radars;

[0068] Specifically, the odometer determines the cumulative driving distance through the rotation of the moving parts to calculate the position information; the visual sensor obtains environmental characteristics and relative position information through image analysis technology; the lidar constructs a three-dimensional model of the surrounding environment and performs precise positioning by emitting lasers and receiving reflected signals. External sources complement and assist GNSS PNT sources to effectively improve the accuracy, robustness and reliability of positioning.

[0069] The local source includes a local atomic clock and an inertial device;

[0070] Specifically, the local atomic clock is a clock device that can provide a time reference; inertial devices include gyroscopes and accelerometers, which indirectly obtain position information and speed information by measuring the motion state of an object. Local sources provide independent, local PNT-related data and support, enhancing the reliability of positioning and navigation.

[0071] Specifically, the message authentication unit is used to receive the navigation message and implement one-way broadcast authentication of the navigation message through asymmetric cryptography technology to finally obtain the authentication result, which includes pass or fail;

[0072] The spread spectrum code authentication unit is used to receive the navigation signal, and encrypt part of the spread spectrum code of the pseudo-random noise code broadcast by the satellite, replace the original public spread spectrum code chip with the encrypted spread spectrum code chip generated by the cryptographic algorithm, perform authentication according to the code sequence, and obtain the authentication result, which includes pass or fail;

[0073] Specifically, the GNSS PNT source refers to the GNSS PNT information provided including navigation, positioning and timing.

[0074] Specifically, the alarm module sequentially analyzes and obtains several groups of data information based on the external PNT information and local PNT information received from the PNT information source, and a single group of data information includes longitude and latitude coordinates and corresponding acquisition time points;

[0075] The alarm module is used to determine whether the PNT information is qualified according to the comparison results of each group of data information, including:

[0076] If the data of each group is consistent, the PNT information is judged to be qualified;

[0077] If there is inconsistent data, the PNT information is determined to be unqualified, and the acquisition frequency of the PNT information is adjusted according to the proportion of the amount of unmatched data to the total amount of data in each group of data information.

[0078] Specifically, the alarm module is used to adjust the acquisition frequency of PNT information based on the proportion of data volume, wherein:

[0079] The acquisition frequency of PNT information determined based on the data volume ratio is proportional to the data volume ratio.

[0080] In this embodiment, optionally, the data volume proportion B is compared with the first preset data volume proportion B1 and the second preset data volume proportion B2:

[0081] If B≤B1, the acquisition frequency of PNT information is determined as the first frequency f1, and f1=1.11f0;

[0082] If B1<B≤B2, the acquisition frequency of PNT information is determined as the second frequency f2, and f2=1.22f0 is set;

[0083] If B>B2, the acquisition frequency of PNT information is determined to be the third frequency f3, and f3=1.33f0;

[0084] Among them, f0 is the initial acquisition frequency, B1 is selected in the interval [0.13, 0.2], and B2 is selected in the interval [0.31, 0.4].

[0085] Specifically, asymmetric cryptography technology uses various asymmetric cryptography schemes to achieve one-way broadcast authentication of navigation messages, and ultimately obtain reliable GNSS navigation messages; the process of authenticating navigation signals based on cryptographic algorithms is a method of using spread spectrum technology to improve the signal's ability to resist interference and deception attacks. It encrypts part of the spread spectrum code of the pseudo-random noise code broadcast by the satellite, and uses encrypted spread spectrum code chips generated based on cryptographic algorithms to replace the original public spread spectrum code chips, thereby ensuring the source and integrity of the signal.

[0086] Specifically, the alarm module is used to determine the pass rate based on each PNT information that is reacquired, including:

[0087] Calculate the ratio of the number of PNT information determined to be qualified to the total number of PNT information re-acquired, and determine the ratio as the qualified rate;

[0088] The alarm module is used to determine the acquisition method of the final credible PNT information based on the qualification rate, including:

[0089] If the qualified rate is greater than the preset qualified rate, the PNT information judged as qualified is determined as the final credible PNT information;

[0090] If the qualified rate is less than or equal to the preset qualified rate, the data source of each obtained matching abnormal information is recorded as an abnormal source, and the abnormal source is processed.

