Personnel positioning method and system based on Internet of Things equipment

Abstract

The invention is suitable for the technical field of personnel positioning, and particularly relates to a personnel positioning method and system based on Internet of Things equipment, and the method comprises the steps: constructing a construction site BIM model; establishing data connection, and verifying the identity of the wireless communication terminal; recording the first signal strength of the wireless communication terminal, detecting the second signal strength of the wireless communication terminal through the wireless communication Internet of Things equipment, and generating a first alternative position through the construction site BIM model; and after the personnel move, recording the signal emission intensity of the wireless communication terminal as third signal intensity, detecting the fourth signal intensity of the wireless communication terminal, and screening the first alternative positions to obtain personnel position information. According to the method, the BIM model is constructed, and the wireless communication terminals are arranged on site, so that the personnel can be positioned under the condition that a very small number of wireless communication terminals are arranged, the position of the personnel can be specifically determined, the positioning precision is greatly improved, and the construction safety is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of personnel positioning, and in particular, relates to a personnel positioning method and system based on an Internet of Things device. Background Art

[0002] Indoor artificial positioning technology refers to the use of various sensors, wireless communication technologies and algorithms to accurately identify and track the location of people or objects in indoor environments where outdoor positioning technologies such as GPS cannot work effectively. This technology sends signals through infrastructure deployed indoors (such as Wi-Fi access points, Bluetooth beacons, RFID readers, etc.), and the receiving device calculates the location information based on parameters such as the received signal strength and flight time. Indoor artificial positioning is widely used in shopping mall navigation, museum tours, hospital patient monitoring, factory asset management and other fields, providing users with convenient service experience and efficient management methods. With the development of technology, its accuracy and reliability are also constantly improving, becoming an important part of the construction of smart buildings and smart cities.

[0003] In the current construction process, when construction workers are working indoors, it is difficult to accurately locate the workers using traditional GPS positioning equipment, and it is impossible to know the exact location of the construction workers indoors. Summary of the invention

[0004] The purpose of the present invention is to provide a personnel positioning method based on Internet of Things devices, aiming to solve the problem that when construction workers are working indoors, it is difficult to accurately locate personnel using traditional GPS positioning devices and the exact position of construction workers indoors cannot be known.

[0005] The present invention is implemented as follows: a personnel positioning method based on an Internet of Things device, the method comprising:

[0006] Construct a BIM model of the construction site, set up wireless communication terminals at the construction site, and equip employees with wireless communication IoT devices. The BIM model of the construction site includes a wall structure model, and at least one wireless communication terminal is set up on each floor of the building;

[0007] Establish a data connection with the wireless communication terminal through the wireless communication IoT device to verify the identity of the wireless communication terminal;

[0008] Record the first signal strength of the wireless communication terminal, detect the second signal strength of the wireless communication terminal through the wireless communication IoT device, and generate a first candidate position through the construction site BIM model;

[0009] After the person moves, the signal transmission strength of the wireless communication terminal is recorded as the third signal strength, the fourth signal strength of the wireless communication terminal is detected, the first candidate position is screened, and the person position information is obtained.

[0010] Preferably, the step of establishing a data connection with the wireless communication terminal through the wireless communication IoT device and verifying the identity of the wireless communication terminal includes:

[0011] The identity information is broadcasted through the wireless communication terminal, and the wireless communication IoT device establishes a data connection with the wireless communication terminal according to the broadcast identity information;

[0012] Sending a communication terminal verification code to the wireless communication IoT device via a wireless communication terminal;

[0013] The wireless communication IoT device queries the background based on the communication terminal verification code. If the communication terminal verification code matches the corresponding wireless communication terminal, it is determined that the identity authentication is successful.

[0014] Preferably, the step of recording the first signal strength of the wireless communication terminal, detecting the second signal strength of the wireless communication terminal by the wireless communication IoT device, and generating the first candidate location by the construction site BIM model specifically includes:

[0015] Acquire the transmission signal strength of the wireless communication terminal through data transmission to obtain a first signal strength, and detect the second signal strength of the wireless communication terminal through the wireless communication IoT device;

[0016] The position of the wireless communication terminal is located in the BIM model of the construction site, and multiple positioning selection areas are obtained with the position of the wireless communication terminal as the center of the circle;

[0017] The signal loss parameters are determined based on the structure of the wall, a signal loss equation is constructed, and based on the signal loss equation, points on each positioning area that meet the signal propagation position relationship are determined to obtain the first candidate position.

[0018] Preferably, after the personnel moves, the step of recording the signal transmission strength of the wireless communication terminal as the third signal strength, detecting the fourth signal strength of the wireless communication terminal, screening the first candidate position, and obtaining the personnel position information specifically includes:

[0019] The moving direction and displacement of personnel are recorded through the three-axis acceleration sensor in the wireless communication IoT device;

[0020] When the offset is greater than a preset value, the signal transmission strength of the wireless communication terminal is recorded as the third signal strength, and the signal strength detected by the wireless communication IoT device is recorded as the fourth signal strength;

[0021] Based on the constructed signal loss model, multiple second candidate positions are solved and obtained, and personnel position information is generated in combination with the three-axis acceleration sensor data.

