An inertial navigation compensation method and system for satellite navigation signal loss

Abstract

This invention discloses an inertial navigation compensation method and system for situations where satellite navigation signals are missing, belonging to the field of navigation technology. The method involves acquiring navigation geographic information of the area where the carrier is located and inertial navigation data at preset navigation reference points; calculating the motion trajectory based on the inertial navigation data and constructing a spatiotemporal trajectory stacking model corresponding to each navigation reference point in chronological order; calculating the path closure of each trajectory based on the matching degree between trajectories to select key compensation nodes; selecting the optimal reference point through compensation consistency analysis; and using the key compensation node corresponding to the optimal reference point as a benchmark to compensate for the inertial navigation data during the period of missing navigation signals. This invention, by constructing a spatiotemporal trajectory stacking model and quantifying the path closure and compensation consistency between trajectories, can adaptively select the optimal compensation benchmark and effectively suppress the error accumulation of the inertial navigation system.

Description

Technical Field

[0001] This invention relates to the field of navigation technology, specifically to an inertial navigation compensation method and system for situations where satellite navigation signals are missing. Background Technology

[0002] In the field of navigation technology, satellite navigation systems (such as GPS and BeiDou) have become the primary means for various vehicles (such as vehicles, drones, and ships) to obtain position, speed, and attitude information due to their advantages such as high precision and all-weather operation. However, in practical applications, satellite navigation signals are highly susceptible to interference from the external environment. For example, in tunnels, urban canyons, mountainous areas, underground parking lots, or when subjected to electromagnetic interference, the signal may attenuate or even be completely lost, causing the navigation system to be unable to provide continuous and reliable positioning services.

[0003] To address the problem of missing satellite navigation signals, inertial navigation systems (INS) are often used as an auxiliary navigation method due to their high autonomy and insensitivity to external environmental influences. INS calculates the vehicle's position, velocity, and attitude information by measuring the vehicle's acceleration and angular velocity and performing integration calculations. However, INS suffers from an inherent error accumulation problem; its integration characteristics cause even small sensor errors to amplify over time, leading to a sharp decline in navigation accuracy. Therefore, how to effectively utilize limited information to compensate for inertial navigation data during periods of missing satellite navigation signals, in order to suppress error divergence, has become a critical issue that urgently needs to be addressed in the field of navigation technology.

[0004] Existing integrated satellite and inertial navigation schemes typically calibrate the inertial navigation system using fusion algorithms such as Kalman filtering when satellite signals are normal. Once satellite signals are lost, the system switches to pure inertial navigation mode until signals are restored. In this mode, common compensation strategies include motion constraint-based compensation (such as vehicle non-integrity constraints) or matching correction based on pre-acquired reference trajectories. However, existing technologies have the following shortcomings: First, motion constraint-based methods make strict assumptions about the vehicle's motion state and cannot adapt to complex and changing motion scenarios; second, reference trajectory matching methods often rely on only a single reference point or a fixed reference trajectory, lacking the ability to model trajectory changes under different spatiotemporal conditions, making it difficult to select the optimal compensation benchmark, resulting in unstable compensation effects; third, existing technologies fail to fully utilize the inherent correlation between trajectory data generated by multiple navigation reference points at different times, and cannot quantitatively evaluate the reliability of different compensation nodes, thus affecting compensation accuracy and system adaptability.

[0005] Therefore, there is an urgent need for an inertial navigation compensation method that can fully exploit the spatiotemporal correlation features in historical trajectory data and adaptively select the optimal compensation benchmark when satellite navigation signals are missing, so as to effectively suppress error accumulation and improve the continuity and accuracy of the navigation system. Summary of the Invention

[0006] The purpose of this invention is to provide an inertial navigation compensation method and system when satellite navigation signals are missing, so as to solve the problems mentioned in the background art.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0008] An inertial navigation compensation system for when satellite navigation signals are missing, the system comprising: the inertial navigation compensation system comprising:

[0009] The data acquisition module is used to acquire navigation geographic information of the area where the carrier is located and inertial navigation data at preset navigation reference points;

[0010] The model building module is used to calculate the motion trajectory based on the inertial navigation data and to build a spatiotemporal trajectory stacking model corresponding to each navigation reference point according to the time sequence.

[0011] The node selection module is used to calculate the path closure of each trajectory based on the degree of matching between trajectories in the spatiotemporal trajectory stacking model, and select the trajectory corresponding to the maximum path closure as the key compensation node.

