A motion carrier multi-modal vector compensation method

Abstract

The application is suitable for the field of high-precision positioning technology, and provides a motion carrier multi-mode vector compensation method, which comprises the following steps: acquiring a power consumption mode of a mobile device, and judging the validity of a satellite positioning coordinate; different control methods are adopted for the positioning mode of the mobile device in different modes, and finally the global positioning coordinate of the mobile device is obtained. The application has the advantages that the errors caused by directly comparing and directly weighting two types of RSSI can be reduced. When the high-speed carrier turns, the relative position of the device inside the carrier can be synchronously rotated to the geodetic coordinate system according to the current advancing azimuth; for a long train or other carrier, the systematic deviation caused by directly taking the carrier reference point as the position of the mobile device can be avoided, and thus the positioning accuracy is obviously improved.

Description

Technical Field

[0001] This invention belongs to the field of high-precision positioning technology, and in particular relates to a multimodal vector compensation method for moving carriers. Background Technology

[0002] Current smart terminals typically use BeiDou or GPS satellite positioning to obtain global location. Satellite positioning can directly output geodetic coordinates, but satellite signals are easily blocked by tunnels, mountains, and metal carriages. When high-speed trains or vehicles enter areas with obstructions, the terminal may not be able to continuously obtain valid satellite positioning data. For devices in smoothly moving trains or cars, if the determination of whether the device is moving is based on sensors such as accelerometers, it may misjudge, assuming that the device has not moved. Based on power-saving strategies or other technical logic, it may stop retrieving satellite signals. When the device is reactivated, it may be unable to obtain the latest satellite coordinates due to signal interference.

[0003] When satellite positioning data is unavailable, existing technologies can also use WiFi, GPS, or Bluetooth signals for assisted positioning.

[0004] However, current positioning methods each have their drawbacks. For WiFi positioning, high-speed movement of the carrier shortens the effective observation time of the wireless signal, making the position and velocity results obtained based on signal measurement characteristics or time information prone to fluctuations. When Bluetooth beacons are fixed inside the vehicle, it is difficult to determine the carrier's current global position solely based on the in-vehicle Bluetooth beacon, and it is also difficult to directly convert the terminal's local coordinates into real-time geodetic coordinates. Satellite positioning consumes a lot of power, and in the event of prolonged interruptions, if linear extrapolation is performed based solely on historical position and single velocity, changes in carrier speed and line curvature will cause the extrapolation error to accumulate continuously. Even if only the wireless positioning results are weighted and superimposed, it is difficult to solve the dynamic conversion problem between local and global coordinates.

[0005] Therefore, in scenarios where the terminal remains stationary relative to a high-speed moving vehicle, how to obtain the terminal's real-time high-precision position while reducing satellite positioning power consumption remains a technical problem that needs to be solved in the high-speed vehicle positioning process. Summary of the Invention

[0006] The purpose of this application is to provide a multimodal vector compensation method for moving carriers, which aims to solve the problem that current positioning methods are unable to obtain the real-time high-precision position of the terminal while minimizing the power consumption of satellite positioning.

[0007] This application provides a method for multimodal vector compensation of a moving vehicle, the method comprising:

[0008] Obtain the power consumption mode of the mobile device to determine the validity of the satellite positioning coordinates;

[0009] When the satellite positioning coordinates are valid and the mobile device is in high power mode, the satellite positioning coordinates are used as the device's global positioning coordinates.

[0010] The high-speed carrier is equipped with several Bluetooth hotspots inside, and several WiFi hotspots are set along the moving path of the high-speed carrier. The mobile device communicates with the Bluetooth hotspots via Bluetooth and obtains WiFi communication data from the WiFi hotspots.

[0011] When the mobile device is in low-power mode or the satellite positioning coordinates are invalid, the device local coordinates in the carrier local coordinate system of the high-speed carrier are obtained based on the Bluetooth communication data between the Bluetooth hotspot and the mobile device. ;

[0012] Based on the WiFi communication data and the pre-calibrated geodetic coordinates of each WiFi hotspot, the global coordinates of the high-speed carrier's reference point in the geodetic coordinate system are obtained. and the azimuth angle of the high-speed vehicle ;

[0013] According to the travel azimuth angle The rotation matrix from the local coordinate system of the carrier to the geodetic coordinate system is obtained. :

[0014]

[0015] According to the rotation matrix For the local coordinates of the device Perform coordinate transformation to obtain the geodetic coordinate displacement of the mobile device relative to the carrier reference point. ;

[0016] According to the global coordinates of the carrier and the aforementioned geodetic coordinate displacement Obtain the device's global location coordinates. :

[0017] .

[0018] Another objective of this application is to provide a multimodal vector compensation system for a moving vehicle, including a memory and a processor. The memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the high-speed vehicle multimodal vector compensation and positioning method as described above.

[0019] This application provides a multimodal vector compensation method for moving vehicles, with the key advantage being that it retains the directness of satellite positioning when the satellite positioning quality is good. When satellite signals are unavailable or satellite positioning is actively turned off to reduce power consumption, it can continue to output the device's global position without waiting for satellite re-acquisition. Bluetooth positioning and WiFi line positioning operate simultaneously, reducing errors caused by directly comparing or weighting the two types of RSSI. When a high-speed vehicle turns, the device's relative position within the vehicle can be synchronously rotated to the Earth coordinate system based on the current azimuth angle. For vehicles such as long-formation trains, it avoids systematic deviations caused by directly using the vehicle's reference point as the device's position, thus significantly improving positioning accuracy. Attached Figure Description

[0020] Figure 1 A flowchart of a multimodal vector compensation method for a moving carrier provided in an embodiment of this application. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0022] It is understood that the terms "first," "second," etc., used in this application may be used herein to describe various elements, but unless otherwise specified, these elements are not limited by these terms. These terms are used only to distinguish the first unit or module from another unit or module. For example, without departing from the scope of this application, the first unit may be referred to as the second unit, and similarly, the second module may be referred to as the first module.

[0023] like Figure 1 As shown, in one embodiment, a multimodal vector compensation method for a moving vehicle is proposed, which may specifically include the following steps:

[0024] Step S10: Obtain the power consumption mode of the mobile device and determine the validity of the satellite positioning coordinates.

