CN114257959B - Self-calibration home monitoring method and system based on audio indoor positioning - Google Patents

Abstract

The present invention relates to a self-calibration family monitoring method and system based on audio indoor positioning. The method includes: step 1: arranging audio base stations and positioning tags in the monitoring area; Time difference and send it to the terminal; Step 3: The terminal calculates the location of the tag according to the received information, and divides and updates the dangerous area and hotspot area in real time according to the location of the tag; Step 4: When the ward enters the dangerous area, the terminal alarms and takes protection Measures; when the dangerous source enters the hotspot area, the terminal prompts that the location of the dangerous source is unreasonable. In order to realize the method, the system includes: synchronization equipment, audio transmission equipment, POE power supply module, positioning label, terminal, back-end server and intelligent monitoring equipment. The present invention does not need to pre-set dangerous areas, and the design of independent dangerous source tags can track dangerous sources in real time and calibrate and update the divided dangerous areas. The division of hot spots further reduces the risk rate from the perspective of guardians. Compared with indoor positioning monitoring systems using other positioning technologies, this audio indoor positioning family monitoring system has the advantages of decimeter-level high precision and low cost.

Description

A self-calibration home monitoring method and system based on audio indoor positioning

Technical Field

The invention relates to a self-calibration family monitoring method and system based on audio indoor positioning, belonging to the technical field of indoor positioning and family monitoring activities.

Background Art

In a family, the most worrying and most in need of care are the elderly and children. The safety of the elderly and children has always been a concern for everyone in the family. Children are lively and active by nature, and many potentially dangerous items in life may cause harm to children; the elderly react slowly when danger comes, and many items in life are dangerous to the elderly, especially for those with limited mobility. Therefore, a home monitoring system that can track the source of danger in real time and divide dangerous areas is not only a blessing for parents who are too busy to accompany the elderly and children all the time, but also a guarantee for the safety of the elderly and children. Traditional monitoring systems generally use visual image analysis or wireless radio frequency identification technology. The monitoring system based on visual image analysis captures the target through a camera. The disadvantage of this method is that it will infringe on the privacy of the person being monitored and there is a blind spot in the field of vision; the monitoring system based on wireless radio frequency identification cannot obtain the specific location of the person being monitored, and the application scenario is relatively narrow. Relatively speaking, a home monitoring system using indoor positioning technology can overcome such problems to a certain extent.

With the improvement and progress of indoor positioning technology, indoor positioning solutions based on various technologies such as Bluetooth, WIFI, geomagnetism, infrared, RFID, UWB, etc. have been proposed one after another, and the application potential of indoor positioning in security, monitoring, medical and other fields has gradually been tapped. In particular, the application of indoor positioning in the field of family monitoring has been increasingly valued in recent years, such as the RFID-based home indoor tracking system proposed by Sc kim in 2013, the indoor positioning family monitoring system based on WIFI fingerprint library proposed by J.Torres in 2016, and the Bluetooth-based infant monitoring system proposed by Zhipeng Cao in 2019. Analyzing the existing indoor positioning methods, Bluetooth, WIFI, and geomagnetic positioning are not accurate enough and are not suitable for the design of positioning tags in a small range such as family monitoring; infrared positioning has too harsh environmental requirements; RFID and UWB positioning are too expensive and are not suitable for family monitoring. Audio indoor positioning has the advantages of low cost, high positioning accuracy, and easy development, and is particularly suitable for application in the field of family monitoring.

In addition, current indoor positioning family monitoring systems are all divided into dangerous areas or prohibited areas in advance. Since the family living environment is not static, the location of the danger source may also change, which leads to certain limitations in the use scenarios of such monitoring systems. At the same time, in family daily life, guardians are likely to place dangerous items in areas where the elderly or children often move due to negligence. This behavior will inevitably increase the safety risks of the wards, so it is necessary to divide the hot spots of the wards' activities.

Summary of the invention

The technology of the present invention solves the following problems: In order to overcome the limitations of the existing family monitoring system, a self-calibration family monitoring method and system based on audio indoor positioning are provided to better monitor family members and reduce the possibility of the ward encountering danger; the danger zone is divided by real-time tracking of the location of the danger source, calibration and update, and the timeliness of the system is improved; the hot spot area is divided by analyzing the historical positioning information of the ward, and the danger rate is further reduced.