[0022] Preferably, the second candidate positions are screened according to the moving direction and offset of the personnel, and the second candidate positions satisfying the offset direction and offset are screened out and used as the current position of the personnel.

[0023] Another object of the present invention is to provide a personnel positioning system based on an Internet of Things device, the system comprising:

[0024] A model building module is used to build a BIM model of the construction site. Wireless communication terminals are set up at the construction site, and employees are equipped with wireless communication IoT devices. The BIM model of the construction site includes a wall structure model, and at least one wireless communication terminal is set up on each floor of the building;

[0025] An identity authentication module is used to establish a data connection with a wireless communication terminal through a wireless communication IoT device and verify the identity of the wireless communication terminal;

[0026] An initial position positioning module is used to record the first signal strength of the wireless communication terminal, detect the second signal strength of the wireless communication terminal through the wireless communication IoT device, and generate a first candidate position through the construction site BIM model;

[0027] The repeated positioning and screening module is used to record the signal transmission strength of the wireless communication terminal as the third signal strength after the personnel moves, detect the fourth signal strength of the wireless communication terminal, screen the first candidate position, and obtain the personnel position information.

[0028] Preferably, the identity verification module includes:

[0029] An information broadcasting unit is used to broadcast identity information through a wireless communication terminal, and the wireless communication IoT device establishes a data connection with the wireless communication terminal according to the broadcast identity information;

[0030] A data transceiver unit, used to send a communication terminal verification code to a wireless communication IoT device via a wireless communication terminal;

[0031] The verification code verification module is used for wireless communication IoT devices to query the background based on the communication terminal verification code. If the communication terminal verification code matches the corresponding wireless communication terminal, it is determined that the identity authentication is passed.

[0032] Preferably, the initial position positioning module includes:

[0033] A first signal detection unit, configured to obtain a transmission signal strength of the wireless communication terminal through data transmission to obtain a first signal strength, and detect a second signal strength of the wireless communication terminal through a wireless communication IoT device;

[0034] A selection area division unit is used to locate the position of the wireless communication terminal in the BIM model of the construction site, and obtain multiple positioning selection areas with the position of the wireless communication terminal as the center of the circle;

[0035] The loss equation construction unit is used to determine the signal loss parameters based on the structure of the wall, construct the signal loss equation, determine the points on each positioning area that meet the signal propagation position relationship based on the signal loss equation, and obtain the first candidate position.

[0036] Preferably, the duplicate positioning screening module comprises:

[0037] A signal strength adjustment unit is used to record the movement direction and displacement of a person through a three-axis acceleration sensor in a wireless communication IoT device;

[0038] A second signal detection unit is used to record the signal transmission strength of the wireless communication terminal as a third signal strength and the signal strength detected by the wireless communication IoT device as a fourth signal strength when the offset is greater than a preset value;

[0039] The position screening unit is used to solve a plurality of second candidate positions based on the constructed signal loss model, and generate personnel position information in combination with the three-axis acceleration sensor data.

[0040] Preferably, the second candidate positions are screened according to the moving direction and offset of the personnel, and the second candidate positions satisfying the offset direction and offset are screened out and used as the current position of the personnel.

[0041] The present invention provides a personnel positioning method based on IoT devices. By constructing a BIM model and setting up wireless communication terminals on site, personnel can be positioned when only a small number of wireless communication terminals are set up. The position of the personnel can be specifically determined, which greatly improves the positioning accuracy and ensures construction safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A flowchart of a personnel positioning method based on an IoT device provided in an embodiment of the present invention;

[0043] Figure 2 A flowchart of the steps of establishing a data connection between a wireless communication IoT device and a wireless communication terminal and verifying the identity of the wireless communication terminal provided by an embodiment of the present invention;

[0044] Figure 3 A flowchart of the steps of recording a first signal strength of a wireless communication terminal, detecting a second signal strength of the wireless communication terminal through a wireless communication IoT device, and generating a first candidate location through a construction site BIM model provided in an embodiment of the present invention;

[0045] Figure 4 A flowchart of the steps of changing the signal transmission strength to a third signal strength through a wireless communication terminal, detecting a fourth signal strength of the wireless communication terminal, screening a first candidate position, and obtaining personnel position information provided by an embodiment of the present invention;

[0046] Figure 5 An architectural diagram of a personnel positioning system based on IoT devices provided in an embodiment of the present invention;

[0047] Figure 6 An architecture diagram of an identity authentication module provided in an embodiment of the present invention;

[0048] Figure 7 An architecture diagram of an initial position positioning module provided in an embodiment of the present invention;

[0049] Figure 8 An architectural diagram of a duplicate location screening module provided in an embodiment of the present invention;

[0050] Fig. 9 A schematic diagram of dividing a positioning selection area provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0052] like Figure 1 FIG. 1 is a flowchart of a method for locating personnel based on an IoT device provided by an embodiment of the present invention, the method comprising:

[0053] S100, construct a construction site BIM model, set up wireless communication terminals at the construction site, and equip employees with wireless communication IoT devices. The construction site BIM model includes a wall structure model, and at least one wireless communication terminal is set up on each floor of the building.

