A single base station three-dimensional positioning method and system based on rotating UWB

Abstract

The application discloses a kind of based on rotating UWB's single base station three-dimensional positioning method and system, the method includes: the state information of label is collected based on the double UWB unit of omnidirectional positioning system;Estimate label position in navigation coordinate system is calculated based on the state information of label;The estimate label position is clustered based on sliding window method and DBSCAN clustering algorithm, and cluster label estimate coordinate is obtained;The cluster label estimate coordinate is compensated, and label estimate coordinate is obtained.The system includes omnidirectional positioning system module, estimate label position calculation module, estimate coordinate clustering module and compensation module.By using the application, the number of base stations under a single area can be effectively reduced, while providing more accurate positioning services for indoor flight of unmanned aerial vehicles.The application can be widely applied in base station positioning technology field.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of base station positioning, in particular to a single base station three-dimensional positioning method and system based on rotating UWB. BACKGROUND

[0002] In recent years, with the vigorous development of Internet of Things technology and the increasing refinement of indoor positioning technology, the application demand of unmanned aerial vehicles in indoor environments has grown dramatically, and higher requirements for the accuracy and reliability of positioning and navigation technology for unmanned aerial vehicles in indoor environments have also been put forward.

[0003] The existing unmanned aerial vehicle indoor positioning based on ultra-wideband is mainly in the form of multiple base stations, at least four base stations are arranged in a single area, and the current position is estimated according to sensor information. Although the existing multi-base station deployment of ultra-wideband (UWB) technology can provide high-precision positioning, it is high in cost and complex. First of all, multi-base station deployment requires the installation of multiple UWB base stations in the target area, and the hardware cost and installation cost of each base station are quite high. The installation of the base station also requires professional technicians to carry out accurate calibration and positioning to ensure the positioning accuracy, which increases the technical difficulty and time cost of deployment. In addition, in order to ensure the data synchronization and coordination between each base station, the system needs complex network connection and synchronization mechanism. This not only increases the complexity of the system, but also requires continuous maintenance and management, further increasing the operation cost. Therefore, the existing multi-base station deployment of ultra-wideband technology faces high cost and complex technical challenges in large-scale applications, limiting its application in some cost-sensitive and complex environment scenarios. SUMMARY

[0004] In order to solve the above technical problems, the purpose of the present application is to provide a single base station three-dimensional positioning method and system based on rotating UWB, which can effectively reduce the number of base stations in a single area and provide more accurate positioning services for indoor flight of unmanned aerial vehicles.

[0005] The first technical solution adopted by the present application is: a single base station three-dimensional positioning method based on rotating UWB, comprising the following steps:

[0006] The dual UWB unit based on the omnidirectional positioning system collects the state information of the tag;

[0007] Calculate the estimated tag position in the navigation coordinate system based on the state information of the tag;

[0008] Cluster the estimated tag position based on the sliding window method and DBSCAN clustering algorithm to obtain the clustered tag estimated coordinates;

[0009] Compensate the clustered tag estimated coordinates to obtain the tag estimated coordinates.

[0010] Further, the state information of the tag includes an angle of the tag, a distance of the tag, and an estimated height of the tag.

[0011] Further, the step of calculating an estimated tag position in a navigation coordinate system based on the state information of the tag specifically includes:

[0012] calculating a three-dimensional positioning polar coordinate of the tag based on the angle of the tag and the distance of the tag;

[0013] calculating an estimated coordinate of the tag under different rotation angles based on the estimated height of the tag and the three-dimensional positioning polar coordinate of the tag;

[0014] converting the estimated coordinate of the tag under the different rotation angles into the navigation coordinate system to obtain the estimated tag position.

[0015] Further, the step of clustering the estimated tag position based on the sliding window method and the DBSCAN clustering algorithm to obtain a clustered tag estimated coordinate specifically includes:

[0016] updating the estimated tag position based on the sliding window method to obtain an updated estimated tag position;

[0017] clustering the updated estimated tag position based on the DBSCAN clustering algorithm to obtain the clustered tag estimated coordinate.

