CN113885022A - Fall detection method and radar equipment - Google Patents

Fall detection method and radar equipment Download PDF

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CN113885022A
CN113885022A CN202111256842.XA CN202111256842A CN113885022A CN 113885022 A CN113885022 A CN 113885022A CN 202111256842 A CN202111256842 A CN 202111256842A CN 113885022 A CN113885022 A CN 113885022A
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human body
target human
radar
characteristic information
target
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慕安臻
郭世盛
杨晓波
唐川田
张博
石靖峰
韩海力
丁从张
孙铁军
丁子洲
崔国龙
贾勇
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Qingdao Hisense Hitachi Air Conditioning System Co Ltd
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/103—Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes
    • A61B5/11—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb
    • A61B5/1116—Determining posture transitions
    • A61B5/1117—Fall detection
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
    • A61B5/6887—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient mounted on external non-worn devices, e.g. non-medical devices
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/74—Details of notification to user or communication with user or patient ; user input means
    • A61B5/746—Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • G01S13/886—Radar or analogous systems specially adapted for specific applications for alarm systems

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Abstract

The embodiment of the application provides a falling detection method and radar equipment, relates to the technical field of signal processing, can perform falling detection on the premise of protecting privacy and safety of a user, and can ensure the accuracy of falling detection. The method comprises the following steps: collecting radar data in a target space; according to the radar data, first posture characteristic information of a target human body at a first moment and second posture characteristic information of the target human body at a second moment are obtained, and a time interval between the first moment and the second moment is smaller than or equal to a preset time interval; determining whether the target human body falls down in a first direction according to the first posture characteristic information and the second posture characteristic information, wherein the first direction is a direction from the radar equipment to the target human body in a horizontal plane; and/or determining whether the target human body falls down in a second direction according to the first posture characteristic information and the second posture characteristic information, wherein the second direction is perpendicular to the first direction in the horizontal plane.

Description

Fall detection method and radar equipment
Technical Field
The present application relates to the field of signal processing technologies, and in particular, to a fall detection method and a radar apparatus.
Background
Falls occur frequently in daily life of people, and the falls may cause injuries to the body to different degrees due to different physical conditions of the people. For the old, because the falling of the human body has uncertainty and unpredictability, if the old cannot be timely and effectively treated for a long time after falling, long-term paralysis and even life threatening can be caused. Therefore, in order to ensure that the old people can be timely treated after falling down, it is very necessary to perform falling detection on the old people.
The existing contact type fall detection technology is generally based on wearable equipment, and the fall state is judged through the motion characteristics of an acceleration sensor. However, the detection accuracy of such fall detection methods is affected by the wearing condition of the wearable device, for example, the wearing position is incorrect, and the detection result has a large error. The existing non-contact fall detection technology is generally a detection method based on image video. However, this method is a method that violates the privacy of people and cannot be applied to a monitoring area sensitive to privacy such as a bathroom or a bedroom.
Disclosure of Invention
The embodiment of the application provides a fall detection method and radar equipment, which are used for improving the accuracy of fall detection on the premise of protecting the privacy and safety of a user.
In a first aspect, an embodiment of the present application provides a fall detection method, including: collecting radar data in a target space; according to the radar data, first posture characteristic information of a target human body at a first moment and second posture characteristic information of the target human body at a second moment are obtained, and a time interval between the first moment and the second moment is smaller than or equal to a preset time interval; determining whether the target human body falls down in a first direction according to the first posture characteristic information and the second posture characteristic information, wherein the first direction is a direction from the radar equipment to the target human body in a horizontal plane; and/or determining whether the target human body falls down in a second direction according to the first posture characteristic information and the second posture characteristic information, wherein the second direction is perpendicular to the first direction in the horizontal plane.
Based on the technical scheme, the falling detection is carried out by collecting the radar data, the image video information of the user is not required to be acquired, the personal privacy of the user can be protected, and the method and the device are suitable for privacy areas such as bedrooms and bathrooms. In addition, attitude characteristic information at different moments (namely first attitude characteristic information at the first moment and second attitude characteristic information at the second moment) is extracted from radar data, and the time interval between the first moment and the second moment is smaller than a preset time interval, so that the motion condition of the target human body in a short time can be known by combining the first attitude characteristic information and the second attitude characteristic information, and whether the target human body falls down in the first direction and/or the second direction can be judged, and the falling detection can be performed more clearly and accurately.
