A denial condition-based spatio-temporal enhanced positioning method and system

Abstract

The application discloses a kind of denial under spatiotemporal enhancement positioning method and system, the method includes the following steps: spatiotemporal enhancement positioning system configuration microwave synchronous base station and user terminal equipment, user terminal equipment includes inertial measurement unit and microwave antenna module;Establish local space-time reference of user terminal equipment;Time mark, inertial navigation solution is carried out, constructs unified state vector, obtains key output through clock error clock drift joint model;According to the two-way ranging interaction constructs ranging observation, constructs observation equation, and carries out filtering update, outputs correction quantity feedback;Carry out closed-loop correction, output fusion positioning result.This scheme constructs the space-time reference collaborative architecture of "microwave synchronous base station-user terminal equipment", receives end clock error and clock drift are included in unified state vector and are recursively estimated, from the root, the core defect that traditional fusion positioning scheme ignores clock drift error accumulation is solved.

Description

Technical Field

[0001] This invention belongs to the field of navigation, positioning and time synchronization technology, and particularly relates to a spatiotemporal augmentation positioning method and system under rejection conditions. Background Technology

[0002] In typical scenarios such as indoor spaces and deep tunnels, Global Navigation Satellite System (GNSS) signals are easily blocked by buildings, terrain, or electromagnetic interference, creating signal rejection environments. This causes traditional satellite positioning technologies to completely fail or experience a significant drop in accuracy. Therefore, achieving reliable high-precision positioning in such environments has become a core technological challenge that the industry urgently needs to overcome. To solve this problem, existing technologies generally adopt a technical solution that integrates Inertial Navigation Systems (INS) with wireless signals. Essentially, this approach uses wireless signal observations as external constraints to directly correct the position, velocity, and other results output by the INS solution. However, it generally ignores the cumulative error effect caused by the receiver's local clock drift during the inertial calculation process, which poses a critical hidden danger to the stability of long-term positioning accuracy.

[0003] In practical applications, the duration of denial environments often lasts for several minutes or even tens of minutes. The local clock at the receiving end is inevitably affected by factors such as temperature changes, circuit noise, and component aging, leading to drift. This, in turn, causes the continuous accumulation and amplification of errors during integration. As the denial time extends, the positioning results show significant positional shifts, and accuracy deteriorates rapidly. This passive and crude processing mode cannot fundamentally curb the transmission and accumulation of clock drift errors to the positioning results, making it difficult for the system to control the long-term divergence of errors. This severely limits the depth and breadth of application of existing fusion positioning schemes in complex, long-term denial scenarios. Therefore, there is an urgent need to propose a novel spatiotemporal augmentation positioning technology that can accurately control clock drift errors to overcome existing technological bottlenecks. Summary of the Invention

[0004] This invention provides a spatiotemporal augmentation positioning method and system under rejection conditions to solve the technical problem of long-term accumulation and divergence of positioning errors in inertial navigation systems due to receiver clock drift under satellite navigation signal rejection conditions.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: On one hand, the present invention provides a spatiotemporal augmentation localization method under rejection conditions, the spatiotemporal augmentation localization method under rejection conditions comprising: S1: The spatiotemporal augmentation positioning system is configured with a microwave synchronization base station and user terminal equipment. The microwave synchronization base station generates and periodically broadcasts microwave signals carrying timestamps and three-dimensional coordinate information of the base station. The user terminal equipment includes an inertial measurement unit and a microwave antenna module. The microwave antenna module receives the microwave signals from the microwave synchronization base station and performs down-conversion and demodulation. S2: Based on the microwave synchronization base station time and the user terminal equipment clock, establish a local spatiotemporal reference for the user terminal equipment, and use the demodulation time information of the first available microwave synchronization base station to form an initial arrival time observation; determine the initial navigation state of the user terminal equipment; S3: Time-mark the data collected by the inertial measurement unit using the local time reference and perform inertial navigation calculation; construct a unified state vector and process the clock state using a clock difference and clock drift joint model; output the predicted navigation state and local time information to the error dynamic filtering and correction module. S4: The user terminal equipment and the microwave synchronization base station conduct two-way ranging interaction; the error dynamic filtering correction module constructs ranging observations based on the two-way ranging interaction, builds the observation equations, performs filtering updates, and outputs the correction amounts of clock error, clock drift, and navigation error as correction amount feedback. S5: Based on the correction amount, perform closed-loop correction on the inertial navigation solution and time reference, and output the fused positioning result.

[0006] Preferably, step S1 includes: The spatiotemporal augmentation positioning system is configured with a microwave synchronous base station and user terminal equipment; A microwave synchronous base station is deployed within the positioning area. The number of microwave synchronous base stations is greater than or equal to one. The microwave synchronous base station serves as the spatiotemporal reference source for the spatiotemporal augmentation positioning system. It generates a stable microwave carrier and a high-precision time reference internally, and generates and periodically broadcasts microwave signals carrying timestamps and three-dimensional coordinate information of the base station to provide a unified time and space reference for user terminal equipment. At the same time, the microwave synchronous base station has ranging response capability. When it receives a ranging query signal sent by the user terminal equipment, it records the receiving time and sends back a response signal to support the user terminal equipment in realizing microwave two-way ranging. The user-end equipment includes an inertial measurement unit and a microwave antenna module; The inertial measurement unit is located inside the user terminal equipment. The inertial measurement unit acquires the angular velocity and acceleration of the user terminal equipment. Through integration calculation, the attitude information of the user terminal equipment can be calculated from the angular velocity and acceleration. The microwave antenna module is located inside the user terminal equipment and is used for front-end signal interaction with the microwave synchronization base station. It receives, down-converts and demodulates the microwave signal from the microwave synchronization base station, extracts the timestamp and key information of the microwave synchronization base station coordinates, and sends the demodulated data to the subsequent processing stage. At the same time, the microwave antenna module provides the local oscillator and radio frequency link required for synchronization locking, establishes stable locking conditions between the local clock and the base station clock, and undertakes the transmission and reception of bidirectional ranging signals and timestamp capture. After the user terminal equipment is started, the microwave antenna module receives the microwave signal from the microwave synchronization base station and completes down-conversion and demodulation, outputting the microwave synchronization base station timestamp, microwave synchronization base station coordinate identifier, and local oscillator required for synchronization locking.