The technical solution of the present invention is a self-calibration home monitoring method based on audio indoor positioning, comprising the following steps:

Step 1: Place the audio base station on the wall or ceiling of the room that needs to be monitored, and stick multiple hazard source positioning tags on the surface of potentially dangerous objects. The target positioning tag is worn on the person being monitored.

Step 2: The positioning tag calculates the time difference of arrival (TDOA) based on the audio signal transmitted by the receiving base station, and sends the TDOA information and the positioning tag serial number to the terminal;

Step 3: The terminal calculates the location of the positioning tag through TDOA information, positioning tag serial number and base station coordinate information, and calibrates and updates the dangerous area in real time according to the location of the dangerous source tag, and divides the hot spot area according to the historical positioning information of the target tag;

Step 4: When the person wearing the target tag enters the dangerous area, the terminal will sound an alarm and take protective measures; when the dangerous object with the hazard source tag enters the hot spot area, the terminal will prompt that the location of the dangerous object is unreasonable;

The danger zone is located, calibrated and updated in real time by a separately designed danger source location tag. There is no need to pre-set the danger zone. A circle of a set size is drawn as the danger zone according to the location of the danger source tag. The danger zone is updated in real time as the danger source tag moves, which greatly improves the timeliness of the monitoring system.

The hotspot area is divided according to the historical positioning information of the target tag. When a dangerous object with a hazard source tag is placed in the hotspot area by the guardian, the terminal prompts the guardian that the location of the dangerous object is unreasonable, and the hotspot area will be updated regularly.

The hotspot area division method comprises the following steps:

Step 1: Filter and average sample the target positioning tag historical positioning information set of the set time period stored in the backend server: G = {(x ₁ ,y ₁ ),(x ₂ ,y ₂ ),(x ₃ ,y ₃ ),…,(x _N ,y _N )}, where (x _N ,y _N ) represents the positioning coordinates at positioning time sequence N;

a. Filtering: remove the data with abnormal positioning in the historical positioning information to obtain a new historical positioning information set G′={(x′ ₁ ,y′ ₁ ),(x′ ₂ ,y′ ₂ ),(x′ ₃ ,y′ ₃ ),…,(x′ _M ,y′ _M )};

[]为取整符号，再对每组数据进行平均，只保留每组数据的平均数

得到一个数据量较小的历史定位信息集合

其中：b. Average sampling: The set G′ is grouped according to the positioning time sequence in the historical positioning information. Each group contains D positioning data and is divided into T groups, that is, G′ _i = {(x′ _1+i*D , y′ _1+i*D ), (x′ _2+i*D , y′ _2+i*D ), …, (x′ _D+i*D , y′ _D+i*D )}, i = 0, 1, 2, …, T-1, where

[] is the integer symbol, and then each group of data is averaged, and only the average of each group of data is retained.

Get a smaller set of historical positioning information

in:

的个数W，计算其定位点密度Q_k，k＝1,2,…,K，其中：Step 2: Divide the monitoring area into K cells, calculate the area of the cell S _k , k = 1, 2, ..., K, and count the coordinate points in each cell

The number of W, calculate its positioning point density Q _k , k = 1, 2, ..., K, where:

的单元格，即：

由这些单元格组合形成热点区域。Step 3: Select the density greater than the set threshold

The cell, that is:

The hotspot area is formed by the combination of these cells.

The self-calibration home monitoring system based on audio indoor positioning of the present invention comprises: a synchronization device, an audio transmission device, a POE power supply module, a positioning tag, a terminal, a back-end server and an intelligent monitoring device;

The synchronization device generates control pulses according to the set timing according to the audio transmission scheme;

The audio transmitting device is triggered by a control pulse generated by a synchronization device to transmit a set audio linear frequency modulation signal (Chirp);

The positioning tag is used to receive the audio Chirp signal and send the calculated signal arrival time difference (TDOA) information to the terminal through the wireless transmission device; the positioning tag is divided into a hazard source positioning tag and a target positioning tag, the hazard source positioning tag is used to locate and identify the hazard source, and the target positioning tag is used to locate and identify the guardian, and the positioning tag serial number transmitted by the wireless transmission device is used to identify and distinguish the two; both positioning tags are composed of an audio receiving device, a computing control core, and a wireless transmission device. The audio receiving device receives the audio signal, and the TDOA information calculated by the computing control core is sent to the terminal through the wireless transmission device;

The terminal is a mobile phone or a computer, which receives the TDOA information and the serial number of the positioning tag sent by the positioning tag, calculates the precise position of the positioning tag, uploads the coordinate information and the positioning timing to the back-end server, and displays the position of the positioning tag in real time, and calibrates and updates the dangerous areas and hot spots divided according to the tag category; when the ward enters the dangerous area or the dangerous source enters the hot spot, an alarm prompt is implemented and protective measures are taken;

The backend server stores historical positioning information of the target positioning tag, including tag coordinates and corresponding positioning timing;

The intelligent monitoring device includes an intelligent switch controller, an intelligent speaker, and an intelligent railing, which are used to protect or remind the person being monitored.