In a second aspect, a radar apparatus is provided, which includes an obtaining unit and a processing unit, wherein the obtaining unit is configured to collect radar data in a target space; the processing unit is used for acquiring first attitude characteristic information of the target human body at a first moment and second attitude characteristic information of the target human body at a second moment according to the radar data, wherein the time interval between the first moment and the second moment is less than or equal to a preset time interval; the processing unit is further used for determining whether the target human body falls down in a first direction according to the first posture characteristic information and the second posture characteristic information, wherein the first direction is a direction from the radar equipment to the target human body in a horizontal plane; and/or determining whether the target human body falls down in a second direction according to the first posture characteristic information and the second posture characteristic information, wherein the second direction is perpendicular to the first direction in the horizontal plane.
In a third aspect, there is provided a radar apparatus including: at least one processor and at least one memory; the at least one memory has stored therein computer instructions that, when executed by the radar apparatus, cause the radar apparatus to perform any of the methods of the first aspect described above.
In a fourth aspect, there is provided a computer readable storage medium comprising computer instructions which, when run on a computer, cause the computer to perform any of the methods of the first aspect described above.
In a fifth aspect, there is provided a computer program product comprising computer instructions which, when run on a computer, cause the computer to perform any of the methods provided by the first aspect above.
The technical effects brought by any one of the possible schemes in the second aspect to the fifth aspect may be analyzed in the beneficial effects corresponding to the first aspect, and are not described herein again.
Drawings
Fig. 1 is a flowchart of a fall detection method provided in an embodiment of the present application;
fig. 2 is a schematic view of an application scenario provided in an embodiment of the present application;
fig. 3 is a flowchart of another fall detection method provided by an embodiment of the present application;
fig. 4 is a flowchart of another fall detection method provided by an embodiment of the present application;
fig. 5 is a schematic composition diagram of a radar apparatus according to an embodiment of the present disclosure;
fig. 6 is a schematic diagram of a hardware structure of a radar apparatus according to an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless otherwise specified.
In the description of the present application, it is to be noted that the terms "connected" and "connected" are to be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, unless explicitly stated or limited otherwise. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art. In addition, when a pipeline is described, the terms "connected" and "connected" are used in this application to have a meaning of conducting. The specific meaning is to be understood in conjunction with the context.
In the embodiments of the present application, words such as "exemplary" or "for example" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "e.g.," is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.
As described in the background art, in the existing contact type fall detection method based on the wearable device, when the wearable device is worn incorrectly, the detection result has a large error. The existing fall detection method based on the image video relates to the problem of invading the personal privacy of the user.
In view of this, embodiments of the present application provide a fall detection method and a radar apparatus. The method comprises the following steps: collecting radar data in a target space; according to the radar data, first posture characteristic information of a target human body at a first moment and second posture characteristic information of the target human body at a second moment are obtained, and a time interval between the first moment and the second moment is smaller than or equal to a preset time interval; determining whether the target human body falls down in a first direction according to the first posture characteristic information and the second posture characteristic information, wherein the first direction is a direction from the radar equipment to the target human body in a horizontal plane; and/or determining whether the target human body falls down in a second direction according to the first posture characteristic information and the second posture characteristic information, wherein the second direction is perpendicular to the first direction in the horizontal plane.
Compared with the existing direction-indistinguishable falling detection method, the method has the advantages that the change conditions of the posture characteristic information of the user are analyzed according to different posture characteristic information, falling detection in different directions is carried out, and the falling detection accuracy can be improved. And the falling detection is carried out by collecting radar data, the image video information of the user does not need to be acquired, and the personal privacy of the user can be protected.
The following detailed description of embodiments of the present application will be made with reference to the accompanying drawings.
As shown in fig. 1, a fall detection method is provided for an embodiment of the present application, the method including the following steps:
s101, radar data in a target space are collected by radar equipment.
The target space refers to a preset space monitored by the radar, and may be a space in which a fall is likely to occur, such as a bathroom or a bedroom.
A radar is an electronic device that can detect an object using electromagnetic waves. The radar emits electromagnetic waves to irradiate the target and receives an echo signal (namely radar data) of the target, so that information such as the distance from the target to an electromagnetic wave emission point, the distance change rate (radial speed), the azimuth and the altitude is obtained.
Optionally, the radar device may be disposed above the target space, and the height of the radar device may be higher than the height of the human body in the target space, so that the radar device may collect radar data of the human body in the target space. For example, the radar may be mounted 2m, 3m from the ground within the target space. For example, as shown in fig. 2, the radar 1 may be placed on an air conditioner 2 having a height of 2m in a target space. Optionally, the radar 1 may establish a communication connection with the air conditioner 2, so that the radar 1 may perform information interaction with the air conditioner 2.
Optionally, the radar installed in the target space may be a millimeter wave radar.
The millimeter wave radar is a radar working in a millimeter wave band (millimeter wave), and can transmit signals with the wavelength of 1-10mm and the frequency of 30-300 GHZ. In the electromagnetic spectrum, such wavelengths are considered short wavelengths, which means high accuracy. A millimeter wave system with an operating frequency of 76-81 GHz (corresponding to a wavelength of about 4mm) will be able to detect movements as small as a few tenths of a millimeter.