[0091] Specifically, the preset pass rate L0 is selected within the interval [0.75, 0.83].

[0092] Specifically, the alarm module is used to process the abnormal source, including:

[0093] If the abnormal source is a GNSS PNT source, the GNSS PNT source is self-checked and the key length of the message authentication unit is adjusted to the corresponding value;

[0094] If the abnormal source is an external source, self-check the external source;

[0095] If the abnormal source is a local source, self-check the local source.

[0096] Specifically, the alarm module performs self-verification processing according to the unique characteristics of different PNT information sources. For the PNT information source data of GNSS, the RAIM / ARAIM technology can be used to implement the self-verification function. At the same time, in a complete trusted PNT user-side architecture, self-verification units of other external sources and other local sources should also be included to perform self-verification on external sources and local sources.

[0097] The cross-check will be based on the result of the self-check, and the data of different PNT sources will be processed comprehensively to perform multi-source cross-check. After the cross-check is completed, the result of the cross-check is fed back to the resilience module.

[0098] Specifically, the resilience module should include an abnormality isolation / recovery unit, a control and backup unit, and an information fusion processing unit.

[0099] Specifically, the toughness module is used to adjust the weight coefficient for the corresponding abnormal source in the information fusion process to a corresponding value based on the qualified rate, wherein:

[0100] The correction range of the weight coefficient for the corresponding abnormal source determined based on the qualified rate is inversely proportional to the qualified rate.

[0101] In this embodiment, optionally, the qualified rate L is compared with a first pre-qualified rate comparison threshold L1 and a second preset qualified rate comparison threshold L2:

[0102] If L≤L1, the weight coefficient of the corresponding abnormal source is corrected to x1, and x1=0.74x0 is set;

[0103] If L1<L≤L2, the weight coefficient of the corresponding abnormal source is corrected to x2, and x2=0.82x0 is set;

[0104] If L>L2, the weight coefficient of the corresponding abnormal source is corrected to x3, and x3=0.9x0 is set;

[0105] Among them, x0 is the initial weight coefficient corresponding to the abnormal source, x0=α, β, γ, L1=0.7L0, L2=0.8L0.

[0106] Specifically, the alarm module is used to adjust the key length of the electronic message authentication unit to a corresponding value based on the pass rate, wherein:

[0107] The correction range of the key length of the message authentication unit determined based on the pass rate is inversely proportional to the pass rate.

[0108] In this embodiment, optionally, the qualified rate L is compared with a first pre-qualified rate comparison threshold L1 and a second preset qualified rate comparison threshold L2:

[0109] If L≤L1, the key length of the message authentication unit is determined to be the first length d1, and d1=1.24d0;

[0110] If L1<L≤L2, the key length of the electronic message authentication unit is determined to be the second length d2, and d2=1.18d0;

[0111] If L>L2, the key length of the message authentication unit is determined to be the third length d3, and d3=1.1d0;

[0112] Wherein, d0 is the initial key length of the message authentication unit, L1=0.7L0, L2=0.8L0.

[0113] Specifically, the resilience module is used to fuse the PNT information determined to be re-acquired by the alarm module.

[0114] Specifically, the resilience module is used to fuse the PNT information determined and re-acquired by the alarm module, including:

[0115] Get the current longitude through formula (1):

[0116]

[0117] The current latitude is obtained by formula (2).

[0118]

[0119] Get the current time using formula (3):

[0120]

[0121] Where α is the GNSS PNT source weight coefficient, β is the local source weight coefficient, and γ is the external source weight coefficient. , , They are respectively the current longitude, latitude and time determined based on GNSS PNT information; , , They are respectively the current longitude, latitude and time determined based on the local PNT information; , , They are respectively the current longitude, latitude and time determined based on external PNT information.

