Long-distance orientation and low-power-consumption tracking method for UWB anti-lost equipment

Abstract

The invention relates to the technical field of wireless communication and electronic anti-lost, in particular to a long-distance orientation and low-power-consumption tracking method for UWB anti-lost equipment, the UWB anti-lost equipment comprises master equipment and slave equipment, and the method comprises the following steps: step 1, link establishment: after the master equipment and the slave equipment are powered on and initialized, the master equipment and the slave equipment are powered on and initialized; an encrypted wireless link is established through the UWB communication module, and pairing binding is completed; 2, self-adaptive power consumption scheduling: the master device dynamically switches working modes based on the real-time distance between the master device and the slave device, wherein the working modes comprise a low-power-consumption monitoring mode and a high-precision tracking mode; through cooperation of the TWR and the high-gain antenna, UWB communication of 150 meters or above is achieved, dependence on external networks such as a GPS and Wi-Fi is not needed, the method is suitable for indoor and outdoor full scenes, TWR centimeter-level distance measurement and AoA degree-level direction finding technologies are fused, IMU motion compensation is combined, accurate and stable direction guidance is provided, and the problem of inaccurate finding is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wireless communication and electronic anti-lost technology, in particular to a long-distance directional and low-power tracking method for UWB anti-lost equipment. BACKGROUND

[0002] The tracking method of the existing anti-lost equipment has obvious defects: the Bluetooth anti-lost method has a short effective distance (<50 meters) and no directional guidance capability; the UWB tracking method relying on public network is invalid in outdoor network environment and cannot realize real-time anti-lost; at the same time, the traditional method needs to maintain high transmission power if long-distance communication is pursued, resulting in a sharp increase in power consumption and a short battery life; in addition, non-line-of-sight (NLOS) propagation in complex environments will cause positioning errors, seriously affecting the tracking reliability.

[0003] Although the existing UWB technology can realize distance measurement through two-way ranging (TWR) and direction recognition through angle of arrival (AoA) technology, it lacks a systematic method of deeply integrating the two with low-power management and anti-interference mechanism, and cannot meet the full-scene anti-lost demand. Therefore, a long-distance directional and low-power tracking method for UWB anti-lost equipment is proposed. SUMMARY

[0004] Therefore, the present application provides a long-distance directional and low-power tracking method for UWB anti-lost equipment to solve or alleviate the technical problems existing in the prior art and at least provide a beneficial choice.

[0005] The technical solution of the present application is as follows: a long-distance directional and low-power tracking method for UWB anti-lost equipment, the UWB anti-lost equipment comprising a master device and a slave device, the method comprising the following steps:

[0006] Step one, link establishment: after the master device and the slave device are powered on and initialized, an encrypted wireless link is established through a UWB communication module to complete pairing and binding;

[0007] Step two, adaptive power consumption scheduling: the master device dynamically switches the working mode based on the real-time distance from the slave device, the working mode comprising a low-power listening mode and a high-precision tracking mode;

[0008] Step three, two-way ranging (TWR): the master and slave devices obtain time stamps through UWB signal interaction and calculate the signal flight time to obtain the real-time distance;

[0009] Step four, angle of arrival (AoA) direction finding: the master device analyzes the phase difference of the slave device signal through an antenna array and calculates the direction of the slave device relative to the master device;

[0010] Step 5: Data Fusion and Guidance Generation: The main device fuses distance and direction data with motion data from the inertial measurement unit (IMU) to generate dynamic direction guidance;

[0011] Step 6, Non-Line-of-Sight (NLOS) Error Compensation: The main device analyzes the UWB signal characteristics to identify the obstructing environment, starts the compensation algorithm to correct the positioning results and prompts the user.

[0012] More preferably, the triggering condition for the adaptive power consumption scheduling in step two is: when the distance between the master and slave devices is ≤ a preset safety threshold (20 meters), the low-power monitoring mode is activated; when the distance is > the safety threshold, the mode is automatically switched to high-precision tracking mode.

[0013] Further preferably, the operating parameters of the low-power monitoring mode are: the master device performs TWR ranging at a frequency of 0.5Hz, and the slave device enters a sleep state after intermittent response; the operating parameters of the high-precision tracking mode are: the master device performs TWR ranging and AoA direction finding synchronously at a frequency of 10Hz, and the slave device continuously responds to signal interaction.

[0014] More preferably, the specific process of bidirectional ranging in step three is as follows:

[0015] 1. The master device sends a data packet to the slave device at time t1, and the slave device receives it at t2;

[0016] 2. After processing by the device, a response packet is sent at t3, and the master device receives it at t4.

[0017] 3. The main equipment calculates the one-way flight time ToF = [(t4-t1)-(t3-t2)] / 2 using the formula, and then combines it with the speed of light c to obtain the distance d = ToF × c.

[0018] More preferably, the AoA direction finding in step four is implemented as follows: the master device acquires the slave device signal through a multi-element antenna array, analyzes the phase difference of the signal reaching different antennas, and calculates the azimuth and elevation angles of the slave device.