Optionally, after the radar device collects radar data in the target space, the radar device may process the acquired radar data to remove clutter signals in the radar data.
Optionally, the acquired radar data may be processed by using a moving target display technology.
The moving target display technology is a technology for extracting target information by using difference of Doppler effect of a moving target and clutter on frequency spectrum and adopting stop band filtering to suppress clutter frequency spectrum. Is one of the general radar technologies.
The processing formula using the moving object display technique can be shown as formula (1):
SBMTI(t)＝SB(t)-SB(t-Tr) (1)
wherein S isB(t) represents all radar data acquired by the radar equipment; sBM1I(t) an echo signal representing a target human body in the radar data; sB(t-Tr) Representing clutter signals in the radar data.
It should be noted that, under the influence of the specific environment of the target space, the radar data acquired by the radar device may include a large number of clutter signals generated by indoor furnishings such as beds, closets, sofas, and the like, and these clutter signals are mixed with the echo signal generated by the target human body, which may interfere with the subsequent analysis of the echo signal generated by the target human body. Therefore, the radar device may first perform preprocessing on the acquired radar data of the target space, remove the acquired background clutter signal, and thus perform the following step S102 according to the processed radar data.
S102, the radar equipment acquires first attitude characteristic information of the target human body at a first moment and second attitude characteristic information of the target human body at a second moment according to radar data.
And the time interval between the first moment and the second moment is less than or equal to a preset time interval.
The preset time interval may be a maximum time duration, such as 0.5 ms, 1 s, etc., for which the human body may transit from the normal state to the fall state.
Therefore, the first time and the second time can be any two times in the falling detection process, and the time interval is smaller than or equal to the preset time interval, so that the first time and the second time can be any time in the falling process of the target human body. Further, the first posture characteristic information and the second posture characteristic information of the target human body may also be posture information in a falling process of the target human body, so that the radar device can acquire the first posture characteristic information and the second posture characteristic information to perform falling detection of the target human body.
Optionally, the posture feature information may include one or more of the following: the relative distance between the target human body and the radar, the movement speed of the target human body, the angle between the target human body and the radar, or horizontal point cloud data.
The following briefly describes the determination method of each parameter in the pose feature information.
(1) Distance between two adjacent plates
The radar device may determine the relative distance between the user and the radar according to radar ranging principles. In particular, the radar device may transmit the time T of the electromagnetic wave signal by the radar1And the time T of the radar receiving the reflected signal2And determining the delay time length t of the received reflection signal. Wherein the delay time T is the time T of the radar receiving the reflected signal2Minus the time T of the radar emitting the electromagnetic wave signal1Difference value T of2-T1. Further, since the electromagnetic wave propagates at the speed of light, the radar apparatus can determine the relative distance between the user and the radar within the target space based on t.
For example, the radar device may determine a one-dimensional range profile between the target human body and the radar device according to the following formula (1):
Figure BDA0003324135820000061
TR(m，k)denotes the amplitude at k, W, of the m-th pulse signaluIs a predetermined window function, S(n-u，m)And data representing the n-u sampling point of the m-th pulse signal.
(2) Speed of rotation
According to the actual situation of daily life, under the action of gravity, the target human body has larger motion acceleration when falling down, so that the motion speed of the target human body has certain change, and the radar equipment can judge whether the target human body is in the falling down state or not by calculating the motion speed of the target human body in the target space.
Illustratively, the moving speed of the target human body is determined according to the wave properties of the echo reflected by the target human body in conjunction with Doppler Shift (Doppler Shift).
Among them, the difference between the transmitted and received frequencies caused by the Doppler effect (Doppler effect) is called Doppler shift. It reveals the law that the wave properties change during motion.
The doppler effect is the change in the wavelength of the object radiation due to the relative motion of the source and the observer. In front of the moving wave source, the wave is compressed, the wavelength becomes shorter and the frequency becomes higher, called blue shift; the opposite effect occurs when the moving wave source is behind. The wavelength becomes longer and the frequency becomes lower, called red shift; the higher the velocity of the wave source, the greater the effect produced. The speed of the wave source moving along the observation direction can be calculated based on the degree of blue-shift or red-shift of the wave.
In the embodiment of the present application, the echo reflected by the target human body also has a doppler shift. The velocity of movement of the target body can thus be determined according to the following equation (2):
Figure BDA0003324135820000062
where ω is the phase difference between the two echoes, λ is the wavelength, TcV is the transmission time length of the echo, and is the movement speed of the target human body.