[0025] In this embodiment, the mobile device can be a smartphone, vehicle terminal, handheld terminal, or other electronic device that simultaneously possesses satellite positioning, WiFi communication, and Bluetooth communication capabilities. The power consumption mode of the mobile device is mainly used to characterize the working state of the satellite positioning RF acquisition module. In high power consumption mode, the satellite positioning RF acquisition module remains operational; in low power consumption mode, the satellite positioning RF acquisition module can be turned off, while retaining WiFi and Bluetooth monitoring functions. The validity of satellite positioning coordinates reflects whether the current satellite positioning result can be used as the device's geodetic coordinates. This can be determined by combining the number of valid satellites, satellite positioning quality parameters, and whether the positioning coordinates can be correctly resolved. Power consumption mode and satellite positioning validity respectively reflect whether the mobile device actively uses satellite positioning and whether satellite positioning is currently available. Detecting these two separately distinguishes between two situations: actively turning off satellite positioning and satellite positioning unavailability caused by external environmental factors, ensuring that subsequent compensation positioning uses the same coordinate processing method in both cases.

[0026] Step S20: When the satellite positioning coordinates are valid and the mobile device is in high power mode, the satellite positioning coordinates are used as the device global positioning coordinates of the mobile device.

[0027] In this embodiment, when the satellite positioning coordinates meet the validity condition, the satellite positioning result is already directly in the geodetic coordinate system, without needing to undergo a conversion from the carrier's local coordinates to geodetic coordinates. Therefore, it can be used as the current device's global positioning coordinates. During the validity period of the satellite positioning coordinates, Bluetooth data and WiFi data can still be collected according to a preset cycle to update the mobile device's position inside the carrier, the carrier's direction of travel, and the carrier's reference coordinates for subsequent use.

[0028] Step S30: Several Bluetooth hotspots are set inside the high-speed carrier, and several WiFi hotspots are set along the moving path of the high-speed carrier. The mobile device communicates with the Bluetooth hotspots via Bluetooth to obtain WiFi communication data from the WiFi hotspots.

[0029] In this embodiment, the Bluetooth hotspots are fixedly located inside the high-speed carrier, and their positions move with the overall movement of the carrier. Therefore, the spatial relationships between the Bluetooth hotspots remain unchanged in the carrier's local coordinate system. Bluetooth communication data may include information such as hotspot identifiers, received signal strength, and sampling timestamps, used to obtain the position of the mobile device relative to a carrier reference point. WiFi hotspots are located along the high-speed carrier's movement path, and their positions are fixed relative to the Earth's coordinate system. The Earth's coordinates of each WiFi hotspot can be pre-measured and stored on the mobile device, a local server, or the cloud. WiFi communication data can originate from WiFi scanning, and it is not required that the mobile device establish a network data connection with the corresponding WiFi hotspot. For example, the mobile device can obtain the hotspot's MAC address, SSID, received signal strength, and sampling time based on the scan message. Bluetooth hotspots and WiFi hotspots along the route provide different coordinate references. Bluetooth hotspots inside the carrier are suitable for describing the position of the mobile device relative to the carrier, while WiFi hotspots along the route are suitable for providing a reference for the Earth's position as the high-speed carrier moves along the route.

[0030] Step S40: When the mobile device is in low-power mode or the satellite positioning coordinates are invalid, based on the Bluetooth communication data between the Bluetooth hotspot and the mobile device, obtain the device local coordinates of the mobile device in the carrier local coordinate system of the high-speed carrier. .

[0031] In this embodiment, the carrier local coordinate system is fixed to the high-speed carrier, and its origin is set at a preset fixed position on the high-speed carrier. The device local coordinates represent the position of the mobile device relative to the carrier reference point and do not change with the overall translation of the high-speed carrier in the geodetic coordinate system. For example, for a carrier arranged longitudinally along the vehicle body, one axis of the carrier local coordinate system can be set along the longitudinal direction of the carrier, and the other axis can be set along the transverse direction of the carrier. When a passenger moves a mobile device from the front to the rear of the carriage, the device local coordinates change; when the passenger remains seated while the high-speed carrier travels along the track, the device local coordinates remain basically stable. The introduction of this coordinate system allows the system to retain the actual position of the mobile device inside the high-speed carrier. For trains with a long length, if the center position of the carrier is directly used as the position of all mobile devices, there may be positional differences of tens of meters or even more between different carriages.

[0032] Step S50: Based on the WiFi communication data and the pre-calibrated geodetic coordinates of each WiFi hotspot, obtain the global coordinates of the carrier reference point of the high-speed carrier in the geodetic coordinate system. and the azimuth angle of the high-speed vehicle .

[0033] In this embodiment, the carrier global coordinates represent the position of the carrier reference point on the high-speed carrier in the geodetic coordinate system, which is distinct from the device global positioning coordinates of the mobile device itself. The travel azimuth angle describes the directional relationship between the longitudinal direction of the carrier's local coordinate system and the coordinate axes of the geodetic coordinate system. The pre-calibrated geodetic coordinates of each WiFi hotspot can be directly obtained from the hotspot installation location, or they can be pre-converted to corresponding line reference coordinates based on the fixed relationship between the hotspot installation location and the line reference position when the high-speed carrier passes that hotspot. For curved lines, the movement distance between adjacent WiFi reference positions can be the arc length on the line trajectory, not limited to the straight-line distance between the geodetic coordinates of two hotspots. When the high-speed carrier passes different WiFi hotspots sequentially along the line, each WiFi hotspot simultaneously provides spatial position and time references, from which the movement speed and direction of different line segments can be obtained. Compared to obtaining the position based on only one WiFi positioning result, this method can continuously update the carrier position.

[0034] Step S60, according to the travel azimuth angle The rotation matrix from the local coordinate system of the carrier to the geodetic coordinate system is obtained. :

[0035] .