[0007] Preferably, step S2 includes: Establish a local spatiotemporal reference for user equipment based on the timestamp of microwave synchronous base station and the clock of user equipment; The user terminal equipment uses the demodulation time information of the first available microwave synchronization base station to form an initial time of arrival observation, combines the known coordinates of the microwave synchronization base station to obtain the initial geometric constraints, and jointly determines the initial navigation state of the user terminal equipment with the initial attitude information of the inertial measurement unit. Output the initial position of the user terminal device Initial velocity Initial posture and the initial clock state ( ),in, Indicates the clock bias at the receiving end. Indicates clock drift at the receiver. These represent the initial receiver clock bias and the initial receiver clock drift, respectively, with init indicating the initial state. The key output of this step is: (1) INS initial navigation solution , , ; (2) Initial clock state ; (3) Local time reference after being synchronized and locked with the microwave synchronous base station signal.

[0008] Preferably, step S3 includes: The inertial measurement unit (IMU) of the user terminal device continuously acquires angular velocity and acceleration data. The IMU data is time-stamped using a synchronized local time base, and continuous integration of position, velocity, and attitude is achieved through inertial mechanical orchestration to obtain the inertial navigation calculation results. , , ), to achieve inertial navigation solution; A unified state vector containing navigation error, IMU bias, and clock error is constructed, and a discrete propagation model is established so that clock bias and clock drift participate in error propagation and subsequent observation updates as state variables; the state vector is at least as follows: ; in Indicates positional error. Indicates speed error, Indicates attitude error. This indicates that the accelerometer has zero bias. This indicates zero bias of the gyroscope, and T indicates transpose calculation; In discrete time In the propagation, k represents discrete time, which is an integer; In addition to the standard INS error state propagation, the clock state is handled using a joint clock bias and clock drift model, as follows: ; in, This represents the receiver clock bias at discrete time k+1. This represents the receiver clock bias at discrete time k. This represents the receiver clock drift at discrete time k+1. This represents the receiver clock drift at discrete time k. The time interval between two merge updates. This represents the process noise at discrete time k; The predicted navigation status and local time information are output to the error dynamic filtering and correction module. The key outputs of this step are as follows: (1) Predicting navigation solution ( , , ); (2) Predicting clock state ; (3) Predicting covariance ; (4) For use in observation modeling .

[0009] Preferably, step S4 includes: The user terminal device initiates a ranging query to the microwave synchronization base station through the microwave antenna module. After receiving the query, the microwave synchronization base station responds and returns a response. The user terminal receives the response and forms a round-trip time observation. The user terminal device and the microwave synchronization base station conduct bidirectional ranging interaction. The error dynamic filtering and correction module constructs ranging observations based on the two-way ranging interaction and forms an observation update in conjunction with the INS prediction state; it explicitly writes the cumulative impact of clock drift on continuous measurements into the observation model and estimates it together with the INS error state, thereby achieving joint observability and correctability based on clock error, clock drift and navigation error. The specific steps are as follows: (1) Observational structure: For the i-th microwave synchronization base station, the user terminal equipment forms an equivalent ranging observation. The equivalent distance can be calculated by subtracting the known or estimated response delay from the round-trip time delay. At the filtering level, it is uniformly referred to as the equivalent distance observation. (2) Construct the observation equation and adopt the following unified observation model: ; Where P represents the actual location of the user terminal device in the current epoch. Let c represent the coordinates of the i-th microwave synchronization base station, and c represent the speed of light. Indicates the noise of the i-th observation. Indicates the time interval since the last synchronization / update; Linearize the observation equation at the INS prediction points; For the observation row of the i-th microwave synchronization base station, the sensitivity of the geometric distance term to position error is a unit vector along the line of sight: ; in, This indicates the calculation of partial derivatives. This represents the transpose of the error at position i. This represents the position error of the i-th position. Represents norm calculation, Indicates the predicted location of the user terminal device; The partial derivative with respect to the clock term is as follows: ; Caused the clock to drift It has clear observability that increases over time; (3) Filter update: The error dynamic filtering correction module uses extended Kalman filtering for recursive updates. The filter output includes clock correction. Clock drift correction amount and navigation error correction amount The filtered output is then used as a correction feedback.

[0010] Preferably, step S5 includes: After receiving the correction amount output by the error dynamic filtering and correction module, the inertial navigation solution and time base are corrected in a closed loop, so that the clock error is not only estimated in the filter, but also actively compensated on the time axis of the inertial navigation integration. Update local clock parameters and correct time base: ; Dynamic compensation is applied to the sampling interval used for IMU integration. ; in, This indicates the sampling interval after dynamic compensation. Indicates the average of the sampling intervals; This achieves the reduction of integral time axis scaling error caused by local oscillator frequency deviation at the source, while simultaneously... Feedback is used to correct the current navigation solution, achieving coordinated convergence of the inertial navigation solution and the clock solution; The output is the fused positioning result after closed-loop correction, including position, velocity, attitude and trajectory records, to achieve continuous spatiotemporal augmentation positioning service under denial conditions.