(3) Angle of rotation
The angle between the target human body and the radar can be changed when the target human body is in different states such as a falling state, a walking state and a standing state, so that the angle information between the target human body and the radar can be acquired, and whether the target human body is in the falling state or not can be judged more accurately.
For example, the radar apparatus may determine a moving speed of the target human body according to formula (2), and determine an angle between the target human body and the radar according to the following formula (3):
Figure BDA0003324135820000071
wherein, w2Is the phase difference caused by the change of the target human body distance, l is the wavelength, d is the distance between two antennas, and q is the meshMarking the included angle between the human body and the radar.
(4) Horizontal point cloud
The point cloud refers to a massive point set of the target surface characteristics. The horizontal point cloud is obtained by calculating the distance between the radar and the target and the angle between the radar and the target through the aperture of the radar in the horizontal direction, and then obtaining a mass point set of the scattering characteristics of the surface of the target, which is extracted in the horizontal direction.
Specifically, the radar device performs range dimension pulse compression on the acquired radar data to obtain range information between the target human body and the radar, and then performs Capon beam forming in the horizontal direction by using range image data of a plurality of antennas of a virtual antenna array of the radar device. And then, detecting the distance azimuth point to the target by using a constant false alarm detection technology to obtain the horizontal point cloud data of the target.
Wherein Capon beamforming: by performing weighted summation on the outputs of the array elements, the antenna array beam is 'guided' to one direction in a time, and the DOA estimation is given to the guide position of the expected signal with the maximum output power. Although the directional pattern of the array antenna of the radar device is omnidirectional, the output of the array can be adjusted after weighted summation so that the directional gain received by the array is focused in one direction, which is equivalent to forming a "beam". In the embodiment of the present application, the radar apparatus may form a Capon beam in the horizontal direction.
DOA Estimation, also known as Angle spectrum Estimation (Angle Spectral Estimation), and Angle Of Arrival (Angle Of Arrival) Estimation. By utilizing the linear propagation principle of electromagnetic waves, the received reflected signals can be processed by a radar, and the incoming wave direction of the reflected signals is estimated, so that the azimuth information of a user is acquired.
Constant False-Alarm Rate (CFAR) is a technique in which a radar system determines whether a target signal exists by discriminating between a signal output from a receiver and noise while keeping a False-Alarm probability Constant. The principle is that firstly, after the input noise is processed, a threshold is determined, the threshold is compared with an input end signal, if the input end signal exceeds the threshold, the target is judged to be present, otherwise, the target is judged to be absent. The signal is transmitted from signal source, and is affected by various interferences in the process of propagation, and after reaching the receiver, the signal is processed and output to the detector, and then the detector makes decision on the input signal according to proper criteria. It should be understood that the above determination manner for each parameter in the pose characteristic information is exemplary and not limited to specific limitations, and other manners may also be adopted in practical applications.
Alternatively, after step S102, the radar apparatus may perform step S103 and/or step S104 described below.
S103, the radar equipment determines whether the target human body falls down in the first direction according to the first posture characteristic information and the second posture characteristic information.
Wherein the first direction is a direction from the radar apparatus to the target human body in a horizontal plane.
It should be noted that, if the target human body falls down in the first direction, and the direction of the target human body and the direction of the radar device are not changed during the falling process, the distance change is obvious during the falling process of the target human body, and the distance between the target human body and the radar device is suddenly reduced or suddenly increased. Therefore, whether the target human body falls down in the first direction can be determined according to the change in the distance between the target human body and the radar device.
In addition, when the human body falls down, the movement speed of the target human body is suddenly increased under the action of gravity, so that the radar equipment can further use the movement speed of the target human body as a basis for judging whether the target human body falls down in the first direction.
Thus, to determine whether the target human body falls in the first direction, the first posture characteristic information includes a first distance between the target human body and the radar device, and the second posture characteristic information includes a second distance between the target human body and the radar device, and a second speed of the target human body. Based on this, step S103 may be specifically implemented as: in the case where the first preset condition is satisfied, the radar apparatus may determine that the target human body falls in the first direction. In a case where the first preset condition is not satisfied, the radar apparatus determines that the target human body has not fallen in the first direction.
The first preset condition comprises that the difference value between the second distance and the first distance is larger than or equal to a first threshold value, and the second speed is larger than or equal to a second threshold value. The first threshold may be a distance change value that is possible within a preset time interval when the target human body falls in the first direction. The second threshold may be a minimum possible movement speed of the target person when the target person is in a fall state.
And S104, the radar equipment determines whether the target human body falls down in the second direction according to the first posture characteristic information and the second posture characteristic information.
Wherein the second direction is perpendicular to the first direction in a horizontal plane.
It should be noted that, as a result of analyzing the data of the existing human body movement speed, when the human body falls down in the second direction, the speed change rate is larger than that of other movements. Thus, the radar apparatus can determine whether the target human body falls in the second direction according to the change of the movement speed of the target human body.