[0036] In this embodiment, the rotation matrix is ​​used to describe the coordinate representation of the same displacement vector in both the local coordinate system and the geodetic coordinate system. The longitudinal axis of the local coordinate system can be set to align with the direction of travel of the high-speed vehicle, and the azimuth angle is measured according to a preset rotation direction, starting from a preset coordinate axis in the geodetic coordinate system. The azimuth angle is calculated using radians in trigonometric functions. The rotation matrix changes synchronously when the azimuth angle changes. For the device's local coordinates, the values ​​describe the longitudinal and lateral distances of the mobile device relative to the carrier reference point. Without the aforementioned rotation, the same device local coordinates would yield the same geodetic coordinate displacement regardless of the carrier's orientation, failing to reflect the actual direction of travel of the high-speed vehicle.

[0037] Step S70, according to the rotation matrix For the local coordinates of the device Perform coordinate transformation to obtain the geodetic coordinate displacement of the mobile device relative to the carrier reference point. .

[0038] In this embodiment, the geodetic coordinate displacement obtained by the coordinate transformation represents the components of the spatial vector pointing from the carrier reference point to the mobile device along the two coordinate axes of the geodetic coordinate system. For example, the mobile device is located 20m behind the carrier reference point along the longitudinal direction of the carrier. When the high-speed carrier travels eastward, it is represented by an east-west displacement on the ground; after the high-speed carrier turns and travels northward, the same local coordinates of the device are represented by a north-south displacement on the ground. The rotation matrix allows the position of the device inside the carrier to be synchronously transformed to the geodetic coordinate system according to the orientation of the carrier.

[0039] Step S80, based on the global coordinates of the carrier and the aforementioned geodetic coordinate displacement Obtain the device's global location coordinates. :

[0040] .

[0041] In this embodiment, the carrier's global coordinates provide the geodetic position of the carrier's reference point, and the geodetic coordinate displacement provides the geodetic coordinate offset of the mobile device relative to this reference point. The two are vector-superimposed to obtain the mobile device's own global positioning coordinates. Using the carrier reference point as an intermediate coordinate reference allows the WiFi side to primarily handle the large-scale movement of the high-speed carrier, while the Bluetooth side primarily handles the small-scale movement of the mobile device within the carrier. The two positioning data do not need to be directly weighted and fused under the same error model.

[0042] In the embodiments of this application, the processing method provided by this solution is particularly suitable for high-speed vehicles whose vehicle dimensions cannot be ignored. There is a fixed or slowly changing spatial difference between the position of the high-speed vehicle itself and the position of the passenger terminal. If only the route is extrapolated for the high-speed vehicle, the final result is equivalent to positioning all mobile devices in the vehicle near the same reference point. By adding the local coordinates of the devices, the positional differences caused by different carriages, different seats, and movement within the vehicle can be preserved.

[0043] The advantage of the method provided in this embodiment is that it retains the directness of satellite positioning when the satellite positioning quality is good. When satellite signals are unavailable or satellite positioning is actively turned off to reduce power consumption, it can continue to output the device's global position without waiting for satellite positioning to be reacquired. Bluetooth positioning and WiFi line positioning work simultaneously, which can reduce the errors caused by directly comparing or weighting the two types of RSSI. When a high-speed vehicle turns, the relative position of the device inside the vehicle can be synchronously rotated to the geodetic coordinate system according to the current azimuth angle. For vehicles such as long-formation trains, it can avoid the systematic deviation caused by directly using the vehicle reference point as the position of the mobile device, thereby significantly improving the positioning accuracy.

[0044] In a preferred embodiment, based on the Bluetooth communication data between the Bluetooth hotspot and the mobile device, the device local coordinates in the carrier local coordinate system of the high-speed carrier are obtained. The method is as follows:

[0045] A local coordinate system of the carrier is established with a preset fixed position inside the high-speed carrier as the carrier reference point and the carrier reference point as the origin.

[0046] Obtain the pre-calibrated Bluetooth hotspot coordinates of each Bluetooth hotspot in the local coordinate system of the carrier, and then... The Bluetooth hotspot coordinates of the Bluetooth hotspots are as follows: Select at least three non-co-wired Bluetooth hotspots to participate in the location service. , ;

[0047] Extract the first from the Bluetooth communication data The hotspot identifier of each Bluetooth hotspot and the received signal strength of the mobile device. , obtain the Reference received signal strength of a Bluetooth hotspot at a reference distance and path loss coefficient ;

[0048] According to the received signal strength The reference received signal strength and the path loss coefficient , obtain mobile devices and the The distance between Bluetooth hotspots :

[0049]

[0050] Let the coordinates of the mobile device in the local coordinate system of the carrier be... According to the coordinates of each Bluetooth hotspot and the corresponding distance Construct distance residuals;

[0051] The local coordinates of the equipment are obtained by solving the distance residuals using the least squares method. :

[0052] .

[0053] In this embodiment, the carrier reference point can be a structural point inside the high-speed carrier that is fixed and easy to calibrate, such as the geometric center of the vehicle body, a designated end of the vehicle compartment, or the installation location of the on-board positioning controller. The position of each Bluetooth hotspot is measured relative to this reference point before the device is put into use, and a corresponding hotspot identifier is written into it, enabling the mobile device to retrieve the corresponding Bluetooth hotspot coordinates after obtaining the hotspot identifier. At least three Bluetooth hotspots are arranged non-collinearly to avoid all ranging constraints being concentrated in the same direction, which would cause the two-dimensional position to be unstable. More than three Bluetooth hotspots can be arranged inside the actual carrier, and multiple hotspots that can currently receive stably can be selected for calculation.

[0054] In this embodiment, the reference received signal strength represents the signal strength measured in advance at a preset reference distance, and the path loss coefficient reflects the degree of signal attenuation with distance as the signal propagates within the current carrier. High-speed carriers typically contain reflective or obstructive factors such as metal bodies, seats, partitions, and passengers, and propagation conditions may differ at different installation locations. Therefore, the reference received signal strength and path loss coefficient can be calibrated separately for each Bluetooth hotspot, without needing to use the same parameters for all Bluetooth hotspots. The distance residual reflects the deviation between the candidate device's location and each Bluetooth ranging result. Using the least squares method to obtain the location with the smallest overall residual allows for the acquisition of stable local device coordinates even when ranging results contain some error.