[0018] Further, the step of compensating the clustered tag estimated coordinate to obtain a tag estimated coordinate specifically includes:

[0019] dividing an effective positioning area of the clustered tag estimated coordinate into a grid to obtain a plurality of grid point coordinates;

[0020] calculating a compensation weight of each grid point based on the grid point coordinates and a tag reference coordinate, and normalizing to obtain a weight matrix;

[0021] calculating a deviation between the clustered tag estimated coordinate and the tag reference coordinate, and updating the weight matrix based on the deviation to obtain a compensation matrix;

[0022] compensating the clustered tag estimated coordinate based on the compensation matrix to obtain the tag estimated coordinate.

[0023] Further, the omnidirectional positioning system includes a dual-UWB unit positioning module and a rotating platform module, wherein:

[0024] the dual-UWB unit positioning module includes a left UWB detection unit, a right UWB detection unit, an IMU detection unit, and a master control unit;

[0025] The rotating platform module comprises a rotating platform and a servo motor;

[0026] The main control unit is connected with the rotating platform module through a motor control interface, and is configured to output a control signal of the rotating platform module, so as to control a rotating angle of the rotating platform and an output power of the servo motor.

[0027] The main control unit is connected with the UWB detection unit through a data communication interface, and is configured to control the UWB detection unit to collect original positioning data of a tag, and receive data collected by the UWB detection unit by using a universal asynchronous receiver-transmitter protocol.

[0028] The main control unit is connected with the host computer through a data upload interface, and is configured to send all data collected by the UWB detection unit to the host computer by using an asynchronous receiver-transmitter protocol.

[0029] The main control unit is connected with the IMU detection unit through an IMU communication interface, and is configured to control the IMU detection unit to collect attitude angle data of a base station, and receive data collected by the IMU detection unit by using an IIC protocol.

[0030] Further, the step of calculating an estimated coordinate of the tag under different rotating angles based on the estimated height of the tag and the three-dimensional positioning circular coordinates of the tag comprises the following steps.

[0031] Selecting a UWB unit on one side, and selecting a coordinate meeting an estimated height tolerance range of the tag based on a Z-axis coordinate of the three-dimensional positioning circular coordinates of the tag to obtain a conditional coordinate.

[0032] Traversing three-dimensional positioning circular coordinates of a tag of a UWB unit on the other side based on the three-dimensional positioning circular coordinates of the conditional coordinate, and calculating an Euclidean distance of the positioning circular coordinates.

[0033] Determining three-dimensional positioning circular coordinates of the tag of the UWB unit on the other side corresponding to a minimum value of the Euclidean distance.

[0034] Performing an average operation on the three-dimensional positioning circular coordinates of the tag of the UWB unit on the other side to obtain an estimated coordinate.

[0035] The second technical solution adopted by the application is a single-base-station three-dimensional positioning system based on a rotating UWB, comprising:

[0036] An omnidirectional positioning system module is configured to collect state information of a tag.

[0037] An estimated tag position calculation module is configured to calculate an estimated tag position in a navigation coordinate system based on the state information of the tag.

[0038] An estimated coordinate clustering module clusters the estimated tag position based on a sliding window method and a DBSCAN clustering algorithm to obtain clustered tag estimated coordinates;

[0039] A compensation module is configured to compensate the clustered tag estimated coordinates to obtain tag estimated coordinates.

[0040] The application further provides a single-base-station three-dimensional positioning device based on rotating UWB, which comprises:

[0041] At least one processor;

[0042] At least one memory configured to store at least one program;

[0043] When the at least one program is executed by the at least one processor, the at least one processor implements the single-base-station three-dimensional positioning method based on rotating UWB.

[0044] The method and system have the following advantages: the application designs a hardware structure of an omnidirectional positioning system, collects data from all directions and positions tags by rotating a platform to control two UWB detection units, greatly widens the coverage range, realizes identification of an estimated point opposite to a UWB unit on-board antenna, effectively simplifies the setting process and reduces the deployment cost of the positioning system; based on the hardware design, an omnidirectional three-dimensional positioning algorithm combining a three-dimensional circle estimation method is provided, two UWB units are arranged on a base station, and direction finding and distance measurement are performed on tags respectively, a spatial positioning circle is drawn according to the measured angle and distance data, the height information of the tags is fused to perform three-dimensional positioning on the tags, the technical difficulty and time cost of deployment are effectively reduced; then, intermediate estimated points in different coordinate systems are adjusted to a fixed coordinate system, and the estimated coordinates of the tags are obtained by clustering; finally, the estimated coordinates are compensated based on a compensation matrix of sampling points and a position error vector method to obtain tag estimated coordinates, the number of base stations in a single area is effectively reduced, and relatively accurate positioning services are provided for indoor flight of unmanned aerial vehicles. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 is a step flow chart of the single-base-station three-dimensional positioning method based on rotating UWB;