And compared with other motion actions of the human body, when the human body falls down in the second direction, the point clouds in the horizontal direction are obviously increased. Therefore, the radar equipment can further determine whether the target human body falls down in the second direction by combining the horizontal point cloud data, and the accuracy and the stability of fall detection in the second direction can be improved.
Thus, to determine whether the target person falls over in the second aspect, the first posture feature information may include first horizontal point cloud data, and the second posture feature information may include a second speed of the target person and second horizontal point cloud data. Based on this, step S104 may be specifically implemented as: and under the condition that a second preset condition is met, the radar equipment determines that the target human body falls down in a second direction. In a case where the second preset condition is not satisfied, the radar apparatus determines that the target human body has not fallen in the second direction.
The second preset condition includes that the second speed is greater than or equal to a third threshold, and a difference between the number of point data included in the second horizontal point cloud data and the number of point data included in the first horizontal point cloud data is greater than or equal to a fourth threshold.
It should be understood that the radar apparatus may preset a reasonable speed change value as the third threshold and a reasonable number of point data as the fourth threshold according to the change of the existing movement speed and horizontal point cloud data when the radar apparatus falls down in the second direction.
Based on the embodiment described in fig. 1, the fall detection is performed by collecting radar data, without acquiring image video information of the user, the personal privacy of the user can be protected, and the method is suitable for privacy areas such as bedrooms and bathrooms. In addition, compared with the existing direction falling detection method which is not distinguished, the method has the advantages that the change conditions of the posture characteristic information of the posture are analyzed according to different posture characteristic information, falling detection in different directions is carried out, and the falling detection accuracy can be improved.
Optionally, based on the embodiment shown in fig. 1, as shown in fig. 3, after the step S104, the fall detection method may further include the following steps:
s105, when the target human body falls down, the radar equipment acquires the distance between the target human body and the radar equipment and the horizontal included angle of the target human body relative to the radar equipment.
For example, the radar device may determine the distance between the target human body and the radar device according to the above formula (1).
The radar apparatus may construct a two-dimensional coordinate system in a horizontal plane with itself as an origin, with any one direction in the horizontal plane as an X-axis, and with a direction perpendicular to the X-axis in the horizontal plane as a Y-axis. Furthermore, the horizontal included angle of the target human body relative to the radar device is the included angle between the direction from the radar device to the target human body in the horizontal plane and the X axis.
And S106, the radar equipment determines the position of the target human body when falling according to the distance between the target human body and the radar equipment and the horizontal included angle of the target human body relative to the radar equipment.
Specifically, the radar device can determine the position of the target human body in the target space when the target human body falls down by taking the position of the radar device on the horizontal plane as a center according to the distance between the target human body and the radar device when the target human body falls down and the horizontal included angle of the target human body relative to the radar device.
For example, the coordinates of the fall location of the target person in the two-dimensional coordinate system can be determined according to the following formula (4):
Figure BDA0003324135820000101
wherein d represents the distance between the target human body and the radar equipment, theta is a horizontal included angle, x is the value of the abscissa of the falling position, and y is the value of the ordinate of the falling position.
Based on the embodiment, when the user falls down, the radar equipment can further determine the position information of the user when the user falls down, so that rescue workers can quickly find the user according to the position information and timely provide help and treatment for the user.
Alternatively, based on the embodiment shown in fig. 1, as shown in fig. 4, after the step S104, the fall detection method may further include the following step S107:
and S107, after the target human body falls down, the radar equipment sends alarm information.
In a possible implementation manner, in the case that the target human body is identified to be in a falling state, the radar device may send alarm information to the terminal device.
The alarm information may include a falling condition of the target human body, such as a falling time of the target human body, posture characteristic information of the target human body when the target human body falls, and a position of the target human body when the target human body falls.
In addition, the radar equipment can be connected with terminal equipment in advance, and the terminal equipment can be portable terminal equipment such as a mobile phone, an intelligent watch and an intelligent bracelet of the emergency contact person corresponding to the target human body, so that the emergency contact person corresponding to the target human body can timely receive alarm information sent by the radar equipment.
In another possible implementation manner, in the case that the target human body is identified to be in a falling state, the radar device may further control the alarm device to send out alarm information.
Wherein, above-mentioned alarm information can also include alarm signals such as warning prompt tone, warning indicator lamp of presetting. The alarm device may be a device having an indicator light and/or having a sound playing function.
Alternatively, the alarm device may be integrated in the radar apparatus.