[0055] Preferably, four or more Bluetooth hotspots can be installed on the top or side walls of the train carriage. After a passenger's mobile device simultaneously receives broadcast signals from multiple hotspots, it obtains the two-dimensional coordinates inside the carriage based on the pre-calibrated positions of each hotspot and the RSSI ranging results. Even if some hotspots are obstructed by passengers, causing a certain ranging deviation, the remaining hotspots can still participate in the position calculation, reducing the impact of a single ranging error on the local coordinates of the device. After the high-speed vehicle enters a tunnel, even if the geodetic positioning conditions change significantly, the relative geometric relationship between the Bluetooth hotspots fixed inside the vehicle and the mobile device still exists, continuing to reflect the specific area where the mobile device is located inside the vehicle.

[0056] In a preferred embodiment, based on the WiFi communication data and the pre-calibrated geodetic coordinates of each WiFi hotspot, the global coordinates of the carrier reference point in the geodetic coordinate system are obtained. and the azimuth angle of the high-speed vehicle The method is as follows:

[0057] Obtain the carrier reference coordinates stored before the satellite positioning coordinates fail or before the mobile device enters low power mode. and its base timestamp Obtain the hotspot identifier and pre-calibrated geodetic coordinates of each WiFi hotspot;

[0058] The system continuously acquires the hotspot identifiers and received signal strengths of WiFi hotspots scanned by the mobile device. When the received signal strength of a target WiFi hotspot meets a preset reference condition, a WiFi reference event is obtained, and the corresponding reference timestamp is recorded. And obtain the pre-calibrated geodetic coordinates of the corresponding target WiFi hotspot. ;

[0059] Sequentially obtain the reference timestamps corresponding to two adjacent WiFi reference events. , and pre-calibrated geodetic coordinates , The pre-calibrated travel distance of the corresponding line segment is obtained based on two adjacent pre-calibrated geodetic coordinates. The reference time interval is obtained based on two adjacent reference timestamps. :

[0060]

[0061] According to the pre-calibrated movement distance and the reference time interval , obtained the The driving speed corresponding to each route segment :

[0062]

[0063] The first [number] is obtained based on the pre-calibrated geodetic coordinates of two adjacent WiFi hotspots. The travel azimuth angle corresponding to each line segment :

[0064]

[0065] Based on the aforementioned reference timestamp up to the current location time The corresponding driving speeds for each section of the route traversed during the trip azimuth of travel and the corresponding duration The cumulative displacement components of the carrier reference point in the two geodetic coordinate axes are obtained. and :

[0066]

[0067] According to the carrier reference coordinates and the cumulative displacement components and Obtain the global coordinates of the carrier at the current positioning time. :

[0068]

[0069] The azimuth angle corresponding to the latest route segment at the current positioning time is used as the current azimuth angle of the high-speed vehicle. .

[0070] In this embodiment, WiFi reference events are used to convert continuously changing wireless signals into line reference points with a clear time-location correspondence. Preset reference conditions can be set according to the actual line wireless environment. Each WiFi reference event is associated with a pre-calibrated location on the line. For cases where there is a lateral distance between the hotspot installation location and the actual operating line of the high-speed vehicle, the hotspot's physical coordinates can be mapped to the corresponding line reference location during deployment, and this line reference location will be used for subsequent calculations. The reference time interval corresponds to the time elapsed between two line reference locations for the high-speed vehicle. The ratio of the pre-calibrated travel distance to this time interval is used to characterize the average travel speed of the line segment. The azimuth angle is obtained from the spatial direction of adjacent reference locations, reflecting the overall travel direction of the high-speed vehicle on the line segment. The movement process from the reference timestamp to the current positioning time is accumulated according to the actual line segments traversed. For each line segment, the displacement components on the two geodetic coordinate axes are obtained using the corresponding speed, azimuth angle, and duration, and then the displacements of each segment are accumulated. This processing can reflect the speed and line direction changes of the high-speed vehicle after satellite positioning failure, avoiding the use of a single current speed and a single current azimuth angle to extrapolate the travel distance during the entire failure period.

[0071] In a preferred embodiment, the carrier reference coordinates stored before the satellite positioning coordinates fail or before the mobile device enters a low-power mode are obtained. and its base timestamp The method is as follows:

[0072] When the satellite positioning coordinates are valid, acquire the satellite positioning coordinates. ;

[0073] Get the device's local coordinates at the current moment and the azimuth angle of the high-speed vehicle ;

[0074] According to the travel azimuth angle Obtain the rotation matrix from the local coordinate system of the carrier to the geodetic coordinate system. According to the current satellite positioning coordinates and the local coordinates of the device The reference coordinates of the carrier reference point in the geodetic coordinate system are obtained. :

[0075]

[0076] The timestamp corresponding to the current satellite positioning coordinates is used as the reference coordinates of the carrier. base timestamp ;

[0077] The carrier reference coordinates and its base timestamp Associated storage covers the historical carrier reference coordinates and their historical reference timestamps in the local cache;

[0078] When the mobile device enters low-power mode or the satellite positioning coordinates become invalid, the last stored carrier reference coordinates before entering low-power mode or before the coordinates become invalid are retrieved from the local cache. and its base timestamp .

[0079] In this embodiment, the carrier reference coordinates represent the position of the high-speed carrier reference point in the geodetic coordinate system. Their purpose is to serve as the starting position for carrier motion simulation after satellite positioning is turned off or fails. The geodetic position of the carrier reference point at the same moment can be obtained by subtracting the geodetic coordinate displacement from the mobile device's satellite positioning coordinates. In this scheme, the carrier reference coordinates can be periodically refreshed during the effective period of satellite positioning, and the local cache only retains the most recent result that meets the conditions. When satellite positioning suddenly fails, the carrier reference state closest to the time of failure can be directly obtained, reducing the timeliness error caused by long-term accumulated data, and also improving the position continuity when switching between satellite positioning mode and compensated positioning mode.

