Low-cost single-base-station high-precision positioning system and method

Abstract

The invention discloses a low-cost single-base-station high-precision positioning system and method.The system comprises a master control MCU, a UWB single chip, an RF switch and an antenna array, the antenna array is composed of a plurality of A1-AM antennas evenly distributed on a circle at intervals, and the center of the circle is provided with an antenna A0; the main control MCU is in communication connection with the UWB single chip, an RF1 port of the UWB single chip is respectively connected with A1-AM antennas in an antenna array through an RF switch, and the main control MCU controls the RF switch to sequentially select the antennas in the antenna array to access through a GPIO port; and an RF2 port of the UWB single chip is connected with the antenna A0. In the field of high-precision indoor positioning, three-dimensional high-precision positioning can be realized only by matching a single UWB chip with a radio frequency switch and an antenna array, and the overall cost and the working power consumption of a positioning system are effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless high-precision three-dimensional positioning technology, and in particular to a low-cost single-base station high-precision positioning system and method. Background Art

[0002] In recent years, with the continuous development of mobile internet technology, location-based services have gradually become integrated into many aspects of social life, providing significant convenience. Currently, most 3D indoor positioning systems utilize multiple base stations, calculating the target location through methods such as triangulation or trilateration. While these methods can achieve high positioning accuracy under ideal conditions, multi-base station system deployment is complex, hardware costs are high, and some systems face issues with inter-base station clock synchronization. Current single-base station positioning solutions typically utilize multiple UWB transceiver chips connected to an antenna array, which significantly increases system power consumption and hardware costs.

[0003] In response to the above problems, how to achieve low-cost, high-precision positioning has become a technical problem that people urgently need to solve. Summary of the Invention

[0004] In response to the above technical problems in related technologies, the present invention proposes a low-cost single-base station high-precision positioning system and method, which can achieve high-precision indoor three-dimensional positioning using only a single UWB transceiver chip, and can overcome the above-mentioned shortcomings of the existing technology.

[0005] To achieve the above technical objectives, the technical solution of the present invention is implemented as follows:

[0006] A low-cost single-base station high-precision positioning system includes a main control MCU, a UWB single chip, an RF switch, and an antenna array. The antenna array consists of several A1 to A1 uniformly distributed on a circle. M Antenna composition, the center of the circle is provided with antenna A0;

[0007] The main control MCU is connected to the UWB single chip, and the RF1 port of the UWB single chip is connected to A1~A1 in the antenna array through the RF switch. M Antenna connection, the main control MCU controls the RF switch through the GPIO port to select the antenna access in the antenna array in turn; the RF2 port of the UWB single chip is connected to the antenna A0.

[0008] A low-cost single-base station high-precision positioning method, using the system described in claim 1, comprising the following steps:

[0009] The S1 positioning base station controls the RF switch through the GPIO port of the MCU to turn A1 to A MAntenna access, the positioning base station obtains antenna A through UWB communication with the positioning device n Distance d from the positioning device n , and the incident signal of the positioning device and A n PDOA phase difference between A0 and n is 1...M;

[0010] S2 obtains all PDOA phase differences based on all connected antennas Obtain a vector r consisting of PDOA information;

[0011] S3 calculates the covariance matrix R of the vector r;

[0012] S4 calculates the eigenvalues ​​and eigenvectors of the covariance matrix of step S3, removes the eigenvector corresponding to the largest eigenvalue, and combines the remaining M-1 groups of vectors into a noise feature matrix U N :

[0013] S5 via U N Construct spatial spectrum P music (θ, φ);

[0014] S6 obtains the direction angle of the positioning device relative to the positioning base station through array signal processing algorithm and pitch angle The calculation formula is as follows:

[0015]

[0016] S7 passes through d1~d m And the calculated A fusion framework of unscented Kalman filtering is constructed to obtain high-precision three-dimensional coordinates of the positioning device relative to the positioning base station.

[0017] Furthermore, the formula of the vector r composed of PDOA information in step S2 is:

[0018]

[0019] Where e is the exponent and j is a complex number.

[0020] Furthermore, the formula of the covariance matrix R in step S3 is:

[0021] R=rr h

[0022] where r h The conjugate transpose matrix of r.

[0023] Furthermore, step S5 is performed by U N Construct spatial spectrum P musicThe calculation formula for (θ, φ) is:

[0024]

[0025] Where a is a vector containing the parameters θ and φ to be estimated, H represents the conjugate transpose operation of the matrix, and U N represents the noise characteristic matrix, θ is the true value of the direction angle of the positioning device relative to the positioning base station, and φ is the true value of the elevation angle of the positioning device relative to the positioning base station.

[0026] Beneficial effects of the present invention: In the field of high-precision indoor positioning, the present invention only requires a single UWB chip, which, in conjunction with a radio frequency switch and an antenna array, can achieve three-dimensional high-precision positioning, effectively reducing the overall cost and operating power consumption of the positioning system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 2 is a schematic structural diagram of a low-cost single-base station high-precision positioning system according to an embodiment of the present invention;

[0029] Figure 2 3. This is a structural diagram of the circular array antenna distribution of the low-cost single-base station high-precision positioning system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention are within the scope of protection of the present invention.

