WO2022088436A1

WO2022088436A1 - Method and apparatus for positioning person in water

Info

Publication number: WO2022088436A1
Application number: PCT/CN2020/137439
Authority: WO
Inventors: 刘广松; 陆倚敏
Original assignee: 苏州触达信息技术有限公司
Priority date: 2020-10-28
Filing date: 2020-12-18
Publication date: 2022-05-05
Also published as: CN112327253A

Abstract

A method and apparatus for positioning a person in water, the method comprising: on the basis of a first sound detection module (18) and a second sound detection module (19) comprised in each sound receiving apparatus (a1, a2, a3, a4) among N sound receiving apparatuses (a1, a2, a3, a4) arranged in a swimming space, for a receiving time difference of a direct sound signal sent by a wearable device worn by the person in water in the swimming space, determining the relative angle between each sound receiving apparatus (a1, a2, a3, a4) and the wearable device, wherein N is greater than or equal to 2; and on the basis of respective extension lines of N relative angles, positioning the person in water so as to improve the safety of the person in water.

Description

A method and device for locating persons in water

technical field

Embodiments of the present invention relate to the technical field of positioning, and more particularly, to a method and device for positioning a person in water.

Background technique

The World Health Organization once identified swimming as "one of the best sports in the world", which can strengthen the body and relax the body and mind. Therefore, more and more people like to engage in underwater sports, learn to swim, and participate in swimming activities. However, due to the huge physical exertion of water sports, there will be a series of safety problems, such as convulsions or suffocation, or physical discomfort but insisting on underwater sports, which may cause irreversible tragedies.

At present, most of the drowning monitoring of people in the water relies on ambulance personnel, who are determined by visual observation. There is no perfect scientific equipment and means to provide timely and effective drowning information to ambulance personnel, such as whether someone is drowning and the correct location of the drowning person. , causing the drowning person to drown for too long and delay the rescue time.

SUMMARY OF THE INVENTION

The embodiments of the present invention provide a method and device for locating a person in water.

The technical scheme of the embodiment of the present invention is as follows:

A method for locating persons in water, the method comprising:

Based on the first sound detection module and the second sound detection module included in each of the N sound receiving devices arranged in the swimming space, for the wearable devices worn by the water personnel in the swimming space Determine the relative angle between each sound receiving device and the wearable device, where N is greater than or equal to 2;

The person in the water is located based on the respective extension lines of the N relative angles.

In one embodiment, the N is equal to 2, the N sound receiving devices are a first sound receiving device and a second sound receiving device, and the relative angle between the first sound receiving device and the wearable device is the same as the second sound receiving device. The sum of the relative angles of the sound receiving device and the wearable device is not equal to 180 degrees.

In one embodiment, the N is equal to 2, and the N sound sources are a first sound receiving device and a second sound receiving device;

The positioning of the person in the water based on the respective extension lines of the N relative angles includes:

When the extension line of the relative angle of the first sound receiving device and the wearable device coincides with the extension line of the relative angle of the second sound receiving device and the wearable device, based on the third sound receiving device arranged in the swimming space The first sound detection module and the second sound detection module included in the device determine the relative angle between the third sound receiving device and the wearable device according to the receiving time difference of the direct sound signal sent by the wearable device worn by the person in the water, wherein the The third sound receiving device, the first sound receiving device and the second sound receiving device are not on the same straight line;

determining the first straight line based on the arrangement position point of the first sound receiving device and the arrangement position point of the second sound receiving device;

The person in the water is located based on the intersection of the extension line of the relative angle between the third sound receiving device and the wearable device and the first straight line.

In one embodiment, the N is greater than or equal to 3, and the N sound receiving devices and the wearable device are not on the same straight line;

Three relative angles are determined based on the descending order of the signal-to-noise ratio of each direct sound signal received by each sound receiving device;

The person in the water is located based on the intersection of the respective extension lines of the three relative angles.

In one embodiment, the determining the relative angle between each sound receiving device and the wearable device includes:

For each sound receiver:

based on

Determine θ; wherein arcsin is an arcsine function, d=t*c, t is the first sound detection module and the second sound detection module in each sound receiving device for the reception of the direct sound signal sent by the wearable device Time difference, c is the speed of sound propagation, D is the distance between the first sound detection module and the second sound detection module in each sound receiving device; determine the distance between each sound receiving device and the wearable device based on θ relative angle of

in

In one embodiment, it also includes:

When it is determined that the position of the person in the water does not change within a predetermined time or the position of the person in the water is in a predetermined danger area, an alarm message is issued.

A positioning device for people in water, comprising:

The relative angle determination module is used for, based on the first sound detection module and the second sound detection module included in each of the N sound receiving devices arranged in the swimming space, for water personnel in the swimming space The receiving time difference of the direct sound signal sent by the wearable device, determine the relative angle between each sound receiving device and the wearable device, where N is greater than or equal to 2;

A positioning module, configured to locate the person in the water based on the respective extension lines of the N relative angles.

In one embodiment, N is equal to 2, the N sound receiving devices are a first sound receiving device and a second sound receiving device, and the relative angle between the first sound receiving device and the wearable device is the same as the second sound receiving device The sum of the relative angles of the device and the wearable device is not equal to 180 degrees.

The positioning module is used for, when the extension line of the relative angle of the first sound receiving device and the wearable device coincides with the extension line of the relative angle of the second sound receiving device and the wearable device, based on the layout in the swimming space The first sound detection module and the second sound detection module included in the third sound receiving device determine the difference between the third sound receiving device and the wearable device according to the receiving time difference of the direct sound signal sent by the wearable device worn by the person in the water. relative angle, wherein the third sound receiving device, the first sound receiving device and the second sound receiving device are not on the same straight line; the first sound receiving device is determined based on the arrangement position point of the first sound receiving device and the arrangement position point of the second sound receiving device. A straight line; based on the intersection of the extension line of the relative angle between the third sound receiving device and the wearable device and the first straight line, locate the person in the water.

The positioning module is used for determining three relative angles based on the descending order of the signal-to-noise ratio of each direct sound signal received by each sound receiving device; based on the intersection of the respective extension lines of the three relative angles, positioning Said water personnel.

In one embodiment, it also includes:

The alarm module is configured to issue an alarm message when it is determined that the position of the person in the water has not changed within a predetermined time or the position of the person in the water is in a predetermined danger area.