[0046] Figure 2 is a structural block diagram of the single-base-station three-dimensional positioning system based on rotating UWB;

[0047] Figure 3 is an actual object diagram of the omnidirectional positioning system of the single-base-station three-dimensional positioning method based on rotating UWB;

[0048] Figure 4It is the effective direction finding range schematic diagram of the UWB detection unit of the single base station three-dimensional positioning method based on rotating UWB of the application;

[0049] Figure 5 It is the rotating platform actual object graph of the single base station three-dimensional positioning method based on rotating UWB of the application;

[0050] Figure 6 It is the omnidirectional positioning system hardware structure block diagram of the single base station three-dimensional positioning method based on rotating UWB of the application;

[0051] Figure 7 It is the UWB detection unit hardware structure block diagram of the single base station three-dimensional positioning method based on rotating UWB of the application;

[0052] Figure 8 It is the omnidirectional positioning framework diagram of the single base station three-dimensional positioning method based on rotating UWB of the application;

[0053] Figure 9 It is the circle in three-dimensional space schematic diagram of the single base station three-dimensional positioning method based on rotating UWB of the application;

[0054] Figure 10 It is the positioning plane and positioning circle schematic diagram of the single base station three-dimensional positioning method based on rotating UWB of the application;

[0055] Figure 11 It is the omnidirectional three-dimensional positioning coordinate schematic diagram of the single base station three-dimensional positioning method based on rotating UWB of the application;

[0056] Figure 12 It is the sampling calibration point diagram of the single base station three-dimensional positioning method based on rotating UWB of the application;

[0057] Figure 13 It is the calibration work flow diagram of the single base station three-dimensional positioning method based on rotating UWB of the application;

[0058] Figure 14 It is the positioning experiment trajectory diagram of the single base station three-dimensional positioning method based on rotating UWB of the application. DETAILED DESCRIPTION

[0059] The application will be further described in detail below in combination with the drawings and specific embodiments. For the step numbers in the following embodiments, only the setting is for the convenience of setting and explaining, and the order between the steps is not limited in any way, and the execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0060] Reference Figure 1 And Figure 8The application provides a single-base-station three-dimensional positioning method based on rotating UWB.

[0061] S1, a dual-UWB unit based on an omnidirectional positioning system collects state information of a tag;

[0062] Specifically, referring to Figure 3 and Figure 6 , the hardware structure of the omnidirectional positioning system comprises a dual-UWB unit positioning module and a rotating platform module, wherein

[0063] The dual-UWB unit positioning module comprises a left UWB detection unit, a right UWB detection unit, an IMU detection unit and a master control unit; the angle and distance data measured by a single UWB detection unit can only determine the position of an estimated point in front of an antenna, and cannot determine the estimated point on the back of the on-board antenna of the UWB detection unit; since the direction-finding data of the two UWB detection units and the tag form a certain angle, the tag can be determined to be located on the front or back of the antenna, therefore, the same tag is measured by two UWB units.

[0064] The rotating platform module comprises a rotating platform and a servo motor;

[0065] Referring to Figure 4 , since the effective measurement range of the PDOA positioning method of the UWB detection unit is a range of 60 degrees in the center of the direction of the UWB antenna, the positioning range is limited, in order to expand the omnidirectional positioning, the application designs a rotating platform to drive the base station to rotate to realize omnidirectional positioning.

[0066] Referring to Figure 5 , the rotating platform in the specific embodiment of the application carries a servo motor, so that the UWB device realizes 360° omnidirectional detection; the motor comprises a stator and a rotor; the stator part is fixed on the rotating platform; a copper column is used to fix the UWB master control board and the measurement unit carried thereby above the motor rotor; a via hole slip ring is arranged at the center of the servo motor; the power supply and signal lines of the master control board can pass through the slip ring structure; the slip ring structure can prevent winding interference when the motor rotates 360° omnidirectionally.