[0011] On the other hand, the present invention also provides a spatiotemporal augmentation positioning system under rejection conditions, the spatiotemporal augmentation positioning system under rejection conditions comprising: The microwave synchronization base station serves as the spatiotemporal reference source of the system. It internally generates a stable microwave carrier and a high-precision time reference, and broadcasts microwave signals carrying timestamps and its own three-dimensional coordinate information into space according to a preset period to provide a unified time and space reference for user equipment. At the same time, the microwave synchronization base station has ranging response capability. When it receives a ranging query signal from the user equipment, it records the reception time and sends back a response signal to support the user equipment in realizing microwave bidirectional ranging. The microwave antenna module completes the front-end signal interaction with the microwave synchronization base station. It receives, down-converts, and demodulates the microwave signals from the microwave synchronization base station, extracts key information such as timestamps and coordinates of the microwave synchronization base station, and sends the demodulated data to the subsequent processing stage. At the same time, the microwave antenna module provides the local oscillator and RF links required for synchronization locking, establishes stable locking conditions between the local clock and the base station clock, and undertakes the transmission and reception of bidirectional ranging signals and timestamp capture. It outputs the ranging-related transmission / reception time information to the downstream processing module. The microwave time synchronization and fusion processing module establishes a local spatiotemporal reference and performs inertial navigation calculations based on the received microwave signals. First, it aligns the local clock with the timestamp of the microwave synchronization base station based on the demodulated data output by the microwave antenna module to achieve clock synchronization. On this basis, it performs initial positioning and initial clock bias calculations by combining the coordinates of the microwave synchronization base station and the initial attitude information to obtain the initial position and clock deviation of the user terminal equipment. Second, it timestamps and performs inertial navigation calculations on the raw data of the inertial measurement unit, continuously calculates the position, velocity, and attitude of the user terminal equipment, and sends the current position prediction value and local time information as state predictions to the error dynamic filtering and correction module. Third, it receives the clock bias, clock drift, and navigation error corrections fed back from the error dynamic filtering and correction module, performs forward compensation and closed-loop correction on the local clock and inertial navigation calculation process, and suppresses long-term drift from the source. The error dynamic filtering and correction module uses microwave two-way ranging observation to estimate and correct errors in inertial navigation prediction results. First, based on the round-trip delay information obtained from the two-way ranging interaction between the microwave antenna module and the microwave synchronization base station, and combined with the prediction state output by the microwave time synchronization and fusion processing module, an observation equation including geometric distance terms and the cumulative effects of clock bias and clock drift is constructed. Second, the Kalman filter equivalent recursive algorithm is used to dynamically estimate the position error, velocity error, attitude error, and clock error state to obtain correction amounts for clock bias, clock drift, and navigation errors. Third, the above correction amounts are fed back to the microwave time synchronization and fusion processing module in real time to realize closed-loop updates of clock and navigation solutions. The high-precision positioning output module, located at the end of the user terminal equipment, provides the final positioning result after clock error suppression and inertial / microwave fusion. This module receives the fused positioning result output by the microwave time synchronization and fusion processing module, formats the position, velocity, and attitude, records the necessary trajectory, and publishes the positioning information to the host system or user equipment through wired or wireless interfaces. Under conditions of interference or rejection of satellite navigation, the high-precision positioning output module outputs the spatiotemporal augmented positioning result provided by the system, enabling continuous and reliable navigation and timing services for the target platform or personnel.

[0012] The beneficial effects of the technical solution provided by this invention include at least the following: 1. An innovative unified state modeling mechanism accurately tracks dynamic clock errors, significantly improving long-term positioning consistency. Traditional denial-of-environment fusion positioning schemes generally treat the receiver clock error as a fixed constant after a one-time synchronization, failing to consider its dynamic changes with the environment and time. This leads to the superposition of clock errors and inertial navigation errors, causing positioning drift as the operating time increases. This invention overcomes this technical limitation by incorporating clock bias, clock drift, position, velocity, attitude errors, and IMU zero bias into the same state vector for unified modeling, constructing a full-dimensional error dynamic model. During system operation, this model can continuously propagate over time and recursively update state parameters according to observation epochs, enabling real-time capture of slow-varying deviations of the local clock caused by factors such as temperature fluctuations, device aging, and vibration interference. By accurately separating clock errors from inertial navigation errors and estimating and correcting them separately, the continuous interference of clock instability on inertial calculations is effectively avoided. This significantly reduces the gradual drift of positioning solutions and data inconsistency in long-term operation scenarios, providing core model support for stable positioning in long-term denial environments. Compared with traditional fixed error assumption schemes, positioning consistency and long-term reliability are significantly improved. 2. The observation model incorporates a clock drift accumulation term to enhance clock state observability and ensure long-term rejection accuracy stability. A key challenge in clock drift motion state estimation lies in its insufficient observability. Existing technologies in microwave ranging observation models rely solely on clock error terms, making it difficult to stably distinguish systematic shifts caused by frequency deviations through the observation sequence. This results in low accuracy and poor convergence of clock drift estimation. This invention addresses this issue by innovatively introducing the cumulative effect of clock drift within the interval between two filter updates into the microwave two-way ranging observation model, constructing an observation equation containing a clock drift accumulation term. This design makes the continuous ranging sequence directly sensitive to systematic shifts caused by frequency deviations. The temporal evolution characteristics of the observations can be effectively captured and stably distinguished by the filter, thereby promoting clock drift motion state convergence. Compared with existing observation modeling methods that only consider clock bias, this invention significantly improves the observability and estimation reliability of clock drift, ensuring that clock errors can still be accurately estimated even in scenarios with long-term GNSS signal rejection and sparse external observations. It effectively curbs the trend of deterioration in positioning accuracy caused by the accumulation of clock drift and ensures stable accuracy output of the system under long-term rejection conditions. This solution is based on the broadcast timestamp and coordinate information of microwave synchronous base stations, combined with user-end inertial navigation calculation and microwave two-way ranging observation. By dynamically estimating clock bias and clock drift and compensating the inertial navigation time reference in a closed loop, it achieves high-precision and continuous positioning and timing services. 3. Constructing a closed-loop time reference compensation mechanism to suppress error accumulation at its source and enhance adaptability to complex scenarios. Traditional fusion positioning schemes often limit clock error correction to the results at the filter output, failing to fundamentally address the source impact of time reference deviation on inertial navigation calculations. This results in persistent deviations between the IMU sampling interval and the integration time axis, with errors amplified through integration operations. This is particularly problematic in scenarios involving intense maneuvering or long-term operation, easily leading to calculation divergence. This invention, based on accurate clock error and drift estimation at the filter layer, further constructs a closed-loop compensation link. This feeds back the clock correction amount to the core inertial navigation calculation process in real time, performing forward compensation and dynamic correction on the IMU time stamp, sampling interval, and integration time axis. This suppression strategy, originating from the error source, completely changes the passive "post-correction" mode of traditional schemes, fundamentally reducing the amplification effect of time reference scaling on velocity and position integration, and significantly reducing the accumulation rate of inertial navigation errors. Even in extreme scenarios such as sparse observations, intense maneuvers, or long-term continuous operation, the system can still maintain the stability of the solution process, and the output positioning results are continuous and not easily divergent. This greatly improves the adaptability of the solution to complex denial environments. Compared with traditional output correction schemes, the error accumulation rate is significantly reduced, and the positioning stability advantage in complex scenarios is outstanding. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall execution flow of a spatiotemporal augmentation localization method under rejection conditions provided by an embodiment of the present invention; Figure 2 This is a schematic diagram of the overall execution flow of a spatiotemporal augmentation positioning system under rejection conditions, provided as an embodiment of the present invention. Detailed Implementation

