Fall detection method, apparatus, device, and storage medium

Abstract

The application provides a fall detection method, device and equipment and a storage medium, which can perform fall detection without involving user privacy and without contact. The method comprises: acquiring motion features of a target object in each unit time length in a plurality of continuous unit time lengths. The motion features comprise at least one of distance data, speed data, Doppler signal data and angle data. Based on a first judgment rule and the motion features of the target object in each unit time length, a first state of the target object in each unit time length is determined, and a first state sequence of the target object in the plurality of unit time lengths is obtained. The first state comprises a fall state, a motion state or a stationary state, and the first state sequence comprises the first states sorted by time. In the case where the first state sequence meets a preset first fall rule, it is determined that the target object falls.

Description

Technical Field

[0001] This application relates to the field of radar detection technology, and in particular to a fall detection method, apparatus, device, and storage medium. Background Technology

[0002] Currently, falls affect millions of people each year and cause numerous injuries, especially among the elderly. Therefore, real-time fall detection technology has significant practical implications for protecting human health.

[0003] Existing fall detection methods typically rely on capturing images of users to identify their behavior. However, this approach carries the risk of privacy breaches and may raise information security concerns. Summary of the Invention

[0004] This application provides a fall detection method, apparatus, device, and storage medium that enables contactless fall detection without infringing on user privacy.

[0005] Firstly, a fall detection method is provided, the method comprising:

[0006] The motion characteristics of the target object are acquired within each unit of time across multiple consecutive time units. These motion characteristics include at least one of distance data, velocity data, Doppler signal data, and angle data. Distance data indicates the maximum change in distance. Velocity data indicates the maximum velocity and the change in velocity area, with the change in velocity area indicating the ratio of the target velocity to the total velocity, where the target velocity exceeds a first threshold. Doppler signal data indicates the maximum Doppler signal intensity. Angle data indicates the maximum change in angle. Based on a first judgment rule and the motion characteristics of the target object within each unit of time, a first state of the target object within each unit of time is determined, resulting in a first state sequence of the target object across multiple time units. The first state includes a fallen state, a moving state, or a stationary state, and the first state sequence includes first states ordered by time. If the first state sequence satisfies a preset first falling rule, the target object is determined to have fallen.

[0007] The technical solution provided in this application, applied to radar equipment, enables contactless motion detection without infringing on user privacy, effectively improving the user experience. Furthermore, the radar equipment is unaffected by the environment, thus avoiding the reduction in accuracy caused by environmental factors such as lighting, smoke, and obstruction. In addition, the technical solution provided in this application determines the state sequence of the target object within each unit of time in a series of consecutive time units based on the motion characteristics of the target object. It then determines whether the state sequence meets a preset fall rule, and if so, determines that the target object has fallen. In other words, this application uses logical judgment to implement human fall detection, which has low algorithm complexity and low hardware computing power requirements, thus saving development costs while ensuring the detection of a fall.

[0008] As one possible implementation, each unit of time includes multiple frames. When the motion features include distance data, velocity data, Doppler signal data, and angle data, the aforementioned "acquiring the motion features of the target object within each unit of time in a series of consecutive unit of time" includes:

[0009] The radar equipment acquires echo signals corresponding to each frame across multiple frames, resulting in multiple frame-specific echo signals. Each frame's echo signal includes signals reflected by the target object after the radar equipment transmits multiple detection signals in each frame. Based on these echo signals, the maximum and minimum movement distances of the target object in each frame are determined, and the difference between these distances is defined as the target object's distance data per unit time. Similarly, the maximum and velocity area change values ​​of the target object in each frame are determined, and these values ​​are defined as the target object's velocity data per unit time. Furthermore, the maximum Doppler signal intensity of the target object in each frame is determined, and this maximum intensity is defined as the target object's Doppler signal data per unit time. Finally, the maximum and minimum motion angles of the target object in each frame are determined, and the difference between these angles is defined as the target object's angle data per unit time.

[0010] In this way, the radar equipment can determine the distance data, velocity data, Doppler signal data and angle data by processing the echo signal corresponding to each frame. Based on these feature data, it can perform body motion detection without contact without infringing on user privacy, effectively improving the user experience.

[0011] In one possible implementation, the first judgment rule includes a first motion rule, a first stillness rule, and a first fall rule. Based on the first judgment rule and the motion characteristics of the target object within each unit of time, the first state of the target object within each unit of time is determined, including: determining the first state as a motion state if the motion characteristics of the target object within each unit of time satisfy the first motion rule; or determining the first state as a stillness state if the motion characteristics of the target object within each unit of time satisfy the first stillness rule; or determining the first state as a fall state if the motion characteristics of the target object within each unit of time satisfy the first fall rule. In this way, the state for each unit of time can be determined based on the first judgment rule.

[0012] In one possible implementation, the method further includes: if the first state sequence does not satisfy the first fall rule, determining the second state of the target object within each unit time period based on the second judgment rule and the motion characteristics of the target object within each unit time period, thus obtaining a second state sequence of the target object within multiple unit time periods; the second state includes a fall state, a moving state, or a stationary state, and the second state sequence includes second states ordered by time. If the second state sequence satisfies the preset second fall rule, it is determined that the target object has fallen. Thus, if the radar device determines that the target object has not fallen based on the first judgment rule, it then determines whether the target object has fallen based on the second judgment rule. If the second state of the target object within each unit time period satisfies the preset second fall rule based on the second judgment rule, it is determined that the target object has fallen. This avoids the situation where the target object falls but is not detected.

[0013] In one possible implementation, the method further includes: if the target object remains stationary for a preset period of time after it is determined to have fallen, an alarm message is generated; the alarm message is used to indicate that the target object has fallen. In this way, after the first determination that the target object has fallen, a second fall detection is performed on the target object, thereby avoiding false alarms.

[0014] Secondly, a fall detection device is provided, comprising: an acquisition unit and a determination unit. The acquisition unit is used to acquire the motion characteristics of a target object within each unit of time span across multiple consecutive unit time spans; the motion characteristics include at least one of distance data, velocity data, Doppler signal data, and angle data, wherein the distance data indicates the maximum change in motion distance; the velocity data indicates the maximum value of motion velocity and the velocity area change value, the velocity area change value indicates the ratio of the target motion velocity to the multiple motion velocities, and the target motion velocity is greater than a first threshold; the Doppler signal data indicates the maximum value of Doppler signal intensity; and the angle data indicates the maximum change in motion angle. The determination unit is used to determine a first state of the target object within each unit of time span based on a first judgment rule and the motion characteristics of the target object within each unit of time span, obtaining a first state sequence of the target object within multiple unit time spans; the first state includes a fall state, a motion state, or a stationary state, and the first state sequence includes first states ordered by time. The determination unit is further used to determine that the target object has fallen if the first state sequence satisfies a preset first fall rule.

[0015] In one possible implementation, each unit time includes multiple frames. Given that the motion features include distance data, velocity data, Doppler signal data, and angle data, the acquisition unit is specifically used for: acquiring the echo signal corresponding to each frame in the multiple frames using radar equipment, obtaining echo signals corresponding to multiple frames; the echo signal corresponding to each frame includes the signal reflected by the target object after the radar equipment sends multiple detection signals in each frame; based on the echo signals corresponding to the multiple frames, determining the maximum and minimum motion distances of the target object in the multiple frames, and determining the difference between the maximum and minimum motion distances as the distance data of the target object in each unit time; based on the echo signals corresponding to the multiple frames, determining the maximum motion velocity and velocity area change value of the target object in the multiple frames, and determining the maximum motion velocity and velocity area change value as the velocity data of the target object in each unit time; and based on the echo signals corresponding to the multiple frames, determining the maximum Doppler signal intensity of the target object in the multiple frames, and determining the maximum Doppler signal intensity as the Doppler signal data of the target object in each unit time. Based on the echo signals corresponding to multiple frames, the maximum and minimum motion angles of the target object in each frame are determined, and the difference between the maximum and minimum motion angles is determined as the angle data of the target object in each unit of time.