[0012] The reference point determination module is used to calculate the compensation consistency coefficient based on the maximum path closure of each navigation reference point, and select the navigation reference point corresponding to the maximum compensation consistency coefficient as the optimal reference point for inertial navigation compensation when navigation signals are missing.

[0013] The compensation execution module is used to compensate the inertial navigation data of the carrier during the period of missing navigation signals, using the key compensation node corresponding to the optimal reference point as a benchmark.

[0014] Furthermore, the data acquisition module includes:

[0015] A geographic information retrieval unit is used to retrieve a navigation geographic information map of the area where the carrier is located, wherein the navigation geographic information map contains several geographic feature markers;

[0016] The reference point setting unit is used to set several navigation reference points within the movement area of ​​the vehicle based on geographic feature markers.

[0017] The data acquisition unit is used to acquire the inertial navigation data of the carrier at the navigation reference point. The inertial navigation data consists of the position, velocity and attitude information of the carrier in the navigation coordinate system.

[0018] The sampling setting unit is used to initialize and set the sampling frequency, with a fixed time interval as the cycle of cyclic sampling, and to collect the inertial navigation data of the carrier at each fixed sampling time.

[0019] Furthermore, the model building module includes:

[0020] The trajectory calculation unit is used to calculate the motion trajectory based on the inertial navigation data of the carrier, detect trajectory feature points by the rate of curvature change, and collect the detected feature points in chronological order into a trajectory feature point sequence to form an inertial navigation trajectory layer.

[0021] The stacking model establishment unit is used to establish a three-dimensional trajectory stacking model. The horizontal cross-section of the three-dimensional trajectory stacking model is the inertial navigation trajectory layer. The vertical axis independent variable of the three-dimensional trajectory stacking model is the sequence number of the fixed sampling time. According to the order of the fixed sampling time from first to last, all the inertial navigation trajectory layers generated by each navigation reference point are arranged in the three-dimensional trajectory stacking model to obtain the spatiotemporal trajectory stacking model of each navigation reference point.

[0022] Furthermore, the node selection module includes:

[0023] The path closure calculation unit is used to select any inertial navigation trajectory layer as the trajectory to be compensated in the spatiotemporal trajectory stacking model, and select any inertial navigation trajectory layer other than the selected trajectory layer as the reference trajectory. Based on the dynamic time warping algorithm, it analyzes the optimal number of matching points between the two trajectories and obtains the path closure of the trajectory to be compensated at each navigation reference point.

[0024] The key compensation node determination unit is used to select the inertial navigation trajectory layer corresponding to the maximum path closure as the key compensation node for each navigation reference point.

[0025] Furthermore, the compensation execution module includes:

[0026] The reference trajectory determination unit is used to obtain the inertial navigation trajectory layer corresponding to the key compensation node at the optimal reference point as the reference trajectory layer.

[0027] The real-time trajectory construction unit is used to collect the carrier's real-time inertial navigation data at the current moment and construct the current real-time trajectory layer according to the preset time window;

[0028] The error acquisition unit is used to acquire the position error, velocity error and attitude error of the current real-time trajectory layer and the reference trajectory layer at the location to be calibrated in the navigation geographic information map after time alignment;

[0029] The compensation and correction unit is used to take the obtained error as the compensation and correction amount and generate the compensated navigation data.

[0030] An inertial navigation compensation method for satellite navigation signal loss, comprising the following steps:

[0031] Step S1: Obtain navigation geographic information of the area where the vehicle is located and inertial navigation data at preset navigation reference points;

[0032] Step S2: Calculate the motion trajectory based on the inertial navigation data, and construct a spatiotemporal trajectory stacking model corresponding to each navigation reference point according to the time sequence;

[0033] Step S3: In the spatiotemporal trajectory stacking model, calculate the path closure of each trajectory based on the degree of matching between trajectories, and select the trajectory corresponding to the maximum path closure as the key compensation node.

[0034] Step S4: Calculate the compensation consistency coefficient based on the maximum path closure of each navigation reference point, and select the navigation reference point corresponding to the maximum compensation consistency coefficient as the optimal reference point for inertial navigation compensation when the navigation signal is missing; use the key compensation node corresponding to the optimal reference point as a benchmark to compensate the inertial navigation data of the carrier during the period of missing navigation signal.