[0054] In this step, a construction site BIM model is constructed. In the existing construction process, BIM technology has been gradually applied. The construction project can be monitored throughout the entire cycle through three-dimensional modeling. In the construction site BIM model, the specific composition structure of each wall is recorded, such as brick wall, concrete wall, stone strong and lightweight partition wall, etc., and the thickness and position information of the wall are recorded. In order to realize the positioning of personnel, the personnel are equipped with wireless communication IoT devices. The wireless communication IoT device can be a mobile device, such as a mobile phone, or other devices with a wireless communication module and a mobile network. The wireless communication terminal is a device with a wireless communication function, which is installed at the construction site. When installing the wireless communication terminal, it should be avoided to install it on the symmetry line of the construction plan to facilitate subsequent positioning. At least one wireless communication terminal is set for each floor of the building. When the single-story area of ​​the building is large, multiple wireless communication terminals are set to cover the entire construction plane. Each wireless communication terminal is set with an independent unique code for identifying the identity of the wireless communication terminal. The wireless communication terminal is set with a corresponding position in the construction site BIM model. The floor where the construction personnel are located can be determined according to the identity of the wireless communication terminal.

[0055] S200, establishing a data connection with a wireless communication terminal through the wireless communication IoT device, and verifying the identity of the wireless communication terminal.

[0056] In this step, a data connection is established between the wireless communication IoT device and the wireless communication terminal. When the wireless communication IoT device detects the wireless communication terminal, the wireless communication terminal broadcasts its identity information to the outside, and the wireless communication IoT device verifies the identity of the wireless communication terminal. Specifically, its identity can be determined by online verification. After the verification is completed, the wireless communication IoT device can be jointly positioned with the wireless communication terminal to determine the location of the person.

[0057] S300, recording a first signal strength of the wireless communication terminal, detecting a second signal strength of the wireless communication terminal through a wireless communication IoT device, and generating a first candidate location through a construction site BIM model.

[0058] In this step, the first signal strength of the wireless communication terminal is recorded. The first signal strength is the signal strength emitted by the wireless communication terminal. The wireless signal emitted by the wireless communication terminal will pass through the wall and will eventually be captured by the wireless communication IoT device. At this time, the wall will block the wireless signal and the wireless signal strength will be weakened. Therefore, the signal strength detected by the wireless communication IoT device is the second signal strength. Different materials have different absorption capacities for wireless signals, that is, different walls have different absorption rates for wireless signals. Therefore, when the wireless signal passes through different walls of different thicknesses, the attenuation of the signal strength is different. After obtaining the first signal strength and the second signal strength, Afterwards, the BIM model of the construction site is retrieved. Since the location of the wireless communication terminal is known, the process of wireless signal transmission can be simulated according to the BIM model of the construction site. Different signal attenuation coefficients are set for different walls according to previous tests. In the simulation process, the signal strength emitted by the wireless communication terminal is the first signal strength. The wireless signal is emitted to the surrounding areas of the wireless communication terminal and diverges outward through different paths. Therefore, it will pass through walls of different materials and thicknesses. Then, the simulated signal strength of the wireless signal arriving at each position in the area is determined according to the signal attenuation coefficient. The position where all simulated signal strengths are equal to the second signal strength is the first alternative position.

[0059] S400, after the person moves, the signal transmission strength of the wireless communication terminal is recorded as the third signal strength, the fourth signal strength of the wireless communication terminal is detected, the first candidate position is screened, and the person position information is obtained.

[0060] In this step, after the person moves, the signal transmission strength of the wireless communication terminal is recorded as the third signal strength. Since different walls have different signal attenuation coefficients and different propagation distances, the number of first candidate positions may be multiple. In order to further improve the positioning range, the wireless communication IoT device establishes a data connection with the wireless communication terminal, and the wireless communication terminal continues to transmit wireless signals. Similarly, the wireless communication IoT device performs detection again to obtain a fourth signal strength. According to the calculation method in step S300, the simulated signal strength of the wireless signal reaching each position on the current floor is determined according to the signal attenuation coefficient. All simulated signal strengths are equal to the fourth signal strength. The position of degrees is the second candidate position. At this time, the moving direction and offset of the personnel recorded in the three-axis acceleration sensor data are retrieved. If the moving distance from south to north is M, the first candidate position and the second candidate position are screened, and the first candidate position and the second candidate position that meet the above requirements are selected. At this time, the second candidate position is the real-time position of the current personnel. If there are multiple second candidate positions that meet the above conditions, wait for the generation of the next round of second candidate positions. At this time, the personnel moves twice, such as moving from south to north M, and then moving from west to east N. The second candidate positions generated in the new round are screened accordingly to obtain the real-time position of the personnel and generate the personnel position information.