[0067] The left UWB detection unit and the right UWB detection unit are used to collect raw positioning data of the tag;

[0068] The master control unit is connected with the rotating platform module through a motor control interface, and is used to output a control signal of the rotating platform module, so as to control the rotating angle of the rotating platform and the output power of the stepping motor;

[0069] The master control unit is connected with the UWB detection unit through a data communication interface, and is used for controlling the UWB detection unit to collect original positioning data of the tag, and receiving the data collected by the UWB detection unit by using a universal asynchronous receiver protocol;

[0070] The master control unit is connected with the IMU detection unit through an IMU communication interface, and is used for controlling the IMU detection unit to collect attitude angle data of the base station, and receiving the data collected by the IMU detection unit by using an IIC protocol;

[0071] The master control unit is connected with the host computer through a data uploading interface, and when the master control unit completes a complete UWB data and IMU data collection, the master control unit sends all the data collected by the UWB detection unit to the host computer by using an asynchronous transceiver protocol; the host computer calculates an estimated point of the current tag by using the UWB data, and performs visual display and trajectory tracking, and the IMU data is used for observing the attitude and heading of the base station during operation.

[0072] The state information of the tag includes an angle of the tag, a distance of the tag and an estimated height of the tag.

[0073] Refer to Figure 7 , the UWB detection unit includes an STM32 minimum system and a UWB module; in order to conveniently observe the running state and configuration information of the tag, the peripheral OLED display device and LED indicator lamp are added in the embodiment of the application.

[0074] S2, calculating an estimated tag position in a navigation coordinate system based on the state information of the tag;

[0075] Specifically, the left and right UWB detection units of the omnidirectional positioning system sample the angle (θ Ri , θ Li ), distance information (d Ri , d Li ) and estimated height H ei of the tag in the i-th sampling period; the rotation angle a i of the rotating platform is obtained by the master control unit, therefore, the state information of the tag can be defined as S Ti =[θ Ri , θ Li , d Ri , d Li , H ei , a i ] T .

[0076] S2.1, calculating a three-dimensional positioning circular coordinate of the tag based on the angle of the tag and the distance of the tag;

[0077] Specifically, in three-dimensional space, there inevitably exists a spatial circle as shown in Figure 9 with the center coordinate C(x c ,y c ,z c ) and the radius r, and the normal vector In the plane of the spatial circle, there exist two perpendicular unit vectors and The intersection of the vector and the circle is defined as point P; the angle between the vector and is θ, θ∈[0,2π]; the projection of the vector on the unit vector is expressed as follows:

[0078]

[0079] wherein, denotes the projection of the vector on the vector ; denotes the projection of the vector on the vector .

[0080] The vectors and can be written as follows:

[0081]

[0082] Therefore, the coordinates of the point P(x pθ ,y pθ ,z pθ ) in the spatial circle are expressed as follows:

[0083]

[0084] wherein, x pθ denotes the x-axis coordinate of the point P; y pθ denotes the y-axis coordinate of the point P; z pθ denotes the z-axis coordinate of the point P; (x a ,y a ,z a ) denotes the coordinates of the unit vector ; (x b ,y b ,z b ) denotes the coordinates of the unit vector ; (x c ,y c ,z c ) denotes the coordinates of the center C.

[0085] Therefore, when the base station is stationary, the system can determine the location of the tag within the effective coverage area of ​​the base station antenna, by referring to... Figure 10 Taking the measurement data of the right-hand UWB detection unit as an example, the right-hand UWB detection unit detects all possible positions P of the tag. Rθ It is concentrated in the three-dimensional positioning circle where the right-side UWB element can be obtained, and its expression is as follows:

[0086]

[0087] Among them, (X) Rθ ,Y Rθ Z Rθ ) indicates the possible location P of the label. Rθ The coordinates; (x R ,y R ,z R ) represents the center A of the three-dimensional positioning circle. R The coordinates of d; Ri This represents the radius of the three-dimensional positioning circle for the i-th label.