[0035] Furthermore, the specific implementation process of step S1 includes:

[0036] Retrieve a navigation geographic information map of the area where the carrier is located. The navigation geographic information map contains several geographic feature markers. Based on the geographic feature markers, set several navigation reference points in the movement area of ​​the carrier. Collect inertial navigation data of the carrier at the navigation reference points. The inertial navigation data consists of the position, velocity and attitude information of the carrier in the navigation coordinate system.

[0037] The initial sampling frequency is set, and the sampling cycle is set at a fixed time interval. Inertial navigation data of the carrier is collected at each fixed sampling time.

[0038] Furthermore, the specific implementation process of step S2 includes:

[0039] The motion trajectory is calculated based on the inertial navigation data of the carrier. Trajectory feature points are detected by the rate of curvature change. The detected feature points are then collected in chronological order to form a trajectory feature point sequence, which constitutes the inertial navigation trajectory layer. ,in, For navigation reference point numbers, Let A be the total number of feature points in the trajectory feature point sequence, where the sampling time number is fixed.

[0040] A three-dimensional trajectory stacking model is established, where the horizontal cross-section of the three-dimensional trajectory stacking model represents the inertial navigation trajectory layer. The vertical axis of the three-dimensional trajectory stacking model is determined by the sequence number of a fixed sampling time. Following the order of the fixed sampling times from first to last, the three-dimensional trajectory stacking model is used to... Arrange all inertial navigation trajectory layers generated by the first navigation reference point to obtain the second... A spatiotemporal trajectory stacking model of navigation reference points, denoted as .

[0041] Furthermore, the specific implementation process of step S3 includes:

[0042] Stacked models of spatiotemporal trajectories In the middle, select any inertial navigation trajectory layer As the trajectory to be compensated, and excluding the inertial navigation trajectory layer, the following layers are selected. Using any inertial navigation trajectory layer other than the reference trajectory, the optimal number of matching points between the two trajectories is analyzed based on the dynamic time warping algorithm to obtain the th... Path closure of the trajectory to be compensated for for each navigation reference point:

[0043] ;

[0044] In the formula, Indicates the first The navigation reference point is at the first The inertial navigation trajectory layers generated at fixed sampling times, A and B respectively represent and The total number of feature points in the middle, Let K be the number of matching points solved by the dynamic time warping algorithm, and let K represent the total number of fixed sampling times. The matching method for the matching points is as follows: the trajectory is aligned by the DTW algorithm. For each pair of aligned feature points, if the Euclidean distance between the feature points is less than the preset distance accuracy threshold, it is counted as a matching point. If the Euclidean distance between the feature points is greater than or equal to the preset distance accuracy threshold, it is counted as a non-matching point.

[0045] Select the maximum path closure Corresponding inertial navigation trajectory layer As the first The key compensation node for each navigation reference point.

[0046] Furthermore, the specific implementation process of step S4 includes:

[0047] Based on the maximum path closure Retrieve the same fixed sampling time as the key compensation node. The maximum value of the closure of all paths is used to generate a set of compensated feature vectors. ,in This represents the total number of navigation reference points. To ensure that the same fixed sampling time is selected, interpolation between adjacent time points can be used for trajectory alignment and fitting.

[0048] To compensate for the feature vector set mean Based on this, calculate the compensation consistency coefficient:

[0049] ;

[0050] In the formula, To prevent division by zero, For the first The maximum path closure value corresponding to each navigation reference point;

[0051] Select the maximum value of the compensation consistency coefficient The corresponding navigation reference point serves as the optimal reference point for inertial navigation compensation when navigation signals are missing.

[0052] Using the key compensation node corresponding to the optimal reference point as a benchmark, the inertial navigation data of the carrier during the period of missing navigation signals is compensated:

[0053] The inertial navigation trajectory layer corresponding to the key compensation node at the optimal reference point is obtained as the reference trajectory layer;

[0054] Collect the carrier's real-time inertial navigation data at the current moment, and construct the current real-time trajectory layer according to the preset time window;

[0055] The position error, velocity error, and attitude error of the current real-time trajectory layer and the reference trajectory layer at the location to be calibrated in the navigation geographic information map are obtained after time-series alignment.

[0056] The obtained error is used as a compensation correction amount to generate compensated navigation data.

[0057] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0058] First, this invention constructs a spatiotemporal trajectory stacking model, stacking inertial navigation trajectories at different sampling times along the time dimension to form a spatiotemporal representation of the carrier's motion patterns. This model not only preserves the geometric features of individual trajectories but also reveals the evolutionary patterns of trajectories as they change with sampling times through time axis expansion. Based on this, this invention introduces the quantitative indicator of path closure and analyzes the matching degree between different trajectory layers using a dynamic time warping algorithm, accurately identifying trajectory nodes with high consistency in the time series.

[0059] Second, this invention proposes a compensation consistency coefficient. By analyzing the cross-reference point consistency of the maximum path closure at different navigation reference points, the globally optimal reference point is selected. This coefficient is based on the compensation feature vector set and, through the normalization calculation of relative deviations, effectively avoids the influence of deviations caused by local noise or abnormal trajectories between different reference points. Compared with the fixed reference point or locally optimal strategy used in the prior art, this invention can adaptively determine the optimal reference point from a global perspective, making the compensation benchmark more representative and generalizable.

[0060] Third, this invention uses the key compensation node corresponding to the optimal reference point as a benchmark to compensate for errors in real-time inertial navigation data. This compensation process fully utilizes the spatiotemporal consistency and high closure characteristics of the trajectory at the optimal reference point, and can provide accurate position, velocity, and attitude error corrections for the real-time trajectory, which helps to suppress the accumulation of errors in the inertial navigation system. Attached Figure Description

[0061] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0062] Figure 1 This is a schematic diagram illustrating the steps of an inertial navigation compensation method for satellite navigation signal loss according to the present invention. Detailed Implementation

[0063] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0064] In this first embodiment: an inertial navigation compensation system is provided when satellite navigation signals are missing. The system includes:

[0065] The data acquisition module is used to acquire navigation geographic information of the area where the carrier is located and inertial navigation data at preset navigation reference points;

[0066] Specifically, the geographic information retrieval unit is used to retrieve the navigation geographic information map of the area where the carrier is located. In the field of navigation technology, the navigation geographic information map contains several geographic feature markers.

[0067] The reference point setting unit is used to set several navigation reference points within the movement area of ​​the vehicle based on geographic feature markers.

[0068] The data acquisition unit is used to acquire the inertial navigation data of the carrier at the navigation reference point in the field of navigation technology. The inertial navigation data in the field of navigation technology consists of the position, velocity and attitude information of the carrier in the navigation coordinate system.

[0069] The sampling setting unit is used to initialize and set the sampling frequency, with a fixed time interval as the cycle of cyclic sampling, and to collect the inertial navigation data of the carrier at each fixed sampling time.

[0070] The model building module is used to calculate motion trajectories based on inertial navigation data in the field of navigation technology, and to build spatiotemporal trajectory stacking models corresponding to each navigation reference point according to time sequence.

[0071] Specifically, the trajectory calculation unit is used to calculate the motion trajectory based on the inertial navigation data of the carrier, detect trajectory feature points by the rate of curvature change, and collect the detected feature points in chronological order into a trajectory feature point sequence to form an inertial navigation trajectory layer.

[0072] The stacking model building unit is used to build a three-dimensional trajectory stacking model. The horizontal section of the three-dimensional trajectory stacking model in the field of navigation technology is the inertial navigation trajectory layer in the field of navigation technology. The vertical axis independent variable of the three-dimensional trajectory stacking model in the field of navigation technology is the sequence number of the fixed sampling time. According to the order of the fixed sampling time from first to last, all the inertial navigation trajectory layers generated by each navigation reference point are arranged in the three-dimensional trajectory stacking model in the field of navigation technology to obtain the spatiotemporal trajectory stacking model of each navigation reference point.

[0073] The node selection module is used in the spatiotemporal trajectory stacking model in the field of navigation technology to calculate the path closure of each trajectory based on the degree of matching between trajectories, and select the trajectory corresponding to the maximum path closure as the key compensation node.

[0074] Specifically, the path closure calculation unit is used to select any inertial navigation trajectory layer as the trajectory to be compensated in the spatiotemporal trajectory stacking model, and select any inertial navigation trajectory layer other than the selected trajectory layer as the reference trajectory. Based on the dynamic time warping algorithm, it analyzes the optimal number of matching points between the two trajectories and obtains the path closure of the trajectory to be compensated for each navigation reference point.

[0075] The key compensation node determination unit is used to select the inertial navigation trajectory layer corresponding to the maximum path closure as the key compensation node for each navigation reference point.

[0076] The reference point determination module is used to calculate the compensation consistency coefficient based on the maximum path closure of each navigation reference point, and select the navigation reference point corresponding to the maximum compensation consistency coefficient as the optimal reference point for inertial navigation compensation when navigation signals are missing.