A computer-readable storage medium stores a computer program on the computer-readable storage medium, and when the computer program is executed by a processor, implements the method for locating a person in water according to any one of the above.

It can be seen from the above technical solutions that in the embodiment of the present invention, the use of acoustic waves as elastic waves to propagate in water has the advantages of small loss and long propagation distance. Accurate location information to achieve a low-cost and easy-to-use precise positioning of people in the water.

Description of drawings

FIG. 1 is an exemplary flowchart of a method for determining a relative angle between smart devices according to the present invention.

FIG. 2 is a schematic diagram of the principle of determining relative angles between smart devices according to the present invention.

FIG. 3 is a schematic diagram of the calculation principle of the relative angle between the smart devices of the present invention.

FIG. 4 is a first exemplary schematic diagram of determining a pair of direct signals according to the present invention.

FIG. 5 is a second exemplary schematic diagram of determining a pair of direct signals according to the present invention.

6 is a schematic diagram of a first exemplary arrangement of the first sound detection module and the second sound detection module of the present invention in a smart device.

FIG. 7 is a schematic diagram of a second exemplary arrangement of the first sound detection module and the second sound detection module in the smart device of the present invention.

FIG. 8 is a schematic diagram of relative positioning of the first smart device and the second smart device according to the present invention.

FIG. 9 is a schematic diagram showing relative angles in a smart device interface according to the present invention.

FIG. 10 is an exemplary processing flow chart of the indoor positioning method of the present invention.

FIG. 11 is a flowchart of a method for locating a smart device according to the present invention.

FIG. 12 is a schematic diagram of positioning a smart device according to the present invention.

FIG. 13 is an exemplary schematic diagram of positioning a smart device according to the present invention.

FIG. 14 is a flow chart of a method for locating a person in water according to the present invention.

FIG. 15 is a schematic diagram of the positioning of a person in the water according to the present invention.

FIG. 16 is a structural diagram of a positioning device for a person in water according to the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

For the sake of brevity and intuition in description, the solution of the present invention is explained below by describing several representative embodiments. Numerous details in the embodiments are provided only to aid in understanding the aspects of the invention. However, it is obvious that the technical solutions of the present invention may not be limited to these details during implementation. In order to avoid unnecessarily obscuring aspects of the present invention, some embodiments are not described in detail, but merely framed. Hereinafter, "including" means "including but not limited to", and "according to..." means "at least in accordance with, but not limited to, only in accordance with...". Due to Chinese language habits, when the number of a component is not specified below, it means that the component may be one or more, or it may be understood as at least one.

In order not to add additional hardware, use software to realize the relative direction positioning between smart devices, so that the relative positioning is universal, and devices from different manufacturers can achieve interoperability and compatibility. Based on this, we explore innovative applications of smart devices. The embodiment of the invention proposes a sound (preferably ultrasound)-based relative direction recognition solution between smart devices, without additional hardware, software can be used to realize the relative direction recognition between two smart devices, and the positioning result is accurate and reliable. First of all, intelligent device refers to any kind of equipment, apparatus or machine with computing processing capability.

FIG. 1 is an exemplary flowchart of a method for determining a relative angle between smart devices according to the present invention. The method is applicable to a first smart device, and the first smart device includes a first sound detection module and a second sound detection module. The first sound detection module and the second sound detection module are fixedly installed in the first smart device. For example, the first sound detection module may be implemented as a microphone or a set of microphone arrays arranged in the first smart device. Likewise, the second sound detection module may be implemented as a microphone or a set of microphone arrays arranged in the first smart device different from the first sound detection module.

As shown in Figure 1, the method includes:

Step 101: Enable the first sound detection module to detect the first sound signal sent by the second smart device and reach the first sound detection module, and enable the second sound detection module to detect the sound signal sent by the second smart device and reach the second sound detection module. The second sound signal, wherein the first sound signal and the second sound signal are simultaneously sent out by the second smart device.

Here, the second smart device can send out one sound signal or a plurality of sound signals at the same time.

For example, when the second smart device sends out a sound signal, the first sound detection module and the second sound detection module in the second smart device detect the sound signal respectively. Wherein: the detection signal detected by the first sound detection module and the sound signal directly reaching the first sound detection module is determined as the first sound signal; the sound signal detected by the second sound detection module and the sound signal directly reaching the first sound detection module The detection signal is determined as the second sound signal.

For another example, when the second smart device sends out multiple sound signals at the same time, for example, sends out an ultrasonic signal and an audible sound signal. The first sound detection module in the second smart device is adapted to detect ultrasonic signals, and the second sound detection module is adapted to detect audible sound signals. The first sound detection module detects the ultrasonic signal, and the second sound detection module detects the audible sound signal. Wherein: the detection signal detected by the first sound detection module, the ultrasonic signal directly reaching the first sound detection module is determined as the first sound signal; the audible sound signal detected by the second sound detection module, the audible sound signal directly reaches the second sound detection module The detection signal of the module is determined as the second sound signal.

In other words, the first sound signal and the second sound signal may be the respective detection signals of the first sound detection module and the second sound detection module for the same sound signal sent by the second smart device. Or, the first sound signal and the second sound signal may be the respective detection signals of the first sound detection module and the second sound detection module for different sound signals simultaneously emitted by the second smart device.

Step 102: Determine the time difference between the time when the first sound signal is received and the time when the second sound signal is received.

Here, the first smart device (for example, the CPU in the first smart device) may record the reception time of the first sound signal and the reception time of the second sound signal, and calculate the time difference between the two.

Step 103: Determine the relative angle between the first smart device and the second smart device based on the distance and the time difference between the first sound detection module and the second sound detection module.

For example, step 103 may be performed by the CPU of the first smart device.

In one embodiment, determining the relative angle between the first smart device and the second smart device in step 103 includes: based on

Determine θ; wherein arcsin is an arcsine function, d=t*c, t is the time difference, c is the speed of sound propagation, D is the distance between the first sound detection module and the second sound detection module; Determined based on θ The relative angle between the first smart device and the second smart device

in

The value of the time difference determined in step 102 may be a positive number or a negative number. When the value of the time difference is a positive number, the reception time of the second sound signal is earlier than the reception time of the first sound signal, so the relative angle φ between the first smart device and the second smart device is usually an acute angle; when the time difference When the value of is negative, the reception time of the first sound signal is earlier than the reception time of the second sound signal, so the relative angle φ between the first smart device and the second smart device is usually an obtuse angle.