[0088] Because the plane of the three-dimensional positioning circle of the UWB detection unit on the right is perpendicular to X... b O b Y b Planes, therefore their intersection is a unit vector. Represents a unit vector The coordinates are based on the measured angle θ Ri Confirmed, unit vector Then with unit vector Since it is vertical, the expression for the 3D positioning circle unit vector of the UWB detection unit on the right is as follows:

[0089]

[0090] Combining formulas 4 and 5, formula 4 can be simplified to the following form:

[0091]

[0092] Therefore, it can be done through θ = θ ri Get a set Similarly, taking the measurement data of the left-side UWB detection unit as an example, the parametric equation of the three-dimensional positioning circle of the left-side UWB element can be obtained as P. Lθ (X Lθ ,Y Lθ Z Lθ ).

[0093] S2.2 Calculate the estimated coordinates of the label under different rotation angles based on the estimated height of the label and the three-dimensional positioning circular coordinates of the label;

[0094] Specifically, in order to minimize the number of iterations of calculation, the estimated position of the left UWB unit is selected, and the coordinates meeting the estimated height tolerance range of the tag are screened out based on the Z-axis coordinates of the three-dimensional positioning circle of the tag, to obtain conditional coordinates; the Z-axis coordinates of the conditional coordinates satisfy (H est -H mse , H est +H mse ), wherein H est represents the estimated height of the tag; H mse represents the mean square deviation of the height of the tag.

[0095] In the conditional coordinates, any coordinate P Lθ =[X Lθ ,Y Lθ ,Z Lθ ] T is selected, and the three-dimensional positioning circle coordinates P Rθ =[X Rθ ,Y Rθ ,Z Rθ ] T of the tag of the other side UWB unit are traversed, and the Euclidean distance of the two positioning circle coordinates is calculated, and the expression is as follows:

[0096]

[0097] wherein, DS represents the Euclidean distance, represents the three-dimensional positioning circle coordinates of the tag of the left UWB unit when the observation angle is θ l ; represents the three-dimensional positioning circle coordinates of the tag of the right UWB unit when the observation angle is θ r .

[0098] Then the minimum value of the Euclidean distance of the two positioning circle coordinates is updated in the traversal process, and the expression is as follows:

[0099]

[0100] wherein, P mL and P mR represent the three-dimensional positioning circle coordinates of the tags of the two sides UWB units corresponding to the minimum value of the Euclidean distance; i, j represent the observation angle serial number.

[0101] Until the traversal of the positioning circle coordinates of the two sides is completed, the three-dimensional positioning circle coordinates of the tags of the two sides UWB units corresponding to the minimum value of the Euclidean distance are determined.

[0102] Finally, the three-dimensional positioning circle coordinates of the tags of the two sides UWB units are averaged to obtain the estimated coordinates, and the expression is as follows:

[0103]

[0104] wherein P b,e represents the estimated coordinates.

[0105] S2.3, converting the estimated coordinates of the tag under different rotation angles into the navigation coordinate system to obtain the estimated tag position.

[0106] Specifically, referring to Figure 11 , the UWB base station framework E b is constantly changing with the rotation of the rotating body. b The transformation matrix of the UWB base station coordinate system E I to the navigation coordinate system E

[0107]

[0108] wherein α i represents the rotation angle of the rotating platform.

[0109] Since the current angle information can be accurately recorded by using a stepper motor to drive the rotating structure, the positioning system rotates at a fixed angle interval . The current angle of the rotating platform can be written as

[0110] Combined with formula 10 and formula 9, the estimated tag position in the navigation coordinate system can be obtained, and the expression is as follows:

[0111]

[0112] wherein P b,e-i and represent the estimated coordinates of the tag i; P I,e-i and (X I,e-i , Y I,e-i , Z I,e-i ) represent the estimated tag position of the tag i.

[0113] S3, clustering the estimated tag positions based on the sliding window method and the DBSCAN clustering algorithm to obtain the clustered tag estimated coordinates;

[0114] Specifically, after obtaining the serial estimated position points of the tag under different rotation angles by S2, since the effective direction detection range of the UWB unit is 120° in front, and the rotating structure rotates at a fixed angle interval , it can be inferred that at least The omnidirectional positioning system of the present application can observe significant differences for data outside the effective range, and therefore adopts the DBSCAN clustering algorithm to cluster the estimated points collected at the effective angle, which can filter out any abnormal information and obtain more accurate coordinates of the final estimated points.