[0031] Ultra Wideband (UWB) is a wireless communication technology that uses narrow, non-sinusoidal nanosecond pulses to transmit data, occupying a very wide spectrum. Due to its unique pulse signal characteristics, this technology offers significant advantages in many areas.

[0032] Phase Difference of Arrival (PDOA) is the phase difference between the two RF ports of a UWB chip during UWB signal propagation. The PDOA signal can be used to calculate the direction of the incoming signal toward a target object.

[0033] ToF (Time of flight) is a distance measurement technology. UWB chips can obtain ToF through communication and further use it to calculate the distance between UWB chips.

[0034] like Figure 1-2 As shown, a low-cost single-base station high-precision positioning system according to an embodiment of the present invention includes a main control MCU, a UWB single chip, an RF switch and an antenna array, wherein the antenna array consists of a plurality of A1 to A1 uniformly distributed on a circle. M Antenna composition, the center of the circle is provided with antenna A0;

[0035] The main control MCU is connected to the UWB single chip, and the RF1 port of the UWB single chip is connected to A1~A1 in the antenna array through the RF switch. M Antenna connection, the main control MCU controls the RF switch through the GPIO port to select the antenna access in the antenna array in turn; the RF2 port of the UWB single chip is connected to the antenna A0.

[0036] A low-cost single-base station high-precision positioning method, using the system described in claim 1, comprising the following steps:

[0037] The S1 positioning base station controls the RF switch through the GPIO port of the MCU to turn A1 to A M Antenna access, the positioning base station obtains antenna A through UWB communication with the positioning device n Distance d from the positioning device n , and the incident signal of the positioning device and A n PDOA phase difference between A0 and n is 1...M;

[0038] S2 obtains all PDOA phase differences based on all connected antennas Obtain a vector r consisting of PDOA information;

[0039] S3 calculates the covariance matrix R of the vector r;

[0040] S4 calculates the eigenvalues ​​and eigenvectors of the covariance matrix of step S3, removes the eigenvector corresponding to the largest eigenvalue, and combines the remaining M-1 groups of vectors into a noise feature matrix U N :

[0041] S5 via U N Construct spatial spectrum P music (θ,φ);

[0042] S6 obtains the direction angle of the positioning device relative to the positioning base station through array signal processing algorithm and pitch angle The calculation formula is as follows:

[0043]

[0044] S7 passes through d1~d m And the calculated A fusion framework of unscented Kalman filtering is constructed to obtain high-precision three-dimensional coordinates of the positioning device relative to the positioning base station.

[0045] In the embodiment, the formula of the vector r composed of PDOA information in step S2 is:

[0046]

[0047] Where e is the exponent and j is a complex number.

[0048] In the embodiment, the formula of the covariance matrix R in step S3 is:

[0049] R=rr h

[0050] where r h The conjugate transpose matrix of r.

[0051] In the embodiment, step S5 is performed by U N Construct spatial spectrum P music The calculation formula for (θ, φ) is:

[0052]

[0053] Where a is a vector containing the parameters θ and φ to be estimated, H represents the conjugate transpose operation of the matrix, and U N represents the noise characteristic matrix, θ is the true value of the direction angle of the positioning device relative to the positioning base station, and φ is the true value of the elevation angle of the positioning device relative to the positioning base station.

[0054] In order to facilitate understanding of the above technical solutions of the present invention, the above technical solutions of the present invention are described in detail below through specific usage methods.

[0055] In specific use, a low-cost single-base station high-precision positioning system according to the present invention includes a main control MCU, a single UWB transceiver chip, a radio frequency switch, and an antenna array.

[0056] In the embodiment, the antenna array is formed into a circular array, A1~A M The antennas are evenly spaced around the circle and connected to the RF1 port of the UWB chip through an RF switch. An antenna A0 is also placed at the center of the circle and directly connected to the RF2 port of the UWB chip.

[0057] A method for a low-cost three-dimensional high-precision positioning system based on a single UWB chip includes the following steps:

[0058] Step 1: Each time the positioning device starts to obtain a three-dimensional high-precision position, the positioning base station controls the RF switch through the MCU's GPIO to select the A1 antenna for access. The positioning base station uses the A1 and A0 chips to achieve UWB communication with the positioning device, and obtains the distance d1 between the A1 antenna and the positioning device, as well as the PDOA phase difference between the positioning device's incident signal and A1 and A0 from the communication process.

[0059] Step 2: Position the base station through the MCU's GPIO, control the RF switch to select A2 antenna access, and go through the same process as step 1 to obtain d2 and

[0060] Step 3: The positioning base station controls the RF switch through the MCU's GPIO to connect the antennas in sequence. Following the same process as step 1, the remaining distance and PDOA information are obtained.