In an embodiment of the present invention, the first sound signal is a signal from the second smart device directly to the first sound detection module, and the second sound signal is a signal from the second smart device directly to the second sound detection module. In fact, both the first sound detection module and the second sound detection module may receive non-direct signals from the second smart device (for example, one reflection or multiple transmissions through obstacles). Therefore, how to determine the direct signal from the received multiple signals is significant.

The applicant found that: under normal circumstances, the received signal stream (steam) of each sound detection module includes a direct channel and a reflected channel. The direct channel can be simply and conveniently determined according to the following principle: among all the signals detected by the sound detection module, the signal strength of the direct channel is generally the strongest. Therefore, in one embodiment, the method further includes: determining a sound signal whose intensity is greater than a predetermined threshold within a predetermined time window in the sound signal stream of the second smart device received by the first sound detection module as the sound signal a first sound signal; determine a sound signal whose intensity is greater than the predetermined threshold value in the sound signal stream of the second smart device received by the second sound detection module as the second sound signal within the predetermined time window .

FIG. 4 is a first exemplary schematic diagram of determining a pair of direct signals according to the present invention. In FIG. 4 , the sound signal stream detected by the first sound detection module is steam1 , steam1 includes a plurality of pulse signals that vary along time (t), and the threshold value of the predetermined signal strength is T. It can be seen that within the range of the time window 90, the signal strength of the pulse signal 50 in steam1 is greater than the threshold value T. The sound signal stream detected by the second sound detection module is steam2, steam2 includes a plurality of pulse signals that vary along time (t), and the threshold value of the predetermined signal strength is also T. It can be seen that within the range of the time window 90, the signal strength of the pulse signal 60 in steam2 is greater than the threshold value T. Therefore, it is determined that the pulse signal 50 is the first sound signal; the pulse signal 60 is the second sound signal.

In addition, the applicant also found that the direct channel can be accurately determined by comprehensively considering the following two principles: principle (1), among all the signals detected by the sound detection module, the signal strength of the direct channel is generally the strongest; principle (2) ), joint discrimination method: the distance difference d converted from the arrival time difference of two direct channel signals (the first sound signal and the second sound signal) should not be greater than the distance between the first sound detection module and the second sound detection module .

Therefore, in one embodiment, the method further includes: determining a sound signal whose strength is greater than a predetermined threshold value in the sound signal stream of the second smart device detected by the first sound detection module, so as to form a first candidate signal set; The second sound detection module detects a sound signal whose strength is greater than the predetermined threshold value in the sound signal stream of the second smart device to form a second candidate signal set; determines the reception of each sound signal in the first candidate signal set the respective time difference between the moment and the receiving moment of each sound signal in the second candidate signal set; a pair of sound signals whose time difference is less than M is determined as the first sound signal and the second sound signal, Wherein M=(D/c), D is the distance between the first sound detection module and the second sound detection module, and c is the propagation speed of the sound.

FIG. 5 is a second exemplary schematic diagram of determining a pair of direct signals according to the present invention. In FIG. 5 , the sound signal stream detected by the first sound detection module is steam1 , steam1 includes a plurality of pulse signals varying along time (t), and the threshold value of the predetermined signal strength is T. It can be seen that in steam1, the signal strength of the pulse signal 50 is greater than the threshold value T, so the first candidate signal set includes the pulse signal 50. The sound signal stream detected by the second sound detection module is steam2, steam1 includes a plurality of pulse signals that vary along time (t), and the threshold value of the predetermined signal strength is also T. It can be seen that in steam2, the signal strengths of the pulse signal 60 and the pulse signal 70 are both greater than the threshold value T, so the second candidate signal set includes the pulse signal 60 and the pulse signal 70. Furthermore, the time difference d1 between the reception instants of the pulse signal 50 in the first candidate signal set and the pulse signal 60 in the second candidate signal set is determined, and the pulse signal 50 in the first candidate signal set and the pulse in the second candidate signal set are determined The time difference d2 between the reception instants of the signal 70. It is assumed that d1 is less than M and d2 is greater than M, where M=(D/c), D is the distance between the first sound detection module and the second sound detection module, and c is the speed of sound propagation. Therefore, the pulse signal 50 of the pair of sound signals related to d1 is determined to be the first sound signal, and the pulse signal 60 of the pair of sound signals is determined to be the second sound signal.

Preferably, the first sound signal and the second sound signal are ultrasonic waves in a code division multiple access format and include a media access control address (MAC) of the second smart device. Therefore, the first smart device can accurately identify the source of the sound signal based on the MAC address of the second smart device included in the sound signal. When there are multiple sound sources that emit sound signals in the environment, the first smart device can accurately use the two direct signals from the same sound source to determine the relative angle to the sound source based on the MAC address extracted from the sound signal, while No interference from other sound sources.

The embodiment of the present invention also provides a method for determining a relative angle between smart devices. The method is applicable to a first intelligent device, and the first intelligent device includes a first sound detection module and a second sound detection module, and the method includes: determining that the ultrasonic signal sent by the second intelligent device reaches the first part of the first sound detection module. time; determine the second time when the ultrasonic signal reaches the second sound detection module; determine the time difference between the first time and the second time; based on the distance and the time difference between the first sound detection module and the second sound detection module, determine the first time The relative angle between a smart device and a second smart device.

In one embodiment, the determining the relative angle between the first smart device and the second smart device includes: based on

in

In one embodiment, the method further includes at least one of the following treatments:

(1), the first sound detection module receives the ultrasonic signal whose intensity is greater than the predetermined threshold value in the ultrasonic signal flow of the second intelligent device, and is determined to be the ultrasonic signal directly to the first sound detection module, and the The moment of receiving the ultrasonic signal directly to the first sound detection module is determined as the first moment; the second sound detection module receives the ultrasonic signal stream of the second intelligent device, the intensity is greater than the predetermined time window within the predetermined time window. The ultrasonic signal of the predetermined threshold value is determined as the ultrasonic signal directly reaching the second sound detection module, and the moment when the ultrasonic signal directly reaching the second sound detection module is received is determined as the second moment.