[0016] In one possible implementation, the first judgment rule includes a first motion rule, a first stillness rule, and a first fall rule. Based on the first judgment rule and the motion characteristics of the target object within each unit of time, a unit is determined, specifically for: determining the first state as a motion state when the motion characteristics of the target object within each unit of time satisfy the first motion rule; or, determining the first state as a stillness state when the motion characteristics of the target object within each unit of time satisfy the first stillness rule; or, determining the first state as a fall state when the motion characteristics of the target object within each unit of time satisfy the first fall rule.

[0017] In one possible implementation, the determining unit is further configured to, when the first state sequence does not satisfy the first falling rule, determine the second state of the target object within each unit of time based on the second judgment rule and the motion characteristics of the target object within each unit of time, thereby obtaining a second state sequence of the target object within multiple unit of time; the second state includes a falling state, a moving state, or a stationary state, and the second state sequence includes second states ordered by time. The determining unit is also configured to, when the second state sequence satisfies a preset second falling rule, determine that the target object has fallen.

[0018] In one possible implementation, the device further includes a generation unit. The generation unit is configured to generate an alarm message if, within a preset time period after the target object has fallen, the target object remains stationary for that preset time period; the alarm message is used to indicate that the target object has fallen.

[0019] Thirdly, a radar device is provided, comprising: one or more processors; one or more memories; wherein the one or more memories are used to store computer program code, the computer program code including computer instructions, and when the one or more processors execute the computer instructions, the radar device performs the fall detection method of the first aspect.

[0020] Fourthly, a computer-readable storage medium is provided, comprising computer-executable instructions that, when executed on a computer, cause the computer to perform the fall detection method of the first aspect. Attached Figure Description

[0021] Figure 1 A schematic diagram of an antenna for a radar device provided in an embodiment of this application;

[0022] Figure 2 This is a schematic diagram of a radar device detecting a target object, provided in an embodiment of this application.

[0023] Figure 3 This is a schematic diagram of a fall detection system provided in an embodiment of this application;

[0024] Figure 4 One of the flowcharts for a fall detection method provided in this application embodiment;

[0025] Figure 5 A schematic diagram illustrating a first judgment rule provided in an embodiment of this application;

[0026] Figure 6 A second flowchart illustrating a fall detection method provided in this application embodiment;

[0027] Figure 7 A schematic diagram of a target object angle message provided in an embodiment of this application;

[0028] Figure 8 A flowchart for processing echo signals is provided as an embodiment of this application;

[0029] Figure 9 A schematic diagram illustrating the acquisition of motion features of a target object, provided as an embodiment of this application;

[0030] Figure 10 This is a schematic diagram illustrating the acquisition of distance information of a target object, provided in an embodiment of this application.

[0031] Figure 11 This is a schematic diagram illustrating the acquisition of speed information of a target object, provided in an embodiment of this application.

[0032] Figure 12 This is a schematic diagram illustrating the acquisition of angle information of a target object, provided in an embodiment of this application.

[0033] Figure 13 A third flowchart illustrating a fall detection method provided in this application embodiment;

[0034] Figure 14 A flowchart of a fall detection method provided in this application embodiment;

[0035] Figure 15 A schematic diagram illustrating a second judgment rule provided in an embodiment of this application;

[0036] Figure 16 A flowchart for the first fall detection provided in this application embodiment;

[0037] Figure 17 A flowchart for the second fall detection provided in this application embodiment;

[0038] Figure 18 A flowchart for the secondary fall confirmation judgment provided in this application embodiment;

[0039] Figure 19This is a schematic diagram of the structure of a fall detection device provided in an embodiment of this application;

[0040] Figure 20 This is a schematic diagram of the structure of a radar device provided in an embodiment of this application. Detailed Implementation

[0041] The following is a detailed description of a method and apparatus for detecting body movement provided in this application, with reference to the accompanying drawings.

[0042] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0043] The terms "first" and "second," etc., used in the specification and drawings of this application are used to distinguish different objects or to distinguish different treatments of the same object, rather than to describe a specific order of objects.

[0044] Furthermore, the terms "comprising" and "having," and any variations thereof, used in the description of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include other steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0045] It should be noted that in the embodiments of this application, the words "exemplary" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the words "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0046] In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0047] As described in the background section, falls currently affect millions of people annually and cause numerous injuries, particularly among the elderly. Therefore, real-time fall detection technology has significant practical implications for protecting human health.

[0048] Existing fall detection methods typically rely on capturing images of users to identify their behavior. However, this approach carries the risk of privacy breaches and may raise information security concerns. Furthermore, the accuracy of the detection method is significantly affected by environmental factors such as lighting, smoke, and obstructions, all of which can reduce the accuracy of the detection results.

[0049] To address the aforementioned technical problems, this application provides a fall detection method that acquires the motion characteristics of a target object within each unit of time across multiple consecutive unit time periods. The motion characteristics include at least one of distance data, velocity data, Doppler signal data, and angle data. Distance data indicates the maximum change in motion distance; velocity data indicates the maximum value of motion velocity and the change in velocity area, with the change in velocity area indicating the ratio of the target motion velocity to the multiple motion velocities, where the target motion velocity is greater than a first threshold; Doppler signal data indicates the maximum value of the Doppler signal intensity; and angle data indicates the maximum change in motion angle. Based on preset state judgment rules and the motion characteristics of the target object within each unit of time period, the state of the target object within each unit of time period is determined, resulting in a state sequence of the target object across multiple consecutive unit time periods. The state includes falling, moving, or stationary, and the state sequence includes states ordered by time. If the state sequence satisfies the preset fall rules, the target object is determined to have fallen.

[0050] The technical solution provided in this application, applied to radar equipment, enables contactless motion detection without infringing on user privacy, effectively improving the user experience. Furthermore, the radar equipment is unaffected by the environment, thus avoiding the reduction in accuracy caused by environmental factors such as lighting, smoke, and obstruction. In addition, the technical solution provided in this application determines the state sequence of the target object within each unit of time in a series of consecutive time units based on the motion characteristics of the target object. It then determines whether the state sequence meets a preset fall rule, and if so, determines that the target object has fallen. In other words, this application uses logical judgment to implement human fall detection, which has low algorithm complexity and low hardware computing power requirements, thus saving development costs while ensuring the detection of a fall.

[0051] In the embodiments of this application, the radar device is an electronic device that uses electromagnetic waves to detect targets, such as millimeter-wave radar, microwave radar, ultra-wideband radar, etc.

[0052] Millimeter waves refer to electromagnetic waves in the 30–300 GHz frequency domain (wavelength 1–10 mm). Since the wavelength of millimeter waves falls between that of centimeter waves and light waves, they combine the advantages of microwave guidance and photoelectric guidance. Millimeter waves have extremely wide bandwidth, alleviating the problem of limited frequency resources; their narrow beam allows for clearer observation of target details. Therefore, some embodiments of this application employ millimeter waves for fall detection, effectively improving the anti-interference capability, resolution, and measurement accuracy of radar equipment.

[0053] For example, a radar device can consist of a radar transmitter, a radar receiver, and an antenna. The radar device can be a frequency-modulated continuous wave (FMCW) millimeter-wave radar device.

[0054] A radar transmitter is a radio device that provides high-power radio frequency signals to radar equipment. It generates high-power radio frequency signals, i.e., electromagnetic waves, with a modulated carrier wave. Based on the modulation method, transmitters can be divided into two categories: continuous wave transmitters and pulse transmitters. A transmitter consists of a single-stage radio frequency oscillator and a pulse modulator.

[0055] A radar receiver is a device in radar equipment that performs frequency conversion, filtering, amplification, and demodulation. Through appropriate filtering, it selects the weak high-frequency signals received by the antenna from accompanying noise and interference, and after amplification and detection, uses them for target detection, display, or other radar signal processing.