[0080] In a preferred embodiment, the method further includes:

[0081] Get the The global coordinates of the carrier obtained from the secondary positioning process The travel speed of high-speed vehicles and azimuth angle Construct observation vectors :

[0082]

[0083] Constructing the state vector of a high-speed carrier :

[0084]

[0085] State prediction is performed based on the updated state vector from the previous positioning time:

[0086]

[0087] Obtain the prediction error covariance matrix :

[0088]

[0089] in, Here is the state transition matrix. The process noise covariance matrix;

[0090] According to the observation vector Obtain Kalman gain :

[0091]

[0092] in, For the observation matrix, To observe the noise covariance matrix;

[0093] The predicted state is updated based on the Kalman gain:

[0094]

[0095] Update the error covariance matrix:

[0096]

[0097] The corrected global coordinates, speed, and azimuth of the vehicle are obtained based on the updated state vector.

[0098] Based on the corrected global coordinates of the carrier, the azimuth angle of travel, and the current local coordinates of the device, the corrected global positioning coordinates of the device are obtained;

[0099] in, Indicates the speed of a high-speed vehicle. Indicates the azimuth angle of the high-speed vehicle. Indicates transpose. This represents the state vector at the k-th positioning time. This represents the state vector updated after observation at the previous positioning time. This represents the error covariance matrix after the observation update was completed at the previous positioning time. Represents the transpose of the observation matrix. This represents the updated error covariance matrix. Represents the identity matrix.

[0100] In this embodiment, the global coordinates, speed, and azimuth of the vehicle in the observation vector are derived from the current WiFi reference event and line motion calculation results, serving as the vehicle motion observations directly obtainable at the current moment. The state vector is used to store the vehicle motion state after correction by historical states and current observations. Considering that position, speed, and azimuth are used as state variables, and that there is a trigonometric function relationship between position change and speed / azimuth, the vehicle motion equation can be established based on the state estimate of the previous positioning moment and the current positioning cycle time interval, and local linearization can be performed near the current state. The resulting state transition Jacobian matrix is ​​used as... Therefore, the prediction and update process can be completed using an extended Kalman filter. For cases where the azimuth angle crosses the boundary of an angular cycle, such as changing from near the positive half-cycle to the negative half-cycle, the azimuth observation residual can be normalized to the same preset angular interval before participating in the filter update. This avoids misinterpreting abrupt changes in angle values ​​as large-angle instantaneous turns by the high-speed vehicle. The updated state vector directly provides the filtered and corrected global coordinates, velocity, and azimuth angle of the vehicle. Subsequent device position calculations continue to use the corrected vehicle state and the current local coordinates of the Bluetooth device, ensuring that instantaneous fluctuations in vehicle motion observation are not directly and uniformly transmitted to the device's global positioning results.

[0101] For example, when a high-speed vehicle passes through the boundary between two WiFi hotspot coverage areas, the location and time corresponding to the reference event may change slightly due to RSSI fluctuations, and the calculated instantaneous velocity may be too high or too low. State prediction can use the motion trend of the previous moment to provide continuous constraints, and the current observation can then make appropriate corrections to the prediction results, reducing the jumps in global positioning coordinates caused by errors in a single wireless observation.

[0102] In a preferred embodiment, the method for the mobile device to enter a low-power mode is as follows:

[0103] Continuously collect three-axis acceleration data from the mobile device and obtain the acceleration changes in each of the three axes within a preset detection time period. , and ;

[0104] The acceleration change parameters of the mobile device are obtained based on the acceleration changes along the three coordinate axes. :

[0105]

[0106] According to the preset time interval Continuously acquire device local coordinates of mobile devices The change in local position of the mobile device relative to the high-speed carrier is obtained based on the local coordinates of the device at adjacent time points. :

[0107]

[0108] When the acceleration change parameter Less than the preset acceleration change threshold And the amount of change in the local position Less than the preset position change threshold And maintain a preset still time continuously. hour:

[0109]

[0110] If the mobile device is determined to be stationary relative to the high-speed carrier, the satellite positioning radio frequency acquisition module of the mobile device is turned off, and the mobile device enters a low-power mode that retains WiFi and Bluetooth listening.

[0111] In this embodiment, the three-axis acceleration change reflects the degree of change in the mobile device's motion state within the detection period. The difference between the maximum and minimum acceleration values ​​for each coordinate axis within the preset detection period is obtained as the acceleration change for that axis. The maximum value among the three coordinate axis changes is then taken as the acceleration change parameter. Relying solely on acceleration data is insufficient to fully represent whether the mobile device has changed position relative to the high-speed carrier. Therefore, the change in the local coordinates of the Bluetooth device is introduced to check whether the mobile device's position relative to the high-speed carrier has changed. The local position change can be represented by the Euclidean distance between two adjacent local coordinates. A small value indicates that the mobile device's position in the carrier's local coordinate system has remained essentially unchanged. A preset static time is used to establish temporal continuity constraints; for example, a small single change in the local coordinates is insufficient to indicate that the device has entered a long-term static state. After entering low-power mode, WiFi and Bluetooth listening are retained, allowing the mobile device to still acquire the carrier's motion state and the device's local position. Disabling the satellite positioning RF acquisition module does not interrupt the compensated positioning data source in this application. This solution combines the device's own motion information with the device's position change relative to the carrier, reducing the possibility of misjudgment and lowering operating energy consumption.

[0112] In a preferred embodiment, the method for determining that satellite positioning coordinates are invalid is as follows:

[0113] When the satellite positioning radio frequency acquisition module is in working condition, the number of valid satellites currently participating in the positioning is obtained. And satellite positioning quality parameters;

[0114] When the number of effective satellites Below the preset satellite number threshold If the satellite positioning quality parameters do not meet the preset positioning quality conditions, or the satellite positioning coordinates cannot be resolved, the current satellite positioning coordinates will be set to invalid.

[0115] When the number of effective satellites Not less than the preset satellite number threshold When the satellite positioning quality parameters meet the preset positioning quality conditions and the satellite positioning coordinates can be obtained by parsing, the current satellite positioning coordinates are set to valid.

[0116] In this embodiment, the effective satellite count refers to the number of satellites that have passed the reception quality screening and actually participate in the current positioning calculation. Different types of quality parameters can be set with corresponding conditions. For parameters representing error magnitude or horizontal accuracy factors, the positioning quality conditions can be considered met when the parameter is not higher than the corresponding threshold. When the effective satellite count is insufficient, the satellite geometry and available observables are usually insufficient to support stable positioning. When coordinates can be resolved but the positioning quality parameters are poor, large drift may also occur. Therefore, the effective satellite count, positioning quality, and coordinate resolution status are used together as the basis for judging the validity of satellite positioning coordinates.