Compared with the prior art, the advantages of the present invention are: the present invention does not require pre-setting of danger zones; the design of independent danger source labels can track danger sources in real time and calibrate and update the divided danger zones, which is more timely than the existing monitoring systems; the division of hot spots further reduces the danger rate from the perspective of the guardian, and reduces the alarm frequency and alarm costs to a certain extent; compared with indoor positioning monitoring systems that use other positioning technologies, the audio indoor positioning home monitoring system of the present invention has the advantages of decimeter-level high precision and low cost.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

FIG1 is a flow chart of a self-calibration home monitoring method based on audio indoor positioning according to the present invention;

FIG2 is a schematic diagram of the division of dangerous areas in an embodiment of the present invention;

FIG3 is a flow chart of a method for dividing hotspot areas in an embodiment of the present invention;

FIG4 is a structural diagram of a self-calibration home monitoring system based on audio indoor positioning according to the present invention;

5 is a diagram showing the structure of a synchronization device in an embodiment of the present invention;

FIG6 is an audio transmission scheme in an embodiment of the present invention;

7 is a diagram showing the structure of an audio transmission base station in an embodiment of the present invention;

FIG8 is a diagram showing the structure of a positioning tag in an embodiment of the present invention;

FIG. 9 is a diagram showing the structure of a terminal development module in an embodiment of the present invention.

DETAILED DESCRIPTION

The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

As shown in FIG1 , the self-calibration home monitoring method based on audio indoor positioning includes the following steps:

A. Place the audio base station on the wall or ceiling of the room that needs to be monitored, and attach multiple hazard source positioning tags to the surface of potentially dangerous objects. The target positioning tag is worn on the person being monitored.

B. The positioning tag calculates the time difference of arrival (TDOA) based on the audio signal transmitted by the received base station, and sends the TDOA information and the positioning tag serial number to the terminal;

C. The terminal calculates the location of the positioning tag through TDOA information, positioning tag serial number and base station coordinate information, and calibrates and updates the dangerous area in real time according to the location of the dangerous source tag, and divides the hot spot area according to the historical positioning information of the target tag;

D. When a person wearing a target tag enters a dangerous area, the terminal will sound an alarm and take protective measures; when a dangerous object with a hazard source label enters a hot spot, the terminal will prompt that the location of the dangerous object is unreasonable.

As shown in Figure 2, it is a schematic diagram of the division of dangerous areas. The dangerous areas are located, calibrated and updated in real time by the independently designed dangerous source positioning tags. There is no need to pre-set the dangerous areas. The dangerous areas are drawn according to the locations of the dangerous source tags. For example, a radius of 50cm is drawn at the location of the dangerous source tags as the dangerous area. The dangerous areas are updated in real time as the dangerous source tags move, which greatly improves the timeliness of the monitoring system.

As shown in FIG3 , it is a flow chart of a hotspot area division method, which includes the following steps:

Step 1: Filter and average sample the target positioning tag historical positioning information set of the set time period stored in the backend server: G = {(x ₁ ,y ₁ ),(x ₂ ,y ₂ ),(x ₃ ,y ₃ ),…,(x _N ,y _N )}, where (x _N ,y _N ) represents the positioning coordinates at positioning time sequence N;

a. Filtering: Remove data with abnormal positioning in the historical positioning information to obtain a new historical positioning information set G′={(x′ ₁ ,y′ ₁ ),(x′ ₂ ,y′ ₂ ),(x′ ₃ ,y′ ₃ ),…,(x′ _M ,y′ _M )}, such as the tag positioning coordinates are outside the monitoring area, and are significantly different from the coordinate information at the previous moment.

[]为取整符号，再对每组数据进行平均，只保留每组数据的平均数

从而得到一个数据量较小的历史定位信息集合

其中：b. Average sampling: The set G′ is grouped according to the positioning time sequence in the historical positioning information. Each group contains D positioning data and is divided into T groups, that is: G′ _i = {(x′ _1+i*D , y′ _1+i*D ), (x′ _2+i*D , y′ _2+i*D ), …, (x′ _D+i*D , y′ _D+i*D )}, i = 0, 1, 2, …, T-1, where

[] is the integer symbol, and then each group of data is averaged, and only the average of each group of data is retained.