[0056] An antenna is a device in radar equipment used to transmit or receive electromagnetic waves and determine its detection direction. When transmitting, it concentrates energy to radiate in the direction to be illuminated; when receiving, it receives the echo in the detection direction and distinguishes the target's azimuth and / or angle.

[0057] For example, the antenna arrangement diagram is as follows: Figure 1 As shown, T1, T2, T3, and T4 are the transmitting antennas of the array antenna, used to transmit microwave signals, and R1, R2, and R3 are the receiving antennas of the array antenna, used to receive echo signals. The millimeter-wave radar can determine the location information of the target object based on the echo signals received by the receiving antennas. The distance between the transmitting antennas is d, and the distance between the receiving antennas is 2d.

[0058] The principle behind radar equipment for measuring distance is that it measures the time difference between transmitting and receiving electromagnetic waves to determine the distance to a target object.

[0059] The principle behind radar speed measurement is based on the Doppler frequency shift phenomenon caused by the relative motion between the radar equipment and the target object. When an electromagnetic wave encounters a stationary target object, the reflected electromagnetic wave is emitted from the target object at its original frequency. When the electromagnetic wave encounters a moving target object, the target's velocity modulates the electromagnetic wave, causing the frequency of the reflected electromagnetic wave to increase or decrease, thus producing the Doppler frequency shift phenomenon. Using this Doppler frequency shift phenomenon, the Doppler frequency associated with the moving target object can be extracted. The amplitude of the Doppler frequency fluctuation is directly proportional to the target object's speed; that is, when the target object moves slowly, the Doppler frequency fluctuation amplitude is small, and when the target object moves quickly, the Doppler frequency fluctuation amplitude is large. Therefore, the target object's speed can be determined based on the amplitude of the Doppler frequency fluctuation.

[0060] The principle of radar equipment in measuring azimuth is that the radar equipment measures the distance and elevation angle based on the azimuth beam and elevation beam of the antenna, and then obtains the angle of the target object.

[0061] In some embodiments, the radar device is installed on the indoor ceiling and is activated upon receiving an activation command from an electronic device to detect falls on indoor target objects.

[0062] The aforementioned radar equipment can be applied to scenarios involving human fall detection. For example... Figure 2 As shown, when a target object falls, the radar equipment transmits electromagnetic waves into the space where the target object is located via a transmitting antenna. The receiving antenna receives the electromagnetic waves reflected by the target object, i.e., the echo signal, and sends this echo signal to the receiver for signal processing. After processing such as frequency conversion, filtering, amplification, or demodulation, the receiver extracts relevant information about the target object (e.g., the distance between the target object and the radar, the angle of the target object, the speed of the target object, etc.). By analyzing this relevant information, it can be determined whether the target object has fallen.

[0063] like Figure 3 The diagram shown is a schematic representation of a fall detection system 10 provided in an embodiment of this application. The system may include a radar device 101 and an electronic device 102. The radar device 101 and the electronic device 102 can be connected via wired or wireless means. For example, the radar device 101 and the electronic device 102 can be connected via a wireless local area network.

[0064] The electronic device 102 is used to send control commands to the radar device 101 and receive fall detection results from the radar device 101. Exemplarily, the electronic device in this embodiment can be a mobile phone, tablet computer, desktop computer, laptop computer, handheld computer, notebook computer, ultra-mobile personal computer (UMPC), netbook, cellular phone, personal digital assistant (PDA), augmented reality (AR) / virtual reality (VR) device, etc. This application does not impose any special limitations on the specific form of the electronic device. It can interact with the user through one or more methods such as a keyboard, touchpad, touchscreen, remote control, voice interaction, or handwriting device.

[0065] After detecting a target falling, radar device 101 can simultaneously upload the time of the fall and its motion characteristics to a server. This allows the server to obtain relevant fall data, preventing data loss and facilitating subsequent statistical analysis of the fall. The server can be a cloud server.

[0066] The solution provided in this application will be described in detail below with reference to the accompanying drawings.

[0067] This application provides a fall detection method, applied to the aforementioned radar device. For example... Figure 4 As shown, the method includes the following steps: S201-S204.

[0068] S201. The radar equipment acquires the motion characteristics of the target object within each unit of time in a series of consecutive unit time periods.

[0069] The motion features include at least one of distance data, velocity data, Doppler signal data, and angle data. The distance data is used to indicate the maximum change in motion distance; the velocity data is used to indicate the maximum value of motion velocity and the velocity area change value. The velocity area change value is used to indicate the ratio of the target motion velocity to the multiple motion velocities, where the target motion velocity is greater than a first threshold; the Doppler signal data is used to indicate the maximum value of Doppler signal intensity; and the angle data is used to indicate the maximum change in motion angle.

[0070] One possible approach is to process the echo signal reflected by the target object to obtain the motion characteristics of the target object within each unit of time in a series of consecutive unit time periods.

[0071] In some embodiments, the radar device processes the echo signal reflected by the target object to obtain distance data and / or velocity data of the target object within each unit time period in a series of unit time periods.

[0072] For example, taking a unit duration of 1 second (s) and multiple unit durations of 4 seconds as an example, the radar equipment acquires the maximum change in distance and the maximum value of velocity per second of the target object within a continuous 4 seconds.

[0073] In some embodiments, the radar device processes the echo signal reflected by the target object to obtain velocity data and / or Doppler signal data of the target object within each unit time period in a series of unit time periods.

[0074] For example, taking a unit duration of 1 second (s) and multiple unit durations of 4 seconds as an example, the radar equipment acquires the maximum value of the target object's velocity per second and the maximum value of the Doppler signal strength over a continuous 4 seconds.

[0075] In some embodiments, the radar device processes the echo signal reflected by the target object to obtain distance data, velocity data, Doppler signal data, and angle data of the target object within each unit time period in a series of multiple unit time periods.

[0076] For example, taking a unit duration of 1 second (s) and multiple unit durations of 4 seconds as an example, the radar equipment acquires the maximum value of the target object's velocity per second, the maximum velocity value, the velocity area change value, and the maximum value of the Doppler signal strength for the target object in a continuous 4 seconds.

[0077] It should be noted that this application does not specifically limit the duration of multiple consecutive units or the duration of a single unit. The duration of a unit can be a second or other time unit, and the duration of multiple consecutive units can be 4 seconds, 6 seconds, or other time lengths.

[0078] S202. The radar equipment determines the first state of the target object within each unit of time based on the first state judgment rule and the motion characteristics of the target object within each unit of time, thereby obtaining the first state sequence of the target object within multiple consecutive units of time.

[0079] The first state includes falling, moving, or being at rest, and the sequence of the first states includes states ordered by time.

[0080] As one possible implementation, when the first judgment rule includes a first motion rule, a first stationary rule, and a first fall rule, the radar device determines whether the motion characteristics within a first unit of time satisfy the first motion rule, the first stationary rule, or the first fall rule. If the motion characteristics within the first unit of time satisfy the first fall rule, the radar device determines that the target object's first state within the first unit of time is a fall state. If the motion characteristics within the first unit of time do not satisfy the first fall rule, the radar device then determines whether the motion characteristics within the first unit of time satisfy the first motion rule. The first unit of time can be any one of a series of consecutive unit of time.

[0081] Furthermore, if the motion characteristics within the first unit of time satisfy the first motion rule, the radar device determines the first state of the target object within the first unit of time as a moving state. Subsequently, if the motion characteristics within the first unit of time do not satisfy the first motion rule, the radar device determines the first state of the target object within the first unit of time as a stationary state. Finally, the radar device acquires multiple first states and sorts them sequentially according to time order to obtain a sequence of first states of the target object within multiple consecutive units of time.