(2), in the ultrasonic signal flow of the second intelligent device detected by the first sound detection module, determine the ultrasonic signal whose intensity is greater than the predetermined threshold value to form the first candidate signal set; detect the second intelligent device in the second sound detection module Determine the ultrasonic signal whose strength is greater than the predetermined threshold value in the ultrasonic signal flow of the device to form a second candidate signal set; determine the receiving time of each ultrasonic signal in the first candidate signal set and each ultrasonic signal in the second candidate signal set. The respective time differences between the receiving moments of the ultrasonic signals; the receiving moments of a pair of ultrasonic signals whose time difference is less than M are determined as the first and second moments, where M=(D/c), D is the distance between the first sound detection module and the second sound detection module, and c is the speed of sound propagation.

The principle and calculation process of the relative positioning of the present invention are exemplarily described below. FIG. 2 is a schematic diagram of the principle of determining relative angles between smart devices according to the present invention. FIG. 3 is a schematic diagram of the calculation principle of the relative angle between the smart devices of the present invention.

As shown in FIG. 2 , the microphone a1 arranged at the bottom of the smart device A transmits an ultrasonic signal, the ultrasonic signal contains the MAC address of the smart device A, and the smart device B (not shown in FIG. 2 ) has two microphones arranged spaced apart, respectively are microphone b1 and microphone b2. The microphone b1 receives the direct signal L1 of the ultrasonic signal, and the microphone b2 receives the direct signal L2 of the ultrasonic signal. The ultrasonic signal is transmitted through the obstacle and reaches the indirect signal of the microphone b1 and the microphone b2, and does not participate in the subsequent relative angle calculation.

Since the smart devices are small, especially when the two smart devices are far apart, the direct signals L ₁ and L ₂ can be regarded as parallel lines. As shown in FIG. 3 , L ₁ and L ₂ represent the direct signals (not the signals reflected by obstacles) received by the microphone b1 and the microphone b2 of the smart device B respectively; D is the distance between the microphone b1 and the microphone b2. For example, if the microphone b1 and the microphone b2 are respectively arranged at the upper and lower ends of the smart device B, then D can be the length of the smart device B _; d is the distance difference between L1 and _L2 , and the direct signal L can be determined by using the signal correlation algorithm ₁ Relative to the delay time difference t of the direct signal L ₂ , d can be calculated based on the delay time difference t, where d=t*c, c is the propagation speed of sound in a medium (such as air); θ is the auxiliary angle, where

Therefore, the relative angle of smart device A and smart device B can be calculated

in

Preferably, the smart device A and the smart device B can be implemented as at least one of the following: smart phones; tablet computers; smart watches; smart bracelets; smart speakers; smart TVs; smart earphones; smart robots, and so on. The first sound detection module and the second sound detection module may be arranged at multiple locations of the smart device.

FIG. 6 is a schematic diagram of a first exemplary arrangement of the first sound detection module and the second sound detection module of the present invention in a smart device. In FIG. 6 , the first sound detection module 18 and the second sound detection module 19 are respectively arranged at both ends of the smart device in the length direction, so the length D of the smart device can be directly determined as the first sound detection module 18 and the second sound detection module 19. The distance between the two sound detection modules 19 . FIG. 7 is a schematic diagram of a second exemplary arrangement of the first sound detection module and the second sound detection module in the smart device of the present invention. In FIG. 7 , the first sound detection module 18 and the second sound detection module 19 are respectively arranged at both ends of the smart device in the width direction, so the width D of the smart device can be directly determined as the first sound detection module 18 and the second sound detection module 19. The distance between the two sound detection modules 19 .

The above exemplarily describes the schematic diagram of the arrangement of the first sound detection module and the second sound detection module in the smart device. Those skilled in the art can realize that this description is only exemplary and is not intended to limit the implementation of the present invention. protected range.

In fact, current smart devices usually have two sets of microphones, which can be used as the first sound detection module and the second sound detection module in the embodiments of the present invention without changing the hardware of the smart device. The following describes a typical example of calculating the relative angle between smart devices using ultrasound based on an embodiment of the present invention.

FIG. 8 is a schematic diagram of relative positioning of the first smart device and the second smart device according to the present invention. FIG. 10 is an exemplary process flow chart of relative positioning between smart devices according to the present invention. In FIG. 7 , the respective processing paths of the two combined microphones for detecting sound signals are shown, wherein the analog-to-digital converter (Analog-to-Digital Converter, ADC) converts the continuous variable analog signal into a discrete digital signal A band-pass filter (BPF) is a device that allows waves in a specific frequency band to pass while shielding other frequency bands. The steps of identifying the relative direction between two smart devices based on ultrasound include:

Step 1: The first smart device transmits a positioning signal in an ultrasound format, where the positioning signal includes the Mac address of the smart device 1 . Step 2: The two sets of microphones of the second smart device detect the positioning signals respectively, parse out the Mac addresses from the respective detected positioning signals, and confirm that the respective detected positioning signals originate from the same sound source based on the Mac addresses. Step 3: The second smart device calculates the distance difference d between the two direct signals for the positioning signal based on the time difference between the two direct signals detected by the two groups of microphones included in the second smart device. Step 4: Second Smart Device Calculation

Then the signal incident angle

That is, the relative angle between the first smart device and the second smart device, where D is the distance between the two groups of microphones in the second smart device. Step 5: The second smart device displays the relative angle on its own display interface

Thus, the user is prompted for the relative direction of the first smart device. For example, FIG. 9 is a schematic diagram showing relative angles in a smart device interface according to the present invention.

For example, it is assumed that in the environment shown in FIG. 8 , the first smart device is embodied as a smart speaker, and the first smart device is embodied as a smart phone. Step 1: The smart speaker transmits an ultrasonic signal, the ultrasonic signal includes the Mac address of the smart speaker, and is a signal based on a CDMA code division multiple access technology architecture. Step 2: The two sets of microphone arrays of the smartphone receive the ultrasonic signal and calculate the Mac address of the smart speaker. At the same time, the smartphone calculates the distance difference d between the two direct signals of the two sets of microphone arrays. Among them: it is assumed that in the respective received signal streams stream1 and stream2 of the two groups of microphone arrays, there are direct signals whose signal strength peak value is greater than the threshold value T, so the principle 1 is satisfied; then it is assumed that the arrival time difference of the two direct signals

Calculate d corresponding to this Δt, where

The distance D between the two groups of microphones is known (that is, the length of the mobile phone), and is assumed to be 0.145m. It can be seen that d<D, so the principle 2 is satisfied. Therefore, the two direct signals can be selected to calculate the relative angle, where d=0.014(m). Step 3: Smartphone Computing

Then the angle of incidence of the signal

The smartphone displays an angle of 84.4° on its own display screen, that is, the smart speaker is in the 84.4° direction of the smartphone.