[0115] S3.1, updating the estimated tag position based on the sliding window method to obtain an updated estimated tag position;

[0116] Specifically, considering that the robot is in a moving state in actual application, the sliding window method is used to update the estimated position P I,e-i The earliest collected data in the buffer will be eliminated after the first complete rotation cycle of tag data is collected, and the updated data is obtained, and the positioning algorithm is executed using the updated data.

[0117] S3.2, clustering the updated estimated tag position based on the DBSCAN clustering algorithm to obtain clustered tag estimated coordinates.

[0118] S4, compensating the clustered tag estimated coordinates to obtain tag estimated coordinates.

[0119] Specifically, the compensation process can refer to Figure 13 which specifically includes the following steps:

[0120] S4.1, dividing the effective positioning area of the clustered tag estimated coordinates into a grid to obtain a plurality of grid point coordinates;

[0121] Specifically, considering the rotation characteristics of the omnidirectional positioning system and the Z-axis data provided by the robot height, the deviation of the tag estimated coordinates is mainly observed on the x-axis and y-axis, and therefore a compensation matrix is used to adjust the data of these two axes; the estimated position is sampled according to the predetermined square boundary sampling points, and the sampling correction data set is represented as P Figure 12 cal {P c,e-i ,P c,r-i}, i∈(1, 2,..., n), wherein P c,e-i (x c,e-i ,y c,e-i ,z c,e-i ) and P c,r-i (x c,r-i ,y c,r-i ,z c,r-i ) represent the estimated position and the reference position of the i-th sampling point, respectively. In order to calculate the compensation of the estimated position, the effective positioning area is divided into m×m grids according to the accuracy requirement, and a plurality of grid point coordinates are obtained.

[0122] ​S4.2, calculate the compensation weight of each grid point based on the grid point coordinates and label reference coordinates, and normalize to obtain a weight matrix;

[0123] Specifically, the weight matrix has the following expression:

[0124]

[0125] wherein R ω represents the weight matrix; ω ij represents the normalized i-th row, j-th column element; ω ij represents the i-th row, j-th column element; d ij represents the distance deviation of grid point j and label reference coordinate point i; (X j ,Y j ,Z j ), j∈(1,2,...,m 2 ) represents the coordinates of grid point P g,j .

[0126] S4.3, calculate the deviation of the cluster label estimated coordinates and the label reference coordinates, and update the weight matrix based on the deviation to obtain a compensation matrix;

[0127] Specifically, the compensation matrix ΔP cal,j (X cal,j ,Y cal,j ) contains the compensation amount of the x-axis and the compensation amount of the y-axis, and has the following expression:

[0128]

[0129] wherein X cal,j represents the compensation amount of the x-axis; Y cal,j represents the compensation amount of the y-axis; ω ij represents the normalized i-th row, j-th column element; P c,e-i (x c,e-i ,y c,e-i ,z c,e-i ) and P c,r-i (x c,r-i ,y c,r-i ,z c,r-i ) represent the estimated position and reference position of the i-th sampling point, respectively; represents the deviation of the reference position.

[0130] S4.4, compensate the cluster label estimated coordinates based on the compensation matrix to obtain label estimated coordinates.

[0131] Specifically, the compensation matrix is stored in R comIn this process, the estimated coordinates of the clustered labels are compensated to obtain the estimated coordinates of the labels, the expression of which is as follows:

[0132]

[0133] Among them, P est Indicates the estimated coordinates of the label; P I,et Indicates the estimated coordinates of the cluster labels; It indicates that it is stored in R com Coordinate compensation amount in; f(·) represents the label coordinate clustering estimation compensation amount; f(·) represents the label coordinate clustering compensation amount calculation function.

[0134] To verify the feasibility of the method of the present invention, a positioning experiment was conducted in a specific embodiment of the present invention. Three drones equipped with positioning tags were used to fly along designated routes, and an omnidirectional positioning system performed real-time positioning and tracking of the three drones. The positioning results of the rotating UWB single-base station positioning system for the three drones are as follows: Figure 14 As shown in the figure, the true trajectories of the three drones are marked with lines, circles represent the estimated points of the three drones before compensation, and asterisks represent the estimated points of the three drones after compensation. The positioning data is obtained based on the rotational omnidirectional 3D positioning algorithm, and the positioning errors of the three drones are calculated as shown in Table 1.