[0082] Specifically, such as Figure 5 As shown, the radar device determines whether the motion characteristics of the target object within the first unit of time satisfy the first falling rule. If the first falling rule is satisfied, the radar device determines that the target object is in a falling state within the first unit of time and sets the flag bit of the state within the first unit of time to 1. If the first falling rule is not satisfied, the radar device determines whether the motion characteristics within the first unit of time satisfy the first motion rule. If the first motion rule is satisfied, the radar device determines that the target object is in a moving state within the first unit of time and sets the flag bit of the state within the first unit of time to 0. If the first motion rule is not satisfied, it is determined that the first stationary rule is satisfied, and the radar device determines that the target object is in a stationary state within the first unit of time and sets the flag bit of the state within the first unit of time to 2. Finally, the radar device obtains the flag bits of multiple states of the target object within multiple units of time and sorts the flag bits of multiple states in chronological order to obtain the first state sequence of the target object within multiple consecutive units of time.

[0083] For example, taking a unit duration of 1 second and multiple unit durations of 4 seconds as an example. Based on the above first judgment rule, the radar device sequentially determines the state of the target object within 4 seconds: falling, moving, stationary, stationary, and obtains the first state sequence of the target object within 4 seconds: 1, 0, 0, 2.

[0084] For example, taking a unit duration of 1 second and multiple units of 5 seconds as an example. Based on the above first judgment rule, the radar device sequentially determines the state of the target object within 5 seconds: falling, moving, stationary, stationary, moving, and obtains the first state sequence of the target object within 4 seconds: 1, 0, 0, 2, 0.

[0085] It should be noted that the radar device can also first determine whether the motion characteristics of the target object within the first unit time period satisfy the first stationary rule, or first determine whether the motion characteristics of the target object within the first unit time period satisfy the first motion rule, or simultaneously determine which of the following rules—the first stationary rule, the first motion rule, and the first fall rule—the motion characteristics of the target object within the first unit time period satisfy. The value of the flag bit representing the first state can also be other values; this application does not specifically limit this.

[0086] The specific implementation method for this step can be found in the steps above, and will not be repeated here.

[0087] S203. The radar equipment determines whether the first state sequence meets the preset first fall rule.

[0088] As one possible approach, the radar device acquires the state parameters of each sequence in the first state sequence and sequentially determines whether each state sequence parameter satisfies the preset first fall rule.

[0089] In some embodiments, the radar device sequentially determines whether each state sequence parameter satisfies a preset first fall rule.

[0090] For example, taking the first state sequence: 1, 0, 0, 2 as an example. The radar device acquires the first state sequence: 1, 0, 0, 2, and based on a preset first fall rule, determines whether the first parameter of the first state sequence is 1. If it is confirmed that the first parameter of the first state sequence is 1, the radar device sequentially determines whether the second and third parameters of the first state sequence are not 1, and then determines whether the fourth parameter of the first state sequence is 2.

[0091] As another possible implementation, the radar device acquires multiple preset state sequences from a preset first fall rule and determines whether the first state sequence is consistent with any of the multiple preset state sequences.

[0092] Obtain the state parameters of each sequence in the first state sequence, and determine in turn whether each state sequence parameter satisfies the first fall rule.

[0093] For example, taking the first state sequence as 1, 0, 0, 2, and the preset first fall rule including four preset state sequences: [1, 0, 0, 2], [1, 2, 0, 2], [1, 0, 2, 2], [1, 2, 2, 2]. The radar device determines whether the first state sequence is consistent with any one of the four preset state sequences.

[0094] It should be noted that the preset first fall rule is stored in the radar equipment in advance by the maintenance personnel.

[0095] S204. If the radar equipment determines that the target object has fallen when the first state sequence meets the preset first fall rule, the radar equipment determines that the target object has fallen.

[0096] As one possible approach, the radar device determines that the target object has fallen if each state sequence parameter satisfies a preset first fall rule.

[0097] In another scenario, the radar device acquires the state within the first unit of a series of consecutive time units. Based on the state within the first unit and the first fall rule, it determines whether the state within the first unit satisfies the first fall rule. If the first fall rule is not met, the radar device determines that the target object is not falling and stops the evaluation. If the first fall rule is met, the radar device then determines whether the state within the second unit of a series of consecutive time units satisfies the first fall rule. In this way, the radar device sequentially determines whether the state within each unit of a series of consecutive time units satisfies the first fall rule.

[0098] For example, taking a unit duration of 1 second and multiple units of 4 seconds as an example. The radar device acquires the state of the target object in the 1st second and determines whether the state in the 1st second meets the first falling rule. If the state in the 1st second does not meet the first falling rule, the radar device determines that the target object is not falling and does not further determine the state of the target object in the 2nd second based on the first judgment rule. If the state in the 1st second meets the first falling rule, the radar device determines the state of the target object in the 2nd second based on the first judgment rule and determines whether the state in the 2nd second meets the first falling rule. In this way, the radar device judges whether the state of the target object within each 4 seconds meets the first falling condition, and if the state in any second does not meet the first falling rule, it determines that the target object is not falling and does not continue to judge the state in the next second.

[0099] Subsequently, in some embodiments, the radar device sends the target object's fall time, motion characteristics, state sequence, and fall result to electronic devices and servers.

[0100] The technical effects of the solution provided in this application are as follows: it enables contactless fall detection without infringing on user privacy, effectively improving the user experience. Furthermore, the radar device is unaffected by the environment, thus avoiding the reduction in accuracy caused by environmental factors such as lighting, smoke, and obstructions. In addition, the technical solution provided in this application determines the state sequence of the target object within each unit of time in a series of consecutive time units. It then determines whether the state sequence meets a preset fall rule, and if so, confirms that the target object has fallen. In other words, this application uses logical judgment to implement human fall detection, which has low algorithm complexity and low hardware computing power requirements, thus saving development costs while ensuring the detection of a fall.

[0101] In one design, each unit duration includes multiple frames. Given that motion features include distance data, velocity data, Doppler signal data, and angle data, in order to obtain the motion features of the target object within each unit duration across multiple consecutive unit durations, such as... Figure 6 As shown, S201 provided in the embodiments of this application specifically includes the following S2011-S2019.

[0102] S2011. The radar equipment acquires the echo signal corresponding to each frame in multiple frames, and obtains the echo signal corresponding to multiple frames.

[0103] The echo signal corresponding to each frame includes the signal reflected by the target object after the radar device sends multiple detection signals in each frame.

[0104] As one possible approach, the receiving antenna of the radar device acquires the echo signal corresponding to each frame in multiple frames, thus obtaining the echo signal corresponding to multiple frames.

[0105] Specifically, the radar equipment's transmitting antennas sequentially transmit multiple frames of chirp signals in a specific order, thus forming an effective virtual antenna array. Each transmitting antenna transmits multiple chirp signals within a single frame. Subsequently, the radar equipment's receiving antennas acquire multiple frames of chirp signals reflected by the target object.

[0106] Furthermore, the radar equipment processes the echo signal of the first frame among multiple received frames. The first frame can be any one of the multiple frames. Specific processing steps include steps 11-14.

[0107] Step 11: The radar equipment performs pulse compression on the received echo signal of the first frame to obtain the target range image.

[0108] Pulse compression refers to the compression and sidelobe suppression of the echo of a linear frequency modulated signal or phase-coded signal, compressing a wide pulse into a narrow pulse, causing the output signal to peak at the target's range gate, while simultaneously improving the signal-to-noise ratio. Radar equipment transmits signals with large time and bandwidth at the transmitting antenna end to improve the accuracy and resolution of signal velocity measurement. At the receiving antenna end, pulse compression further compresses the wide pulse signal into a narrow pulse signal, improving the radar equipment's range resolution accuracy and range resolution against the target.

[0109] In some embodiments, the above pulse compression process can satisfy the following formula (1):

[0110]

[0111] Among them, TR (m,k) This represents the amplitude of the m-th linear frequency modulated signal (chirp signal) at frequency k. Frequency k can represent the distance unit. Frequency k is proportional to the distance. Frequency k can satisfy the following formula (2):

[0112]

[0113] Where s is the slope of the frequency modulation signal of the radar device, D represents the distance between the radar device and the target object, and c represents the speed of light.