The relative distance between the two smart devices can be further obtained by using the method for identifying the relative direction between the two smart devices. Consider the following scenario: there are at least two smart devices, at least one smart device a is used to transmit an ultrasonic positioning signal, the ultrasonic positioning signal contains the MAC address of the smart device a; at least one smart device b is used to receive the ultrasonic positioning signal And solve the signal incident angle, and calculate the relative distance to the smart device a after further movement.

In order to meet the requirements of cost control, rapid deployment, and accurate positioning of indoor personnel using mobile terminals in small space application scenarios, the present invention also provides an indoor positioning method and system for simple layout in small spaces. The indoor positioning system includes a plurality of smart devices arranged indoors as sound sources, and a positioned mobile terminal for receiving sound. Each sound source has a respective arrangement position for transmitting a positioning signal in sound format (preferably ultrasound), the signal containing the MAC address of the smart device.

The mobile terminal to be positioned receives and calculates the incident angle of each direct positioning signal, thereby obtaining the relative position of the user requesting positioning, and corresponding the relative position to the cloud indoor map, so as to realize the position sharing of each user requesting positioning in an indoor environment.

Specifically, based on the above detailed calculation process description about the relative angle, the embodiment of the present invention also proposes a positioning method of the smart device based on the relative angle.

FIG. 11 is a flowchart of a method for a smart device of the present invention. The method includes:

Step 1101: The first sound detection module and the second sound detection module included in each of the N sound receiving devices in the predetermined space determine the difference in the receiving time of the direct sound signal sent by the smart device. The relative angle between the sound receiving device and the smart device.

The individual sound receiving devices are preferably arranged next to the walls in the space. For each sound receiver: based on

Determine θ; where arcsin is an arc sine function, d=t*c, t is the direct signal sent by the first sound detection module and the second sound detection module in each sound receiving device for the smart device (as a sound source) The receiving time difference of the sound signal, c is the propagation speed of the sound, and D is the distance between the first sound detection module and the second sound detection module in each sound receiving device; relative angle between devices

in

Therefore, based on the above calculation process, the relative angle between each sound receiving apparatus and the smart device can be determined, that is, N relative angles can be determined.

Step 1102: Position the smart device based on the respective extension lines of the N relative angles.

FIG. 12 is a schematic diagram of positioning a smart device (eg, smart glasses) according to the present invention. It can be seen from FIG. 12 that both the sound receiving device a1 and the sound receiving device a2 are arranged on the wall. The relative angle between the sound receiving device a1 and the smart glasses is

The relative angle between the sound receiving device a2 and the smart glasses is

It is possible to start from the sound receiving device a1, along the relative angle

Make an extension line (equivalent to an extension surface in the three-dimensional space) in the direction of the

An extension line (equivalent to an extension surface in a three-dimensional space) is made, and the intersection of the two extension lines is the position of the smart glasses, so that the smart glasses can be accurately positioned. In one embodiment, N is equal to 2, the N sound receiving devices are a first sound receiving device and a second sound receiving device, and the relative angle between the first sound receiving device and the wearable device is the same as that of the second sound receiving device and the second sound receiving device. The sum of the relative angles of the wearable devices is not equal to 180 degrees. In one embodiment, N is equal to 2, and the N sound sources are a first sound receiving device and a second sound receiving device; the locating the person in the water based on the respective extension lines of the N relative angles includes: when the first sound receiving device is When the extension line of the relative angle between the sound receiving device and the wearable device coincides with the extension line of the relative angle between the second sound receiving device and the wearable device, the third sound receiving device arranged in the swimming space contains The first sound detection module and the second sound detection module determine the relative angle between the third sound receiving device and the wearable device according to the receiving time difference of the direct sound signal sent by the wearable device worn by the person in the water, wherein the third sound receiving device The device, the first sound receiving device and the second sound receiving device are not on the same straight line; the first straight line is determined based on the arrangement position point of the first sound receiving device and the arrangement position point of the second sound receiving device; based on the third sound receiving device The intersection of the extension line of the relative angle between the sound receiving device and the wearable device and the first straight line locates the person in the water.

It can be seen that the embodiments of the present invention can realize positioning without blind spots based on three sound receiving devices that are not located on the same straight line (equivalent to not located on the same plane in space). In addition, due to the weak ultrasonic penetration, additional sound receiving devices need to be added when the indoor shape has irregular corners (that is, there are at least 4 sound receiving devices in the room). At this time, the smart devices that need to be located may be In the overlapping area of multiple ultrasonic positioning signals, then, based on the descending order of the signal-to-noise ratio of each direct sound signal received by each sound receiving device, three relative angles are determined, and based on the respective The intersection of the extension lines, locate the smart device.

In one embodiment, N is greater than or equal to 3, the N sound receiving devices and the wearable device are not on the same straight line (equivalent to not being on the same plane in space); the respective extension lines based on the N relative angles, the positioning The intelligent device includes: determining three relative angles based on the descending order of the signal-to-noise ratio of each direct sound signal received by each sound receiving device; based on the intersection of the respective extension lines of the three relative angles, Locate smart devices. Wherein: any two relative angles can be selected from the three relative angles, and the smart device is positioned based on the intersection of the respective extension lines of the selected two relative angles.

FIG. 13 is an exemplary schematic diagram of positioning a smart device according to the present invention. Assuming that N is equal to 4, the four sound receiving devices a1, a2, a3 and a4 are non-linearly arranged around the wall. The smart device b held by the user transmits an ultrasonic positioning signal, and the ultrasonic positioning signal includes the MAC address of the smart device b, which is a signal based on a CDMA code division multiple access technology architecture.