[0014] The present invention will be further described below with reference to the accompanying drawings, but this is not intended to limit the present invention in any way. Any modifications or substitutions made based on the teachings of the present invention shall fall within the protection scope of the present invention.

[0015] Example 1 This embodiment provides a spatiotemporal augmentation positioning method under rejection conditions, which can be implemented by an electronic device, such as... Figure 1 As shown. Specifically, the method of this embodiment includes the following steps: The spatiotemporal augmentation positioning system is configured with a microwave synchronous base station and user terminal equipment; Microwave synchronous base stations are deployed within the positioning area, with a number of microwave synchronous base stations greater than or equal to one. Information exchange can be achieved between microwave synchronous base stations. In this scheme, the number of microwave synchronous base stations is four. Ranging response can be achieved between microwave synchronous base stations and user terminal equipment. The microwave synchronous base station serves as the spatiotemporal reference source for the spatiotemporal augmentation positioning system. It internally generates a stable microwave carrier and a high-precision time reference, and generates and periodically broadcasts microwave signals carrying high-precision timestamps and three-dimensional coordinates of the base station to provide a unified time and space reference for user terminal equipment. At the same time, the microwave synchronous base station has ranging response capability. When it receives a ranging query signal sent by the user terminal equipment, it records the reception time and sends back a response signal, providing necessary support for the user terminal equipment to achieve microwave two-way ranging. The user-end equipment includes an inertial measurement unit and a microwave antenna module. In other words, the sensors and signal transmission devices configured in the user-end equipment are mainly inertial measurement units and microwave antenna modules. The inertial measurement unit is located inside the user terminal equipment. The inertial measurement unit acquires the angular velocity and acceleration of the user terminal equipment. Through integration calculation, the attitude information of the user terminal equipment can be calculated from the angular velocity and acceleration. It should be further clarified that the Inertial Measurement Unit is abbreviated as IMU, therefore, the following... Figure 2 In this context, IMU is used to represent an inertial measurement unit; The microwave antenna module is located inside the user terminal equipment and is used for front-end signal interaction with the microwave synchronization base station. It receives, down-converts and demodulates the microwave signals from the microwave synchronization base station, extracts the timestamp and key information of the microwave synchronization base station coordinates, and sends the demodulated data to the subsequent processing stage. At the same time, the microwave antenna provides the local oscillator and radio frequency links required for synchronization locking, establishes stable locking conditions between the local clock and the base station clock, and undertakes the transmission and reception of bidirectional ranging signals and timestamp capture. After the user terminal equipment is started, the microwave antenna module receives the microwave signal from the microwave synchronization base station and completes down-conversion and demodulation, outputting the base station timestamp, base station coordinate identifier, and local oscillator required for synchronization locking.

[0016] Based on the microwave-synchronized base station time and user terminal equipment clock, a local spatiotemporal reference for the user terminal equipment is established. Specifically, the microwave time synchronization and fusion processing module completes the synchronization and locking of the local clock and the base station time according to the above steps, forming a local spatiotemporal reference for the user terminal.

[0017] The user terminal equipment uses the demodulation time information of the first available microwave synchronization base station to form an initial time of arrival observation, combines the known coordinates of the microwave synchronization base station to obtain the initial geometric constraints, and jointly determines the initial navigation state of the user terminal equipment with the initial attitude information of the inertial measurement unit. Output the initial position of the user terminal device Initial velocity, initial attitude, and initial clock state ( ),in, Indicates the clock bias at the receiving end. This indicates the clock drift (frequency deviation / drift rate) at the receiver. These represent the initial receiver clock bias and initial receiver clock drift, respectively, which serve as the initial values ​​for subsequent fusion estimation. `init` indicates the initial state. The key output of this step is: (1) INS initial navigation solution , , ,in Indicates the initial speed of the user's device. Indicates the initial posture of the user terminal device; Further explanation is needed regarding INS, which stands for Inertial Navigation System, i.e., the navigation system built by the IMU on the user terminal device; (2) Initial clock state ; (3) Local time reference after synchronization and locking with the base station signal (for IMU time stamping).