In yet another possible implementation, the radar device may be connected to other smart homes, such as an air conditioner, a refrigerator, and the like, or the radar device may be integrated in the smart home. Under the condition that the target human body is recognized to be in a falling state, the radar equipment can send alarm information to the intelligent home, so that the intelligent home can send an alarm signal to prompt other people around the intelligent home to take care of the falling target human body as soon as possible.
In some embodiments, after a fall in the target person, the radar device may send a fall record to the server.
The fall record may include one or more of the time when the target person falls, the position when the target person falls, radar data of the fall, and the like.
Further, the radar device may be connected in advance with a server, which may be a device having data processing capability as well as data storage capability.
Based on the embodiment shown in fig. 4, when the user is in a falling state, falling alarm information can be sent out in time to remind relevant people that the user has fallen, so that the user can be timely treated after falling.
It should be understood that the embodiments shown in fig. 3 and 4 described above may be used in combination with each other.
The above description has presented the scheme provided herein primarily from a methodological perspective. It is to be understood that the radar apparatus includes a hardware structure and/or a software module for performing the respective functions in order to implement the above-described functions. Those of skill in the art will readily appreciate that the present invention can be implemented in hardware or a combination of hardware and computer software, in conjunction with the exemplary algorithm steps described in connection with the embodiments disclosed herein. Whether a function is performed as hardware or computer software drives hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
The radar device may be divided into functional modules according to the above method example, for example, each functional module may be divided corresponding to each function, or two or more functions may be integrated into one processing module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. It should be noted that, the division of the modules in the present application is schematic, and is only a logical function division, and there may be another division manner in actual implementation.
Fig. 5 shows a schematic composition diagram of a radar apparatus provided in an embodiment of the present application. As shown in fig. 5, the radar apparatus 1000 includes an acquisition unit 1001 and a processing unit 1002. Optionally, the radar apparatus 1000 further includes an alarm unit 1003.
An obtaining unit 1001 is configured to collect radar data in a target space.
The processing unit 1002 is configured to obtain, according to the radar data, first posture characteristic information of the target human body at a first time and second posture characteristic information at a second time, where a time interval between the first time and the second time is smaller than or equal to a preset time interval.
The processing unit 1002 is further configured to determine whether the target human body falls down in a first direction according to the first posture characteristic information and the second posture characteristic information, where the first direction is a direction from the radar device to the target human body in a horizontal plane; and/or determining whether the target human body falls down in a second direction according to the first posture characteristic information and the second posture characteristic information, wherein the second direction is perpendicular to the first direction in the horizontal plane.
In some embodiments, the first pose feature information includes a first distance between the target human body and the radar device, the second pose feature information includes a second distance between the target human body and the radar device, and a second velocity of the target human body; the processing unit 1002 is specifically configured to determine that the target human body falls down in the first direction when a first preset condition is met, where the first preset condition includes that a difference between the second distance and the first distance is greater than or equal to a first threshold, and the second speed is greater than or equal to a second threshold; or, in a case where the first preset condition is not satisfied, it is determined that the target human body has not fallen in the first direction.
In some embodiments, the first pose feature information comprises first horizontal point cloud data, and the second pose feature information comprises second velocity of the target human body and second horizontal point cloud data; the processing unit 1002 is specifically configured to determine that the target human body falls down in the second direction when a second preset condition is met, where the second preset condition includes that the second speed is greater than or equal to a third threshold, and a difference between the number of point data included in the second horizontal point cloud data and the number of point data included in the first horizontal point cloud data is greater than or equal to a fourth threshold; and determining that the target human body does not fall in the second direction if the second preset condition is not met.
In some embodiments, the obtaining unit 1001 is further configured to obtain a distance between the target human body and the radar device and a horizontal angle of the target human body relative to the radar device when the target human body falls down. The processing unit 1002 is further configured to determine a position where the target human body falls according to a distance between the target human body and the radar device and a horizontal included angle between the target human body and the radar device.
In some embodiments, the alarm unit 1003 is configured to send out alarm information after the target human body falls down.
The elements in fig. 5 may also be referred to as modules, for example, the processing elements may be referred to as processing modules. In the embodiment shown in fig. 5, the names of the respective units may not be the names shown in the figure, and for example, the transceiver unit may also be referred to as a communication unit.
The respective units in fig. 5, if implemented in the form of software functional modules and sold or used as separate products, may be stored in a computer-readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present application may be essentially implemented or make a contribution to the prior art, or all or part of the technical solutions may be implemented in the form of a software product stored in a storage medium, and including several instructions for causing a computer device (which may be a personal computer, a server, a network device, or the like) or a processor (processor) to execute all or part of the steps of the methods described in the embodiments of the present application. A storage medium storing a computer software product comprising: various media capable of storing program codes, such as a usb disk, a removable hard disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.