[0061] like Figure 2 As shown, as a preferred embodiment of the present invention, the step of establishing a data connection with a wireless communication terminal through a wireless communication IoT device and verifying the identity of the wireless communication terminal includes:

[0062] S201, broadcasting identity information through a wireless communication terminal, and the wireless communication IoT device establishing a data connection with the wireless communication terminal according to the broadcast identity information.

[0063] In this step, identity information is broadcasted through the wireless communication terminal so that the wireless communication networking device can identify the wireless communication terminal. When there are signals sent by multiple wireless communication terminals at the same time, a data connection is established with the wireless communication networking device with the highest signal strength. Specifically, the altitude sensor on the wireless communication IoT device can also be used to locate the floor where the person is located.

[0064] S202, sending a communication terminal verification code to the wireless communication IoT device via the wireless communication terminal.

[0065] S203, the wireless communication IoT device queries the background based on the communication terminal verification code. If the communication terminal verification code matches the corresponding wireless communication terminal, it is determined that the identity authentication is passed.

[0066] In this step, a communication terminal verification code is sent to the wireless communication Internet of Things device through the wireless communication terminal. The communication terminal verification code is bound to the wireless communication terminal one-to-one and is automatically updated at a preset time interval. The wireless communication Internet of Things device sends the communication terminal verification code to the background for inquiry to determine whether the current wireless communication terminal is a trusted device. If it is trusted, data transmission can continue with it.

[0067] like Figure 3 As shown, as a preferred embodiment of the present invention, the step of recording the first signal strength of the wireless communication terminal, detecting the second signal strength of the wireless communication terminal through the wireless communication IoT device, and generating the first candidate position through the construction site BIM model specifically includes:

[0068] S301, obtaining the transmission signal strength of the wireless communication terminal through data transmission to obtain a first signal strength, and detecting the second signal strength of the wireless communication terminal through a wireless communication IoT device.

[0069] In this step, the transmission signal strength of the wireless communication terminal is obtained through data transmission to obtain the first signal strength. The signal strength of all wireless communication terminals before personnel positioning is the first signal strength. After the wireless signal emitted by the wireless communication terminal passes through the wall and reaches the wireless communication Internet of Things device, its signal strength is only the second signal strength.

[0070] S302, locating the position of the wireless communication terminal in the construction site BIM model, and obtaining a plurality of positioning selection areas with the position of the wireless communication terminal as the center of a circle.

[0071] In this step, the position of the wireless communication terminal is located in the construction site BIM model, and then a circular area is drawn in the construction site BIM model with the position of the wireless communication terminal as the center. The radius of the circular area is the maximum signal coverage range of the wireless communication terminal. The circular area is then gridded and divided into multiple grid units. The size of the grid unit is set according to demand. The larger the diameter of the circular area, the higher the required accuracy, and the smaller the size of the grid unit. Conversely, the larger the size of the grid unit, each grid unit is a positioning selection.

[0072] S303, determining a signal loss parameter based on the structure of the wall, constructing a signal loss equation, and determining a point on each positioning area that meets the signal propagation position relationship based on the signal loss equation to obtain a first candidate position.

[0073] In this step, the signal loss parameters are determined based on the structure of the wall. In the early stage of positioning, the signal loss parameters of the wireless signal passing through various walls are determined by performing signal testing. Each time a positioning area is selected, the center of the positioning area is used as the positioning point, and the thickness S of various walls passing between the positioning point and the wireless communication terminal is counted. i and the unobstructed distance d i , the signal strength loss model of wireless signals in the air is:

[0074]

[0075] Where L0 is the path loss at the reference distance d0 (in dB); n is the path loss exponent (usually between 2 and 4); d is the propagation distance (in meters); d0 is the reference distance;

[0076] Then the signal loss of the wireless signal when it propagates d meters in the air is L0-L path ;

[0077] The signal strength model of the wireless signal in the wall is:

[0078] L pen =αt

[0079] Where α is the attenuation coefficient per unit thickness (unit: dB / m), and t is the wall thickness;

[0080] That is, after the wireless signal passes through a wall with a thickness of t, its signal loss is L pen .

[0081] like Fig. 9 As shown in the figure, it is a schematic diagram for dividing the positioning selection area. It is assumed that the wireless signal emitted by the wireless communication terminal passes through the barrier-free distance L1, Class A wall L2, barrier-free distance L3, Class B wall L4 and barrier-free distance L5 in the process of reaching the wireless communication IoT device. Then, according to the first signal strength emitted by the wireless communication terminal and the signal loss in each medium, the signal strength when arriving at the positioning selection area can be calculated, which is the simulated signal strength. If the simulated signal strength is equal to the second signal strength, the positioning selection area is the first alternative position.

[0082] like Figure 4 As shown, as a preferred embodiment of the present invention, after the personnel moves, the signal transmission strength of the wireless communication terminal is recorded as the third signal strength, the fourth signal strength of the wireless communication terminal is detected, the first candidate position is screened, and the step of obtaining the personnel position information specifically includes:

[0083] S401, recording the movement direction and displacement of the person through the three-axis acceleration sensor in the wireless communication IoT device.

[0084] S402, when the offset is greater than a preset value, recording the signal transmission strength of the wireless communication terminal as a third signal strength, and recording the signal strength detected by the wireless communication IoT device as a fourth signal strength.

[0085] In this step, the movement of personnel is monitored. If there is only one first alternative position, the first alternative position is directly used as the current position of the personnel. If the number of first alternative positions is not one, it is necessary to monitor again after the personnel move. At this time, the signal transmission strength of the wireless communication terminal is the third signal strength, and the signal strength detected by the wireless communication Internet of Things device is the fourth signal strength.

[0086] S403, solving a plurality of second candidate positions based on the constructed signal loss equation, screening out the second candidate positions that overlap with the first candidate positions, and obtaining personnel position information.

[0087] In this step, multiple second candidate positions are obtained by solving the constructed signal loss equation. According to the same steps as in S302 and S303, the third signal strength is regarded as the first signal strength, and the fourth signal strength is regarded as the second signal strength. Then a circular area is constructed, a positioning area is delineated, and the positioning area whose calculated simulated signal strength is equal to the fourth signal strength is selected as the second candidate position. The movement direction and offset of the personnel recorded in the three-axis acceleration sensor data are retrieved. If the moving distance from south to north is M, the first candidate position and the second candidate position are screened, and the first candidate position and the second candidate position that meet the above requirements are selected. The second candidate position at this time is the real-time position of the current person. If there are multiple second candidate positions that meet the above conditions, wait for the generation of the next round of second candidate positions. At this time, the person moves twice, such as moving from south to north by M, and then moving from west to east by N. Based on this, the second candidate positions generated in the new round are screened to obtain the real-time position of the person and generate the personnel position information.

[0088] like Figure 5 As shown, a personnel positioning system based on an Internet of Things device is provided in an embodiment of the present invention, and the system includes:

[0089] The model building module 100 is used to build a construction site BIM model. A wireless communication terminal is set up at the construction site, and employees are equipped with wireless communication IoT devices. The construction site BIM model includes a wall structure model, and at least one wireless communication terminal is set up on each floor of the building.

[0090] In this embodiment, the model building module 100 builds a BIM model of the construction site. In the existing construction process, BIM technology is gradually applied. The construction project can be monitored throughout the entire cycle through three-dimensional modeling. In the BIM model of the construction site, the specific composition structure of each wall is recorded, such as brick wall, concrete wall, stone strong and lightweight partition wall, etc., and the thickness and position information of the wall are recorded. In order to realize the positioning of personnel, the personnel are equipped with wireless communication IoT devices. The wireless communication IoT device can be a mobile device, such as a mobile phone, or other devices with a wireless communication module and a mobile network. The wireless communication terminal is a device with a wireless communication function, which is installed at the construction site. When installing the wireless communication terminal, it should be avoided to install it on the symmetry line of the construction plan to facilitate subsequent positioning. At least one wireless communication terminal is set for each floor of the building. When the single-story area of ​​the building is large, multiple wireless communication terminals are set to cover the entire construction plane. Each wireless communication terminal is set with an independent unique code for identifying the identity of the wireless communication terminal. The wireless communication terminal is set with a corresponding position in the BIM model of the construction site. The floor where the construction personnel are located can be determined according to the identity of the wireless communication terminal.

[0091] The identity authentication module 200 is used to establish a data connection with a wireless communication terminal through a wireless communication IoT device and verify the identity of the wireless communication terminal.

[0092] In this embodiment, the identity authentication module 200 establishes a data connection with the wireless communication terminal through the wireless communication IoT device. When the wireless communication IoT device detects the wireless communication terminal, the wireless communication terminal broadcasts its identity information to the outside, and the wireless communication IoT device verifies the identity of the wireless communication terminal. Specifically, its identity can be determined by online verification. After the verification is completed, the wireless communication IoT device can be jointly positioned with the wireless communication terminal to determine the location of the person.

[0093] The initial position positioning module 300 is used to record the first signal strength of the wireless communication terminal, detect the second signal strength of the wireless communication terminal through the wireless communication IoT device, and generate a first candidate position through the construction site BIM model.

[0094] In this embodiment, the initial position positioning module 300 records the first signal strength of the wireless communication terminal. The first signal strength is the signal strength emitted by the wireless communication terminal. The wireless signal emitted by the wireless communication terminal will pass through the wall and will eventually be captured by the wireless communication IoT device. At this time, the wall will block the wireless signal and the wireless signal strength will be weakened. Therefore, the signal strength detected by the wireless communication IoT device is the second signal strength. Different materials have different absorption capacities for wireless signals, that is, different walls have different absorption rates for wireless signals. Therefore, when the wireless signal passes through different walls of different thicknesses, the attenuation of the signal strength is different. After obtaining the first signal strength and the second signal strength, the attenuation of the signal strength is different. After the second signal strength is measured, the BIM model of the construction site is retrieved. Since the location of the wireless communication terminal is known, the process of wireless signal transmission can be simulated according to the BIM model of the construction site. Different signal attenuation coefficients are set for different walls according to previous tests. In the simulation process, the signal strength emitted by the wireless communication terminal is the first signal strength. The wireless signal is emitted to the surrounding areas of the wireless communication terminal and diverges outward through different paths. Therefore, it will pass through walls of different materials and thicknesses, and then the simulated signal strength of the wireless signal arriving at each position in the area is determined according to the signal attenuation coefficient. The position where all simulated signal strengths are equal to the second signal strength is the first alternative position.

[0095] The repeated positioning screening module 400 is used to record the signal transmission strength of the wireless communication terminal as the third signal strength after the person moves, detect the fourth signal strength of the wireless communication terminal, screen the first candidate position, and obtain the person position information.

[0096] In this embodiment, after the person moves, the repeated positioning screening module 400 records the signal transmission strength of the wireless communication terminal as the third signal strength. Since different walls have different signal attenuation coefficients and different propagation distances, the number of first candidate positions may be multiple. In order to further improve the positioning range, the wireless communication IoT device establishes a data connection with the wireless communication terminal, and the wireless communication terminal continues to transmit wireless signals. Similarly, the wireless communication IoT device performs detection again to obtain the fourth signal strength. According to the calculation method in step S300, the analog signal strength of the wireless signal reaching each position on the current floor is determined according to the signal attenuation coefficient, and all analog signal strengths are equal. The position at the fourth signal strength is the second alternative position. At this time, the personnel movement direction and offset recorded in the three-axis acceleration sensor data are retrieved. If the moving distance from south to north is M, the first alternative position and the second alternative position are screened, and the first alternative position and the second alternative position that meet the above requirements are selected. At this time, the second alternative position is the real-time position of the current personnel. If there are multiple second alternative positions that meet the above conditions, wait for the next round of second alternative positions to be generated. At this time, the personnel moves twice, such as moving from south to north by M, and then moving from west to east by N. The second alternative positions generated in the new round are screened accordingly to obtain the real-time position of the personnel and generate personnel position information.

[0097] like Figure 6 As shown, as a preferred embodiment of the present invention, the identity authentication module 200 includes:

[0098] The information broadcast unit 201 is used to broadcast identity information through a wireless communication terminal, and the wireless communication IoT device establishes a data connection with the wireless communication terminal according to the broadcast identity information.

[0099] In this module, the information broadcast unit 201 broadcasts identity information through the wireless communication terminal so that the wireless communication networking device can identify the wireless communication terminal. When there are signals sent by multiple wireless communication terminals at the same time, a data connection is established with the wireless communication networking device with the highest signal strength. Specifically, the altitude sensor on the wireless communication IoT device can also be used to locate the floor where the person is located.

[0100] The data transceiver unit 202 is used to send a communication terminal verification code to the wireless communication IoT device via the wireless communication terminal.

[0101] The verification code verification module 203 is used for the wireless communication IoT device to query the background based on the communication terminal verification code. If the communication terminal verification code matches the corresponding wireless communication terminal, it is determined that the identity authentication is passed.

[0102] In this module, the data transceiver unit 202 sends a communication terminal verification code to the wireless communication IoT device through the wireless communication terminal. The communication terminal verification code is bound to the wireless communication terminal one by one and is automatically updated at a preset time interval. The wireless communication IoT device sends the communication terminal verification code to the background for query to determine whether the current wireless communication terminal is a trusted device. If it is trusted, data transmission can continue with it.

[0103] like Figure 7 As shown, as a preferred embodiment of the present invention, the initial position positioning module 300 includes:

[0104] The first signal detection unit 301 is used to obtain the transmission signal strength of the wireless communication terminal through data transmission to obtain the first signal strength, and detect the second signal strength of the wireless communication terminal through the wireless communication IoT device.

[0105] In this module, the first signal detection unit 301 obtains the transmission signal strength of the wireless communication terminal through data transmission to obtain the first signal strength. The signal strength of all wireless communication terminals before positioning personnel is the first signal strength. After the wireless signal emitted by the wireless communication terminal passes through the wall and reaches the wireless communication Internet of Things device, its signal strength is only the second signal strength.

[0106] The selection area division unit 302 is used to locate the position of the wireless communication terminal in the construction site BIM model, and obtain multiple positioning selection areas with the position of the wireless communication terminal as the center of the circle.

[0107] In this module, the area division unit 302 locates the position of the wireless communication terminal in the construction site BIM model, and then draws a circular area in the construction site BIM model with the position of the wireless communication terminal as the center. The radius of the circular area is the maximum signal coverage range of the wireless communication terminal. The circular area is then gridded and divided into multiple grid units. The size of the grid unit is set according to demand. The larger the diameter of the circular area, the higher the required accuracy, and the smaller the size of the grid unit. Conversely, the larger the size of the grid unit, each grid unit is a positioning area.

[0108] The loss equation construction unit 303 is used to determine the signal loss parameter based on the structure of the wall, construct the signal loss equation, and determine the point on each positioning area that meets the signal propagation position relationship based on the signal loss equation to obtain the first candidate position.

[0109] In this module, the loss equation construction unit 303 determines the signal loss parameter based on the structure of the wall. In the early stage of positioning, the signal loss parameter of the wireless signal passing through various walls is determined by performing signal testing. Each time a positioning area is selected, the center of the positioning area is used as the positioning point, and the thickness S of various walls passing between the positioning point and the wireless communication terminal is counted. i and the unobstructed distance d i , the signal strength loss model of wireless signals in the air is:

[0110]

[0111] Where L0 is the path loss at the reference distance d0 (in dB); n is the path loss exponent (usually between 2 and 4); d is the propagation distance (in meters); d0 is the reference distance;

[0112] Then the signal loss of the wireless signal when it propagates d meters in the air is L0-L path ;

[0113] The signal strength model of the wireless signal in the wall is:

[0114] L pen =αt

[0115] Where α is the attenuation coefficient per unit thickness (unit: dB / m), and t is the wall thickness;

[0116] That is, after the wireless signal passes through a wall with a thickness of t, its signal loss is L pen .

[0117] like Fig. 9 As shown in the figure, it is a schematic diagram for dividing the positioning selection area. It is assumed that the wireless signal emitted by the wireless communication terminal passes through the barrier-free distance L1, Class A wall L2, barrier-free distance L3, Class B wall L4 and barrier-free distance L5 in the process of reaching the wireless communication IoT device. Then, according to the first signal strength emitted by the wireless communication terminal and the signal loss in each medium, the signal strength when arriving at the positioning selection area can be calculated, which is the simulated signal strength. If the simulated signal strength is equal to the second signal strength, the positioning selection area is the first alternative position.

[0118] like Figure 8 As shown, as a preferred embodiment of the present invention, the repeated positioning screening module 400 includes:

[0119] The signal strength adjustment unit 401 is used to record the movement direction and offset of a person through a three-axis acceleration sensor in a wireless communication IoT device.

[0120] The second signal detection unit 402 is used to record the signal transmission strength of the wireless communication terminal as the third signal strength and the signal strength detected by the wireless communication IoT device as the fourth signal strength when the offset is greater than a preset value.

[0121] In this module, the signal strength adjustment unit 401 monitors the movement of personnel. If the number of first alternative positions is only one, the first alternative position is directly used as the current position of the personnel. If the number of first alternative positions is not one, it is necessary to monitor again after the personnel move. At this time, the signal transmission strength of the wireless communication terminal is the third signal strength, and the signal strength detected by the wireless communication Internet of Things device is the fourth signal strength.

[0122] The position screening unit 403 is used to obtain multiple second candidate positions based on the constructed signal loss model, and generate personnel position information in combination with the three-axis acceleration sensor data.

[0123] In this module, the position screening unit 403 obtains multiple second candidate positions based on the constructed signal loss equation. According to the same steps as in S302 and S303, the third signal strength is regarded as the first signal strength, and the fourth signal strength is regarded as the second signal strength. Then a circular area is constructed, a positioning selection area is delineated, and the positioning selection area whose calculated simulated signal strength is equal to the fourth signal strength is selected as the second candidate position. The movement direction and offset of the personnel recorded in the three-axis acceleration sensor data are retrieved. If the moving distance from south to north is M, the first candidate position and the second candidate position are screened, and the first candidate position and the second candidate position that meet the above requirements are selected. The second candidate position at this time is the real-time position of the current person. If there are multiple second candidate positions that meet the above conditions, wait for the generation of the next round of second candidate positions. At this time, the person moves twice, such as moving from south to north by M, and then moving from west to east by N. Based on this, the second candidate positions generated in the new round are screened to obtain the real-time position of the person and generate the personnel position information.

[0124] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A personnel positioning method based on IoT devices, characterized in that: The method comprises: Construct a BIM model of the construction site, set up wireless communication terminals at the construction site, and equip employees with wireless communication IoT devices. The BIM model of the construction site includes a wall structure model, and at least one wireless communication terminal is set up on each floor of the building; Establish a data connection with the wireless communication terminal through the wireless communication IoT device to verify the identity of the wireless communication terminal; Record the first signal strength of the wireless communication terminal, detect the second signal strength of the wireless communication terminal through the wireless communication IoT device, and generate a first candidate position through the construction site BIM model; After the person moves, the signal transmission strength of the wireless communication terminal is recorded as the third signal strength, the fourth signal strength of the wireless communication terminal is detected, the first candidate position is screened, and the person position information is obtained.