[0122] Specifically, it includes several information sources, GNSS PNT sources, external sources and local sources, and comprehensively determines the information determined by each information source to determine the final credible PNT information, which effectively improves the credibility of data acquisition. The method of obtaining the final credible PNT information is determined based on the pass rate. When the pass rate is greater than the preset pass rate, there is abnormal data due to accidental abnormal interference. At this time, the PNT information determined to be qualified is determined as the final credible PNT information; when it is less than or equal to the preset pass rate, the information source with abnormalities in this case processes each abnormal source in a targeted manner; and after completing the processing of the abnormal source, the fusion method of each data is determined according to the specific data acquisition situation, which effectively improves the reliability of the data and further improves the efficiency of obtaining PNT information.

[0123] Specifically, the external sources include an odometer, a visual sensor and a lidar. It can be understood that the odometer determines the cumulative driving distance through the rotation of the moving parts to infer the position information. The visual sensor obtains environmental characteristics and relative position information through image analysis technology. The lidar constructs a three-dimensional model of the surrounding environment and performs precise positioning by emitting lasers and receiving reflected signals to determine the longitude and latitude. The current time can be obtained through the clock connected to the odometer combined with the historically determined time.

[0124] Specifically, the local source includes a local atomic clock and an inertial device. It can be understood that the local atomic clock is a clock device that can provide a time reference. The inertial device includes a gyroscope and an accelerometer. The inertial device measures the motion state of an object by itself to indirectly obtain position information and speed information. The local source provides independent, local PNT-related data and support, and can obtain longitude and latitude, as well as the current time.

[0125] Specifically, the abnormal isolation / recovery unit receives abnormal alarm information from the self-checking unit or the mutual-checking unit in the alarm module, generates corresponding isolation or recovery instructions for different abnormalities, and issues the instructions to the control and backup unit;

[0126] The control and backup unit processes the data of the original PNT information source based on the isolation recovery instruction for the abnormal information of the alarm module, and transmits the data to the self-checking unit of the alarm module, and completes the data backup of the PNT information at the same time;

[0127] The information fusion processing unit selects the fusible information source and the corresponding fusion state to fuse the PNT information according to the mutual verification result, and generates the credible PNT information. That is, on the one hand, according to the information of the cross mutual verification unit in the alarm module, the credible PNT information source without alarm (determined to be qualified PNT information) is selected for information fusion. On the other hand, in terms of the selection of the fusion degree, for PNT information with certain deviations or anomalies, loose coupling and other methods can be used for fusion, and for other PNT information without anomalies, tight coupling and other fusion methods can be used.

[0128] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0129] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A typical trusted PNT client is characterized by: include: A PNT information source for obtaining PNT information, including a GNSS PNT source for obtaining GNSS PNT information, an external source for obtaining external PNT information, and a local source for obtaining local PNT information, wherein the GNSS PNT information includes a navigation message and navigation information; an authentication module, comprising a message authentication unit for authenticating the navigation message and a spread spectrum code authentication unit for authenticating the navigation signal, the authentication module being used to send the GNSS PNT information with a failed authentication result to the PNT information source, or to store the GNSS PNT information with a passed authentication result; The alarm module is used to obtain several groups of data information based on the PNT information of the received PNT information source and the GNSS PNT information stored in the authentication module, and determine whether the PNT information is qualified according to the comparison results of each group of data information, and when the PNT information is determined to be unqualified, adjust the acquisition frequency of the PNT information, and determine the final acquisition method of the credible PNT information based on the qualified rate of each re-acquired PNT information, including: Determine the qualified PNT information as the final credible PNT information; or, determining the abnormal source based on the data matching result of the single column data, and adjusting the key length of the electronic message authentication unit to a corresponding value according to the determined abnormal source, performing self-check on the external source or performing self-check on the local source, and controlling the PNT information source to reacquire the PNT information; The resilience module is used to fuse the PNT information re-acquired by the alarm module to finally obtain credible PNT information, including: adjusting the weight coefficient for the corresponding abnormal source in the information fusion process to a corresponding value based on the qualified rate.