[0117] In a preferred embodiment, when the number of collected WiFi hotspots or WiFi reference events is insufficient to obtain the global coordinates of the carrier... When obtaining the last-resort global positioning coordinates of the mobile device, the method includes:

[0118] Multiple historical vehicle global coordinates obtained consecutively before the WiFi reference event were insufficient were used to construct the historical driving trajectory of the high-speed vehicle in chronological order. ;

[0119] Obtain the global trajectory of the high-speed carrier's movement area from the pre-stored data. The historical driving trajectory With the global trajectory of the line Trajectory matching is performed to obtain the target route segment corresponding to the historical driving trajectory and the travel direction of the high-speed vehicle on the target route segment;

[0120] Using the global coordinates of the last valid vehicle in the historical driving trajectory As the starting position for trajectory deduction, obtain the corresponding timestamp. and the last valid driving speed obtained before the WiFi reference event was insufficient. ;

[0121] Based on the current location time With the timestamp The time interval between these intervals yields the predicted travel distance of the high-speed vehicle along the target route segment. :

[0122]

[0123] Traveling along the global trajectory of the route, starting from the trajectory derivation starting position. Extending the predicted driving distance forward The predicted global coordinates of the high-speed carrier at the current positioning time are obtained. ;

[0124] Based on the global trajectory of the described line, predict the global coordinates on the carrier. The tangential direction at the point yields the predicted azimuth angle of the high-speed vehicle. ;

[0125] Based on the predicted azimuth angle Obtain the rotation matrix from the local coordinate system of the carrier to the geodetic coordinate system. :

[0126]

[0127] Predict global coordinates based on the carrier. Current device local coordinates and the rotation matrix Obtain the fallback global positioning coordinates of the mobile device. :

[0128]

[0129] In this embodiment, insufficient WiFi reference events can refer to the absence of new valid reference events within a preset time range, making it impossible to continue updating time, speed, or global coordinates of the vehicle based on adjacent reference locations. Historical global coordinates of the vehicle record the location of the vehicle reference point; the device's global coordinates are not used as the object for route trajectory matching. The global route trajectory can be pre-stored as trajectory points arranged in the driving sequence or as polyline segments. During trajectory matching, the target route segment can be obtained by combining the spatial distance of the historical vehicle location, direction of movement, and the order of trajectory points. When extending forward along the global route trajectory, the actual cumulative distance on the route trajectory is used as the travel distance. Even if a curved route is passed during the prediction period, the corresponding predicted global coordinates of the vehicle can still be obtained from the route trajectory. After obtaining the predicted global coordinates of the vehicle and the predicted azimuth angle, the location of the mobile device is calculated using the current Bluetooth device's local coordinates. When WiFi is temporarily unable to continue providing vehicle status and the location of passengers inside the vehicle changes, the fallback global positioning result can still reflect this local position change.

[0130] In a preferred embodiment, the method for correcting the predicted global coordinates of the carrier based on line constraints is as follows:

[0131] Obtain the predicted global coordinates of the distance from the vehicle in the global trajectory of the line. The nearest target line segment, let the two endpoints of the target line segment be respectively... and ;

[0132] Predict global coordinates based on the carrier. The projection parameters are obtained from the two endpoints of the target line segment. :

[0133]

[0134] when At that time, the projection parameters will be corrected. Set to 0; when At that time, the projection parameters will be corrected. Set as ;when At that time, the projection parameters will be corrected. Set to 1;

[0135] According to the corrected projection parameters The predicted global coordinates of the carrier are obtained as the line constraint coordinates on the target line segment. :

[0136]

[0137] According to the target line segment at the line constraint coordinates The tangent direction at that point is corrected for the travel azimuth angle. ;

[0138] According to the corrected travel azimuth angle Obtain the rotation matrix According to the line constraint coordinates Current device local coordinates and the rotation matrix The final fallback global positioning coordinates of the mobile device are obtained. :

[0139]

[0140] In this embodiment, the line constraint correction is used to handle the lateral position error generated when relying on historical speed for trajectory extrapolation. The projection parameter reflects the relative position of the carrier's predicted global coordinates in the extension direction of the target line segment. When the projection parameter is between 0 and 1, the perpendicular foot is located between the two endpoints, and the perpendicular foot position can be directly used. When the projection parameter is less than 0, it indicates that the perpendicular foot is outside the first endpoint, and the first endpoint is taken after the corrected projection parameter is restricted to 0. When the projection parameter is greater than 1, it indicates that the perpendicular foot is outside the second endpoint, and the second endpoint is taken after the corrected projection parameter is restricted to 1. When the target line consists of multiple continuous line segments, if the carrier position is close to the connection point of the line segment, the tangent direction at the connection point can be obtained by combining adjacent line segments. If the device position is directly projected onto the line, the offset of the actual position inside the vehicle obtained by Bluetooth positioning will be eliminated. By first obtaining the carrier reference point after line constraint, and then converting the local coordinates of the device according to the corrected travel azimuth angle, the line constraint and the position difference of the device inside the carrier can be preserved at the same time.

[0141] For example, trajectory extrapolation causes the predicted global coordinates of the vehicle to deviate by several meters laterally relative to the railway centerline. Projecting this deviation onto the target line segment yields the line-constrained coordinates located on the line. If the mobile device is actually located laterally to the vehicle's reference point, the final device positioning coordinates, after being re-superimposed based on the Bluetooth device's local coordinates and the corrected azimuth angle, will still be located to the side of the line centerline and will not be forcibly pressed onto it. When multiple candidate line segments are close together in the line area, historical travel trajectories, current travel direction, and the previously matched line segment can be further combined to filter out candidate line segments with significantly discontinuous movement directions, reducing erroneous matching at parallel tracks, ramps, or line intersections based solely on the closest spatial distance.