[0019] More preferably, the data fusion logic in step five is as follows: the direction data obtained by AoA direction finding is associated with the distance data obtained by TWR distance finding, and the acceleration and gyroscope data collected by IMU are combined to compensate for the rotation error of the main device itself, so as to generate real-time updated arrow-shaped direction guidance.

[0020] More preferably, the specific method of NLOS error compensation in step six is ​​as follows: the main device analyzes the channel impulse response (CIR) of the signal, calculates the ratio of the first path energy to the total energy, and determines that the NLOS scenario is lower than a preset threshold when the ratio is lower than the preset threshold. The linear compensation model is called to correct the ranging and direction finding results, and the user is prompted by color change and signal grid reduction through the human-machine interface.

[0021] Further preferred features include a dual-mode switching step: when the distance between the master and slave devices exceeds the 150-meter UWB effective range, the slave device connects to the Apple FindMy network to upload a fuzzy location; when the user approaches within 150 meters, it automatically switches back to the UWB high-precision tracking mode.

[0022] The embodiments of the present invention have the following advantages due to the adoption of the above technical solutions:

[0023] I. This invention achieves UWB communication over 150 meters by combining TWR with a high-gain antenna, without relying on external networks such as GPS or Wi-Fi. It is suitable for all indoor and outdoor scenarios. It integrates TWR centimeter-level ranging and AoA degree-level direction finding technology, combined with IMU motion compensation, to provide accurate and stable direction guidance and solve the problem of "not being able to find the right direction".

[0024] Second, the adaptive power consumption scheduling strategy of this invention enables the device to be in low power consumption mode in more than 90% of daily scenarios, extending the battery life by 3 to 5 times compared with traditional methods. The NLOS recognition and compensation algorithm effectively reduces occlusion interference and improves tracking reliability in complex environments. The optional dual-mode switching function realizes a closed loop from "global fuzzy tracking" to "centimeter-level precise search", solving the "cannot find" problem.

[0025] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the invention will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0028] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0029] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0030] like Figure 1 As shown, this embodiment of the invention provides a long-range orientation and low-power tracking method for a UWB anti-loss device. The UWB anti-loss device includes a master device and a slave device. The method includes the following steps:

[0031] Step 1, Link Establishment: After the master and slave devices are powered on and initialized, they establish an encrypted wireless link through the UWB communication module to complete pairing and binding;

[0032] Step 2, Adaptive power consumption scheduling: The master device dynamically switches its working mode based on the real-time distance with the slave device. The working modes include low-power monitoring mode and high-precision tracking mode.

[0033] Step 3, Two-way ranging (TWR): The master and slave devices exchange timestamps via UWB signals and calculate the signal flight time to obtain the real-time distance;

[0034] Step 4, Angle of Arrival (AoA) Direction Finding: The master device analyzes the phase difference of the slave device's signal through the antenna array and calculates the direction of the slave device relative to the master device;

[0035] Step 5: Data Fusion and Guidance Generation: The main device fuses distance and direction data with motion data from the inertial measurement unit (IMU) to generate dynamic direction guidance;

[0036] Step 6, Non-Line-of-Sight (NLOS) Error Compensation: The main device analyzes the UWB signal characteristics to identify the obstructing environment, starts the compensation algorithm to correct the positioning results and prompts the user.

[0037] In one embodiment, the triggering condition for adaptive power consumption scheduling in step two is as follows: when the distance between the master and slave devices is ≤ a preset safety threshold (20 meters), a low-power monitoring mode is activated; when the distance is > the safety threshold, the mode is automatically switched to high-precision tracking mode. The master device uses a Qorvo DW3220 master control chip (supporting TWR / AoA), a 4-unit PCB antenna array, and an STMicroelectronics LSM6DSOXIMU; the slave device uses a Qorvo DW3120 master control chip, a 3dBi gain ceramic antenna, and a CR2032 button battery.

[0038] In one embodiment, the operating parameters of the low-power monitoring mode are as follows: the master device performs TWR ranging at a frequency of 0.5Hz, and the slave device enters a sleep state after intermittent response; the operating parameters of the high-precision tracking mode are as follows: the master device performs TWR ranging and AoA direction finding synchronously at a frequency of 10Hz, and the slave device continuously responds to signal interaction; the safe distance threshold is set to 20 meters, the ranging frequency in the low-power mode is 0.5Hz, the ranging / direction finding frequency in the high-precision mode is 10Hz, the NLOS judgment threshold is 0.3, and the compensation model adopts linear correction of the first diameter energy ratio (correction coefficient k = 0.8 + 0.2 × first diameter energy ratio).

[0039] In one embodiment, the specific process of bidirectional ranging in step three is as follows:

[0040] 1. The master device sends a data packet to the slave device at time t1, and the slave device receives it at t2;

[0041] 2. After processing by the device, a response packet is sent at t3, and the master device receives it at t4.

[0042] 3. The main equipment calculates the one-way flight time ToF = [(t4-t1)-(t3-t2)] / 2 using the formula, and then combines it with the speed of light c to obtain the distance d = ToF × c.