[0077] The compensation execution module is used to compensate the inertial navigation data of the carrier during the period of missing navigation signals, using the key compensation node corresponding to the optimal reference point in the field of navigation technology as a benchmark.

[0078] Specifically, the reference trajectory determination unit is used to obtain the inertial navigation trajectory layer corresponding to the key compensation node at the optimal reference point in the field of navigation technology as the reference trajectory layer.

[0079] The real-time trajectory construction unit is used to collect the carrier's real-time inertial navigation data at the current moment and construct the current real-time trajectory layer according to the preset time window;

[0080] The error acquisition unit is used to acquire the position error, velocity error and attitude error of the current real-time trajectory layer in the navigation technology field and the reference trajectory layer in the navigation technology field at the location to be calibrated in the navigation geographic information map after time alignment.

[0081] The compensation and correction unit is used to take the obtained error as the compensation and correction amount and generate the compensated navigation data.

[0082] Please see Figure 1 In this second embodiment: an inertial navigation compensation method is provided when satellite navigation signals are missing. The method includes the following steps:

[0083] Step S1: Obtain navigation geographic information of the area where the vehicle is located and inertial navigation data at preset navigation reference points;

[0084] For example, a navigation geographic information map of the area where the carrier is located is retrieved. The navigation geographic information map in the field of navigation technology contains several geographic feature markers. Based on the geographic feature markers, several navigation reference points are set in the movement area of ​​the carrier. Inertial navigation data of the carrier is collected at the navigation reference points in the field of navigation technology. The inertial navigation data in the field of navigation technology consists of the position, velocity and attitude information of the carrier in the navigation coordinate system.

[0085] The initial sampling frequency is set, and the sampling cycle is set at a fixed time interval. Inertial navigation data of the carrier is collected at each fixed sampling time.

[0086] Step S2: Calculate the motion trajectory based on inertial navigation data in the field of navigation technology, and construct a spatiotemporal trajectory stacking model corresponding to each navigation reference point according to the time sequence;

[0087] For example, the motion trajectory is calculated based on the inertial navigation data of the carrier, and trajectory feature points are detected by the rate of curvature change. The detected feature points are then collected in chronological order into a trajectory feature point sequence, which constitutes the inertial navigation trajectory layer. ,in, For navigation reference point numbers, Let A be the total number of feature points in the trajectory feature point sequence, where the sampling time number is fixed.

[0088] A three-dimensional trajectory stacking model is established. The horizontal cross-section of this model in the field of navigation technology represents the inertial navigation trajectory layer. The vertical axis of the model represents the sequence number of a fixed sampling time. Following the sequential order of these fixed sampling times, the model is used to determine the sequence of the sampling times. Arrange all inertial navigation trajectory layers generated by the first navigation reference point to obtain the second... A spatiotemporal trajectory stacking model of navigation reference points, denoted as ;

[0089] It should be noted that this invention establishes a three-dimensional spatial coordinate system, with the X and Y axes forming a horizontal reference plane, corresponding to the geographical plane where the carrier moves (eastward and northward positions under the navigation coordinate system), and the Z axis as the vertical axis, whose independent variable is the sequence number of a fixed sampling time, representing the time dimension. This allows the trajectory layers generated at the same navigation reference point (p) and different sampling times (τ) to be stacked sequentially along the Z-axis, forming a visualized spatiotemporal stacking structure. By arranging the inertial navigation trajectories generated by the carrier at the same geographical reference point and at different times in a chronological order in three-dimensional space, the evolution trend of the trajectory shape as the sampling time progresses can be intuitively displayed.

[0090] Step S3: In the spatiotemporal trajectory stacking model in the field of navigation technology, the path closure of each trajectory is calculated based on the degree of matching between trajectories, and the trajectory corresponding to the maximum path closure is selected as the key compensation node.

[0091] For example, in the spatiotemporal trajectory stacking model In the middle, select any inertial navigation trajectory layer As the trajectory to be compensated, and excluding the inertial navigation trajectory layer, the following layers are selected. Using any inertial navigation trajectory layer other than the reference trajectory, the optimal number of matching points between the two trajectories is analyzed based on the dynamic time warping algorithm to obtain the th... Path closure of the trajectory to be compensated for for each navigation reference point:

[0092] ;

[0093] In the formula, Indicates the first The navigation reference point is at the first The inertial navigation trajectory layers generated at fixed sampling times, A and B respectively represent and The total number of feature points in the middle, Let K be the number of matching points solved by the dynamic time warping algorithm, and let K represent the total number of fixed sampling times. In the field of navigation technology, the matching judgment method for matching points is as follows: the trajectory is aligned by the DTW algorithm. For each pair of aligned feature points, if the Euclidean distance between the feature points is less than the preset distance accuracy threshold, it is counted as a matching point; if the Euclidean distance between the feature points is greater than or equal to the preset distance accuracy threshold, it is counted as a non-matching point.

[0094] Select the maximum path closure Corresponding inertial navigation trajectory layer As the first The key compensation node for each navigation reference point.

[0095] Step S4: Calculate the compensation consistency coefficient based on the maximum path closure of each navigation reference point, and select the navigation reference point corresponding to the maximum compensation consistency coefficient as the optimal reference point for inertial navigation compensation when navigation signals are missing; use the key compensation node corresponding to the optimal reference point in the field of navigation technology as a benchmark to compensate the inertial navigation data of the carrier during the period of missing navigation signals.

[0096] For example, based on the maximum path closure Retrieve the same fixed sampling time as key compensation nodes in the navigation technology field. The maximum value of the closure of all paths is used to generate a set of compensated feature vectors. ,in Indicates the total number of navigation reference points;

[0097] To compensate for the feature vector set mean Based on this, calculate the compensation consistency coefficient:

[0098] ;

[0099] In the formula, To prevent division by zero, For the first The maximum path closure value corresponding to each navigation reference point;

[0100] Select the maximum value of the compensation consistency coefficient The corresponding navigation reference point serves as the optimal reference point for inertial navigation compensation when navigation signals are missing.

[0101] Using the key compensation node corresponding to the optimal reference point in the field of navigation technology as a benchmark, the inertial navigation data of the carrier is compensated during the period of missing navigation signals:

[0102] The inertial navigation trajectory layer corresponding to the key compensation node at the optimal reference point in the field of navigation technology is obtained as the reference trajectory layer;

[0103] Collect the carrier's real-time inertial navigation data at the current moment, and construct the current real-time trajectory layer according to the preset time window;

[0104] The position, velocity, and attitude errors of the current real-time trajectory layer and the reference trajectory layer in the navigation technology field, after time alignment, are obtained at the location to be calibrated in the navigation geographic information map.

[0105] The obtained error is used as a compensation correction amount to generate compensated navigation data.

[0106] It should be noted that during the movement of the vehicle, onboard sensors (such as visual cameras, LiDAR, and high-precision positioning modules) perceive the surrounding environment in real time, identify geographical feature markers (such as intersections, traffic signs, and building corners) marked on the navigation geographic information map, and dynamically select these feature points as navigation reference points. As the vehicle passes these reference points sequentially, the inertial navigation system records trajectory data at different sampling times. Although affected by accumulated errors, the trajectories at each reference point exhibit an inherent regularity in the spatiotemporal domain related to geographical features. This invention constructs a spatiotemporal trajectory stacking model, stacking inertial navigation trajectories generated at different sampling times at the same reference point in chronological order, forming a spatiotemporally structured representation of the vehicle's motion patterns. Based on this, a dynamic time warping algorithm is used to calculate the matching degree between different trajectory layers within the same reference point, defining path closure. This index can quantitatively evaluate the potential quality of any trajectory layer as a compensation benchmark; that is, the higher the closure, the stronger the consistency in spatial morphology between the trajectory layer and other trajectories generated at the same reference point at other times, and the higher its reliability as a compensation benchmark. Furthermore, this invention proposes a compensation consistency coefficient. By performing cross-reference point consistency analysis on the maximum path closure values ​​corresponding to navigation reference points at different geographical locations, the globally optimal reference point is selected, ensuring that the selected benchmark has the best representativeness and anti-interference capability in the spatial domain. Finally, using the key compensation node corresponding to the optimal reference point as the benchmark, error compensation is performed on the real-time inertial navigation trajectory, realizing a dual guarantee mechanism of mining the optimal benchmark in the spatiotemporal domain and verifying benchmark consistency in the global domain.

[0107] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0108] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for compensating for inertial navigation when satellite navigation signals are missing, characterized in that, The method includes the following steps: Step S1: Obtain navigation geographic information of the area where the vehicle is located and inertial navigation data at preset navigation reference points; Step S2: Calculate the motion trajectory based on the inertial navigation data, and construct a spatiotemporal trajectory stacking model corresponding to each navigation reference point according to the time sequence; Step S3: In the spatiotemporal trajectory stacking model, calculate the path closure of each trajectory based on the degree of matching between trajectories, and select the trajectory corresponding to the maximum path closure as the key compensation node. Step S4: Calculate the compensation consistency coefficient based on the maximum path closure of each navigation reference point, and select the navigation reference point corresponding to the maximum compensation consistency coefficient as the optimal reference point for inertial navigation compensation when the navigation signal is missing; use the key compensation node corresponding to the optimal reference point as a benchmark to compensate the inertial navigation data of the carrier during the period of missing navigation signal.

2. The inertial navigation compensation method for satellite navigation signal loss according to claim 1, characterized in that, The specific implementation process of step S1 includes: Retrieve a navigation geographic information map of the area where the carrier is located. The navigation geographic information map contains several geographic feature markers. Based on the geographic feature markers, set several navigation reference points in the movement area of ​​the carrier. Collect inertial navigation data of the carrier at the navigation reference points. The inertial navigation data consists of the position, velocity and attitude information of the carrier in the navigation coordinate system. The initial sampling frequency is set, and the sampling cycle is set at a fixed time interval. Inertial navigation data of the carrier is collected at each fixed sampling time.

3. The inertial navigation compensation method for satellite navigation signal loss according to claim 2, characterized in that, The specific implementation process of step S2 includes: The motion trajectory is calculated based on the inertial navigation data of the carrier. Trajectory feature points are detected by the rate of curvature change. The detected feature points are then collected in chronological order to form a trajectory feature point sequence, which constitutes the inertial navigation trajectory layer. ,in, For navigation reference point numbers, Let A be the total number of feature points in the trajectory feature point sequence, where the sampling time number is fixed. A three-dimensional trajectory stacking model is established, where the horizontal cross-section of the three-dimensional trajectory stacking model represents the inertial navigation trajectory layer. The vertical axis of the three-dimensional trajectory stacking model is determined by the sequence number of a fixed sampling time. Following the order of the fixed sampling times from first to last, the three-dimensional trajectory stacking model is used to... Arrange all inertial navigation trajectory layers generated by the first navigation reference point to obtain the second... A spatiotemporal trajectory stacking model of navigation reference points, denoted as .

4. The inertial navigation compensation method for satellite navigation signal loss according to claim 3, characterized in that, The specific implementation process of step S3 includes: Stacked models of spatiotemporal trajectories In the middle, select any inertial navigation trajectory layer As the trajectory to be compensated, and excluding the inertial navigation trajectory layer, the following layers are selected. Using any inertial navigation trajectory layer other than the reference trajectory, the optimal number of matching points between the two trajectories is analyzed based on the dynamic time warping algorithm to obtain the th... Path closure of the trajectory to be compensated for for each navigation reference point: ； In the formula, Indicates the first The navigation reference point is at the first The inertial navigation trajectory layers generated at fixed sampling times, A and B respectively represent and The total number of feature points in the middle, Let K be the number of matching points solved by the dynamic time warping algorithm, and let K represent the total number of fixed sampling times. The matching method for the matching points is as follows: the trajectory is aligned by the DTW algorithm. For each pair of aligned feature points, if the Euclidean distance between the feature points is less than the preset distance accuracy threshold, it is counted as a matching point. If the Euclidean distance between the feature points is greater than or equal to the preset distance accuracy threshold, it is counted as a non-matching point. Select the maximum path closure Corresponding inertial navigation trajectory layer As the first The key compensation node for each navigation reference point.

5. The inertial navigation compensation method for satellite navigation signal loss according to claim 4, characterized in that, The specific implementation process of step S4 includes: Based on the maximum path closure Retrieve the same fixed sampling time as the key compensation node. The maximum value of the closure of all paths is used to generate a set of compensated feature vectors. ,in Indicates the total number of navigation reference points; To compensate for the feature vector set mean Based on this, calculate the compensation consistency coefficient: ； In the formula, To prevent division by zero, For the first The maximum path closure value corresponding to each navigation reference point; Select the maximum value of the compensation consistency coefficient The corresponding navigation reference point serves as the optimal reference point for inertial navigation compensation when navigation signals are missing. Using the key compensation node corresponding to the optimal reference point as a benchmark, the inertial navigation data of the carrier during the period of missing navigation signals is compensated: The inertial navigation trajectory layer corresponding to the key compensation node at the optimal reference point is obtained as the reference trajectory layer; Collect the carrier's real-time inertial navigation data at the current moment, and construct the current real-time trajectory layer according to the preset time window; The position error, velocity error, and attitude error of the current real-time trajectory layer and the reference trajectory layer at the location to be calibrated in the navigation geographic information map are obtained after time-series alignment. The obtained error is used as a compensation correction amount to generate compensated navigation data.