[0142] The method provided in this application can suppress lateral drift caused by short-time trajectory extrapolation, maintain the constraint of high-speed carrier moving along a predetermined path, and will not destroy the internal spatial information of the carrier provided by the local positioning of the equipment.

[0143] In one embodiment, a multimodal vector compensation system for a moving vehicle is provided. The system includes a memory and a processor. The memory stores a computer program, which, when executed by the processor, causes the processor to perform the steps of the compensation method as described above.

[0144] In this embodiment, the system can be a computer hardware system that executes its corresponding method when the system is running. Please refer to the above description of the compensation method; it will not be repeated here.

[0145] It should be understood that although the steps in the flowcharts of the various embodiments of this application are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in each embodiment may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least a portion of the sub-steps or stages of other steps.

[0146] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Furthermore, any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory.

[0147] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A method for multimodal vector compensation of a moving vehicle, characterized in that, The method includes: Obtain the power consumption mode of the mobile device to determine the validity of the satellite positioning coordinates; When the satellite positioning coordinates are valid and the mobile device is in high power mode, the satellite positioning coordinates are used as the device's global positioning coordinates. The high-speed carrier is equipped with several Bluetooth hotspots inside, and several WiFi hotspots are set along the moving path of the high-speed carrier. The mobile device communicates with the Bluetooth hotspots via Bluetooth and obtains WiFi communication data from the WiFi hotspots. When the mobile device is in low-power mode or the satellite positioning coordinates are invalid, the device local coordinates in the carrier local coordinate system of the high-speed carrier are obtained based on the Bluetooth communication data between the Bluetooth hotspot and the mobile device. ; Based on the WiFi communication data and the pre-calibrated geodetic coordinates of each WiFi hotspot, the global coordinates of the high-speed carrier's reference point in the geodetic coordinate system are obtained. and the azimuth angle of the high-speed vehicle ; According to the travel azimuth angle The rotation matrix from the local coordinate system of the carrier to the geodetic coordinate system is obtained. : According to the rotation matrix For the local coordinates of the device Perform coordinate transformation to obtain the geodetic coordinate displacement of the mobile device relative to the carrier reference point. ; According to the global coordinates of the carrier and the aforementioned geodetic coordinate displacement Obtain the device's global location coordinates. : 。 2. The multimodal vector compensation method for a moving carrier according to claim 1, characterized in that, Based on the Bluetooth communication data between the Bluetooth hotspot and the mobile device, the device local coordinates in the carrier local coordinate system of the high-speed carrier are obtained. The method is as follows: A local coordinate system of the carrier is established with a preset fixed position inside the high-speed carrier as the carrier reference point and the carrier reference point as the origin. Obtain the pre-calibrated Bluetooth hotspot coordinates of each Bluetooth hotspot in the local coordinate system of the carrier, and then... The Bluetooth hotspot coordinates of the Bluetooth hotspots are as follows: Select at least three non-co-wired Bluetooth hotspots to participate in the location service. , ; Extract the first from the Bluetooth communication data The hotspot identifier of each Bluetooth hotspot and the received signal strength of the mobile device. , obtain the Reference received signal strength of a Bluetooth hotspot at a reference distance and path loss coefficient ; According to the received signal strength The reference received signal strength and the path loss coefficient , obtain mobile devices and the The distance between Bluetooth hotspots : Let the coordinates of the mobile device in the local coordinate system of the carrier be... According to the coordinates of each Bluetooth hotspot and the corresponding distance Construct distance residuals; The local coordinates of the equipment are obtained by solving the distance residuals using the least squares method. : 。 3. The multimodal vector compensation method for a moving carrier according to claim 1, characterized in that, Based on the WiFi communication data and the pre-calibrated geodetic coordinates of each WiFi hotspot, the global coordinates of the high-speed carrier's reference point in the geodetic coordinate system are obtained. and the azimuth angle of the high-speed vehicle The method is as follows: Obtain the carrier reference coordinates stored before the satellite positioning coordinates fail or before the mobile device enters low power mode. and its base timestamp Obtain the hotspot identifier and pre-calibrated geodetic coordinates of each WiFi hotspot; The system continuously acquires the hotspot identifiers and received signal strengths of WiFi hotspots scanned by the mobile device. When the received signal strength of a target WiFi hotspot meets a preset reference condition, a WiFi reference event is obtained, and the corresponding reference timestamp is recorded. And obtain the pre-calibrated geodetic coordinates of the corresponding target WiFi hotspot. ; Sequentially obtain the reference timestamps corresponding to two adjacent WiFi reference events. , and pre-calibrated geodetic coordinates , The pre-calibrated travel distance of the corresponding line segment is obtained based on two adjacent pre-calibrated geodetic coordinates. The reference time interval is obtained based on two adjacent reference timestamps. : According to the pre-calibrated moving distance and the reference time interval , obtained the The corresponding driving speed of each route segment : The first [number] is obtained based on the pre-calibrated geodetic coordinates of two adjacent WiFi hotspots. The travel azimuth angle corresponding to each line segment : Based on the aforementioned reference timestamp up to the current location time The corresponding driving speeds for each section of the route traversed during this period azimuth of travel and the corresponding duration The cumulative displacement components of the carrier reference point in the two geodetic coordinate axes are obtained. and : According to the carrier reference coordinates and the cumulative displacement components and Obtain the global coordinates of the carrier at the current positioning time. : The azimuth angle corresponding to the latest route segment at the current positioning time is used as the current azimuth angle of the high-speed vehicle. .

4. The multimodal vector compensation method for a moving carrier according to claim 3, characterized in that, Obtain the carrier reference coordinates stored before the satellite positioning coordinates fail or before the mobile device enters low power mode. and its base timestamp The method is as follows: When the satellite positioning coordinates are valid, acquire the satellite positioning coordinates. ; Get the device's local coordinates at the current moment and the azimuth angle of the high-speed vehicle ; According to the travel azimuth angle Obtain the rotation matrix from the local coordinate system of the carrier to the geodetic coordinate system. According to the current satellite positioning coordinates and the local coordinates of the device The reference coordinates of the carrier reference point in the geodetic coordinate system are obtained. : The timestamp corresponding to the current satellite positioning coordinates is used as the reference coordinates of the carrier. base timestamp ; The carrier reference coordinates and its base timestamp Associated storage covers the historical carrier reference coordinates and their historical reference timestamps in the local cache; When the mobile device enters low-power mode or the satellite positioning coordinates become invalid, the last stored carrier reference coordinates before entering low-power mode or before the coordinates become invalid are retrieved from the local cache. and its base timestamp .