[0135] Table 1. Positioning error data of the three UAVs

[0136]

[0137] Under the straight-line trajectory of UAV 1, the root mean square error after compensation is 0.15m, which is 84.6% lower than the root mean square error of 0.98m before compensation. The average absolute error is also reduced by 84.9%.

[0138] Under the vertical climbing trajectory of UAV 2, the compensated root mean square error (RMSE) is 0.14m, compared to the uncompensated RMSE of 0.31m, representing a 54.8% reduction in relative error and a 53.8% reduction in mean absolute error. Under the rectangular trajectory of UAV 3 around the base station, the compensated RMSE is 0.19m, compared to the uncompensated RMSE of 0.69m, representing a 72.4% reduction in relative error and a 78.4% reduction in mean absolute error. It can be seen that the compensation and correction method in the proposed algorithm improves the accuracy of tag coordinate estimation, limiting the RMSE to within a 0.2m error range. Therefore, the positioning system of this invention is sufficient to meet the requirements of indoor robot positioning scenarios.

[0139] Reference Figure 2 This invention provides a single-base station three-dimensional positioning system based on rotating UWB, comprising:

[0140] an omnidirectional positioning system module configured to collect state information of the tag;

[0141] an estimated tag position calculation module configured to calculate an estimated tag position in a navigation coordinate system based on the state information of the tag;

[0142] an estimated coordinate clustering module configured to cluster the estimated tag positions based on a sliding window method and a DBSCAN clustering algorithm to obtain clustered tag estimated coordinates;

[0143] a compensation module configured to compensate the clustered tag estimated coordinates to obtain tag estimated coordinates.

[0144] The contents in the method embodiments are applicable to the system embodiments, the system embodiments specifically implement the functions same as those of the method embodiments, and achieve the same beneficial effects as those of the method embodiments.

[0145] A single-base station three-dimensional positioning device based on rotating UWB:

[0146] at least one processor;

[0147] at least one memory configured to store at least one program;

[0148] When the at least one program is executed by the at least one processor, the at least one processor implements the single-base station three-dimensional positioning method based on rotating UWB.

[0149] The contents in the method embodiments are applicable to the device embodiments, the device embodiments specifically implement the functions same as those of the method embodiments, and achieve the same beneficial effects as those of the method embodiments.

[0150] A storage medium having processor-executable instructions stored therein, the processor-executable instructions, when executed by a processor, are configured to implement the single-base station three-dimensional positioning method based on rotating UWB.

[0151] The contents in the method embodiments are applicable to the storage medium embodiments, the storage medium embodiments specifically implement the functions same as those of the method embodiments, and achieve the same beneficial effects as those of the method embodiments.

[0152] The above is a specific description of the preferred embodiments of the present application, but the present application is not limited to the embodiments, and those skilled in the art can make various equivalent modifications or replacements without departing from the spirit of the present application, and these equivalent modifications or replacements are all included in the scope defined by the claims of the present application.

Claims

1. A single base station three-dimensional positioning method based on rotating UWB, characterized in that, The method comprises the following steps: Collecting state information of the tag based on a dual-UWB unit omnidirectional positioning system; Calculating an estimated tag position in a navigation coordinate system based on the state information of the tag; Clustering the estimated tag position based on a sliding window method and a DBSCAN clustering algorithm to obtain clustered tag estimated coordinates; Compensating the clustered tag estimated coordinates to obtain tag estimated coordinates; The step of clustering the estimated tag position based on the sliding window method and the DBSCAN clustering algorithm to obtain clustered tag estimated coordinates specifically comprises: Updating the estimated tag position based on the sliding window method to obtain an updated estimated tag position; Clustering the updated estimated tag position based on the DBSCAN clustering algorithm to obtain clustered tag estimated coordinates; The step of compensating the clustered tag estimated coordinates to obtain tag estimated coordinates specifically comprises: Grid dividing an effective positioning area of the clustered tag estimated coordinates to obtain a plurality of grid point coordinates; Calculating a compensation weight of each grid point based on the grid point coordinates and a tag reference coordinate, and normalizing to obtain a weight matrix; Calculating a deviation between the clustered tag estimated coordinates and the tag reference coordinate, and updating the weight matrix based on the deviation to obtain a compensation matrix; Compensating the clustered tag estimated coordinates based on the compensation matrix to obtain tag estimated coordinates. 2.The method of claim 1, wherein, The state information of the tag comprises an angle of the tag, a distance of the tag, and an estimated height of the tag.