[0114] In the above formula (1), W u S is a preset window function. (n-u,m) This represents the data of the null-th sampling point of the m-th linear frequency modulated signal. It should be understood that pulse compression can be performed on a frame-by-frame basis. After performing the calculation as shown in formula (1) on a frame of data, the target range image of the first frame of data can be obtained.

[0115] It should be understood that pulse compression of a linear frequency modulated signal across all range cells yields the target range image RI(t).

[0116] Step 12: The radar equipment performs pulse compression processing on the time-range image of the first frame to obtain the target velocity image.

[0117] Because a human body may experience significant acceleration during a fall, radar equipment balances maximum detection speed and velocity resolution when acquiring data. The velocity of the target object acquired by the radar is the target's range change rate; therefore, the target's velocity information is contained in the phase shift of the temporal range image. To extract the target's range-Doppler (RD) processing information, pulse compression processing is performed on each frame of the temporal range image to obtain the target velocity image.

[0118] In some embodiments, the process of pulse compression processing of the above-mentioned time-distance image can satisfy the following formula (3):

[0119]

[0120] in, W represents the velocity-distance amplitude at point d1 obtained on the k-th time-distance image. u For a predefined window function, TR (k,m-u) This represents the distance image data in the k-th row and mu-th column of this frame.

[0121] Subsequently, the Doppler signal strength of the target object corresponding to that frame is calculated using the target velocity-like VR.

[0122] In some embodiments, the Doppler signal strength can satisfy the following formula (4):

[0123] Dooppler_mean = VR / FFT_num (Formula 4)

[0124] Where Doppler_mean represents the Doppler signal strength, and FFT_num represents the length of the fastfourier transform (FFT).

[0125] Step 13: The radar device acquires the first frame of the angle image.

[0126] The angle of a target object in a falling or moving state will change. Therefore, the embodiments of this application add angle information to the feature space to accurately determine the falling action.

[0127] To address changes in the target object's angle, embodiments of this application can employ a direction of arrival (DOA) estimation method. Due to the antenna arrangement of radar equipment, the echo signal travels different distances to reach different receiving antennas, resulting in a phase difference between the echo signals received by different antennas. This principle is used to obtain the target object's angle information. A schematic diagram illustrating the DOA-based estimation of the target object's angle information is shown below. Figure 7 As shown.

[0128] In some embodiments, the signal received echo from a single antenna is xn, and the signal composed of all receiving antennas is given by formula (5):

[0129] X = [x1, x2, x3, ..., xn] Formula (5)

[0130] Where x1 is the first received signal and n is the total number of received signals.

[0131] In some embodiments, the range profile of a single chirp signal is X, and its autocorrelation matrix is ​​given by formula (6):

[0132] R xx =E[XX H ] Formula (6)

[0133] The steering vector of the signal angle is given by formula (7):

[0134] a(θ) = [1, e -j2πdsinθ / c ,e -j2π2dsinθ / c ......,e -j2π(n-1)dsinθ / c ] Formula (7)

[0135] Where a(θ) is the signal angle and d is the distance between the transmitting antennas of the radar equipment.

[0136] Thus, the signal strength CBF of the target echo of the x-th chirp at angle θ. (θ,x) For formula (8):

[0137] CBF (θ,x) =a(θ)R xx Formula (8) for a(θ)

[0138] At the same time, the normalized angular image CBF can be obtained. nor For formula (9):

[0139]

[0140] At the same time, using the angle image CBF nor The target object angular spectral feature information DOA_mean of this frame can be calculated using formula (10):

[0141] DOA_mean=CBF nor / angle_num Formula (10)

[0142] Where angle_num = 181, it represents the change of angle from 0 degrees to 180 degrees.

[0143] How to obtain the distance image, velocity image, and angle image of the target object? Figure 8 As shown.

[0144] Furthermore, since static objects are completely stationary, the detected target object will exhibit slight fluctuations. Therefore, radar equipment can employ moving target indication (MTI) technology, which involves two-pulse cancellation of the received data to eliminate the electromagnetic waves reflected by the static object, thereby achieving static target elimination. The above static target elimination process can satisfy the following formula (11):

[0145] RI MTI (tT r )=RI(tT r Formula (11) -RI(t)

[0146] Where RI(t) is the target range profile at the current time, and RI(t) is the range profile itself. t is the time corresponding to the m-th linear frequency modulated signal. RI(tT) r ) represents the distance T before the current time. r Target distance image at any given time. RI MTI (tT r () represents the target range image after static target elimination.

[0147] In some embodiments, considering that radar devices may lose target objects or track static targets during actual detection, in order to avoid this problem, the radar device in this application determines whether the Doppler signal strength Doppler_mean of the current frame is greater than a second strength threshold.

[0148] If the Doppler signal strength Doppler_mean of the first frame is less than the second strength threshold, the status information flag of the target object corresponding to the first frame will be set to 0.

[0149] If the Doppler signal strength Doppler_mean of the first frame is greater than or equal to the second strength threshold, proceed to step 14 below.

[0150] In some embodiments, since the static object is completely stationary, the detected target object will have slight fluctuations. Therefore, the radar equipment can use moving target indication (MTI) technology, that is, perform two-pulse cancellation on the received data to eliminate the electromagnetic waves reflected by the static object, so as to achieve static target elimination. The above static target elimination process can satisfy the following formula (11):

[0151] RI MTI (tT r )=RI(tT r Formula (11) -RI(t)

[0152] Where RI(t) is the target range profile at the current time, and RI(t) is the range profile itself. t is the time corresponding to the m-th linear frequency modulated signal. RI(tT) r ) represents the distance T before the current time. r Target distance image at any given time. RI MTI (tT r () represents the target range image after static target elimination.

[0153] Step 14: Based on the range image, target image, and angle image of the first frame, the radar device determines the range, velocity, and angle of the target object corresponding to the first frame.

[0154] 1) The radar equipment acquires the range cell Range_wave corresponding to the largest amplitude in the range image of the first frame and calculates the distance of the target object corresponding to the current frame.

[0155] In some embodiments, the motion distance of the target object corresponding to the first frame is calculated using formula (12):

[0156] Range_wave=Location_num×Range_resolution formula (12)

[0157] Here, Range_wave represents the target object's movement distance, and Range_resolution represents the radar device's range resolution.

[0158] 2) The radar equipment acquires the velocity unit Location_cel corresponding to the largest amplitude in the velocity image of the first frame and calculates the velocity of the target object corresponding to the first frame.

[0159] In some embodiments, the velocity of the target object corresponding to the first frame is calculated using formula (13):

[0160] Velocity_wave=(Location_cel-128)×Vel_resolution Formula (13)

[0161] Here, Velocity_wave represents the velocity of the target object, and Vel_resolution represents the velocity resolution of the radar device.

[0162] 3) The radar equipment acquires the angle unit Location_doa corresponding to the largest amplitude in the angle image of the first frame, and calculates the angle of the target object corresponding to the first frame.

[0163] In some embodiments, the angle of the target object corresponding to the first frame is calculated using formula (14):

[0164] Angle_wave=Location_doa formula (14)

[0165] Angle_wave represents the angle of the target object.

[0166] Figure 9 This is a schematic diagram illustrating how radar equipment obtains the range, velocity, and angle information of the first frame based on echo signals corresponding to multiple frames.

[0167] S2012. The radar equipment determines the maximum and minimum movement distances of the target object in multiple frames based on the echo signals corresponding to multiple frames.

[0168] One possible approach is for the radar device to process the echo signals corresponding to multiple frames to obtain the movement distance of the target object across those frames. Furthermore, the radar device extracts the maximum and minimum movement distances from the multiple target object movement distances.