2. The typical trusted PNT client according to claim 1, characterized in that: The method for obtaining the abnormal source is to count the single column data, sort the data in descending order according to the number of identical data, and determine the information source corresponding to each data except the data with the largest proportion as the abnormal source.

3. The typical trusted PNT client according to claim 2, characterized in that: The message authentication unit is used to receive the navigation message and implement one-way broadcast authentication on the navigation message to obtain a first authentication result, where the first authentication result includes pass or fail; The spread spectrum code authentication unit is used to receive the navigation signal, encrypt the spread spectrum code of the pseudo-random noise code broadcast by the satellite, replace the original public spread spectrum code chip with the encrypted spread spectrum code chip generated based on the cryptographic algorithm, perform authentication according to the code sequence, and obtain a second authentication result, which includes pass or fail; The GNSS PNT information includes navigation, positioning and timing.

4. The typical trusted PNT client according to claim 3, characterized in that: The alarm module sequentially analyzes and obtains several groups of data information based on the external PNT information and local PNT information received from the PNT information source, wherein a single group of data information includes longitude and latitude coordinates and corresponding acquisition time points; The alarm module is used to determine whether the PNT information is qualified according to the comparison results of each group of data information, including: If the data of each group is consistent, the PNT information is judged to be qualified; If there is inconsistent data, the PNT information is determined to be unqualified, and the acquisition frequency of the PNT information is adjusted according to the proportion of the amount of unmatched data to the total amount of data in each group of data information.

5. The typical trusted PNT client according to claim 4, characterized in that: The alarm module is used to adjust the acquisition frequency of PNT information based on the proportion of data volume, wherein: The acquisition frequency of PNT information determined based on the data volume ratio is proportional to the data volume ratio.

6. The typical trusted PNT client according to claim 5, characterized in that: The alarm module is used to determine the pass rate based on each PNT information re-acquired, and determine the acquisition method of the final credible PNT information based on the pass rate, including: Calculate the ratio of the number of PNT information determined to be qualified to the total number of PNT information re-acquired, and determine the ratio as the qualified rate; If the qualified rate is greater than the preset qualified rate, the PNT information judged as qualified is determined as the final credible PNT information; If the qualified rate is less than or equal to the preset qualified rate, the data source of each obtained matching abnormal information is recorded as an abnormal source, and the abnormal source is processed.

7. The typical trusted PNT client according to claim 6, characterized in that: The alarm module is used to process the abnormal source, including: If the abnormal source is a GNSS PNT source, the GNSS PNT source is self-checked and the key length of the message authentication unit is adjusted to the corresponding value; If the abnormal source is an external source, self-check the external source; If the abnormal source is a local source, self-check the local source.

8. The typical trusted PNT client according to claim 7, characterized in that: The toughness module is used to adjust the weight coefficient for the corresponding abnormal source in the information fusion process to a corresponding value based on the qualified rate, wherein: The correction range of the weight coefficient for the corresponding abnormal source determined based on the qualified rate is inversely proportional to the qualified rate.

9. The typical trusted PNT client according to claim 8, characterized in that: The alarm module is used to adjust the key length of the electronic message authentication unit to a corresponding value based on the pass rate, wherein: The correction range of the key length of the message authentication unit determined based on the pass rate is inversely proportional to the pass rate.

10. The typical trusted PNT client according to claim 9, characterized in that: The resilience module is used to fuse the PNT information determined and re-acquired by the alarm module; The resilience module is used to fuse the PNT information determined and re-acquired by the alarm module, including: Determine the current longitude, assign corresponding weight coefficients to the current longitude determined by GNSS PNT information, local PNT information and external PNT information, and sum them up to obtain the current longitude after information fusion; Determine the current latitude, assign corresponding weight coefficients to the current latitude determined by GNSS PNT information, local PNT information and external PNT information, and sum them up to obtain the current latitude after information fusion; Determine the current time, assign corresponding weight coefficients to the current time determined by GNSS PNT information, local PNT information and external PNT information, and sum them up to obtain the current time after information fusion.

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