CN117651250A

CN117651250A - Positioning and direction finding method based on UWB and AoA technology

Info

Publication number: CN117651250A
Application number: CN202410118801.1A
Authority: CN
Inventors: 王春华; 李振亚; 赵章博
Original assignee: Shenzhen Huayun Spacetime Technology Co ltd
Current assignee: Shenzhen Huayun Spacetime Technology Co ltd
Priority date: 2024-01-29
Filing date: 2024-01-29
Publication date: 2024-03-05
Anticipated expiration: 2044-01-29
Also published as: CN117651250B

Abstract

The invention discloses a positioning direction finding method based on UWB and AoA technology, wherein the device comprises at least two base stations and a tag, and the tag comprises a UWB antenna array consisting of at least three UWB antennas. The tag communicates with each base station through the UWB antenna array respectively, so that the angle theta of signals of the base stations reaching the tag and the distance d between the base stations and the tag are obtained, the (d, theta) between the tag and each base station is obtained, two calculated tag position coordinates of the tag are calculated according to the position coordinates (x, y) and (d, theta) of each base station in the system, and the error calculated tag position coordinates can be eliminated through the calculated tag position coordinates calculated by at least two base stations, so that the real tag position coordinates of the tag are obtained, and the gesture orientation under a unified coordinate system is obtained.

Description

Positioning and direction finding method based on UWB and AoA technology

Technical Field

The invention relates to the technical field of indoor positioning, in particular to a positioning and direction finding method based on UWB and AoA technologies.

Background

Conventional UWB indoor positioning techniques can only be used for positioning, if direction finding is required, such as IMU, geomagnetic sensor, etc. The use of such means as IMU sensors may lead to increased accumulated errors over time and geomagnetic sensors are susceptible to magnetic field interference.

Before, the applicant disclosed a patent 202211490941.9, which is a direction-finding positioning method based on UWB, and the coordinate of the tag can be obtained by the base station and the UWB antenna array on the tag, and the attitude orientation of the tag under a unified coordinate system can also be obtained by the tag. However, the method needs the base station to be a UWB antenna array with three antennas, so the requirement on the antennas is high, and under the actual use situation, a plurality of antennas are arranged in most use environments, but the quality of the antennas is probably not so high, so the patent provides a positioning and direction-finding method based on UWB and AoA technology, which is based on a plurality of base stations and can simultaneously know the accuracy and cost of the posture orientation of the terminal equipment on the premise that the terminal equipment knows the coordinates of the base station.

Disclosure of Invention

The invention mainly aims to provide a positioning and direction-finding method based on UWB and AoA technology, which is based on a plurality of base stations and can acquire the posture orientation of the terminal equipment on the premise of acquiring the coordinates of the terminal equipment.

The invention provides a positioning direction finding method based on UWB and AoA technology, wherein the device comprises at least two base stations and a tag, and the tag comprises a UWB antenna array consisting of at least three UWB antennas;

the tag firstly transmits a blink frame to each base station through the UWB antenna array, then receives a response frame transmitted back by the base station through each antenna on the UWB antenna array, so as to obtain a receiving phase of each antenna of the UWB antenna array and obtain a phase difference, obtain an angle theta of a signal of the base station reaching the tag according to the phase difference, and then calculate a distance d between the base station and the tag according to transmission and receiving time, so as to obtain (d, theta) between the tag and each base station;

the response frame comprises position coordinates (x, y) of each base station in the system, two calculated tag position coordinates of the tag are calculated according to the position coordinates (x, y) and (d, theta), and the error calculated tag position coordinates can be eliminated through the calculated tag position coordinates calculated by at least two base stations, so that the real tag position coordinates are obtained.

Preferably, when the tag sends a link frame, a first sending time txlink is recorded, when the base station receives the link frame, a first receiving time rxlink is recorded, the base station replies that a response frame of the tag contains the first receiving time rxlink and a second sending time txresp for sending the response frame, and after the tag receives the response frame, the base station records a second receiving time rxresp, and can obtain a frequency offset R of the tag relative to the base station; thereby being capable of calculating the distance d between the tag and the base station;

d= ((rxresp-txblink) - (txresp-rxblink)) (1-R) C/2, where C is the speed of light.

Preferably, the UWB antenna array has three UWB antennas in total, and the three UWB antennas are arranged in a regular triangle.

Preferably, calculating the phase difference of the base station reaching each antenna on the UWB antenna array of the tag may result in PDOA1, PDOA2 and PDOA3, and then according to the calculation formula of θ:

the angle θ at which the signal of the base station reaches the tag, i.e. the orientation of the tag with respect to the base station, can be calculated.

The positioning and direction-finding method based on UWB and AoA technology has the beneficial effects that:

according to the positioning direction finding method based on the UWB and AoA technology, the tag with the UWB antenna array formed by at least three UWB antennas is communicated with the base stations with two single antennas, so that the real tag position coordinates of the tag are obtained, the gesture orientation of the tag is known, and the design purpose is achieved. Compared with the prior art, the technical purpose can be realized with lower cost on the premise of not changing the antenna structure of the base station, so that the use requirement of customers can be met with lower cost.