[0169] Among them, the maximum range_max of the movement distance is obtained by formula (15):

[0170] range_max=[Range_wave[0],Range_wave[1]...Range_wave[n]] max Formula (15)

[0171] The minimum range_min is obtained by formula (16):

[0172] range_min=[Range_wave[0],Range_wave[1]...Range_wave[n]] min Formula (16)

[0173] S2013. The radar equipment determines the distance data of the target object within each unit of time by the difference between the maximum and minimum moving distance.

[0174] The distance data range_change is obtained using formula (17):

[0175] range_change=range_max-range_min formula (17)

[0176] Figure 10 A schematic diagram illustrating the acquisition of maximum and minimum moving distances and distance data for radar equipment.

[0177] S2014. The radar equipment determines the maximum velocity and velocity-area change of the target object in multiple frames based on the echo signals corresponding to multiple frames.

[0178] One possible approach is for the radar device to process echo signals corresponding to multiple frames to obtain the motion velocity of the target object across those frames. Further, the radar device obtains the maximum motion velocity from the multiple target object motion velocities. Additionally, the radar device obtains a first number of motion velocities greater than an eleventh velocity threshold and a second number of motion velocities that are not zero from the multiple target object motion velocity values, and determines the ratio of the first number to the second number as the velocity area change value.

[0179] Among them, the maximum velocity_max is obtained by formula (18):

[0180] velocity_max=[Velocity_wave[0],Velocity_wave[1]...Velocity_wave[n]] max Formula (18)

[0181] Get the first quantity vel above _max is the formula (19):

[0182] vel above _max=[Velocity_wave[0],Velocity_wave[1]...Velocity_wave[n]] >p Formula (19)

[0183] For example, p can be 0.5 or other values, and this application embodiment does not limit it.

[0184] Get the second quantity vel exist _max is the formula (20):

[0185] vel exist _num=[Velocity_wave[0],Velocity_wave[1]...Velocity_wave[n]] ≠0 Formula (20)

[0186] It should be noted that in the embodiments of this application, the second quantity is the quantity whose movement speed is not zero. The second quantity can also be other quantities, for example, the second quantity is the quantity whose movement speed is greater than 0.1.

[0187] Formula (21) for obtaining the velocity area change value:

[0188]

[0189] For example, q can be 10 or other values, and this application embodiment does not limit it.

[0190] Figure 11 A schematic diagram for obtaining the maximum velocity and velocity area change value for radar equipment.

[0191] S2015. Radar equipment determines the maximum value of the moving speed and the value of the change in speed area as the speed data of the target object in each unit of time.

[0192] S2016. The radar equipment determines the maximum value of the Doppler signal intensity of the target object in multiple frames based on the echo signals corresponding to multiple frames.

[0193] One possible approach is for the radar device to process the echo signals corresponding to multiple frames to obtain the Doppler signal intensities for those frames. Further, the radar device obtains the maximum Doppler signal intensity from these multiple intensities.

[0194] The maximum value of the Doppler signal intensity, doppler_max, is obtained by the following formula (22):

[0195] doppler_max=[Doppler_wave[0],Doppler_wave[1]...Doppler_wave[n]] max

[0196] S2017. The radar equipment determines the maximum value of the Doppler signal strength as the Doppler signal data of the target object in each unit of time.

[0197] S2018. The radar equipment determines the maximum and minimum motion angles of the target object in multiple frames based on the echo signals corresponding to multiple frames.

[0198] One possible approach is for the radar device to process the echo signals corresponding to multiple frames to obtain the motion angles corresponding to those frames. Furthermore, the radar device obtains the maximum and minimum motion angle values ​​from these motion angles.

[0199] Among them, the maximum value of the motion angle, angle_max, is obtained by formula (23):

[0200] angle_max=[Angle_wave[0],Angle_wave[1]...Angle_wave[n]] max Formula (23)

[0201] The minimum angle of motion, angle_min, is obtained by formula (24):

[0202] angle_min=[Angle_wave[0],Angle_wave[1]...Angle_wave[n]] min Formula (24)

[0203] S2019. The radar equipment determines the angle data of the target object within each unit of time by the difference between the maximum and minimum motion angles.

[0204] The angle data angle_change is obtained using formula (25):

[0205] angle_change=angle_max-angle_min formula (25)

[0206] In some embodiments of this application, the average value of the motion angles corresponding to multiple frames can also be obtained.

[0207] Figure 12 A schematic diagram illustrating the acquisition of maximum and minimum motion angles and angle data for radar equipment.

[0208] The average value of the motion angles corresponding to multiple frames, doa_mean, is obtained by formula (26):

[0209] doa_mean=[DOA_mean[0]+DOA_mean[1]+...DOA_mean[n]] / n Formula (26)

[0210] Understandably, in the embodiments of this application, the radar device acquires distance data, velocity data, Doppler signal data, and angle data of the target object within each unit of time.

[0211] In one design, the first decision rules include a first motion rule, a first stationary rule, and a first fall rule. This is to determine the state of the target object in each unit of time, such as... Figure 13 As shown, S202 provided in the embodiments of this application specifically includes the following S2021-S2026.

[0212] S2021. The radar equipment determines whether the motion characteristics of the target object within each unit of time meet the first fall rule.

[0213] S2022. If the motion characteristics of the target object within each unit of time satisfy the first motion rule, the radar equipment determines that the state of the target object within each unit of time is a falling state.

[0214] Specifically, if the distance data within the first unit of time is greater than a first distance threshold, and the maximum speed of the target object within the first unit of time is greater than a first speed threshold, the state of the target object within the first unit of time is determined to be a fall. Alternatively, if the angle data value of the target object within the first unit of time is greater than a first angle threshold, and the maximum speed of the target object within the first unit of time is greater than a second speed threshold, the movement of the target object within the first unit of time is determined to be a fall.

[0215] Alternatively, if the target object's angle data is greater than the second angle threshold, the target object's maximum velocity value is greater than the third velocity threshold, every angle value of the target object is greater than the ninth angle threshold, and every distance of the target object is greater than the ninth distance threshold within the first unit of time, then the target object's state within the first unit of time is determined to be a fall. Alternatively, if the target object's maximum velocity value is greater than the fourth velocity threshold, and the target object's velocity-area change value is greater than the first change threshold within the first unit of time, then the target object's state within the first unit of time is determined to be a fall.

[0216] Alternatively, if the maximum velocity of the target object within the first unit of time is greater than the fourth velocity threshold, and the maximum Doppler signal intensity of the target object within the first unit of time is greater than the first Doppler signal intensity threshold, then the state of the target object within the first unit of time is determined to be a fallen state.

[0217] S2023. The radar equipment determines whether the motion characteristics of the target object within each unit of time meet the first motion rule.

[0218] S2024. When the motion characteristics of the target object within each unit of time satisfy the first motion rule, the radar equipment determines the state of the target object within each unit of time as the motion state.

[0219] Specifically, if the distance data of the target object is greater than or equal to the third distance threshold, the maximum speed of the target object is greater than or equal to the fifth speed threshold, or the angle data of the target object is greater than or equal to the third angle threshold within the first unit of time, the state of the target object within the first unit of time is determined to be in motion.

[0220] S2025. The radar equipment determines whether the motion characteristics of the target object within each unit of time satisfy the first stationary rule.

[0221] S2026. When the motion characteristics of the target object within each unit of time satisfy the first stationary rule, the radar equipment determines that the state of the target object within each unit of time is stationary.

[0222] Specifically, if the change in distance of the target object within the first unit of time is less than the third distance threshold, the maximum speed of the target object within the first unit of time is less than the fifth speed threshold, or the angle data of the target object within the first unit of time is less than the third angle threshold, the state of the target object within the first unit of time is determined to be stationary.

[0223] It should be noted that in some embodiments, the radar device first determines whether the motion characteristics of the target object within each unit of time satisfy the first falling rule, and if the motion characteristics within the first unit of time do not satisfy the first falling rule, it then determines whether the motion characteristics within the first unit of time satisfy the first motion rule. Finally, if the motion characteristics within the first unit of time do not satisfy the first motion rule, it then determines whether the motion characteristics within the first unit of time satisfy the first stationary rule.