[0018] The inertial measurement unit (IMU) of the user terminal equipment continuously acquires angular velocity and acceleration data. The microwave time synchronization and fusion processing module uses the local time reference after synchronization lock to time-mark the IMU data, and uses inertial mechanical arrangement to realize continuous integration calculation of position, velocity, and attitude to obtain the inertial navigation calculation results. , , ), to achieve inertial navigation solution; To ensure the system can operate stably in a denied environment for extended periods, a unified state vector containing "navigation error + IMU zero bias + clock error" is constructed in the error dynamic filtering and correction module. A discrete propagation model is also established, allowing clock bias and clock drift to participate in error propagation and subsequent observation updates as state variables. The state vector must be at least: ; in Indicates positional error. Indicates speed error, Indicates attitude error. This indicates that the accelerometer has zero bias. This indicates zero bias of the gyroscope, and T indicates transpose calculation; In discrete time In the propagation, k represents discrete time, which is an integer; In addition to the standard INS error state propagation, the clock state is handled using a joint clock bias and clock drift model, as shown below: ; in, This represents the receiver clock bias at discrete time k+1. This represents the receiver clock bias at discrete time k. This represents the receiver clock drift at discrete time k+1. This represents the receiver clock drift at discrete time k. The time interval between two merge updates. This represents the process noise at discrete time k (which can be modeled as a random walk). The corresponding filtered prediction form is: ; in, This represents the predicted state vector at discrete time k. This represents the state vector at discrete time k-1. This represents the gain at discrete time k. This represents the prediction covariance at discrete time k. This represents the covariance at discrete time k-1. This represents the transpose of the gain at discrete time k. This represents the noise at discrete time k; The predicted navigation state (position / attitude, etc.) and local time information (interval with the last synchronization / update) will be used. The output is sent to the error dynamic filtering and correction module to construct the observation equation and innovation quantity.

[0019] The dynamic error output set for this step is as follows: (1) Predicting navigation solution ( , , ); (2) Predicting clock state ; (3) Predicting covariance ; (4) For use in observation modeling .

[0020] A two-way ranging observation is constructed using ranging queries between the microwave synchronization base station and the user terminal equipment. The user terminal equipment initiates a ranging query to the microwave synchronization base station through its microwave antenna module. Upon receiving the query, the base station responds, and the user terminal receives the response and generates a round-trip time observation. This constitutes a two-way ranging interaction between the user terminal equipment and the microwave synchronization base station. The error dynamic filtering and correction module constructs ranging observation values ​​based on this two-way ranging interaction and combines them with the INS prediction state to form an observation update. To address the core issue of long-term operation under rejection conditions, the key to this invention lies in explicitly incorporating the cumulative impact of clock drift on continuous measurements into the observation model and estimating it together with the INS error state, thereby achieving joint observability and correctability based on clock error, clock drift, and navigation error. The specific steps are as follows: (1) Observational structure: For the i-th microwave synchronization base station, the user terminal equipment forms an equivalent ranging observation. The equivalent distance can be calculated by subtracting the known (or estimated) response delay from the round-trip time delay. At the filtering level, it is uniformly referred to as the equivalent distance observation. (2) Constructing the core observation equation, the present invention adopts the following unified observation model: Where P represents the actual position of the user terminal device in the current epoch (in engineering implementation, the position is linearized using INS prediction). Let c represent the coordinates of the i-th microwave synchronization base station, and c represent the speed of light. Indicates the noise of the i-th observation. Indicates the time interval since the last synchronization / update; Compared to the regular only The model is different, and this invention introduces This method is used to characterize the cumulative error of clock drift over time, and to avoid the error being ignored in the divergence of inertial navigation during long-term operation, thereby achieving active suppression of long-term errors in the denial environment.

[0021] Linearizing the observation equation at the INS prediction points, we get: ; in, This represents the linearized observation at discrete time k. This represents the linearization function for predicting the state vector at discrete time k. This represents the partial derivative of the linearization function with respect to the state vector at discrete time k; For the observation row of the i-th microwave synchronization base station, the sensitivity of the geometric distance term to position error is a unit vector in the line-of-sight direction: ; in, This indicates the calculation of partial derivatives. This represents the transpose of the error at position i. This represents the position error of the i-th position. Represents norm calculation, Indicates the predicted location of the user terminal device; The partial derivative with respect to the clock term is as follows: ; Caused the clock to drift It has clear observability that increases over time; (3) Filter update: The error dynamic filtering correction module uses extended Kalman filtering for recursive updates. ; in, This represents the observation noise covariance matrix at discrete time k. This represents the observation covariance matrix at discrete time k. This represents the extended Kalman gain at discrete time k. Represents the identity matrix. This represents the updated state vector at discrete time k. This represents the observation covariance matrix updated at discrete time k; The filtered output should include at least clock correction. Clock drift correction amount and navigation error correction amount And so on, and output them as correction feedback (clock error / clock drift / navigation error) to the microwave time synchronization and fusion processing module.

[0022] After receiving the correction amount output by the error dynamic filtering and correction module, the microwave time synchronization and fusion processing module performs closed-loop correction on the inertial navigation solution and time reference, so that the clock error is not only estimated in the filter, but also actively compensated on the time axis of the inertial navigation integration.

[0023] Specifically, the local clock parameters are updated and the time base is corrected using the following closed-loop compensation relationship: ; in, Indicates the clock bias at the receiver. Indicates the clock drift deviation at the receiving end; And dynamically compensate for the sampling interval used for IMU integration: ; in, This indicates the sampling interval after dynamic compensation. Indicates the average of the sampling intervals; This achieves the reduction of integral time axis scaling error caused by local oscillator frequency deviation at the source, while simultaneously... Feedback is used to correct the current navigation solution (error state is fed back to nominal state), achieving coordinated convergence of the inertial navigation solution and the clock solution; The high-precision positioning output module outputs the fused positioning results after closed-loop correction, including position, velocity, attitude and trajectory records, to realize continuous spatiotemporal augmentation positioning service under rejection conditions, as well as spatiotemporal augmentation result output under rejection conditions.