Thus, a historical positioning information set with a small amount of data is obtained.

in:

的个数记为W，计算其定位点密度Q_k，k＝1,2,…,K，其中：Step 2: Divide the monitoring area into K cells, calculate the area of the cell S _k , k = 1, 2, ..., K, and count the coordinate points in each cell

The number of is recorded as W, and the density of its positioning points is calculated, Q _k , k = 1, 2, ..., K, where:

的单元格，即：

由这些单元格组合形成热点区域。Step 3: Select the density greater than the set threshold

The cell, that is:

The hotspot area is formed by the combination of these cells.

In addition, the historical positioning information stored in the backend server will be cleared after each hotspot area division is completed, in preparation for storing the next stage of historical positioning information, thereby achieving regular updates of hotspot areas.

As shown in Figure 4, a self-calibration home monitoring system based on audio indoor positioning includes a synchronization device, an audio transmission device, a POE power supply module, a hazard source positioning tag, a target positioning tag, a terminal, a backend server, and an intelligent monitoring device. The hazard source positioning tag and the target positioning tag are used to locate and identify the hazard source and the person being monitored, respectively.

As shown in Figure 5, it is a diagram of the synchronous device. The synchronous device is composed of a microcontroller and a single-ended to differential output device, and the microcontroller generates control pulses according to a specific timing according to a set audio transmission scheme.

As shown in Figure 6, for the audio transmission scheme, nodes 1 and 3 transmit 18-15kHz Chirp signals, and nodes 2 and 4 transmit 19-22kHz Chirp signals. A 1kHz protection bandwidth is set to avoid interference between the two Chirp signals. DT is the signal duration. Nodes 1 and 2 transmit signals at the first moment, and nodes 3 and 4 transmit signals at the second moment. There is a protection time GT between the two. In order to allow the target to distinguish between two adjacent positioning cycles, the remaining time RT is introduced.

As shown in Figure 7, the audio transmission base station is composed of a differential to single-ended input device, a microcontroller, an audio codec, an audio power amplifier, and a speaker. The audio transmission base station transmits a set chirp signal after being triggered by the control pulse of the synchronization device.

As shown in Figure 8, it is a diagram of the positioning tag. The positioning tag consists of an audio receiving device, a computing control core, and a wireless transmission device. The audio receiving device consists of an ultrasonic sensor, an amplifier, and a bandpass filter; the computing control core consists of a digital-to-analog converter, RAM, and a microcontroller; and the wireless transmission device consists of a Bluetooth serial port module. The positioning tag is divided into two types: a hazard source positioning tag and a target positioning tag. The hazard source positioning tag and the target positioning tag are used to locate and identify the hazard source and the guardian, respectively, and the serial number transmitted by the wireless transmission device is used to distinguish the two. The ultrasonic sensor of the audio receiving device receives the audio Chirp signal, and the signal is cached after amplification, filtering, and analog-to-digital conversion. The audio detection algorithm is then executed by the computing control core to calculate the TDOA information, and finally the TDOA information and the tag serial number are transmitted through the Bluetooth serial port module.

As shown in Figure 9, it is a diagram of the terminal development module. The terminal can be a mobile phone or a computer. The developed software includes a Bluetooth scanning module, a positioning algorithm module, a database storage module, a region division module, a positioning display module, and an alarm module. The Bluetooth scanning module receives the TDOA information and the positioning tag serial number sent by the positioning tag. The positioning algorithm module and the database storage module are responsible for calculating the precise position of the positioning tag and uploading it to the back-end server. The region division module and the positioning display module realize real-time display of the positioning tag position and calibrate and update the divided dangerous areas and hot spots according to the tag category. The alarm module realizes alarm prompts and takes protective measures when the ward enters the dangerous area or the dangerous source enters the hot spot.

The above is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed in the present invention should be covered within the protection scope of the present invention.