[0224] In some embodiments, before determining the state within each unit time period, the radar device determines whether the current distance of the target object is less than or equal to the tenth distance threshold. If the current distance of the target object is greater than the tenth distance threshold, the radar device determines that the maximum velocity of the target object within the first unit time period is less than the sixth velocity threshold, or the maximum Doppler signal intensity of the target object within the first unit time period is less than the second Doppler signal intensity threshold, thus determining that the state of the target object within each unit time period is a moving state. Conversely, if the conditions are not met, the state of the target object within the first unit time period is determined to be a stationary state.

[0225] The first distance threshold, third distance threshold, tenth distance threshold, first speed threshold, second speed threshold, third speed threshold, fourth speed threshold, fifth speed threshold, sixth speed threshold, first angle threshold, second angle threshold, third angle threshold, second Doppler signal strength threshold, and first Doppler signal strength threshold are stored in the radar equipment in advance by the maintenance personnel.

[0226] The first unit duration is any one of a series of consecutive unit durations.

[0227] The order in which S2021, S2023, and S2025 are executed is not limited in this embodiment. S2021 can be executed first, S2025 can be executed first, or S2021, S2023, and S2025 can be executed simultaneously.

[0228] If the target object is in motion within the first unit of time, its status flag can be set to 0. If the target object is in a fallen or injured state within the first unit of time, its status flag can be set to 1. If the target object is stationary within the first unit of time, its status flag can be set to 1.

[0229] In one design, to avoid missed alarms, such as Figure 14 Following S204 provided in the embodiments of this application, the following steps S205-S207 are also included.

[0230] S205. If the radar equipment does not meet the first fall rule in the first state sequence, it determines the second state of the target object in each unit of time based on the second judgment rule and the motion characteristics of the target object in each unit of time, and obtains the second state sequence of the target object in multiple units of time.

[0231] The second state includes a fallen state, a moving state, or a stationary state, and the second state sequence includes the second states ordered by time.

[0232] Specifically, the second judgment rule includes a second motion rule, a second stationary rule, and a second fall rule. To determine the state of the target object for each unit of time under the second judgment rule, this application embodiment includes steps 21-23.

[0233] Step 21: The radar equipment determines whether the motion characteristics of the target object within each unit of time satisfy the second falling rule. If the motion characteristics of the target object within each unit of time satisfy the second falling rule, the state of the target object within each unit of time is determined to be a falling state.

[0234] Specifically, if the radar equipment determines that the distance data within the first unit of time is greater than the fourth distance threshold and less than the fifth distance threshold, and the maximum speed of the target object within the first unit of time is greater than the seventh speed threshold, then the target object's state within the first unit of time is determined to be a fallen object. Alternatively, if the angle data value of the target object within the first unit of time is greater than or equal to the fourth angle threshold and less than or equal to the fifth angle threshold, and the maximum speed of the target object within the first unit of time is greater than the eighth speed threshold, then the target object's state within the first unit of time is determined to be a fallen object.

[0235] Alternatively, if the distance data within the first unit of time is greater than the sixth distance threshold, the angle data value of the target object within the first unit of time is greater than or equal to the sixth angle threshold, and the maximum speed of the target object within the first unit of time is greater than the ninth speed threshold, then the state of the target object within the first unit of time is determined to be falling.

[0236] Alternatively, if the distance data within the first unit of time is less than the seventh distance threshold, the angle data value of the target object within the first unit of time is less than or equal to the seventh angle threshold, and the maximum speed of the target object within the first unit of time is greater than the tenth speed threshold, then the state of the target object within the first unit of time is determined to be falling.

[0237] Step 22: The radar equipment determines whether the motion characteristics of the target object within each unit of time satisfy the second motion rule, and if the motion characteristics of the target object within each unit of time satisfy the second motion rule, the state of the target object within each unit of time is determined as the motion state.

[0238] Specifically, if the radar device's distance data within the first unit of time is greater than or equal to the eighth distance threshold, the angle data value of the target object within the first unit of time is greater than or equal to the eighth angle threshold, and the maximum velocity value of the target object within the first unit of time is greater than the eleventh velocity threshold, then the state of the target object within the first unit of time is determined to be moving.

[0239] Step 21: The radar equipment determines whether the motion characteristics of the target object within each unit of time satisfy the second stationary rule, and if the motion characteristics of the target object within each unit of time satisfy the second stationary rule, the state of the target object within each unit of time is determined to be stationary.

[0240] Specifically, if the radar device determines that the target object is in motion within the first unit of time if the distance data within the first unit of time is less than the eighth distance threshold, the angle data value of the target object within the first unit of time is less than the eighth angle threshold, or the maximum speed of the target object within the first unit of time is less than or equal to the eleventh speed threshold.

[0241] Get the state of the target object within the first unit of time, such as Figure 15 As shown.

[0242] It should be noted that the first unit of time is any one of a series of consecutive unit of time.

[0243] The order of steps 21, 22, and 23 in this embodiment is not limited. Step 21 can be performed first, or step 22 can be performed first, or steps 21, 22, and 23 can be performed simultaneously.

[0244] If the target object is in motion within the first unit of time, set its status flag to 0 for that unit of time. If the target object is in a fallen or injured state within the first unit of time, set its status flag to 1 for that unit of time. If the target object is stationary within the first unit of time, set its status flag to 1 for that unit of time.

[0245] In some embodiments, the radar device first determines whether the motion characteristics of the target object within each unit time period satisfy the second falling rule. If the motion characteristics within the first unit time period do not satisfy the second falling rule, it then determines whether the motion characteristics within the first unit time period satisfy the second motion rule. Finally, if the motion characteristics within the first unit time period do not satisfy the second motion rule, it then determines whether the motion characteristics within the first unit time period satisfy the second stationary rule.

[0246] The fourth distance threshold, fifth distance threshold, sixth distance threshold, seventh distance threshold, eighth distance threshold, fourth angle threshold, fifth angle threshold, sixth angle threshold, seventh angle threshold, eighth angle threshold, seventh speed threshold, eighth speed threshold, ninth speed threshold, tenth speed threshold, and eleventh speed threshold are stored in the radar equipment in advance by the maintenance personnel.

[0247] Subsequently, the radar equipment obtains a sequence of second states of the target object over multiple units of time based on the second state of the target object within each unit of time.

[0248] For example, consider multiple units of 6 seconds each. The radar device acquires the target object's state over 6 consecutive seconds as: falling, moving, stationary, stationary, stationary, and stationary. Therefore, the target object's second state sequence over multiple units of time is 1, 0, 2, 2, 2, 2.

[0249] S206. The radar equipment determines whether the second state sequence meets the preset second fall rule.

[0250] As one possible approach, the radar device determines whether the second state sequence is consistent with the state sequence in the second fall rule.

[0251] It should be noted that S206 is similar to S203 above, and can be understood by referring to S203 above, so it will not be repeated here.

[0252] S207. When the radar equipment determines that the target object has fallen if the second state sequence meets the preset second fall rule.

[0253] Understandably, the first judgment rule has a high threshold for judging the fall of the target object. In order to avoid the situation where the target object falls but the radar device fails to detect it, the second judgment rule is used to make a second judgment on the target object in this embodiment.

[0254] In one design, to avoid false alarms, after S207 provided in the embodiments of this application, the following S208 is also included.

[0255] S208. If the radar device determines that the target object has fallen and remains stationary for a preset period of time, it will generate an alarm message.

[0256] The alarm message is used to indicate that the target object has fallen.

[0257] One possible approach is for the radar device to reassess the target's state within a preset time after it has fallen, thus obtaining the target's state during that preset time. Furthermore, if the target remains stationary for the preset duration, an alarm is triggered.