The indoor map is imported in the cloud, in which the relative coordinates of the sound receiving devices a1, a2, a3 and a4 are respectively set. A coordinate system is established as shown in Figure 13, and each sound receiving device includes two sound detection modules, which respectively receive the direct ultrasonic positioning signal sent by the smart device b. Each sound receiving device analyzes the MAC address of each ultrasonic positioning signal based on the CDMA technology, calculates the respective signal-to-noise ratio SNR, and selects the three ultrasonic positioning signals with the largest SNR. Assume the ultrasonic positioning signals received by the sound receiving devices a1, a2 and a3. The sound receiving device a1 uses its own two sound detection modules to receive the time difference of the direct ultrasonic positioning signal sent by the smart device b, and calculates the relative angle between the sound receiving device a1 and the smart device b.

The sound receiving device a2 uses its two sound detection modules to receive the time difference of the direct ultrasonic positioning signal sent by the smart device b, and calculates the relative angle φ2 between the sound receiving device a2 and the smart device b. The sound receiving device a3 uses its two sound detection modules to receive the time difference of the direct ultrasonic positioning signal sent by the smart device b, and calculates the relative angle φ3 between the sound receiving device a3 and the smart device b.

Moreover, the relative angles calculated by the sound receiving device a1, the sound receiving device a2, and the sound receiving device a3 are respectively calculated by

φ2 and φ3 are sent to a computing terminal (eg, a computing computer located in the cloud, a monitoring room, or a hand-held terminal of an ambulance crew by the pool).

According to the installation positions of the sound receiving device a1, the sound receiving device a2 and the sound receiving device a3, the computing terminal

φ2 and φ3 are calculated to obtain the relative coordinates of smart device b.

For example, starting from the sound receiving device a1, along the relative angle

Make an extension line in the direction of , and start from the sound receiving device a2 along the relative angle

An extension line is drawn in the direction of , and the intersection of the two extension lines is the position of the smart device b, so that the smart device b can be located. Since the relative coordinates of the sound receiving device a1 and the sound receiving device a2 in the room can be determined based on the respective installation positions, the relative coordinates of the smart device b can be determined.

For another example, starting from the sound receiving device a2, along the relative angle

Make an extension line, and start from the sound receiving device a3, along the relative angle

An extension line is made, and the intersection of the two extension lines is the position of the smart device b, so that the smart device b can be located. Since the relative coordinates of the sound receiving device a2 and the sound receiving device a3 in the room can be determined based on their respective installation positions, the relative coordinates of the smart device b can be determined.

Then, the computing terminal sends the relative coordinates of the smart device b to the cloud, and the cloud maps the relative coordinates to the indoor map, and shares the relative map with the smart device b in the indoor environment. According to the current location information of smart device b, the cloud can choose to turn on the indoor camera, and the cloud can call the open interface of the camera software according to the current location information of smart device b. The camera rotates with the movement of smart device b to realize real-time video tracking.

Based on the above description, an embodiment of the present invention also proposes a solution for locating a person in water. FIG. 14 is a flow chart of a method for locating a person in water according to the present invention. The method shown in FIG. 14 may be specifically executed by a computing terminal having a communication connection with each sound receiving apparatus. As shown in Figure 14, the method includes:

Step 1401: Based on the first sound detection module and the second sound detection module included in each of the N sound receiving devices arranged in the swimming space, for the wearables worn by the water personnel in the swimming space. The receiving time difference of the direct sound signal sent by the wearable device determines the relative angle between each sound receiving device and the wearable device, where N is greater than or equal to 2.

Step 1402: Based on the respective extension lines of the N relative angles, locate the person in the water.

For example, each sound receiving device can send its own calculation to a computing terminal (for example, a display terminal in a monitoring room, a hand-held terminal for ambulancemen by the pool) or the cloud based on communication methods such as Bluetooth, infrared, ultrasonic, Zifeng, 4G, and 5G. the relative angle out.

In one embodiment, N is equal to 2, the N sound receiving devices are a first sound receiving device and a second sound receiving device, and the relative angle between the first sound receiving device and the wearable device is the same as the second sound receiving device The sum of the relative angles of the device and the wearable device is not equal to 180 degrees. In one embodiment, the N is equal to 2, and the N sound sources are a first sound receiving device and a second sound receiving device; the positioning of the person in the water based on the respective extension lines of the N relative angles includes: When the extension line of the relative angle of the first sound receiving device and the wearable device coincides with the extension line of the relative angle of the second sound receiving device and the wearable device, based on the third sound receiving device arranged in the swimming space The first sound detection module and the second sound detection module included in the device determine the relative angle between the third sound receiving device and the wearable device according to the receiving time difference of the direct sound signal sent by the wearable device worn by the person in the water, wherein the The third sound receiving device, the first sound receiving device and the second sound receiving device are not on the same straight line; the first straight line is determined based on the arrangement position point of the first sound receiving device and the arrangement position point of the second sound receiving device; based on The intersection of the extension line of the relative angle between the third sound receiving device and the wearable device and the first straight line locates the person in the water.

In one embodiment, the N is greater than or equal to 3, and the N sound receiving devices and the wearable device are not on the same straight line; the positioning of the person in the water based on the respective extension lines of the N relative angles includes: based on: Three relative angles are determined in descending order of the signal-to-noise ratio of each direct sound signal received by each sound receiving device; the person in the water is located based on the intersection of the respective extension lines of the three relative angles.

In one embodiment, the determining the relative angle between each sound receiving device and the wearable device includes: for each sound receiving device: based on

in

In one embodiment, the method further comprises: when it is determined that the position of the person in the water does not change within a predetermined time or the position of the person in the water is in a predetermined danger area, sending an alarm message. Therefore, the safety of persons in the water can be improved.

It can be seen that the embodiment of the present invention is a safety monitoring system based on precise positioning of swimmers, and the hardware of the system includes a sound receiving device and a wearable smart device.