5. The multimodal vector compensation method for a moving carrier according to claim 3, characterized in that, The method further includes: Get the The global coordinates of the carrier obtained from the secondary positioning process The travel speed of high-speed vehicles and azimuth angle Construct observation vectors : Constructing the state vector of a high-speed carrier : State prediction is performed based on the updated state vector from the previous positioning time: Obtain the prediction error covariance matrix : in, Here is the state transition matrix. The process noise covariance matrix; According to the observation vector Obtain Kalman gain : in, For the observation matrix, To observe the noise covariance matrix; The predicted state is updated based on the Kalman gain: Update the error covariance matrix: The corrected global coordinates, speed, and azimuth of the vehicle are obtained based on the updated state vector. Based on the corrected global coordinates of the carrier, the azimuth angle of travel, and the current local coordinates of the device, the corrected global positioning coordinates of the device are obtained; in, Indicates the speed of a high-speed vehicle. Indicates the azimuth angle of the high-speed vehicle. Indicates transpose. This represents the state vector at the k-th positioning time. This represents the state vector updated after observation at the previous positioning time. This represents the error covariance matrix after the observation update was completed at the previous positioning time. This represents the transpose of the observation matrix. This represents the updated error covariance matrix. Represents the identity matrix.

6. The multimodal vector compensation method for a moving carrier according to claim 1, characterized in that, The method for the mobile device to enter low-power mode is as follows: Continuously collect three-axis acceleration data from the mobile device and obtain the acceleration changes in each of the three axes within a preset detection time period. , and ; The acceleration change parameters of the mobile device are obtained based on the acceleration changes along the three coordinate axes. : According to the preset time interval Continuously acquire device local coordinates of mobile devices The change in local position of the mobile device relative to the high-speed carrier is obtained based on the local coordinates of the device at adjacent time points. : When the acceleration change parameter Less than the preset acceleration change threshold And the amount of change in the local position Less than the preset position change threshold And maintain a preset still time continuously. hour: If the mobile device is determined to be stationary relative to the high-speed carrier, the satellite positioning radio frequency acquisition module of the mobile device is turned off, and the mobile device enters a low-power mode that retains WiFi and Bluetooth listening.

7. The multimodal vector compensation method for a moving carrier according to claim 1, characterized in that, The method for determining invalid satellite positioning coordinates is as follows: When the satellite positioning radio frequency acquisition module is in working condition, the number of valid satellites currently participating in the positioning is obtained. And satellite positioning quality parameters; When the number of effective satellites Below the preset satellite number threshold If the satellite positioning quality parameters do not meet the preset positioning quality conditions, or the satellite positioning coordinates cannot be resolved, the current satellite positioning coordinates will be set to invalid. When the number of effective satellites Not less than the preset satellite number threshold When the satellite positioning quality parameters meet the preset positioning quality conditions and the satellite positioning coordinates can be obtained by parsing, the current satellite positioning coordinates are set to valid.

8. The multimodal vector compensation method for a moving carrier according to claim 3, characterized in that, When the number of collected WiFi hotspots or WiFi reference events is insufficient to obtain the global coordinates of the carrier. When obtaining the last-resort global positioning coordinates of the mobile device, the method includes: Multiple historical vehicle global coordinates obtained consecutively before the WiFi reference event were insufficient were used to construct the historical driving trajectory of the high-speed vehicle in chronological order. ; Obtain the global trajectory of the high-speed carrier's movement area from the pre-stored data. The historical driving trajectory With the global trajectory of the line Trajectory matching is performed to obtain the target route segment corresponding to the historical driving trajectory and the travel direction of the high-speed vehicle on the target route segment; Using the global coordinates of the last valid vehicle in the historical driving trajectory As the starting position for trajectory deduction, obtain the corresponding timestamp. and the last valid driving speed obtained before the WiFi reference event was insufficient. ; Based on the current location time With the timestamp The time interval between these intervals yields the predicted travel distance of the high-speed vehicle along the target route segment. : Traveling along the global trajectory of the route, starting from the trajectory derivation starting position. Extending the predicted driving distance forward The predicted global coordinates of the high-speed carrier at the current positioning time are obtained. ; Based on the global trajectory of the described line, predict the global coordinates on the carrier. The tangential direction at the point yields the predicted azimuth angle of the high-speed vehicle. ; Based on the predicted travel azimuth angle Obtain the rotation matrix from the local coordinate system of the carrier to the geodetic coordinate system. : Predict global coordinates based on the carrier. Current device local coordinates and the rotation matrix Obtain the fallback global positioning coordinates of the mobile device. : 。 9. The multimodal vector compensation method for a moving carrier according to claim 8, characterized in that, The method for correcting the line constraint of the predicted global coordinates of the carrier is as follows: Obtain the predicted global coordinates of the distance from the vehicle in the global trajectory of the line. The nearest target line segment, let the two endpoints of the target line segment be respectively... and ; Predict global coordinates based on the carrier. The projection parameters are obtained from the two endpoints of the target line segment. : when At that time, the projection parameters will be corrected. Set to 0; when At that time, the projection parameters will be corrected. Set as ;when At that time, the projection parameters will be corrected. Set to 1; According to the corrected projection parameters The predicted global coordinates of the carrier are obtained as the line constraint coordinates on the target line segment. : According to the target line segment at the line constraint coordinates The tangent direction at that point is corrected for the travel azimuth angle. ; According to the corrected travel azimuth angle Obtain the rotation matrix According to the line constraint coordinates Current device local coordinates and the rotation matrix The final fallback global positioning coordinates of the mobile device are obtained. : 。 10. A multimodal vector compensation system for a moving vehicle, characterized in that, It includes a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor causes the processor to perform the steps of the high-speed carrier multimodal vector compensation positioning method as described in any one of claims 1 to 9.

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