The embodiment of the present application further provides a schematic diagram of a hardware structure of a radar apparatus, as shown in fig. 6, the radar apparatus 2000 includes a processor 2001, and optionally, a memory 2002 and a transceiver 2003 connected to the processor 2001 may also be included. The processor 2001, memory 2002, and transceiver 2003 are connected by a bus 2004.
The processor 2001 may be a Central Processing Unit (CPU), a general purpose processor Network (NP), a Digital Signal Processor (DSP), a microprocessor, a microcontroller, a Programmable Logic Device (PLD), or any combination thereof. The processor 2001 may also be any other means having a processing function such as a circuit, device or software module. The processor 2001 may also include a plurality of CPUs, and the processor 2001 may be one single-core (single-CPU) processor or a multi-core (multi-CPU) processor. A processor herein may refer to one or more devices, circuits, or processing cores that process data (e.g., computer program instructions).
Memory 2002 may be a read-only memory (ROM) or other type of static storage device that may store static information and instructions, a Random Access Memory (RAM) or other type of dynamic storage device that may store information and instructions, but is not limited to, electrically erasable programmable read-only memory (EEPROM), compact disk read-only memory (CD-ROM) or other optical disk storage, optical disk storage (including compact disk, laser disk, optical disk, digital versatile disk, blu-ray disk, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. The memory 2002 may be separate or integrated with the processor 2001. The memory 2002 may include, among other things, computer program code. The processor 2001 is configured to execute the computer program code stored in the memory 2002, thereby implementing the methods provided by the embodiments of the present application.
The transceiver 2003 may be used to communicate with other devices or communication networks (e.g., ethernet, Radio Access Network (RAN), Wireless Local Area Networks (WLAN), etc.). The transceiver 2003 may be a module, a circuit, a transceiver, or any device capable of enabling communication.
The bus 2004 may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The bus 2005 can be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown in FIG. 6, but this is not intended to represent only one bus or type of bus.
The embodiment of the present application further provides a computer-readable storage medium, which includes computer-executable instructions, and when the computer-readable storage medium is run on a computer, the computer is caused to execute any one of the methods provided by the above embodiments.
The embodiments of the present application also provide a computer program product containing instructions for executing a computer, which when executed on a computer, causes the computer to perform any one of the methods provided by the above embodiments.
An embodiment of the present application further provides a chip, including: a processor coupled to the memory through the interface, and an interface, when the processor executes the computer program or the computer execution instructions in the memory, the processor causes any one of the methods provided by the above embodiments to be performed.
In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented using a software program, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer-executable instructions. The processes or functions described in accordance with the embodiments of the present application occur, in whole or in part, when computer-executable instructions are loaded and executed on a computer. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer executable instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, the computer executable instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). Computer-readable storage media can be any available media that can be accessed by a computer or can comprise one or more data storage devices, such as servers, data centers, and the like, that can be integrated with the media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.
While the present application has been described in connection with various embodiments, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed application, from a review of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the word "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
Although the present application has been described in conjunction with specific features and embodiments thereof, it will be evident that various modifications and combinations can be made thereto without departing from the spirit and scope of the application. Accordingly, the specification and figures are merely exemplary of the present application as defined in the appended claims and are intended to cover any and all modifications, variations, combinations, or equivalents within the scope of the present application. It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.
The above description is only an embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions within the technical scope of the present disclosure should be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (10)

1. A fall detection method, applied to a radar apparatus, the method comprising:
collecting radar data in a target space;
according to the radar data, first posture characteristic information of a target human body at a first moment and second posture characteristic information of the target human body at a second moment are obtained, and a time interval between the first moment and the second moment is smaller than or equal to a preset time interval;
determining whether the target human body falls down in a first direction according to the first posture characteristic information and the second posture characteristic information, wherein the first direction is a direction from the radar equipment to the target human body in a horizontal plane; and/or the presence of a gas in the gas,
and determining whether the target human body falls down in a second direction according to the first posture characteristic information and the second posture characteristic information, wherein the second direction is vertical to the first direction in a horizontal plane.
2. The method of claim 1, wherein the first pose feature information includes a first distance between the target human body and the radar device, wherein the second pose feature information includes a second distance between the target human body and the radar device, and wherein the second velocity of the target human body;
determining whether the target human body falls down in a first direction according to the first posture characteristic information and the second posture characteristic information, wherein the determining comprises:
determining that the target human body falls in the first direction under the condition that a first preset condition is met, wherein the first preset condition comprises that the difference value between the second distance and the first distance is greater than or equal to a first threshold value, and the second speed is greater than or equal to a second threshold value; alternatively, the first and second electrodes may be,
determining that the target human body does not fall in the first direction if a first preset condition is not met.