Wearable smart devices include speakers, independent APs and display devices, such as smart bracelets, smart foot rings, smart earphones, smart glasses, etc., which are used to send sound positioning signals, which contain positioning information and the MAC address of the smart device. The sound receiving device includes a microphone, a communication unit, a data processing unit, and a power supply unit, and is used to receive and calculate the MAC address and incident angle of each sound localization signal, and upload it to the cloud. The cloud calculates the relative position of the swimmer and corresponds to the cloud water map to realize the precise positioning of the swimmer. The specific implementation is as follows:

The wearable smart device is used to transmit sound positioning signals. The sound positioning signals emitted by each smart device contain its own MAC address information, and the MAC address of each smart device is unique. At least three sound receiving devices are arranged on the wall of the swimming pool or on the floating ball on the seashore according to the nonlinear requirements, which are used to receive and calculate the MAC address and incident angle of each sound positioning signal, and upload them to the cloud. Preferably, the use of ultrasonic waves with high frequency and reduced attenuation can greatly increase the propagation distance of the sound localization signal in water, and further, the distance between adjacent sound receiving devices can be several tens of meters. Regarding the non-linear layout, the positions of the three sound receiving devices are not on a straight line, and if they are collinear, there will be no results and there will be blind spots in positioning. The cloud manages the unique identifiers such as serial numbers and relative coordinates of each sound receiving device in the water. According to the MAC address and incident angle of each sound localization signal, the cloud calculates the relative position of the wearable smart device, that is, the swimmer, through the intersection of the angle extension line. Import environmental maps to manage the location information of individual swimmers in the water.

FIG. 15 is a schematic diagram of the positioning of a person in the water according to the present invention. Assuming that the swimmer needs to achieve underwater positioning requirements in the swimming pool as shown in Figure 15, it is assumed that the time when the upper microphone in the sound receiving device receives the direct positioning signal minus the time when the lower microphone in the sound receiving device receives the direct positioning signal, The reception time difference as a direct sound signal. The positioning process specifically includes: Step 1: Arrange the three sound receiving devices on the wall of the swimming pool in a non-linear manner, import the water map in the cloud, correspond to the unique identifier of each sound receiving device, and set the relative coordinates of each sound receiving device in the swimming pool ; Step 2: the smart device worn by the swimmer transmits a sound localization signal, and the sound localization signal includes the MAC address of the smart device, and is a signal based on a CDMA code division multiple access technology architecture;

Step 3: Each sound receiving device receives the sound localization signal, analyzes the MAC address of the sound localization signal based on CDMA technology, and applies the relative angle positioning method of the smart device to calculate the signal incident angle

and upload to the cloud. Step 4: The cloud receives the MAC address of the sound localization signal and the signal incident angle of each sound receiving device

According to the relative coordinates of each sound receiving device, the relative coordinates of the optimal solution of the smart device are obtained by using the least squares method. Step 5: The cloud maps the relative coordinates to the environment map, especially the map of the swimming pool, and feeds it back to the smart devices worn by the swimmers. Step 6: Based on the real-time location information of the smart device, the cloud can know the swimmer's speed at any segment, swimming trajectory, and other movement states. Further, if the swimmer's underwater position information has not changed for a long time, it is likely that a drowning incident has occurred, and the wearable smart device will automatically alarm, call the ambulance in time, and provide the precise position information of the drowning person.

A detailed example of the implementation process is described below in conjunction with specific numerical values. The implementation process includes:

Step 1: Arrange at least three sound receiving devices on the wall of the swimming pool in a non-linear manner, import the water map in the cloud, and set the relative coordinates of each sound receiving device in the swimming pool corresponding to the unique identifier of each sound receiving device. Assuming that the wearable smart device worn by the user is a smart watch, the layout of the sound receiving device and the position of the swimming child are shown in Figure 15. The coordinate system is established as shown in Figure 15, assuming that the coordinates of the wearable smart device are (x, y), the coordinates of the sound receiving device 1 are (706, 0), the coordinates of the sound receiving device 2 are (274, 0), The coordinates of the sound receiving device 3 are (423, 517).

Step 2: The smart watch transmits a sound positioning signal, the sound positioning signal includes the MAC address of the smart watch, and is a signal based on a CDMA code division multiple access technology architecture.

and upload to the cloud. It is assumed that the specified signal arrival time difference is always the time of the upper microphone minus the time of the lower microphone. The distance D between the two groups of microphones of the sound receiving device is 0.145m.

d _dir =d ₁ ≈-0.145(m),

d _dir =d ₂ ≈0.145(m),

d _dir =d ₃ ≈0.021(m),

Step 4: The cloud receives the MAC address of the sound localization signal and the signal incident angle of each sound receiving device

According to the relative coordinates of each sound receiving device, use the least squares method to obtain the relative coordinates of the optimal solution of the smart device, (x, y)=(498.4, 0).

Step 5: The cloud maps the relative coordinates to the environment map, especially the map of the swimming pool, and feeds it back to the display device worn by the swimmer.

Step 6: Based on the real-time location information of the smart device, the cloud can know the swimmer's speed at any segment, swimming trajectory, and other movement states. Further, if the swimmer's underwater position information has not changed for a long time, it is likely that a drowning incident has occurred, and the wearable smart device will automatically alarm, call the ambulance in time, and provide the precise position information of the drowning person.

FIG. 16 is a structural diagram of a positioning device for a person in water according to the present invention. The device includes: a relative angle determination module for, based on the first sound detection module and the second sound detection module included in each of the N sound receiving devices arranged in the swimming space, for the swimming space Determine the relative angle between each sound receiving device and the wearable device, where N is greater than or equal to 2; The respective extension lines of the relative angles locate the person in the water.

In one embodiment, N is equal to 2, the N sound receiving devices are a first sound receiving device and a second sound receiving device, and the relative angle between the first sound receiving device and the wearable device is the same as the second sound receiving device The sum of the relative angles of the device and the wearable device is not equal to 180 degrees. In one embodiment, the N is equal to 2, and the N sound sources are a first sound receiving device and a second sound receiving device; the positioning module is used for when the first sound receiving device is opposite to the wearable device When the extension line of the angle coincides with the extension line of the relative angle of the second sound receiving device and the wearable device, based on the first sound detection module and the second sound detection included in the third sound receiving device arranged in the swimming space The module determines the relative angle between the third sound receiving device and the wearable device according to the receiving time difference of the direct sound signal sent by the wearable device worn by the person in the water, wherein the third sound receiving device, the first sound receiving device and the second sound receiving device The sound receiving devices are not on the same straight line; the first straight line is determined based on the arrangement position point of the first sound receiving device and the arrangement position point of the second sound receiving device; based on the relative angle between the third sound receiving device and the wearable device The intersection of the extension line and the first straight line locates the person in the water.

In one embodiment, the N is greater than or equal to 3, and the N sound receiving devices and the wearable device are not on the same straight line; the positioning module is configured to be based on the signal-to-noise signal of each direct sound signal received by each sound receiving device In descending order of the ratio, three relative angles are determined; based on the intersection points of the respective extension lines of the three relative angles, the person in the water is located.