[0043] In one embodiment, the AoA direction finding in step four is implemented as follows: the master device acquires the signal from the slave device through a multi-element antenna array, analyzes the phase difference of the signal reaching different antennas, and calculates the azimuth and elevation angles of the slave device; in the LOS scenario, the ranging error is ≤20 cm and the direction finding error is ≤3 degrees; in the NLOS scenario, the error is reduced by more than 50% after compensation; the slave device can last up to 6 months (mainly in low power mode).

[0044] In one embodiment, the data fusion logic in step five is as follows: the direction data obtained by AoA direction finding is associated with the distance data obtained by TWR distance finding, and the acceleration and gyroscope data collected by IMU are combined to compensate for the rotation error of the main device itself, so as to generate real-time updated arrow-shaped direction guidance.

[0045] In one embodiment, the specific method of NLOS error compensation in step six is ​​as follows: the master device analyzes the channel impulse response (CIR) of the signal, calculates the ratio of the first path energy to the total energy, and determines the NLOS scenario when the ratio is lower than a preset threshold. The linear compensation model is called to correct the ranging and direction finding results, and the user is prompted by color change and signal grid reduction through the human-machine interface.

[0046] In one embodiment, a dual-mode switching step is also included: when the distance between the master and slave devices exceeds the 150-meter UWB effective range, the slave device connects to the Apple FindMy network to upload the fuzzy location; when the user approaches within 150 meters, it automatically switches back to the UWB high-precision tracking mode.

[0047] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in the present invention, and these should all be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A long-range directional and low-power consumption tracking method for UWB anti-lost device, characterized in that: The UWB anti-lost device comprises a master device and a slave device, and the method comprises the following steps: Step one, link establishment: after the master device and the slave device are powered on and initialized, an encrypted wireless link is established through a UWB communication module, and pairing and binding are completed; Step two, adaptive power consumption scheduling: the master device dynamically switches the working mode based on the real-time distance from the slave device, and the working mode comprises a low-power consumption monitoring mode and a high-precision tracking mode; Step three, two-way ranging (TWR): the master device and the slave device obtain timestamps through UWB signal interaction, calculate the signal flight time to obtain the real-time distance; Step four, angle of arrival (AoA) direction finding: the master device analyzes the phase difference of the slave device signal through an antenna array, and calculates the direction of the slave device relative to the master device; Step five, data fusion and direction generation: the master device fuses the distance, direction data and motion data of an inertial measurement unit (IMU), and generates a dynamic direction guide; Step six, non-line-of-sight (NLOS) error compensation: the master device analyzes the UWB signal characteristics to identify the shielding environment, starts a compensation algorithm to correct the positioning result, and prompts the user.

2. The method of claim 1, wherein the method is characterized by: In the step two, the trigger condition of the adaptive power consumption scheduling is that when the distance between the master device and the slave device is less than or equal to a preset safety threshold (20 meters), the low-power consumption monitoring mode is started; and when the distance is greater than the safety threshold, the high-precision tracking mode is automatically switched to.

3. The method of claim 1, wherein the method is characterized by: The working parameters of the low-power consumption monitoring mode are that the master device performs TWR ranging at a frequency of 0.5 Hz, and the slave device enters a sleep state after intermittent response; and the working parameters of the high-precision tracking mode are that the master device synchronously performs TWR ranging and AoA direction finding at a frequency of 10 Hz, and the slave device continuously responds to signal interaction.

4. The method of claim 1, wherein the method is characterized by: In the step three, the specific process of the two-way ranging is as follows: One, the master device sends a data packet to the slave device at time t1, and the slave device receives at t2; Two, the slave device sends a response packet at t3 after processing, and the master device receives at t4; Three, the master device calculates the one-way flight time ToF = [(t4-t1)-(t3-t2)] / 2 by formula, and then obtains the distance d = ToF x c in combination with the speed of light c.

5. The method of claim 1, wherein: In the step four, the implementation of the AoA direction finding is that the master device collects the slave device signal through a multi-unit antenna array, analyzes the phase difference of the signal arriving at different antennas, and solves the azimuth and elevation angles of the slave device.

6. The method of claim 1, wherein: In the step five, the logic of the data fusion is that the direction data obtained by the AoA direction finding is associated with the distance data obtained by the TWR ranging, the acceleration and gyroscope data collected by the IMU are combined to compensate for the rotation error of the master device itself, and a real-time updated arrow type direction guide is generated.

7. The method of claim 1, wherein the method is characterized by: In the step six, the specific way of the NLOS error compensation is that the master device calculates the ratio of the first path energy to the total energy by analyzing the channel impulse response (CIR) of the signal, determines that it is an NLOS scene when the ratio is lower than a preset threshold, calls a linear compensation model to correct the ranging and direction finding results, and prompts the user through a color change and signal grid reduction in a human-computer interaction interface.

8. The method of claim 1, wherein the method is a long-range directional and low-power consumption tracking method for UWB anti-lost devices. Also includes a dual-mode switching step: when the master-slave device distance exceeds 150 meters UWB effective range, the slave device accesses the Apple FindMy network to upload the ambiguous location; when the user is close to within 150 meters, automatically switch back to the UWB high-precision tracking mode.

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