6. An inertial navigation compensation system for the absence of satellite navigation signals, comprising an inertial navigation compensation system performing the inertial navigation compensation method as described in any one of claims 1-5, characterized in that, The inertial navigation compensation system includes: The data acquisition module is used to acquire navigation geographic information of the area where the carrier is located and inertial navigation data at preset navigation reference points; The model building module is used to calculate the motion trajectory based on the inertial navigation data and to build a spatiotemporal trajectory stacking model corresponding to each navigation reference point according to the time sequence. The node selection module is used to calculate the path closure of each trajectory based on the degree of matching between trajectories in the spatiotemporal trajectory stacking model, and select the trajectory corresponding to the maximum path closure as the key compensation node. The reference point determination module is used to calculate the compensation consistency coefficient based on the maximum path closure of each navigation reference point, and select the navigation reference point corresponding to the maximum compensation consistency coefficient as the optimal reference point for inertial navigation compensation when navigation signals are missing. The compensation execution module is used to compensate the inertial navigation data of the carrier during the period of missing navigation signals, using the key compensation node corresponding to the optimal reference point as a benchmark.

7. An inertial navigation compensation system for satellite navigation signal loss according to claim 6, characterized in that, The data acquisition module includes: A geographic information retrieval unit is used to retrieve a navigation geographic information map of the area where the carrier is located, wherein the navigation geographic information map contains several geographic feature markers; The reference point setting unit is used to set several navigation reference points within the movement area of ​​the vehicle based on geographic feature markers. The data acquisition unit is used to acquire the inertial navigation data of the carrier at the navigation reference point. The inertial navigation data consists of the position, velocity and attitude information of the carrier in the navigation coordinate system. The sampling setting unit is used to initialize and set the sampling frequency, with a fixed time interval as the cycle of cyclic sampling, and to collect the inertial navigation data of the carrier at each fixed sampling time.

8. An inertial navigation compensation system for satellite navigation signal loss according to claim 6, characterized in that, The model building module includes: The trajectory calculation unit is used to calculate the motion trajectory based on the inertial navigation data of the carrier, detect trajectory feature points by the rate of curvature change, and collect the detected feature points in chronological order into a trajectory feature point sequence to form an inertial navigation trajectory layer. The stacking model establishment unit is used to establish a three-dimensional trajectory stacking model. The horizontal cross-section of the three-dimensional trajectory stacking model is the inertial navigation trajectory layer. The vertical axis independent variable of the three-dimensional trajectory stacking model is the sequence number of the fixed sampling time. According to the order of the fixed sampling time from first to last, all the inertial navigation trajectory layers generated by each navigation reference point are arranged in the three-dimensional trajectory stacking model to obtain the spatiotemporal trajectory stacking model of each navigation reference point.

9. An inertial navigation compensation system for satellite navigation signal loss according to claim 6, characterized in that, The node selection module includes: The path closure calculation unit is used to select any inertial navigation trajectory layer as the trajectory to be compensated in the spatiotemporal trajectory stacking model, and select any inertial navigation trajectory layer other than the selected trajectory layer as the reference trajectory. Based on the dynamic time warping algorithm, it analyzes the optimal number of matching points between the two trajectories and obtains the path closure of the trajectory to be compensated at each navigation reference point. The key compensation node determination unit is used to select the inertial navigation trajectory layer corresponding to the maximum path closure as the key compensation node for each navigation reference point.

10. An inertial navigation compensation system for satellite navigation signal loss according to claim 6, characterized in that, The compensation execution module includes: The reference trajectory determination unit is used to obtain the inertial navigation trajectory layer corresponding to the key compensation node at the optimal reference point as the reference trajectory layer. The real-time trajectory construction unit is used to collect the carrier's real-time inertial navigation data at the current moment and construct the current real-time trajectory layer according to the preset time window; The error acquisition unit is used to acquire the position error, velocity error and attitude error of the current real-time trajectory layer and the reference trajectory layer at the location to be calibrated in the navigation geographic information map after time alignment; The compensation and correction unit is used to take the obtained error as the compensation and correction amount and generate the compensated navigation data.

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