3. The method of claim 1, wherein the first pose feature information comprises first horizontal point cloud data and the second pose feature information comprises a second velocity of the target human body and second horizontal point cloud data;
determining whether the target human body falls down in a second direction according to the first posture characteristic information and the second posture characteristic information, wherein the determining comprises:
determining that the target human body falls down in the second direction under the condition that a second preset condition is met, wherein the second preset condition comprises that the second speed is greater than or equal to a third threshold value, and the difference value between the number of point data contained in the second horizontal point cloud data and the number of point data contained in the first horizontal point cloud data is greater than or equal to a fourth threshold value;
and determining that the target human body does not fall in the second direction if a second preset condition is not met.
4. A method according to any one of claims 1 to 3, characterized in that the method comprises:
when the target human body falls down, acquiring the distance between the target human body and the radar equipment and the horizontal included angle of the target human body relative to the radar equipment;
and determining the position of the target human body when falling according to the distance between the target human body and the radar equipment and the horizontal included angle of the target human body relative to the radar equipment.
5. A method according to any one of claims 1 to 3, characterized in that the method comprises:
and sending alarm information after the target human body falls down.
6. A radar apparatus, characterized in that the radar apparatus comprises:
the acquisition unit is used for acquiring radar data in a target space;
the processing unit is used for acquiring first attitude characteristic information of a target human body at a first moment and second attitude characteristic information of the target human body at a second moment according to the radar data, wherein the time interval between the first moment and the second moment is less than or equal to a preset time interval;
the processing unit is further configured to determine whether the target human body falls down in a first direction according to the first posture characteristic information and the second posture characteristic information, where the first direction is a direction from the radar device to the target human body in a horizontal plane; and/or the presence of a gas in the gas,
and determining whether the target human body falls down in a second direction according to the first posture characteristic information and the second posture characteristic information, wherein the second direction is vertical to the first direction in a horizontal plane.
7. The radar device of claim 6, wherein the first pose feature information includes a first distance between the target human body and the radar device, wherein the second pose feature information includes a second distance between the target human body and the radar device, and wherein the second velocity of the target human body;
the processing unit is specifically configured to determine that the target human body falls down in the first direction when a first preset condition is met, where the first preset condition includes that a difference between the second distance and the first distance is greater than or equal to a first threshold, and the second speed is greater than or equal to a second threshold; alternatively, the first and second electrodes may be,
determining that the target human body does not fall in the first direction if a first preset condition is not met.
8. The radar apparatus of claim 6, wherein the first pose feature information comprises first horizontal point cloud data and the second pose feature information comprises a second velocity of the target human body and second horizontal point cloud data;
the processing unit is specifically configured to determine that the target human body falls down in the second direction when a second preset condition is met, where the second preset condition includes that the second speed is greater than or equal to a third threshold, and a difference between the number of point data included in the second horizontal point cloud data and the number of point data included in the first horizontal point cloud data is greater than or equal to a fourth threshold;
and determining that the target human body does not fall in the second direction if a second preset condition is not met.
9. Radar apparatus according to any one of claims 6 to 7,
the acquisition unit is further configured to acquire a distance between the target human body and the radar device and a horizontal included angle of the target human body relative to the radar device when the target human body falls down;
the processing unit is further configured to determine a position where the target human body falls according to a distance between the target human body and the radar device and a horizontal included angle of the target human body relative to the radar device.
10. The radar apparatus of claim 6, further comprising:
and the alarm unit is used for sending alarm information after the target human body falls down.
CN202111256842.XA 2021-10-27 2021-10-27 Fall detection method and radar equipment Pending CN113885022A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114664054A (en) * 2022-01-12 2022-06-24 广东蓝水花智能电子有限公司 Personnel tumbling detection method and system based on FMCW microwave inductor
CN114924249A (en) * 2022-07-22 2022-08-19 中国科学技术大学 Millimeter wave radar-based human body posture estimation method and device and electronic equipment
CN117636404A (en) * 2024-01-26 2024-03-01 贵州信邦富顿科技有限公司 Fall detection method and system based on non-wearable equipment

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114664054A (en) * 2022-01-12 2022-06-24 广东蓝水花智能电子有限公司 Personnel tumbling detection method and system based on FMCW microwave inductor
CN114924249A (en) * 2022-07-22 2022-08-19 中国科学技术大学 Millimeter wave radar-based human body posture estimation method and device and electronic equipment
CN114924249B (en) * 2022-07-22 2022-10-28 中国科学技术大学 Millimeter wave radar-based human body posture estimation method and device and electronic equipment
CN117636404A (en) * 2024-01-26 2024-03-01 贵州信邦富顿科技有限公司 Fall detection method and system based on non-wearable equipment
CN117636404B (en) * 2024-01-26 2024-04-16 贵州信邦富顿科技有限公司 Fall detection method and system based on non-wearable equipment

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