In one embodiment, an alarm module is further included, configured to issue an alarm message when it is determined that the position of the person in the water has not changed within a predetermined time or the position of the person in the water is in a predetermined danger area.

Embodiments of the present invention further provide a computer-readable storage medium, where a computer program is stored on the computer-readable storage medium. When the computer program is executed by a processor, each process implemented in the above-mentioned embodiments of the present invention can be implemented, and the same can be achieved. In order to avoid repetition, the technical effect will not be repeated here. Wherein, the computer-readable storage medium, such as read-only memory (Read-Only Memory, referred to as ROM), random access memory (Random Access Memory, referred to as RAM), magnetic disk or optical disk and so on. From the description of the above embodiments, those skilled in the art can clearly understand that the method of the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is better implementation. Based on this understanding, the technical solutions of the present invention can be embodied in the form of software products in essence or the parts that make contributions to the prior art, and the computer software products are stored in a storage medium (such as ROM/RAM, magnetic disk, CD-ROM), including several instructions to make a terminal (which may be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) execute the methods described in the various embodiments of the present invention.

The embodiments of the present invention have been described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific embodiments, which are merely illustrative rather than restrictive. Under the inspiration of the present invention, without departing from the spirit of the present invention and the scope protected by the claims, many forms can be made, which all belong to the protection of the present invention.

Claims

A method for locating persons in water, characterized in that the method comprises:

Based on the first sound detection module and the second sound detection module included in each of the N sound receiving devices arranged in the swimming space, for the wearable devices worn by the water personnel in the swimming space Determine the relative angle between each sound receiving device and the wearable device, where N is greater than or equal to 2;

The person in the water is located based on the respective extension lines of the N relative angles.
The method for locating a person in water according to claim 1, wherein the N is equal to 2, the N sound receiving devices are a first sound receiving device and a second sound receiving device, and the first sound receiving device The sum of the relative angle between the device and the wearable device and the relative angle between the second sound receiving device and the wearable device is not equal to 180 degrees.
The method for locating a person in water according to claim 1, wherein the N is equal to 2, and the N sound sources are a first sound receiving device and a second sound receiving device;

The positioning of the person in the water based on the respective extension lines of the N relative angles includes:

When the extension line of the relative angle of the first sound receiving device and the wearable device coincides with the extension line of the relative angle of the second sound receiving device and the wearable device, based on the third sound receiving device arranged in the swimming space The first sound detection module and the second sound detection module included in the device determine the relative angle between the third sound receiving device and the wearable device according to the receiving time difference of the direct sound signal sent by the wearable device worn by the person in the water, wherein the The third sound receiving device, the first sound receiving device and the second sound receiving device are not on the same straight line;

determining the first straight line based on the arrangement position point of the first sound receiving device and the arrangement position point of the second sound receiving device;

The person in the water is located based on the intersection of the extension line of the relative angle between the third sound receiving device and the wearable device and the first straight line.
The method for locating a person in water according to claim 1, wherein the N is greater than or equal to 3, and the N sound receiving devices and the wearable device are not on the same straight line;

The positioning of the person in the water based on the respective extension lines of the N relative angles includes:

Three relative angles are determined based on the descending order of the signal-to-noise ratio of each direct sound signal received by each sound receiving device;

The person in the water is located based on the intersection of the respective extension lines of the three relative angles.
The method for locating people in water according to claim 1, wherein,

The determining of the relative angle between each sound receiving device and the wearable device includes:

For each sound receiver:

based on
Determine θ; wherein arcsin is an arcsine function, d=t*c, t is the first sound detection module and the second sound detection module in each sound receiving device for the reception of the direct sound signal sent by the wearable device Time difference, c is the speed of sound propagation, D is the distance between the first sound detection module and the second sound detection module in each sound receiving device; determine the distance between each sound receiving device and the wearable device based on θ relative angle of
in
The method for locating a person in water according to any one of claims 1-5, further comprising:

When it is determined that the position of the person in the water has not changed within a predetermined time or the position of the person in the water is in a predetermined danger area, an alarm message is issued.
A positioning device for people in water, characterized in that it includes:

The relative angle determination module is configured to, based on the first sound detection module and the second sound detection module included in each of the N sound receiving devices arranged in the swimming space, for the water personnel in the swimming space The receiving time difference of the direct sound signal sent by the wearable device, determine the relative angle between each sound receiving device and the wearable device, where N is greater than or equal to 2;

A positioning module, configured to locate the person in the water based on the respective extension lines of the N relative angles.
The device for locating a person in the water according to claim 7, wherein N is equal to 2, the N sound receiving devices are a first sound receiving device and a second sound receiving device, and the first sound receiving device is the same as the The sum of the relative angle of the wearable device and the relative angle of the second sound receiving device and the wearable device is not equal to 180 degrees.
The device for locating people in the water according to claim 7, wherein the N is equal to 2, and the N sound sources are a first sound receiving device and a second sound receiving device;

The positioning module is used for, when the extension line of the relative angle of the first sound receiving device and the wearable device coincides with the extension line of the relative angle of the second sound receiving device and the wearable device, based on the layout in the swimming space The first sound detection module and the second sound detection module included in the third sound receiving device determine the difference between the third sound receiving device and the wearable device according to the receiving time difference of the direct sound signal sent by the wearable device worn by the person in the water. Relative angle, wherein the third sound receiving device, the first sound receiving device and the second sound receiving device are not on the same straight line; the first sound receiving device is determined based on the arrangement position point of the first sound receiving device and the arrangement position point of the second sound receiving device. A straight line; based on the intersection of the extension line of the relative angle between the third sound receiving device and the wearable device and the first straight line, locate the person in the water.
The device for locating a person in water according to claim 7, wherein the N is greater than or equal to 3, and the N sound receiving devices and the wearable device are not on the same straight line;

The positioning module is used to determine three relative angles based on the descending order of the signal-to-noise ratio of each direct sound signal received by each sound receiving device; Said water personnel.
The positioning device for people in the water according to claim 7, characterized in that, further comprising:

The alarm module is configured to issue an alarm message when it is determined that the position of the person in the water has not changed within a predetermined time or the position of the person in the water is in a predetermined danger area.
A computer-readable storage medium, characterized in that, a computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, the water personnel according to any one of claims 1 to 6 is implemented. positioning method.