3. The single base station three-dimensional positioning method based on rotating UWB according to claim 2, characterized in that, The step of calculating an estimated tag position in a navigation coordinate system based on the state information of the tag specifically comprises: Calculating a three-dimensional positioning circular coordinate of the tag based on the angle of the tag and the distance of the tag; Calculating an estimated coordinate of the tag under different rotation angles based on the estimated height of the tag and the three-dimensional positioning circular coordinate of the tag; Converting the estimated coordinate of the tag under different rotation angles into a navigation coordinate system to obtain an estimated tag position.

4. The single base station three-dimensional positioning method based on rotating UWB according to claim 1, characterized in that, The omnidirectional positioning system comprises a dual-UWB unit positioning module and a rotating platform module, wherein: The dual-UWB unit positioning module comprises a left UWB detection unit, a right UWB detection unit, an IMU detection unit, and a master control unit; The rotating platform module comprises a rotating platform and a servo motor; The master control unit is connected with the rotating platform module through a motor control interface, and is used to output a control signal of the rotating platform module, so as to control a rotation angle of the rotating platform and an output power of the servo motor; The master control unit is connected with the UWB detection unit through a data communication interface, and is used to control the UWB detection unit to collect raw positioning data of the tag, and receive data collected by the UWB detection unit by using a universal asynchronous receiver-transmitter protocol; The master control unit is connected with a host computer through a data upload interface, and sends all data collected by the UWB detection unit to the host computer by using an asynchronous receiver-transmitter protocol; The master control unit is connected with the IMU detection unit through an IMU communication interface, and is configured to control the IMU detection unit to collect attitude angle data of a base station, and receive data collected by the IMU detection unit through an IIC protocol.

5. The single base station three-dimensional positioning method based on rotating UWB according to claim 3, characterized in that, The step of calculating the estimated coordinates of the label under different rotation angles based on the estimated height of the label and the three-dimensional positioning circular coordinates of the label specifically includes: Selecting a UWB unit on one side, and screening coordinates conforming to the estimated height tolerance range of the label based on the Z-axis coordinates of the three-dimensional positioning circle of the label to obtain conditional coordinates; Based on the three-dimensional positioning circular coordinates of the conditional coordinates, traversing the three-dimensional positioning circular coordinates of the label of the UWB unit on the other side, and calculating the Euclidean distance of the positioning circular coordinates; Based on the minimum value of the Euclidean distance, determining the three-dimensional positioning circular coordinates of the label of the UWB unit on the two sides; Performing an average operation on the three-dimensional positioning circular coordinates of the label of the UWB unit on the two sides to obtain estimated coordinates.

6. A single base station three-dimensional positioning system based on rotating UWB, characterized in that, Comprise: An omnidirectional positioning system module configured to collect state information of a label; An estimated label position calculation module configured to calculate an estimated label position in a navigation coordinate system based on the state information of the label; An estimated coordinate clustering module configured to cluster the estimated label positions based on a sliding window method and a DBSCAN clustering algorithm to obtain clustered label estimated coordinates, and specifically includes: updating the estimated label positions based on the sliding window method to obtain updated estimated label positions; and clustering the updated estimated label positions based on the DBSCAN clustering algorithm to obtain clustered label estimated coordinates; A compensation module configured to compensate the clustered label estimated coordinates to obtain label estimated coordinates, and specifically includes: dividing an effective positioning area of the clustered label estimated coordinates into a grid to obtain a plurality of grid point coordinates; calculating a compensation weight of each grid point based on the grid point coordinates and a label reference coordinate, and performing normalization to obtain a weight matrix; calculating a deviation between the clustered label estimated coordinates and the label reference coordinate, and updating the weight matrix based on the deviation to obtain a compensation matrix; and compensating the clustered label estimated coordinates based on the compensation matrix to obtain label estimated coordinates.

7. A single base station three-dimensional positioning device based on rotating UWB, characterized in that, Comprise: At least one processor; At least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the three-dimensional positioning method based on rotating UWB and single base station according to any one of claims 1-5.

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