Drawings

FIG. 1 is a flow chart of a positioning and direction finding method based on UWB and AoA technology of the present invention;

FIG. 2 is a schematic diagram of a positioning and direction finding method based on UWB and AoA technology of the present invention;

reference numerals in the drawings: 1. tag, 2, first base station, 3, second base station, 11, UWB antenna.

The achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

Referring to fig. 1 and 2, an embodiment of the positioning and direction finding method based on UWB and AoA technology of the present invention is presented:

a positioning direction finding method based on UWB and AoA technology includes a first base station 2, a second base station 3 and a tag 1, wherein the tag 1 includes a UWB antenna array composed of three UWB antennas 11. The label 1 is marked with the orientation of the label 1, i.e. the label reference direction.

The specific method comprises the following steps:

the tag 1 sends a blink frame through any UWB antenna 11 on the tag 1, and records a first sending time txblink;

an antenna on the first base station 2 receives the blink frame and records a first receiving time rxblink;

the first base station 2 transmits a response frame to the tag 1 through an antenna, and fills a second transmitting time txresp of the response frame, a first receiving time rxblink and position coordinates (x 1, y 1) of the first base station 2 in the system into the response frame and transmits the response frame to the tag 1;

after three UWB antennas 11 on the tag 1 receive response frames, recording receiving phases phi1, phi2 and phi3 of the three UWB antennas 11, and simultaneously recording a second receiving moment rxresp, and obtaining a frequency offset R of the tag 1 relative to the first base station 2;

tag 1 calculates the reception phase differences of three UWB antennas 11 from reception phases phi1, phi2, and phi 3:

PDOA1 = phi1 - phi2，

PDOA2 = phi2 - phi3，

PDOA3 = phi3 - phi1，

then according to the calculation formula of theta:

the angle theta between the vector of the signal of the first base station 2 reaching the tag 1 and the reference direction of the tag 1, i.e. the orientation of the tag 1 with respect to the first base station 2,

the distance d1 between the tag 1 and the first base station 2 can be calculated,

d1 = ((rxresp-txblink) - (txresp-rxblink)) (1-R) C/2, where C is the speed of light,

thereby obtaining (d 1, θ1) between the tag 1 and the first base station 2;

two calculated tag position coordinates (x 1a, y1 a) and (x 1b, y1 b) of the tag 1 are calculated from the position coordinates (x 1, y 1) and (d 1, θ1), and the calculated tag position coordinates (x 1a, y1 a) and (x 1b, y1 b) are mirror-image-disposed on both sides of a reference line of the first base station 2 with the tag reference direction as a direction;

two calculated tag position coordinates (x 2a, y2 a) and (x 2b, y2 b) of the tag 1 are also calculated by the above-described steps by communicating with the second base station 3;

the (x 1a, y1 a) and (x 1b, y1 b) are identical or similar to one another in (x 2a, y2 a) and (x 2b, y2 b), and the identical or similar calculated label position coordinates are true label position coordinates, so that the label 1 obtains the position coordinates of the label in the system and knows the posture orientation of the label, and the design purpose is achieved.

The foregoing description is only of the preferred embodiments of the present invention and is not intended to limit the scope of the invention, and all equivalent structural changes made by the present invention and the accompanying drawings, or direct or indirect application in other related technical fields, are included in the scope of the present invention.

Claims

1. A positioning and direction finding method based on UWB and AoA technology is characterized in that,

the device comprises at least two base stations and a tag, wherein the tag comprises a UWB antenna array consisting of at least three UWB antennas;

the response frame comprises position coordinates (x, y) of each base station in the system, two calculated tag position coordinates of the tag are calculated according to the position coordinates (x, y) and (d, theta), and the error calculated tag position coordinates can be eliminated through the calculated tag position coordinates calculated by at least two base stations, so that the real tag position coordinates of the tag are obtained, and meanwhile, the gesture orientation under a unified coordinate system is obtained.

2. The positioning and direction-finding method based on UWB and AoA technology according to claim 1, wherein,

when the tag sends a blink frame, a first sending time txblink is recorded, when the base station receives the blink frame, a first receiving time rxblink is recorded, the base station replies that a response frame of the tag contains the first receiving time rxblink and a second sending time txresp for sending the response frame, after the tag receives the response frame, the second receiving time rxresp is recorded, and the frequency offset R of the tag relative to the base station can be obtained; thereby being capable of calculating the distance d between the tag and the base station;

3. The positioning and direction finding method based on UWB and AoA technology according to claim 1, wherein the UWB antenna array has three UWB antennas in total, and the three UWB antennas are arranged in a regular triangle.

4. A positioning and direction finding method based on UWB and AoA technology according to claim 3, wherein calculating the phase difference of the base station to each antenna on the UWB antenna array of the tag yields PDOA1, PDOA2 and PDOA3, and then according to the calculation formula of θ: