Cross-regional activity perception method and system

Abstract

The present application relates to a method and system for sensing cross-regional activities, which is applied to a cross-regional activity sensing system. The cross-regional activity sensing system includes: a sensing signal source, a reflecting surface device, and an activity detection device. The method includes: when the activity detection device detects that the maximum interference value in the activity area of ​​the object to be detected is less than a preset threshold value, the sensing signal source alternately sends a directional beam to the activity area of ​​the object to be detected and the target area; the reflecting surface device adjusts the reflection direction to control the direction of the reflected beam to point to the boundary area between the activity area of ​​the object to be detected and the target area; the activity detection device receives the adjusted beam signal, calculates and obtains the first channel characteristic disturbance value in the activity area of ​​the object to be detected, and the second channel characteristic disturbance value in the target area; according to the difference between the first channel characteristic disturbance value and the second channel characteristic disturbance value, it is determined whether the object to be detected has moved into the target area. This method can improve the accuracy of human body detection for cross-regional activities.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a method and system for sensing cross-regional activities. Background Art

[0002] Using WiFi wireless networks to sense human activity is one of the key development directions in today's wireless application field. By using the impact of the human body on the wireless signal propagation environment, collecting channel state information (CSI) and combining it with artificial intelligence methods, human activity can be identified. Currently, many research institutions have developed CSI technology for human activity sensing, realizing the integration of communication and perception of WiFi networks.

[0003] However, the existing CSI technology based on commercial WiFi networks still has obvious shortcomings. The signal emitted by the WiFi router will be severely attenuated after passing through the walls of the room, resulting in weak human activity detection signals in these places, which are easily drowned out by background noise. As the WiFi network evolves to WiFi6, the signal frequency band has changed from 2.4G to 5GHz. The problem of WiFi signal coverage across rooms has become more prominent, especially when the human body moves across different rooms and areas. The signal-to-noise ratio of human activity perception is greatly reduced, resulting in reduced accuracy and reliability of human activity perception detection in multiple areas. Summary of the invention

[0004] The purpose of this application is to provide a cross-region activity perception method that can achieve multi-region coverage of detection signals and improve the accuracy and reliability of human body detection in cross-region activities.

[0005] The embodiment of the present application is implemented as follows:

[0006] In a first aspect, the present application provides a cross-regional activity perception method, which is applied to a cross-regional activity perception system, wherein the cross-regional activity perception system comprises: a perception signal source, which is used to transmit a directional beam to a specified area; a reflection surface device, which is used to dynamically change the reflection direction of the incident directional beam; and an activity detection device, which is used to receive the beam reflected by the reflection surface device to perform activity perception; the method comprises:

[0007] When the activity detection device detects that the maximum interference value of the activity area of ​​the object to be detected is less than a preset threshold value, the sensing signal source alternately sends directional beams to the activity area of ​​the object to be detected and the target area;

[0008] The reflecting surface device adjusts the reflection direction to control the direction of the reflected beam to point to the boundary area between the active area of ​​the object to be measured and the target area;

[0009] The activity detection device receives the adjusted beam signal and calculates and obtains a first channel characteristic disturbance value in the activity area of ​​the object to be detected and a second channel characteristic disturbance value in the target area;

[0010] It is determined whether the object to be detected moves into the target area according to the difference between the first channel characteristic disturbance value and the second channel characteristic disturbance value.

[0011] In one embodiment, before the sensing signal source alternately sends directional beams to the activity area and the target area of ​​the object to be detected, the method further includes:

[0012] When there is no activity of the object to be detected, the sensing signal source sends a directional beam to all areas within a preset sensing time slot;

[0013] The reflecting surface device receives the directional beam and adjusts the beam direction according to a preset reflection angle;

[0014] The activity detection device receives the adjusted beam signal and calculates and obtains channel characteristic values ​​in all areas within the preset sensing time slot.

[0015] In one embodiment, after the activity detection device receives the adjusted beam signal and calculates and obtains the channel characteristic values ​​in all areas within the preset sensing time slot, the method further includes:

[0016] When the object to be detected is active, the activity detection device calculates the channel characteristic disturbance value in the activity area of ​​the object to be detected within the preset sensing time slot to obtain the maximum value of the channel characteristic disturbance value;

[0017] When the maximum value of the channel characteristic disturbance is greater than a preset threshold, the sensing signal source sends a directional beam to the active area of ​​the object to be detected, and the reflecting surface device adjusts the reflection angle and adjusts the beam direction according to the target reflection angle.

[0018] In one embodiment, the reflecting surface device adjusts the reflection angle and adjusts the beam direction according to the target reflection angle, including:

[0019] The reflection angle of the reflecting surface device corresponding to the maximum value of the channel characteristic disturbance is used as the initial reflection angle. The reflecting surface device uses the direction corresponding to the initial reflection angle as the reflection direction, and adjusts the beam direction according to the preset incremental angle within consecutive preset sensing time slots;

[0020] The activity detection device receives the adjusted beam signal, calculates the channel characteristic disturbance value in the current continuous preset sensing time slots, and obtains the maximum value of the channel characteristic disturbance in the current continuous preset sensing time slots;

[0021] The reflection angle of the reflecting surface device corresponding to the maximum value of the channel characteristic disturbance in the current continuous preset perception time slots is used as the target initial reflection angle. The reflecting surface device uses the direction corresponding to the target initial reflection angle as the reflection direction and adjusts the beam direction according to the target reflection angle.

[0022] In one embodiment, determining whether the object to be detected moves into the target area according to the difference between the first channel characteristic disturbance value and the second channel characteristic disturbance value includes:

[0023] Determine whether the difference between the first channel characteristic disturbance value and the second channel characteristic disturbance value is greater than a preset switching threshold value, and if so, determine that the object to be detected has not moved within the object to be detected activity area;

[0024] If not, determine whether the difference between the second channel characteristic disturbance value and the first channel characteristic disturbance value is greater than a preset switching threshold value, and if so, determine that the object to be measured moves into the target area.

[0025] In one embodiment, the method further comprises:

[0026] When the object to be detected moves to the target area, the sensing signal source continuously sends a directional beam into the target area;

[0027] The reflecting surface device receives the directional beam, adjusts the direction, and points to the object to be measured;

[0028] The activity detection device receives the adjusted beam signal, calculates the channel characteristic disturbance value in the target area, and continuously senses the object to be detected.

[0029] In a second aspect, the present application provides a cross-region activity sensing system, including: a sensing signal source, a reflective surface device, and an activity detection device;

[0030] The sensing signal source is used to alternately send directional beams to the activity area of ​​the object to be detected and the target area when the activity detection device detects that the maximum interference value of the activity area of ​​the object to be detected is less than a preset threshold value;

[0031] The reflecting surface device is used to adjust the reflection direction and control the direction of the reflected beam to point to the boundary area between the active area of ​​the object to be measured and the target area;

[0032] The activity detection device is used to receive the adjusted beam signal, calculate and obtain the first channel characteristic disturbance value in the activity area of ​​the object to be detected, and the second channel characteristic disturbance value in the target area;

[0033] The sensing signal source is further used to determine whether the object to be detected moves into the target area according to a difference between the first channel characteristic disturbance value and the second channel characteristic disturbance value.

[0034] In one embodiment, the sensing signal source is further configured to continuously send a directional beam into the target area after the object to be detected moves into the target area;

[0035] The reflecting surface device is also used to receive the directional beam, adjust the direction, and point it to the object to be measured;

[0036] The activity detection device is also used to receive the adjusted beam signal, calculate the channel characteristic disturbance value in the target area, and continuously sense the object to be detected.

[0037] In one embodiment, the sensing signal source includes: a signal transmitting unit and a scanning control unit;

[0038] The signal transmitting unit receives the control instruction issued by the scanning control unit, and transmits a directional beam to a designated area in a designated order.

[0039] In one embodiment, the activity detection device includes: a signal receiving unit and an activity recognition unit;

[0040] The signal receiving unit receives the adjusted beam signal, performs data processing on the beam signal and sends it to the activity identification unit, and the activity identification unit calculates channel characteristic information.

[0041] Compared with the prior art, the beneficial effects of the present application are as follows: with the help of smart reflective panels distributed in different rooms, the detection signal energy is focused on a narrow beam to scan the room, which greatly improves the sensitivity of wireless channel feature detection and extends the WiFi perception capability to multiple rooms; the smart reflective panels have the characteristic of dynamically adjusting the direction of the reflected beam to achieve tracking of human activities; through the joint scanning of cross-regional smart reflective panels, relay detection of human activities across rooms is completed, continuous tracking of human activities in multiple rooms indoors is achieved, and a complete indoor human activity perception capability is formed. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1A partial structural diagram of a cross-region activity perception system according to an embodiment of the present application;

[0044] Figure 2 A schematic diagram of a process flow of a cross-region activity perception method according to an embodiment of the present application;

[0045] Figure 3 A schematic diagram of a flow chart of a cross-region activity perception method according to another embodiment of the present application;

[0046] Figure 4 A schematic diagram of an application scenario of a cross-region activity perception method according to an embodiment of the present application.

[0047] icon:

[0048] 1-cross-region activity sensing system; 11-sensing signal source; 111-signal transmitting unit; 112-scanning control unit; 12-reflective surface device; 121-intelligent reflective panel; 13-activity detection device; 131-signal receiving unit; 132-activity recognition unit. DETAILED DESCRIPTION

[0049] The terms “first”, “second”, “third”, etc. are only used for distinguishing descriptions and do not indicate the order of arrangement, nor can they be understood as indicating or implying relative importance.

[0050] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0051] In the description of the present application, it should be noted that the terms "inside", "outside", "left", "right", "up", "down", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the products of the present application are usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0052] In the description of this application, unless otherwise clearly specified and limited, the terms "set", "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0053] The technical solution of the present application will be described clearly and completely below in conjunction with the accompanying drawings.

[0054] Please refer to Figure 1 , which is a schematic diagram of the structure of a cross-regional activity perception system 1 shown in an embodiment of the present application. The cross-regional activity perception system 1 includes: a perception signal source 11, a reflection surface device 12 and an activity detection device 13. The perception signal source 11 is used to transmit a directional beam to a specified area, the reflection surface device 12 is used to dynamically change the reflection direction of the incident directional beam, and the activity detection device 13 is used to receive the beam reflected by the reflection surface device 12 to perform activity perception.

[0055] Among them, the sensing signal source 11 is a device with a network access point, which can be a wireless network access point or a wired network access point. The wireless network access point takes a WiFi access point (WiFi Access Point, referred to as WiFiAP) as an example. In this embodiment, the WiFi sensing signal source 11 (WiFi Sensing Source, referred to as WSS) includes: a signal transmitting unit 111 that can access the WiFi signal and a scanning control unit 112 (Scanning Control Unit, referred to as SCU). When the scanning control unit 112 sends a control instruction of "transmitting a directional beam" to the signal transmitting unit 111, the signal transmitting unit 111 receives the instruction and transmits a directional beam to the specified area in a certain order. A directional beam refers to an OFDM signal with different bandwidths, and an OFDM signal is composed of multiple subcarriers. The WiFi sensing signal source 11 reserves a time slot outside the communication service for sensing detection. The time slot is periodically repeated and is called a sensing time slot. Therefore, the signal transmitting unit 111 can transmit an OFDM signal of a specified bandwidth to a specified area in sequence according to the sensing time slot of a specified length and period.

[0056] The reflective surface device 12 is an intelligent reflective panel 121 (Intelligential Reflection Surface, IRS for short) that can converge signal energy, and can also be called a reflective surface. The intelligent reflective panel 121 dynamically changes the reflection direction of the directional beam emitted by the signal transmitting unit 111, and can converge the beam signal energy and expand the beam signal coverage range. Therefore, at least one intelligent reflective panel 121 needs to be arranged in each area to be sensed and detected, and a perception signal source 11 is arranged in one of the areas, and at the same time, it is necessary to ensure that the intelligent reflective panel 121 is arranged in a position that is conducive to receiving the directional beam emitted by the perception signal source 11.

[0057] The activity detection device 13 (Activity Sensing Detector, ASD for short) includes: a signal receiving unit 131 and an activity recognition unit 132 (Activity Recognition Unit, ARU for short). The signal receiving unit 131 takes the WiFi 6 client (Station, STA for short) as an example, and the activity detection device 13 integrates the activity recognition unit 132 on the basis of the WiFi 6 client. In each area to be sensed and detected where the smart reflection panel 121 has been arranged, at least one activity detection device 13 also needs to be arranged accordingly. The reflection direction of the beam emitted by the signal transmitting unit 111 is adjusted by the smart reflection panel 121, and the reflected beam is then received by the signal receiving unit 131 through direct or various reflection paths. After the signal receiving unit 131 performs data processing to obtain the physical layer symbol, it is sent to the activity recognition unit 132 for channel feature information calculation, and then with the help of artificial intelligence methods, the activity perception of the object to be detected is realized.

[0058] It should be noted that the perception signal source 11, the reflection surface device 12 and the activity detection device 13 in the cross-regional activity perception system 1 can use a wired network or a wireless network to exchange information. In this embodiment, the wireless network WiFi6 is used among the three for message exchange.

[0059] Based on the above principles, please refer to Figure 2 , which is a cross-region activity perception method shown in an embodiment of the present application, and the method is applied to Figure 1 The cross-region activity sensing system 1 shown, with the help of the reflective surface devices 12 distributed in each area, converges the signal energy, uses the reflective surface device 12 to dynamically change the reflection direction of the directional beam emitted by the sensing signal source 11, and the activity detection device 13 receives the adjusted beam signal, calculates the channel characteristic information, and then uses the artificial intelligence method to realize the activity perception of the object to be detected; in particular, through the joint relay detection of the activity area of ​​the object to be detected and the target area, it can realize the continuous perception and detection of the cross-regional activities of the object to be detected, and improve the detection accuracy and reliability of the human body in cross-regional activities. The method includes the following steps:

[0060] Step S201: When the activity detection device 13 detects that the maximum interference value of the activity area of ​​the object to be detected is less than a preset threshold value, the sensing signal source 11 sends directional beams alternately to the activity area of ​​the object to be detected and the target area.

[0061] In this step, the activity area of ​​the object to be detected refers to the area where the object to be sensed and detected is currently active, and the target area refers to the area where the object to be sensed and detected is about to move to. The activity area of ​​the object to be detected and the target area are collectively referred to as the designated area. The object to be detected can be a human body or an object that can move, and the designated area can be multiple rooms in a room or a public place with multiple rooms. In this embodiment, the object to be detected is a human body, and the designated area is multiple rooms in a room.

[0062] For example, when there is no human body in multiple rooms indoors, the scanning control unit 112 inside the WiFi sensing signal source 11 sends a control instruction of "transmitting a directional beam" to the signal transmitting unit 111. The signal transmitting unit 111 receives the instruction and transmits a directional beam to each room in turn within the preset sensing time slot. The smart reflection panel 121 in each room dynamically changes the reflection direction of the directional beam. The beam signal after adjusting the direction is received by the signal receiving unit 131 in each room. After the signal receiving unit 131 performs data processing to obtain the physical layer symbol, it sends it to the activity identification unit 132 to calculate the channel characteristic information, and then obtains the stable channel characteristic value of each room through multiple scanning calculations.

[0063] When a person enters one of the rooms, that is, enters the activity area of ​​the object to be detected, the channel characteristic value of the room calculated by the activity detection device 13 in the room changes. The changed channel characteristic value is called the channel characteristic disturbance value. The channel characteristic disturbance value in all sensing time slots is calculated, and the maximum value of the channel characteristic disturbance value is selected. When the maximum value of the channel characteristic interference is greater than the threshold value Δ H , the signal transmitting unit 111 stops transmitting beams to each room, and starts to continuously transmit directional beams to the room where the human body enters. The human body moves in the room, and the activity detection device 13 continuously calculates the channel characteristic disturbance values ​​in all sensing time slots. When the human body moves, the maximum value of the channel characteristic disturbance values ​​in all sensing time slots calculated by the activity detection device 13 in the room is less than the preset threshold value Δ L , it means that the human body is about to move from this room to another room, that is, from the activity area of ​​the object to be detected to the target area. At this time, the perception signal source 11 starts to perform cross-region activity perception detection, and sends a control instruction of "transmitting directional beams" through its internal scanning control unit 112. The signal transmitting unit 111 inside the perception signal source 11 receives the instruction and alternately sends directional beams to the activity area of ​​the object to be detected and the target area.

[0064] Step S202: the reflection surface device 12 adjusts the reflection direction to control the direction of the reflected beam to point to the boundary area between the active area of ​​the object to be measured and the target area.

[0065] It can be seen in step S201 that when a person is about to move from the activity area of ​​the object to be detected to the target area, he will inevitably pass through the boundary area between the activity area of ​​the object to be detected and the target area. For example, when a person enters from one room to another, he needs to pass through the doorway, which is the boundary area between the two rooms. When the person moves to the doorway, the smart reflection panel 121 in the room that the person leaves and the smart reflection panel 121 in the room that the person is about to enter continuously adjust the reflection direction to control the direction of the reflected beam, and both point to the doorway.

[0066] Step S203: the activity detection device 13 receives the adjusted beam signal, and calculates and obtains a first channel characteristic disturbance value within the activity area of ​​the object to be detected, and a second channel characteristic disturbance value within the target area.

[0067] In this step, the signal receiving unit 131 inside the activity detection device 13 in the activity area of ​​the object to be measured and the signal receiving unit 131 inside the activity detection device 13 in the target area both receive the adjusted reflected beam signal, and the corresponding activity identification unit 132 respectively calculates the channel characteristic disturbance value in the activity area of ​​the object to be measured and the channel characteristic disturbance value in the target area. Since the human body leaves the activity area of ​​the object to be measured, the channel characteristic value in the area will change, and the human body will move to the target area, and the channel characteristic value in the target area will also change. Therefore, in order to distinguish the change amount of the channel characteristic value in the two areas, the channel characteristic disturbance value in the activity area of ​​the object to be measured is called the first channel characteristic disturbance value, and the channel characteristic disturbance value in the target area is called the second channel characteristic disturbance value.

[0068] Step S204: Determine whether the object to be detected moves into the target area according to the difference between the first channel characteristic disturbance value and the second channel characteristic disturbance value.

[0069] In this step, the activity detection device 13 in the activity area of ​​the object to be measured reports the calculated first channel characteristic disturbance value, and the activity detection device 13 in the target area reports the calculated second channel characteristic disturbance value to the perception signal source 11. The perception signal source 11 processes and analyzes the difference between the two to determine whether the object to be measured has moved from the activity area of ​​the object to be measured to the target area.

[0070] The above-mentioned cross-regional sensing method is applied to a cross-regional activity sensing system 1, in which a sensing signal source 11 alternately transmits directional beams to the activity area and the target area of ​​the object to be measured, and a reflecting surface device 12 dynamically changes the reflection direction of the incident directional beam. The activity detection device 13 receives the adjusted reflected beam, and respectively calculates the first channel characteristic disturbance value and the second channel characteristic disturbance value of the activity area of ​​the object to be measured. The sensing signal source 11 processes the difference between the first channel characteristic disturbance value and the second channel characteristic disturbance value to be measured, and determines whether the object to be measured has moved from the activity area of ​​the object to be measured to the target area, thereby realizing relay detection of the cross-regional activities of the object to be measured, and providing the accuracy and reliability of continuous sensing detection of moving objects in multiple areas.

[0071] Please refer to Figure 3 , which is a cross-region activity perception method shown in an embodiment of the present application, and the method is applied to Figure 1 The cross-region activity sensing system 1 shown uses the human body as the object to be detected and multiple rooms in the room as the scanning sensing area. The parameters that need to be configured in advance before the cross-region activity sensing system 1 works are as follows:

[0072] The parameters configured by the sensing signal source 11 include: 1. The optimal beam width and direction sent to each room; 2. The length and period of the sensing time slot; 3. The number of sensing time slots N used for room scanning; 4. The cross-room relay switching threshold Δ relay .

[0073] The parameters configured for the reflective surface device 12 in each room include: 1. Initial reflection angle 2. The reflection direction of each sensing time slot increases by an angle of θ; 3. The direction of the reflection beam where the door is located.

[0074] The parameters configured for each room activity detection device 13 include: threshold value Δ L , threshold value Δ H .

[0075] The method shown in this embodiment includes the following steps:

[0076] Step S301: When there is no activity of the object to be detected, the sensing signal source 11 sends a directional beam to all areas within a preset sensing time slot.

[0077] In this step, there are M rooms, each room requires N sensing time slots to complete beam scanning, a sensing signal source 11, a reflective surface device 12 and an activity detection device 13 are arranged in one of the rooms, and a reflective surface device 12 and an activity detection device 13 are arranged in the remaining M-1 rooms. The signal transmitting unit 111 inside the sensing signal source 11 will send directional beams to the M rooms in N sensing time slots, for example, transmitting an OFDM signal with a bandwidth of 20MHz, and the OFDM signal consists of 234 subcarriers. Therefore, the signal transmitting unit 111 needs M*N sensing time slots to complete the beam transmission of all rooms.

[0078] Step S302: The reflecting surface device 12 receives the directional beam and adjusts the beam direction according to a preset reflection angle.

[0079] During the beam scanning process of a room, the reflecting surface device 12 of the room reflects the beam emitted by the signal transmitting unit 111 inside the sensing signal source 11. Assuming the initial reflection angle is θ, the reflection direction of each sensing time slot increases by an angle of θ. After N sensing time slots, the directional beam emission of the room is completed. Then, the reflection angles of the reflecting surface device 12 in the room in the N sensing time slots are {φ, φ+θ, φ+2θ, …, φ+(N-1)*θ} respectively, so that the reflecting surface device 12 adjusts the beam direction according to the above reflection angle, so that the reflection direction of the directional beam changes.

[0080] Step S303: the activity detection device 13 receives the adjusted beam signal and calculates and obtains channel characteristic values ​​in all areas within the preset sensing time slot.

[0081] In this step, the signal receiving unit 131 inside the activity detection device 13 in the room receives the beam signal after the direction is adjusted, performs data processing to obtain the physical layer symbol, and sends it to the activity identification unit 132, which calculates the channel characteristic value (CSI) of the subcarrier in the beam signal. The channel characteristic value set (CSI set) of each sensing time slot represents the characteristics of the wireless transmission channel in the time slot. Therefore, the channel characteristic value CSI set after N beam scans represents the channel characteristics of the room, which is represented by the following matrix:

[0082]

[0083] The i-th row in the matrix represents the channel characteristics corresponding to the i-th sensing time slot. There are N rows in total, which constitute the wireless channel characteristics of the entire room. The above is the result of a room scan. By scanning the room multiple times, we can find H 234*NThe cumulative average value of each channel characteristic value CSI is calculated to obtain the stable channel characteristic matrix of the room. The same method as above is used to calculate and obtain the other M-1 stable channel characteristic matrices of each room.

[0084] Step S304: When the object to be measured is active, within a preset sensing time slot, the activity detection device 13 calculates the channel characteristic disturbance value within the activity area of ​​the object to be measured, and obtains the maximum value of the channel characteristic disturbance value.

[0085] It can be seen from step S303 that after obtaining the stable channel characteristic matrix of all M rooms, if a human body enters a room to carry out activities, the signal transmitting unit 111 in the room continues to transmit a directional beam to the room in each sensing time slot, and the reflecting surface device 12 adjusts the reflection direction of the directional beam. The activity detection device 13 in the room receives the adjusted beam signal, and the calculated channel characteristic value will change. The changed channel characteristic value is called the channel characteristic disturbance value. Suppose the channel characteristic disturbance value CSI set obtained in the i-th sensing time slot is {CSI i,1 ,CSI i,2 , …, CSI i,234}, and characterize this channel difference in the form of standard deviation as follows:

[0086]

[0087] In this formula, CSI (i,j) Indicates the CSI value of the jth subcarrier in the i-th sensing time slot after human activity, CSI_Norm (i,j) represents the CSI value of the jth subcarrier in the i-th sensing time slot in the unmanned environment, δ i is the disturbance amplitude of the i-th time slot. Therefore, the activity detection device 13 in the room calculates the disturbance amplitude sequence corresponding to the N sensing time slots of the room scan as {δ1,δ2,δ3…δ N}, select the maximum value in the disturbance amplitude sequence as the maximum value of the channel characteristic disturbance δ in the activity area of ​​the object to be measured max .

[0088] Step S305: When the maximum value of the channel characteristic disturbance is greater than a preset threshold, the sensing signal source 11 sends a directional beam to the activity area of ​​the object to be measured, and the reflecting surface device 12 adjusts the reflection angle and adjusts the beam direction according to the target reflection angle.

[0089] In this step, the preset threshold is defined as the threshold value Δ H , if the maximum value of the channel characteristic perturbation δ max Greater than the threshold value Δ H, stop the beam scanning process of all rooms, start the activity tracking process of the room where the person is, and the perception signal source 11 continues to transmit a directional beam to the room where the person is within N perception time slots.

[0090] Specifically, the maximum value δ of the channel characteristic perturbation max The corresponding reflection angle of the reflection surface device 12 is used as the initial reflection angle. The reflection surface device 12 uses the direction corresponding to the initial reflection angle as the reflection direction, and adjusts the beam direction according to the preset incremental angle within consecutive preset sensing time slots.

[0091] Assume that the maximum channel disturbance value δ max The corresponding reflection angle of the reflection surface device 12 is The signal transmitting unit 111 continues to transmit the directional beam to the room where the human body is located in the subsequent sensing time slot. The reflection angles of the reflecting surface device 12 in three consecutive sensing time slots are: and in, As the initial reflection direction of the reflection surface, θ is the incremental angle of room scanning. The reflection surface device 12 adjusts the directional beam reflection direction according to the above three reflection angles.

[0092] The activity detection device 13 receives the adjusted beam signal, calculates the channel characteristic disturbance value in the current continuous preset sensing time slots, and obtains the maximum value of the channel characteristic disturbance in the current continuous preset sensing time slots.

[0093] The activity detection device 13 receives the beam signals adjusted in the above three directions, calculates the channel characteristic disturbance values ​​in the current three sensing time slots as δ1, δ2, and δ3, and takes the maximum value δ among the three max ', as the maximum value of the channel characteristic disturbance in the current three consecutive sensing time slots.

[0094] The reflection angle of the reflecting surface device 12 corresponding to the maximum value of the channel characteristic disturbance in the current continuous preset perception time slots is used as the target initial reflection angle. The reflecting surface device 12 uses the direction corresponding to the target initial reflection angle as the reflection direction and adjusts the beam direction according to the target reflection angle.

[0095] δ max The corresponding reflection angle is set up As the target initial reflection angle, the reflecting surface device 12 uses the direction corresponding to the angle as the new reflection direction, and in the next three sensing time slots, respectively according to The reflection angle of the beam is adjusted to adjust the reflection direction of the beam. This reciprocating operation is carried out to realize continuous tracking of the human body through the above-mentioned beam adjustment method. Since the signal transmitting unit 111 always focuses the transmitting energy in the direction of the human body's movement, the beam signal received by the activity detection device 13 has a higher signal-to-noise ratio, thereby improving the reliability of the detection result of the cross-region activity perception system 1.

[0096] Step S306: When the activity detection device 13 detects that the maximum interference value of the activity area of ​​the object to be detected is less than the preset threshold value, the sensing signal source 11 sends directional beams alternately to the activity area of ​​the object to be detected and the target area.

[0097] When a person leaves the room, the activity detection device 13 in the room continues to calculate the channel characteristic disturbance value of the room, and selects the maximum value δ among the channel characteristic disturbance values ​​in N sensing time slots. max ”, when the channel characteristic interference maximum value δ max " is less than the preset threshold value Δ L , it indicates that the human body is about to move from the room to the door. At this time, the sensing signal source 11 starts to perform cross-region activity sensing detection, and sends a control instruction of "transmitting directional beam" through the scanning control unit 112. The signal transmitting unit 111 receives the instruction and alternately sends directional beams to the activity area and the target area of ​​the object to be detected. The implementation method of this step can be specifically referred to the content description in step S201.

[0098] Step S307: the reflection surface device 12 adjusts the reflection direction to control the direction of the reflected beam to point to the boundary area between the active area of ​​the object to be measured and the target area.

[0099] The implementation method of this step may specifically refer to the content description in step S202.

[0100] Step S308: The activity detection device 13 receives the adjusted beam signal, and calculates and obtains a first channel characteristic disturbance value within the activity area of ​​the object to be detected, and a second channel characteristic disturbance value within the target area.

[0101] The implementation method of this step may specifically refer to the description of the content in step S203.

[0102] Step S309: determine whether the difference between the first channel characteristic disturbance value and the second channel characteristic disturbance value is greater than a preset switching threshold value, and if so, determine that the object to be measured is in the activity area of ​​the object to be measured and has not moved.

[0103] If the first channel characteristic disturbance value is greater than the second channel characteristic disturbance value, and the difference between the first channel characteristic disturbance value and the second channel characteristic disturbance value is greater than Δ relay , it is judged that the human body is still in the original room and has not moved, where Δrelay is the defined relay switching threshold.

[0104] Step S310: If not, determine whether the difference between the second channel characteristic disturbance value and the first channel characteristic disturbance value is greater than a preset switching threshold value, and if so, determine that the object to be measured moves into the target area.

[0105] If the first channel characteristic disturbance value is less than the second channel characteristic disturbance value, and the difference between the second channel characteristic disturbance value and the first channel characteristic disturbance value is greater than Δ relay , then it is judged that the human body has moved to another room, otherwise it is judged that the human body is still staying at the door.

[0106] Step S311: When the object to be detected moves to the target area, the sensing signal source 11 continuously sends a directional beam into the target area.

[0107] It can be seen from step S310 that when it is determined that a human body leaves the door and enters another room, the signal transmitting unit 111 inside the sensing signal source 11 stops alternately sending directional beams to the two rooms, and the scanning control unit 112 controls the signal transmitting unit 111 to continue sending directional beams to the other room where the human body enters, thereby starting the activity tracking process for the room where the person is located.

[0108] Step S312: The reflecting surface device 12 receives the directional beam, adjusts its direction, and points it toward the object to be measured.

[0109] The reflective surface device 12 continuously adjusts the beam so that the beam continues to scan and track the human body. The method for adjusting the beam by the reflective surface device 12 in this step can be specifically described in the content of the above step S305.

[0110] Step S313: The activity detection device 13 receives the adjusted beam signal, calculates the channel characteristic disturbance value in the target area, and continuously senses the object to be detected.

[0111] When a human body moves to another room and continues to move in the room, the activity detection device 13 in the room receives the adjusted beam signal and calculates the channel characteristic disturbance value in the room within N sensing time slots, thereby realizing continuous sensing and detection of the human body. For the specific method of continuous sensing of the human body, please refer to the description of steps S304-S305.

[0112] Please refer to Figure 4 , which is a schematic diagram of an application scenario of a cross-region activity perception method according to an embodiment of the present application, using Figure 3 The cross-region activity perception method shown in Figure 1 In the cross-region activity perception system 1 shown. Figure 4In the embodiment, three rooms are taken as an example, and the rooms are named A, B, and C respectively. A sensing signal source 11, an intelligent reflection panel 121, and an activity detection device 13 are arranged in room C in advance, and an intelligent reflection panel 121 and an activity detection device 13 are arranged in room A and room B respectively.

[0113] Please combine Figure 3 When there is no human activity, the signal transmitting unit 111 inside the sensing signal source 11 will first transmit a directional beam to room A in 6 sensing time slots for beam scanning, and then the signal transmitting unit 111 will transmit a directional beam to room B in 6 sensing time slots for beam scanning, and finally transmit a directional beam to room C in 6 sensing time slots for beam scanning.

[0114] Taking beam scanning of room A as an example, the signal transmitting unit 111 transmits a directional beam to room A, and the intelligent reflective panel 121 (IRS A ) receives the reflected beam signal and adjusts the initial reflection angle to θ A , the activity detection device 13 (ASD) in room A A ) receives the adjusted beam signal and calculates the channel characteristic value in room A. In the process of scanning room A, the signal transmitting unit 111 keeps transmitting the directional beam to room A in 6 sensing time slots, and the intelligent reflective panel 121 (IRS A ) in the six sensing time slots, the reflection angles are {φ A ,φ A +θ A ,φ A +2θ A ,…,φ A +5θ A}. The intelligent reflective panel 121 (IRS A ) The reflection direction of the directional beam is adjusted according to the directions of the above 6 reflection angles. The specific method of adjusting the beam can be referred to the content description of step S302.

[0115] Activity detection device 13 (ASD) in room A A ) Calculate the subcarrier CSI values ​​in the 6 sensing time slots and obtain the channel characteristic matrix H representing room A A ,as follows:

[0116]

[0117] Room B and room C also use the same method to calculate the channel feature matrix H B , H C ,as follows:

[0118]

[0119]

[0120] By scanning Room A, Room B, and Room C multiple times, the CSI A 、CSI B 、CSI C The values ​​are accumulated and averaged to obtain the long-term stable channel characteristic matrix of each room. The specific calculation process can refer to the description of step S303.

[0121] Assume that when someone enters room A, the activity detection device 13 (ASD) in room A A ) Calculate the disturbances of the six scanning time slots δ1, δ2, δ3, δ4, δ5, δ6, and select the maximum value δ among these six disturbances max , as the maximum value of the channel characteristic perturbation δ in room A max , if δ max Greater than Δ H , stop the beam scanning process of all rooms, start the activity tracking process of room A, and the sensing signal source 11 continues to transmit the directional beam to room A within 6 sensing time slots. For details, please refer to the description of steps S303 to S304.

[0122] By δ max The corresponding intelligent reflective panel 121 (IRS A ) as the initial reflection angle, the intelligent reflection panel 121 (IRS A ) Take the direction corresponding to the initial reflection angle as the reflection direction, and continuously adjust the reflection angle within 3 consecutive sensing time slots Thus, the reflection direction of the beam is changed, and the continuous movement tracking of the human body in room A is realized. A ) The method for adjusting the beam has been described in detail in the previous step S305 and will not be repeated here.

[0123] Assume that the human body then leaves room A and moves to the door G at the junction of room A and room B. The activity detection device 13 (ASD A ) The perturbation value δ calculated max ”<Δ L , then ASD A Report this information to the sensing signal source 11 and IRS A, the sensing signal source 11 starts to sense and detect cross-regional activities, and sends a control instruction of "transmitting directional beams" through the scanning control unit 112. The signal transmitting unit 111 inside the sensing signal source 11 receives the instruction and sends directional beams alternately to room A and room B. The intelligent reflective panel 121 (IRS A ) and the intelligent reflective panel 121 (IRS B ) will control the reflected beam to point to the boundary area between room A and room B, that is, the door G.

[0124] Activity detection device 13 (ASD) in room A A ) and the activity detection device 13 (ASD in room B) B ) receives the adjusted beam signal and calculates the channel characteristic disturbance value δ A and channel characteristic perturbation value δ B Report to the sensing signal source 11, and compare δ A and δ B The difference between relay The size of δ can be used to determine the direction of human movement. A >δ B , and δ A -δ B >Δ relay , then it is judged that the human body moves to room A; if δ A <δ B , and δ B -δ A >Δ relay , it is determined that the human body has moved to room B; otherwise, the human body is still staying at door G. The specific process can refer to the description of steps S306 to S310.

[0125] When it is determined that the human body leaves the door G and enters room B, the sensing signal source 11 stops sending beams alternately to room A and room B, and sends a directional beam to the new room B where the human body enters, and the relay detection process ends. Thereafter, the human body sensing detection process continues in the room B. The continuous sensing detection process of the human body can refer to the description of steps S311 to S313.

[0126] In this embodiment, with the help of smart reflective panels 121 distributed in different rooms, the detection signal energy is focused on a narrow beam to scan the room, which greatly improves the sensitivity of wireless channel feature detection and extends the WiFi perception capability to multiple rooms. The smart reflective panels 121 have the characteristic of dynamically adjusting the direction of the reflected beam to achieve human activity tracking. Through the joint scanning of cross-regional smart reflective panels 121, relay detection of human activities across rooms is completed, and continuous tracking of human activities in multiple rooms indoors is achieved, forming a complete indoor human activity perception detection.

[0127] It should be noted that, in the absence of conflict, the features in the embodiments of this application may be combined with each other.

[0128] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A cross-region activity perception method, characterized in that: Applied to a cross-region activity perception system, the cross-region activity perception system comprises: a perception signal source, used to transmit a directional beam to a designated area; a reflection surface device, used to dynamically change the reflection direction of the incident directional beam; an activity detection device, used to receive the beam reflected by the reflection surface device, and perform activity perception; the method comprises: When the activity detection device detects that the maximum value of the channel characteristic disturbance value of the activity area of ​​the object to be measured is less than a preset threshold value, the sensing signal source alternately sends directional beams to the activity area of ​​the object to be measured and the target area; wherein the channel characteristic disturbance value is the difference between the channel characteristic value of the designated area when there is no object to be measured and the channel characteristic value of the designated area when there is the object to be measured; The reflecting surface device adjusts the reflection direction to control the direction of the reflected beam to point to the boundary area between the active area of ​​the object to be measured and the target area; The activity detection device receives the adjusted beam signal and calculates and obtains a first channel characteristic disturbance value in the activity area of ​​the object to be detected and a second channel characteristic disturbance value in the target area; It is determined whether the object to be detected moves into the target area according to the difference between the first channel characteristic disturbance value and the second channel characteristic disturbance value.

2. The method according to claim 1, characterized in that Before the sensing signal source alternately sends directional beams to the activity area and the target area of ​​the object to be detected, the method further includes: When there is no activity of the object to be detected, the sensing signal source sends a directional beam to all areas within a preset sensing time slot; The reflecting surface device receives the directional beam and adjusts the beam direction according to a preset reflection angle; The activity detection device receives the adjusted beam signal and calculates and obtains channel characteristic values ​​in all areas within the preset sensing time slot.

3. The method according to claim 2, characterized in that After the activity detection device receives the adjusted beam signal and calculates and obtains the channel characteristic values ​​in all areas within the preset sensing time slot, the method further includes: When the object to be detected is active, the activity detection device calculates the channel characteristic disturbance value in the activity area of ​​the object to be detected within the preset sensing time slot to obtain the maximum value of the channel characteristic disturbance value; When the maximum value of the channel characteristic disturbance value is greater than a preset threshold, the sensing signal source sends a directional beam to the active area of ​​the object to be measured, and the reflecting surface device adjusts the reflection angle and adjusts the beam direction according to the target reflection angle.

4. The method according to claim 3, characterized in that The reflecting surface device adjusts the reflection angle and adjusts the beam direction according to the target reflection angle, including: The reflection angle of the reflecting surface device corresponding to the maximum value of the channel characteristic disturbance value is used as the initial reflection angle. The reflecting surface device uses the direction corresponding to the initial reflection angle as the reflection direction, and adjusts the beam direction according to the preset incremental angle within consecutive preset sensing time slots; The activity detection device receives the adjusted beam signal, calculates the channel characteristic disturbance value in the current continuous preset sensing time slots, and obtains the maximum value of the channel characteristic disturbance value in the current continuous preset sensing time slots; The reflection angle of the reflecting surface device corresponding to the maximum value of the channel characteristic disturbance value in the current continuous preset perception time slots is used as the target initial reflection angle. The reflecting surface device uses the direction corresponding to the target initial reflection angle as the reflection direction and adjusts the beam direction according to the target reflection angle.

5. The method according to claim 1, characterized in that The determining, according to the difference between the first channel characteristic disturbance value and the second channel characteristic disturbance value, whether the object to be detected moves into the target area comprises: Determine whether the difference between the first channel characteristic disturbance value and the second channel characteristic disturbance value is greater than a preset switching threshold value, and if so, determine that the object to be detected has not moved within the object to be detected activity area; If not, determine whether the difference between the second channel characteristic disturbance value and the first channel characteristic disturbance value is greater than a preset switching threshold value, and if so, determine that the object to be measured moves into the target area.

6. The method according to claim 1, characterized in that The method further comprises: When the object to be detected moves to the target area, the sensing signal source continuously sends a directional beam into the target area; The reflecting surface device receives the directional beam, adjusts the direction, and points to the object to be measured; The activity detection device receives the adjusted beam signal, calculates the channel characteristic disturbance value in the target area, and continuously senses the object to be detected.

7. A cross-regional activity perception system, characterized in that: include: Sensing signal sources, reflective surface devices and activity detection devices; The sensing signal source is used to alternately send directional beams to the activity area of ​​the object to be measured and the target area when the activity detection device detects that the maximum value of the channel characteristic disturbance value of the activity area of ​​the object to be measured is less than a preset threshold value; wherein the channel characteristic disturbance value is the difference between the channel characteristic value of the specified area when there is no object to be measured and the channel characteristic value of the specified area when there is the object to be measured; The reflecting surface device is used to adjust the reflection direction and control the direction of the reflected beam to point to the boundary area between the active area of ​​the object to be measured and the target area; The activity detection device is used to receive the adjusted beam signal, calculate and obtain the first channel characteristic disturbance value in the activity area of ​​the object to be detected, and the second channel characteristic disturbance value in the target area; The sensing signal source is further used to determine whether the object to be detected moves into the target area according to a difference between the first channel characteristic disturbance value and the second channel characteristic disturbance value.

8. The system according to claim 7, characterized in that The sensing signal source is further configured to continuously send a directional beam into the target area after the object to be detected moves to the target area; The reflecting surface device is also used to receive the directional beam, adjust the direction, and point it to the object to be measured; The activity detection device is also used to receive the adjusted beam signal, calculate the channel characteristic disturbance value in the target area, and continuously sense the object to be detected.

9. The system according to claim 7, characterized in that The sensing signal source comprises: a signal transmitting unit and a scanning control unit; The signal transmitting unit receives the control instruction issued by the scanning control unit, and transmits a directional beam to a designated area in a designated order.

10. The system according to claim 7, characterized in that The activity detection device comprises: a signal receiving unit and an activity recognition unit; The signal receiving unit receives the adjusted beam signal, performs data processing on the beam signal and sends it to the activity identification unit, and the activity identification unit calculates channel characteristic information.

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