Claims (2)

1. A self-calibration home monitoring method based on audio indoor positioning, characterized in that it includes the following steps: Step 1: Place the audio base station on the wall or ceiling of the room that needs to be monitored, and stick multiple hazard source positioning tags on the surface of potentially dangerous objects. The target positioning tag is worn on the person being monitored. Step 2: The positioning tag calculates the time difference of arrival (TDOA) based on the audio signal transmitted by the receiving base station, and sends the TDOA information and the positioning tag serial number to the terminal; Step 3: The terminal calculates the location of the positioning tag through TDOA information, positioning tag serial number and base station coordinate information, and calibrates and updates the dangerous area in real time according to the location of the dangerous source tag, and divides the hot spot area according to the historical positioning information of the target tag; Step 4: When the person wearing the target tag enters the dangerous area, the terminal will sound an alarm and take protective measures; when the dangerous object with the hazard source tag enters the hot spot area, the terminal will prompt that the location of the dangerous object is unreasonable; The danger zone is located, calibrated and updated in real time by a separately designed danger source location tag. There is no need to pre-set the danger zone. A circle of a set size is drawn as the danger zone according to the location of the danger source tag. The danger zone is updated in real time as the danger source tag moves, which greatly improves the timeliness of the monitoring system. The hotspot area is divided according to the historical positioning information of the target tag. When a dangerous object with a hazard source tag is placed in a hotspot area by a guardian, the terminal prompts the guardian that the location of the dangerous object is unreasonable, and the hotspot area will be updated regularly; The hotspot area division method comprises the following steps: Step 1: Filter and average sample the target positioning tag historical positioning information set of the set time period stored in the backend server: G = {(x ₁ , y ₁ ), (x ₂ , y ₂ ), (x ₃ , y ₃ ), ..., (x _N , y _N )}, where (x _N , y _N ) represents the positioning coordinates at positioning time sequence N; a. Filtering: remove the data with abnormal positioning in the historical positioning information to obtain a new historical positioning information set G′={(x′ ₁ , y′ ₁ ), (x′ ₂ , y′ ₂ ), (x′ ₃ , y′ ₃ ), ..., (x′ _M , y′ _M )}; b. Average sampling: The set G′ is grouped according to the positioning time sequence in the historical positioning information. Each group contains D positioning data and is divided into T groups, i.e., G′ _i = {(x′ _1+i*D , y′ _1+i*D ), (x′ _2+i*D , y′ _2+i*D ), ..., (x′ _D+i*D , y′ _D+i*D )}, i = 0, 1, 2, ..., T-1, where

[] is the integer symbol, and then each group of data is averaged, and only the average of each group of data is retained.

Get a smaller set of historical positioning information

in:

Step 2: Divide the monitoring area into K cells, calculate the area of the cell S _k , k = 1, 2, ..., K, and count the coordinate points in each cell

The number W of locations is used to calculate the location point density Q _k , k = 1, 2, ..., K, where:

Step 3: Select cells whose density is greater than the set threshold α, that is, Q _k >α, and these cells are combined to form a hot spot area. 2. A self-calibration home monitoring system based on audio indoor positioning for implementing the method as claimed in claim 1, characterized in that it comprises: a synchronization device, an audio transmission device, a POE power supply module, a positioning tag, a terminal, a back-end server and an intelligent monitoring device; The synchronization device generates control pulses according to the set timing according to the audio transmission scheme; The audio transmitting device is triggered by a control pulse generated by a synchronization device to transmit a set audio linear frequency modulation signal (Chirp signal); The positioning tag is used to receive the audio Chirp signal and send the calculated signal arrival time difference (TDOA) information to the terminal through the wireless transmission device; the positioning tag is divided into a hazard source positioning tag and a target positioning tag, the hazard source positioning tag is used to locate and identify the hazard source, and the target positioning tag is used to locate and identify the guardian, and the positioning tag serial number transmitted by the wireless transmission device is used to identify and distinguish the two; both positioning tags are composed of an audio receiving device, a computing control core, and a wireless transmission device. The audio receiving device receives the audio signal, and the TDOA information calculated by the computing control core is sent to the terminal through the wireless transmission device; The terminal is a mobile phone or a computer, which receives the TDOA information and the serial number of the positioning tag sent by the positioning tag, calculates the precise position of the positioning tag, uploads the coordinate information and the positioning timing to the back-end server, and displays the position of the positioning tag in real time, and calibrates and updates the dangerous areas and hot spots divided according to the tag category; when the ward enters the dangerous area or the dangerous source enters the hot spot, an alarm prompt is implemented and protective measures are taken; The backend server stores historical positioning information of the target positioning tag, including tag coordinates and corresponding positioning timing; The intelligent monitoring device includes an intelligent switch controller, an intelligent speaker, and an intelligent railing, which are used to protect or remind the person being monitored.

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