[0024] This embodiment uses a two-way ranging and time synchronization network composed of a microwave synchronous base station and user terminal equipment to feed back the estimated receiver clock error / clock drift parameters to the inertial navigation calculation process in real time for closed-loop compensation, thereby suppressing errors from the source and achieving stable long-term precise positioning in indoor, tunnel and other environments.

[0025] Example 2 This embodiment provides a spatiotemporal augmentation positioning system under rejection conditions, such as Figure 2 As shown, the spatiotemporal augmentation positioning system under the rejection condition includes the following modules: The microwave synchronization base station module serves as the system's spatiotemporal reference source. Internally, it generates a stable microwave carrier and a high-precision time reference, broadcasting microwave signals carrying timestamps and its own three-dimensional coordinates to space at preset intervals to provide a unified time and space reference for user equipment. Simultaneously, the microwave synchronization base station possesses ranging response capabilities. When it receives a ranging query signal from a user device, it records the reception time and sends back a response signal, providing necessary support for the user device to achieve two-way microwave ranging. The microwave antenna module completes the front-end signal interaction with the microwave synchronization base station. It receives, down-converts, and demodulates the microwave signals from the microwave synchronization base station, extracts key information such as timestamps and coordinates of the microwave synchronization base station, and sends the demodulated data to the subsequent processing stage. At the same time, the microwave antenna module provides the local oscillator and RF links required for synchronization locking, establishes stable locking conditions between the local clock and the base station clock, and undertakes the transmission and reception of bidirectional ranging signals and timestamp capture. It outputs the ranging-related transmission / reception time information to the downstream processing module. The microwave time synchronization and fusion processing module establishes a local spatiotemporal reference and performs inertial navigation calculations based on the received microwave signals. First, it aligns the local clock with the timestamp of the microwave synchronization base station based on the demodulated data output by the microwave antenna module to achieve clock synchronization. On this basis, it performs initial positioning and initial clock bias calculations by combining the coordinates of the microwave synchronization base station and the initial attitude information to obtain the initial position and clock deviation of the user terminal equipment. Second, it timestamps and performs inertial navigation calculations on the raw data of the inertial measurement unit, continuously calculates the position, velocity, and attitude of the user terminal equipment, and sends the current position prediction value and local time information as state predictions to the error dynamic filtering and correction module. Third, it receives the clock bias, clock drift, and navigation error corrections fed back from the error dynamic filtering and correction module, performs forward compensation and closed-loop correction on the local clock and inertial navigation calculation process, and suppresses long-term drift from the source. The error dynamic filtering and correction module uses microwave two-way ranging observation to estimate and correct errors in inertial navigation prediction results. First, based on the round-trip delay information obtained from the two-way ranging interaction between the microwave antenna module and the microwave synchronization base station, and combined with the prediction state output by the microwave time synchronization and fusion processing module, an observation equation including geometric distance terms and clock error and clock drift cumulative effects is constructed. Second, the Kalman filter equivalent recursive algorithm is used to dynamically estimate the states such as position error, velocity error, attitude error and clock error, and obtain the correction amount for clock error, clock drift and navigation error. Third, the above correction amount is fed back to the microwave time synchronization and fusion processing module in real time to realize the closed-loop update of clock and navigation calculation. The high-precision positioning output module, located at the end of the user terminal device, provides the final positioning result after clock error suppression and inertial / microwave fusion. This module receives the fused positioning result output by the microwave time synchronization and fusion processing module, formats the position, velocity, and attitude, and records the necessary trajectory. It then publishes the positioning information to the host system or user terminal via a wired or wireless interface. Under conditions where satellite navigation is interfered with or denied, the high-precision positioning output module outputs the spatiotemporal augmented positioning result provided by the device of this invention, enabling continuous and reliable navigation and timing services for the target platform or personnel.

[0026] As used herein, the term "preferred" is meant as an example, illustration, or illustration. Any aspect or design described herein as "preferred" need not be construed as being more advantageous than other aspects or designs. Rather, the use of the term "preferred" is intended to present the concept in a specific manner. As used in this application, the term "or" is intended to mean an inclusive "or" rather than an exclusionary "or." That is, unless otherwise specified or clear from the context, "X uses A or B" naturally includes either of the permutations. That is, if X uses A; X uses B; or X uses both A and B, then "X uses A or B" is satisfied in any of the foregoing examples.

[0027] Furthermore, although this disclosure has been shown and described with respect to one or more implementations, equivalent variations and modifications will occur to those skilled in the art based on a reading and understanding of this specification and the accompanying drawings. This disclosure includes all such modifications and variations and is limited only by the scope of the appended claims. In particular, with respect to the various functions performed by the aforementioned components (e.g., elements, etc.), the terminology used to describe such components is intended to correspond to any component (unless otherwise indicated) that performs the specified function of said component (e.g., is functionally equivalent to it), even if structurally not equivalent to the disclosed structure performing the functions in the exemplary implementations of this disclosure shown herein. Moreover, although specific features of this disclosure have been disclosed with respect to only one of several implementations, such features may be combined with one or more features of other implementations that may be desirable and advantageous for a given or particular application. Furthermore, with regard to the use of the terms “comprising,” “having,” “containing,” or variations thereof in the Detailed Description or claims, such terms are intended to be included in a manner similar to the term “including.”

[0028] The functional units in this invention embodiment can be integrated into a processing module, or each unit can exist physically separately, or multiple units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. The aforementioned devices or systems can execute the storage methods in the corresponding method embodiments.

[0029] In summary, the above embodiments are one implementation of the present invention, but the implementation of the present invention is not limited to the embodiments described above. Any changes, modifications, substitutions, combinations, or simplifications made that deviate from the spirit and principle of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention.

Claims

1. A spatiotemporal augmentation localization method under rejection conditions, characterized in that, Includes the following steps: S1: The spatiotemporal augmentation positioning system is configured with a microwave synchronization base station and user terminal equipment. The microwave synchronization base station generates and periodically broadcasts microwave signals carrying timestamps and three-dimensional coordinate information of the base station. The user terminal equipment includes an inertial measurement unit and a microwave antenna module. The microwave antenna module receives the microwave signals from the microwave synchronization base station and performs down-conversion and demodulation. S2: Based on the microwave synchronization base station time and the user terminal equipment clock, establish a local spatiotemporal reference for the user terminal equipment, and use the demodulation time information of the first available microwave synchronization base station to form an initial arrival time observation; Determine the initial navigation state of the user device; S3: Time-mark the data collected by the inertial measurement unit using the local time reference and perform inertial navigation calculation; construct a unified state vector and process the clock state using a clock difference and clock drift joint model; output the predicted navigation state and local time information to the error dynamic filtering and correction module. Clock error, clock drift, position, velocity, attitude error, and inertial measurement unit zero bias are incorporated into the same state vector for unified modeling; S4: Two-way ranging interaction is performed between the user terminal equipment and the microwave synchronization base station; The error dynamic filtering and correction module constructs ranging observations based on the two-way ranging interaction, builds the observation equations, performs filtering updates, and outputs the correction amounts for clock error, clock drift, and navigation error as correction amount feedback. S5: Based on the correction amount, perform closed-loop correction on the inertial navigation solution and time reference, and output the fused positioning result.

2. The spatiotemporal augmentation positioning method under rejection conditions according to claim 1, characterized in that, Step S1 includes: The spatiotemporal augmentation positioning system is equipped with a microwave synchronous base station and user terminal equipment; A microwave synchronous base station is deployed within the positioning area. The number of microwave synchronous base stations is greater than or equal to one. The microwave synchronous base station serves as the spatiotemporal reference source for the spatiotemporal augmentation positioning system. It generates a stable microwave carrier and a high-precision time reference internally, and generates and periodically broadcasts microwave signals carrying timestamps and three-dimensional coordinate information of the base station to provide a unified time and space reference for user terminal equipment. At the same time, the microwave synchronous base station has ranging response capability. When it receives a ranging query signal sent by the user terminal equipment, it records the receiving time and sends back a response signal to support the user terminal equipment in realizing microwave two-way ranging. The user-end equipment includes an inertial measurement unit and a microwave antenna module; The inertial measurement unit is located inside the user terminal equipment. The inertial measurement unit acquires the angular velocity and acceleration of the user terminal equipment. Through integration calculation, the attitude information of the user terminal equipment can be calculated from the angular velocity and acceleration. The microwave antenna module is located inside the user terminal equipment and is used for front-end signal interaction with the microwave synchronization base station. It receives, down-converts and demodulates the microwave signal from the microwave synchronization base station, extracts the timestamp and key information of the microwave synchronization base station coordinates, and sends the demodulated data to the subsequent processing stage. At the same time, the microwave antenna module provides the local oscillator and radio frequency link required for synchronization locking, establishes stable locking conditions between the local clock and the base station clock, and undertakes the transmission and reception of bidirectional ranging signals and timestamp capture. After the user terminal equipment is started, the microwave antenna module receives the microwave signal from the microwave synchronization base station and completes down-conversion and demodulation, outputting the microwave synchronization base station timestamp, microwave synchronization base station coordinate identifier, and local oscillator required for synchronization locking.

3. The spatiotemporal augmentation positioning method under rejection conditions according to claim 1, characterized in that, Step S2 includes: Establish a local spatiotemporal reference for user equipment based on the timestamp of microwave synchronous base station and the clock of user equipment; The user terminal equipment uses the demodulation time information of the first available microwave synchronization base station to form an initial time of arrival observation, combines the known coordinates of the microwave synchronization base station to obtain the initial geometric constraints, and jointly determines the initial navigation state of the user terminal equipment with the initial attitude information of the inertial measurement unit. Output the initial position of the user terminal device Initial velocity Initial posture and the initial clock state ( ),in, Indicates the clock bias at the receiving end. Indicates clock drift at the receiver. These represent the initial receiver clock bias and initial receiver clock drift, respectively, with init indicating the initial state. The key output of this step is: (1) INS initial navigation solution , , ; (2) Initial clock state ; (3) Local time reference after being synchronized and locked with the microwave synchronous base station signal.

4. The spatiotemporal augmentation positioning method under rejection conditions according to claim 3, characterized in that, Step S3 includes: The inertial measurement unit (IMU) of the user terminal device continuously acquires angular velocity and acceleration data. The IMU data is time-stamped using a synchronized local time base, and continuous integration of position, velocity, and attitude is achieved through inertial mechanical orchestration to obtain the inertial navigation calculation results. , , ), to achieve inertial navigation solution; A unified state vector containing navigation error, IMU bias, and clock error is constructed, and a discrete propagation model is established so that clock bias and clock drift participate in error propagation and subsequent observation updates as state variables; the state vector is at least as follows: ； in Indicates positional error. Indicates speed error, Indicates attitude error. This indicates that the accelerometer has zero bias. This indicates zero bias of the gyroscope, and T indicates transpose calculation; In discrete time In the propagation, k represents discrete time, which is an integer; In addition to the standard INS error state propagation, the clock state is handled using a joint clock bias and clock drift model, as follows: ； in, This represents the receiver clock bias at discrete time k+1. This represents the receiver clock bias at discrete time k. This represents the receiver clock drift at discrete time k+1. This represents the receiver clock drift at discrete time k. The time interval between two merge updates. This represents the process noise at discrete time k; The predicted navigation status and local time information are output to the error dynamic filtering and correction module. The key output of this step is: (1) Predicting navigation solution ( , , ); (2) Predicting clock state ; (3) Predicting covariance ; (4) For use in observation modeling .