[0061] Step 4: After all circular array antennas are connected, a vector consisting of PDOA information can be obtained:

[0062]

[0063] Among them, e represents the e exponent, j is the complex number, is the PDOA phase difference between different antennas;

[0064] Step 5: Calculate the covariance matrix of the above vector: R = rr h ; H represents the conjugate transpose operation of the matrix;

[0065] Step 6: Calculate the eigenvalues ​​and eigenvectors of the above covariance matrix, exclude the eigenvector corresponding to the largest eigenvalue, and form the noise matrix U with the remaining M-1 groups of vectors N :

[0066] Step 7: Through U N Constructing a spatial spectrum:

[0067]

[0068] Where a is a vector containing the parameters θ and φ to be estimated, H represents the conjugate transpose operation of the matrix, and U N represents the noise characteristic matrix, θ is the true value of the direction angle of the positioning device relative to the positioning base station, and φ is the true value of the elevation angle of the positioning device relative to the positioning base station.

[0069] Step 8: Obtain the direction angle of the positioning device relative to the positioning base station through the array signal processing algorithm and pitch angle

[0070]

[0071] Step 9: Through d1~d m , and the calculated A fusion framework of the Unscented Kalman Filter (UKF) is constructed to ultimately obtain the high-precision three-dimensional coordinates of the positioning device relative to the positioning base station.

[0072] When the positioning system provided by the present invention communicates with the positioning device, the MCU switches the radio frequency switches in sequence to select A1 to A M The antenna is connected to RF1 in the UWB single chip and A0 in the RF2 port of the UWB single chip, and obtains A1~A M The distance between the antenna and the positioning tag, and A1~A M The PDOA information between the antenna and the positioning tag. Finally, the specific position of the tag in three-dimensional space is calculated based on the distance and PDOA information obtained above. M The antennas can be formed into various antenna array forms, such as linear array, circular array, rectangular array, etc. Compared with other UWB high-precision three-dimensional positioning systems, the present invention only uses a single UWB transceiver chip, which greatly reduces the hardware cost of the positioning system.

[0073] To sum up, with the help of the above technical solutions of the present invention, in the field of high-precision indoor positioning, the present invention only requires a single UWB chip, combined with a radio frequency switch and an antenna array, to achieve three-dimensional high-precision positioning, effectively reducing the overall cost and working power consumption of the positioning system.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A low-cost single-base station high-precision positioning system, characterized in that: It includes a main control MCU, a UWB single chip, an RF switch and an antenna array. The antenna array consists of several A1 to A1 uniformly distributed on a circle. M Antenna composition, the center of the circle is provided with antenna A0; The main control MCU is connected to the UWB single chip, and the RF1 port of the UWB single chip is connected to A1~A1 in the antenna array through the RF switch. M Antenna connection, the main control MCU controls the RF switch through the GPIO port to select the antenna access in the antenna array in turn; the RF2 port of the UWB single chip is connected to the antenna A0.

2. A low-cost single-base station high-precision positioning method, characterized in that: Using the system according to claim 1, comprising the following steps: The S1 positioning base station controls the RF switch through the GPIO port of the MCU to turn A1 to A M Antenna access, the positioning base station obtains antenna A through UWB communication with the positioning device n Distance d from the positioning device n , and the incident signal of the positioning device and A n PDOA phase difference between A0 and n is 1...M; S2 obtains all PDOA phase differences based on all connected antennas Obtain a vector r consisting of PDOA information; S3 calculates the covariance matrix R of the vector r; S4 calculates the eigenvalues ​​and eigenvectors of the covariance matrix of step S3, removes the eigenvector corresponding to the largest eigenvalue, and combines the remaining M-1 groups of vectors into a noise feature matrix U N : S5 via U N Construct spatial spectrum P music (θ, φ); S6 obtains the direction angle of the positioning device relative to the positioning base station through array signal processing algorithm and pitch angle The calculation formula is as follows: S7 passes through d1~d m And the calculated A fusion framework of unscented Kalman filtering is constructed to obtain high-precision three-dimensional coordinates of the positioning device relative to the positioning base station.

3. The low-cost single-base station high-precision positioning method according to claim 2, characterized in that: In step S2, the formula of the vector r composed of PDOA information is: Where e is the exponent and j is a complex number.

4. The low-cost single-base station high-precision positioning method according to claim 3, characterized in that: The formula of the covariance matrix R in step S3 is: R＝rr h where r h The conjugate transpose matrix of r.

5. The low-cost single-base station high-precision positioning method according to claim 4, characterized in that: Step S5 is to pass U N Construct spatial spectrum P music The calculation formula for (θ, φ) is: Where a is a vector containing the parameters θ and φ to be estimated, H represents the conjugate transpose operation of the matrix, and U N represents the noise characteristic matrix, θ is the true value of the direction angle of the positioning device relative to the positioning base station, and φ is the true value of the elevation angle of the positioning device relative to the positioning base station.

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