2. According to claim 1, a personnel positioning method based on an IoT device is characterized in that: The step of establishing a data connection with the wireless communication terminal through the wireless communication IoT device and verifying the identity of the wireless communication terminal includes: The identity information is broadcasted through the wireless communication terminal, and the wireless communication IoT device establishes a data connection with the wireless communication terminal according to the broadcast identity information; Sending a communication terminal verification code to the wireless communication IoT device via a wireless communication terminal; The wireless communication IoT device queries the background based on the communication terminal verification code. If the communication terminal verification code matches the corresponding wireless communication terminal, the identity authentication is determined to be successful.

3. According to the method of claim 1, the method is characterized in that: The step of recording the first signal strength of the wireless communication terminal, detecting the second signal strength of the wireless communication terminal through the wireless communication IoT device, and generating the first candidate location through the construction site BIM model specifically includes: Acquire the transmission signal strength of the wireless communication terminal through data transmission to obtain a first signal strength, and detect the second signal strength of the wireless communication terminal through the wireless communication IoT device; The position of the wireless communication terminal is located in the BIM model of the construction site, and multiple positioning selection areas are obtained with the position of the wireless communication terminal as the center of the circle; The signal loss parameters are determined based on the structure of the wall, a signal loss equation is constructed, and based on the signal loss equation, points on each positioning area that meet the signal propagation position relationship are determined to obtain the first candidate position.

4. A personnel positioning method based on IoT devices according to claim 3, characterized in that: After the person moves, the step of recording the signal transmission strength of the wireless communication terminal as the third signal strength, detecting the fourth signal strength of the wireless communication terminal, screening the first candidate position, and obtaining the person position information specifically includes: The moving direction and displacement of personnel are recorded through the three-axis acceleration sensor in the wireless communication IoT device; When the offset is greater than a preset value, the signal transmission strength of the wireless communication terminal is recorded as the third signal strength, and the signal strength detected by the wireless communication IoT device is recorded as the fourth signal strength; Based on the constructed signal loss model, multiple second candidate positions are solved and obtained, and personnel position information is generated in combination with the three-axis acceleration sensor data.

5. A personnel positioning method based on IoT device according to claim 4, characterized in that: The second candidate position is screened according to the moving direction and offset of the personnel, and the second candidate position that meets the offset direction and offset is screened out and used as the current position of the personnel.

6. A personnel positioning system based on IoT devices, characterized in that: The system comprises: A model building module is used to build a BIM model of the construction site. Wireless communication terminals are set up at the construction site, and employees are equipped with wireless communication IoT devices. The BIM model of the construction site includes a wall structure model, and at least one wireless communication terminal is set up on each floor of the building; An identity authentication module is used to establish a data connection with a wireless communication terminal through a wireless communication IoT device and verify the identity of the wireless communication terminal; An initial position positioning module is used to record the first signal strength of the wireless communication terminal, detect the second signal strength of the wireless communication terminal through the wireless communication IoT device, and generate a first candidate position through the construction site BIM model; The repeated positioning and screening module is used to record the signal transmission strength of the wireless communication terminal as the third signal strength after the personnel moves, detect the fourth signal strength of the wireless communication terminal, screen the first candidate position, and obtain the personnel position information.

7. A personnel positioning system based on IoT devices according to claim 6, characterized in that: The identity verification module comprises: An information broadcasting unit is used to broadcast identity information through a wireless communication terminal, and the wireless communication IoT device establishes a data connection with the wireless communication terminal according to the broadcast identity information; A data transceiver unit, used to send a communication terminal verification code to a wireless communication IoT device via a wireless communication terminal; The verification code verification module is used for wireless communication IoT devices to query the background based on the communication terminal verification code. If the communication terminal verification code matches the corresponding wireless communication terminal, it is determined that the identity authentication is passed.

8. The personnel positioning system based on IoT device according to claim 6, characterized in that: The initial position positioning module includes: A first signal detection unit, configured to obtain a transmission signal strength of the wireless communication terminal through data transmission to obtain a first signal strength, and detect a second signal strength of the wireless communication terminal through a wireless communication IoT device; A selection area division unit is used to locate the position of the wireless communication terminal in the BIM model of the construction site, and obtain multiple positioning selection areas with the position of the wireless communication terminal as the center of the circle; The loss equation construction unit is used to determine the signal loss parameters based on the structure of the wall, construct the signal loss equation, determine the points on each positioning area that meet the signal propagation position relationship based on the signal loss equation, and obtain the first candidate position.

9. The personnel positioning system based on IoT device according to claim 8, characterized in that: The repeated positioning screening module comprises: A signal strength adjustment unit is used to record the movement direction and displacement of a person through a three-axis acceleration sensor in a wireless communication IoT device; A second signal detection unit is used to record the signal transmission strength of the wireless communication terminal as a third signal strength and the signal strength detected by the wireless communication IoT device as a fourth signal strength when the offset is greater than a preset value; The position screening unit is used to solve a plurality of second candidate positions based on the constructed signal loss model, and generate personnel position information in combination with the three-axis acceleration sensor data.

10. A personnel positioning system based on IoT devices according to claim 9, characterized in that: The second candidate position is screened according to the moving direction and offset of the personnel, and the second candidate position that meets the offset direction and offset is screened out and used as the position of the current personnel.

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