5. The spatiotemporal augmentation positioning method under rejection conditions according to claim 4, characterized in that, Step S4 includes: The user terminal device initiates a ranging query to the microwave synchronization base station through the microwave antenna module. After receiving the query, the microwave synchronization base station responds and returns a response. The user terminal receives the response and forms a round-trip time observation. The user terminal device and the microwave synchronization base station conduct bidirectional ranging interaction. The error dynamic filtering and correction module constructs ranging observations based on the two-way ranging interaction and forms an observation update in conjunction with the INS prediction state; it explicitly writes the cumulative impact of clock drift on continuous measurements into the observation model and estimates it together with the INS error state, thereby achieving joint observability and correctability based on clock error, clock drift and navigation error. The specific steps are as follows: (1) Observational structure: For the i-th microwave synchronization base station, the user terminal equipment forms an equivalent ranging observation. The round-trip time delay is converted into the equivalent distance after deducting the known or estimated response delay. At the filtering level, it is uniformly recorded as the equivalent distance observation. (2) Construct the observation equation and adopt the following unified observation model: ； Where P represents the actual location of the user terminal device in the current epoch. Let c represent the coordinates of the i-th microwave synchronization base station, and c represent the speed of light. Indicates the noise of the i-th observation; Linearize the observation equation at the INS prediction points; For the observation row of the i-th microwave synchronization base station, the sensitivity of the geometric distance term to position error is a unit vector along the line of sight: ； in, This indicates the calculation of partial derivatives. This represents the transpose of the i-th position error. This represents the position error of the i-th position. Represents norm calculation, Indicates the predicted location of the user terminal device; The partial derivative with respect to the clock term is as follows: ； Caused the clock to drift It has clear observability that increases over time; (3) Filter update: The error dynamic filtering correction module uses extended Kalman filtering for recursive updates. The filter output includes clock correction. Clock drift correction amount and navigation error correction amount The filtered output is then used as a correction feedback.

6. A spatiotemporal augmentation positioning system under rejection conditions, characterized in that, include: The microwave synchronization base station serves as the spatiotemporal reference source of the system. It internally generates a stable microwave carrier and a high-precision time reference, and broadcasts microwave signals carrying timestamps and its own three-dimensional coordinate information into space according to a preset period to provide a unified time and space reference for user equipment. At the same time, the microwave synchronization base station has ranging response capability. When it receives a ranging query signal from the user equipment, it records the reception time and sends back a response signal to support the user equipment in realizing microwave bidirectional ranging. The microwave antenna module completes the front-end signal interaction with the microwave synchronization base station. It receives, down-converts, and demodulates the microwave signals from the microwave synchronization base station, extracts key information such as timestamps and coordinates of the microwave synchronization base station, and sends the demodulated data to the subsequent processing stage. At the same time, the microwave antenna module provides the local oscillator and RF links required for synchronization locking, establishes stable locking conditions between the local clock and the base station clock, and undertakes the transmission and reception of bidirectional ranging signals and timestamp capture. It outputs the ranging-related transmission / reception time information to the downstream processing module. The microwave time synchronization and fusion processing module establishes a local spatiotemporal reference and performs inertial navigation calculations based on the received microwave signals. First, it aligns the local clock with the timestamp of the microwave synchronization base station based on the demodulated data output by the microwave antenna module to achieve clock synchronization. On this basis, it performs initial positioning and initial clock bias calculations by combining the coordinates of the microwave synchronization base station and the initial attitude information to obtain the initial position and clock deviation of the user terminal equipment. Second, it timestamps and performs inertial navigation calculations on the raw data of the inertial measurement unit, continuously calculates the position, velocity, and attitude of the user terminal equipment, and sends the current position prediction value and local time information as state predictions to the error dynamic filtering and correction module. Third, it receives the clock bias, clock drift, and navigation error corrections fed back from the error dynamic filtering and correction module, performs forward compensation and closed-loop correction on the local clock and inertial navigation calculation process, and suppresses long-term drift from the source. The error dynamic filtering and correction module uses microwave two-way ranging observation to estimate and correct errors in inertial navigation prediction results. First, based on the round-trip delay information obtained from the two-way ranging interaction between the microwave antenna module and the microwave synchronization base station, and combined with the prediction state output by the microwave time synchronization and fusion processing module, an observation equation including geometric distance terms and the cumulative effects of clock bias and clock drift is constructed. Second, the Kalman filter equivalent recursive algorithm is used to dynamically estimate the position error, velocity error, attitude error, and clock error state to obtain correction amounts for clock bias, clock drift, and navigation errors. Third, the above correction amounts are fed back to the microwave time synchronization and fusion processing module in real time to realize closed-loop updates of clock and navigation solutions. The high-precision positioning output module, located at the end of the user terminal equipment, is used to provide the final positioning result to the outside world. This module receives the fused positioning result output by the microwave time synchronization and fusion processing module, performs formatting processing on position, velocity and attitude and necessary trajectory recording, and publishes positioning information to the host system or user equipment terminal through wired or wireless interface. Under the condition that satellite navigation is interfered with or rejected, the output of the high-precision positioning output module is the spatiotemporal augmented positioning result provided by the system, realizing continuous and reliable navigation and timing services for the target platform or personnel. Implement a spatiotemporal augmentation localization method under rejection conditions as described in any one of claims 1-5.

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