[0258] Specifically, after determining that the target object has fallen, the radar equipment judges the state of the target object within the preset time period based on the first or second judgment rule and the state of the target object in each unit of time within the preset time period, and obtains the third state sequence.

[0259] For example, taking a unit duration of 1 second and a preset duration of 3 minutes as an example, after the radar device determines that the target object has fallen, it acquires the target object's state of being stationary for each second, resulting in a third state sequence of 180 state identifier bits all being 2. Subsequently, the radar device determines that the third state sequence is all 2 and generates an alarm message.

[0260] For example, the preset duration can be 3 minutes or 5 minutes, and this application does not specifically limit it.

[0261] Understandably, after determining that a target has fallen, the radar equipment verifies the initial fall result based on the third fall rule. Only if the target's state meets the third fall rule within a preset time period will an alarm be generated to notify the user. This avoids false alarms.

[0262] To better understand the embodiments of this application. Figure 16 A diagram illustrating the judgment of the first fall. Figure 17 A diagram illustrating the judgment of a second fall. Figure 18 This is a diagram illustrating the initial fall assessment, the second fall assessment, and the confirmation of a second fall. Figure 16 Take the state of the target object over 4 consecutive seconds as an example. Figure 17 Take the state of the target object over a continuous 6 seconds as an example.

[0263] The above embodiments mainly describe the solutions provided by the embodiments of this application from the perspective of an apparatus (device). It is understood that, in order to implement the above methods, the apparatus or device includes hardware structures and / or software modules corresponding to the execution of each method flow. These hardware structures and / or software modules corresponding to the execution of each method flow can constitute a material information determination apparatus. Those skilled in the art should readily recognize that, in conjunction with the algorithm steps of the various examples described in the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in a hardware or computer software-driven hardware manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0264] This application embodiment can divide the device or equipment into functional modules according to the above method examples. For example, the device or equipment can be divided into functional modules corresponding to each function, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0265] When dividing each function into modules according to its corresponding function. Figure 19 A schematic diagram of a possible structure for a radar device is shown. For example... Figure 19 As shown, the fall detection device 30 provided in this application embodiment includes an acquisition unit 301 and a determination unit 302.

[0266] The acquisition unit 301 is used to acquire the motion characteristics of the target object within each unit time period in a series of consecutive unit time periods. The motion characteristics include at least one of distance data, velocity data, Doppler signal data, and angle data. The distance data is used to indicate the maximum change value of the motion distance. The velocity data is used to indicate the maximum value of the motion velocity and the velocity area change value. The velocity area change value is used to indicate the ratio of the target motion velocity to the multiple motion velocities. The target motion velocity is greater than a first threshold. The Doppler signal data is used to indicate the maximum value of the Doppler signal intensity. The angle data is used to indicate the maximum change value of the motion angle.

[0267] The determining unit 302 is used to determine the first state of the target object in each unit of time based on the first judgment rule and the motion characteristics of the target object in each unit of time, and to obtain the first state sequence of the target object in multiple units of time; the first state includes a falling state, a moving state or a stationary state, and the first state sequence includes the first states ordered by time.

[0268] The determining unit 302 is also used to determine that the target object has fallen if the first state sequence satisfies the preset first fall rule.

[0269] Optionally, each unit duration includes multiple frames. When the motion features include distance data, velocity data, Doppler signal data, and angle data, the acquisition unit 301 is specifically used for: acquiring the echo signal corresponding to each frame in the multiple frames through the radar device, obtaining the echo signal corresponding to multiple frames; the echo signal corresponding to each frame includes the signal reflected by the target object after the radar device sends multiple detection signals in each frame; based on the echo signals corresponding to the multiple frames, determining the maximum and minimum motion distances of the target object in the multiple frames, and determining the difference between the maximum and minimum motion distances as the distance data of the target object in each unit duration; based on the echo signals corresponding to the multiple frames, determining the maximum motion velocity and velocity area change value of the target object in the multiple frames, and determining the maximum motion velocity and velocity area change value as the velocity data of the target object in each unit duration; based on the echo signals corresponding to the multiple frames, determining the maximum Doppler signal intensity of the target object in the multiple frames, and determining the maximum Doppler signal intensity as the Doppler signal data of the target object in each unit duration. Based on the echo signals corresponding to multiple frames, the maximum and minimum motion angles of the target object in each frame are determined, and the difference between the maximum and minimum motion angles is determined as the angle data of the target object in each unit of time.

[0270] Optionally, the first judgment rule includes a first motion rule, a first stillness rule, and a first fall rule; based on the first judgment rule and the motion characteristics of the target object within each unit of time, the determining unit 302 is specifically used to: determine the first state as a motion state when the motion characteristics of the target object within each unit of time satisfy the first motion rule; or, determine the first state as a stillness state when the motion characteristics of the target object within each unit of time satisfy the first stillness rule; or, determine the first state as a fall state when the motion characteristics of the target object within each unit of time satisfy the first fall rule.

[0271] Optionally, the determining unit 302 is further configured to, when the first state sequence does not satisfy the first falling rule, determine the second state of the target object within each unit time period based on the second judgment rule and the motion characteristics of the target object within each unit time period, thereby obtaining a second state sequence of the target object within multiple unit time periods; the second state includes a falling state, a moving state, or a stationary state, and the second state sequence includes second states ordered by time. The determining unit is also configured to, when the second state sequence satisfies the preset second falling rule, determine that the target object has fallen.

[0272] Optionally, the fall detection device also includes a generation unit 303. The generation unit 303 is used to generate an alarm message if the target object remains stationary for a preset period of time after a fall is determined; the alarm message is used to indicate that the target object has fallen.

[0273] In the case of implementing the functions of the integrated modules described above in hardware, this application provides a possible structural schematic diagram of the radar device involved in the above embodiments. For example... Figure 20 As shown, a radar device 40 is described. The radar device 40 includes a processor 401, a memory 402, and a bus 403. The processor 401 and the memory 402 are connected via the bus 403.

[0274] Processor 401 is the control center of the user equipment. It can be a single processor or a collective term for multiple processing elements. For example, processor 401 can be a general-purpose central processing unit (CPU) 402, or other general-purpose processors. The general-purpose processor can be a microprocessor or any conventional processor.

[0275] As one embodiment, processor 401 may include one or more CPUs, for example Figure 20 CPU 0 and CPU 1 are shown in the diagram.

[0276] The memory 402 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but is not limited thereto.

[0277] As one possible implementation, the memory 402 can exist independently of the processor 401. The memory 402 can be connected to the processor 401 via a bus 403 and is used to store instructions or program code. When the processor 401 calls and executes the instructions or program code stored in the memory 402, it can implement the map drawing method provided in this application embodiment.

[0278] In another possible implementation, the memory 402 can also be integrated with the processor 401.

[0279] Bus 403 can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. This bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 20 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0280] It should be pointed out that, Figure 20 The structure shown does not constitute a limitation on the radar device 40. Except... Figure 20 In addition to the components shown, the radar device 40 may include more or fewer components than illustrated, or combine certain components, or have different component arrangements.

[0281] As an example, combined Figure 20 The functions implemented by the acquisition unit 301, processing unit 302, and generation unit 303 in the fall detection device 30 are the same as those of the acquisition unit 301, processing unit 302, and generation unit 303. Figure 20 The processor 401 in it has the same function.

[0282] Optional, such as Figure 20 As shown, the radar device 40 provided in this application embodiment may also include a communication interface 404.

[0283] Communication interface 404 is used to connect to other devices via a communication network. This communication network can be Ethernet, wireless access network, wireless local area network (WLAN), etc.

[0284] In one design, the communication interface of the radar device provided in this application embodiment can also be integrated into the processor.

[0285] Through the above description of the embodiments, those skilled in the art will clearly understand that, for the sake of convenience and brevity, only the division of the above functional units is used as an example. In practical applications, the above functions can be assigned to different functional units as needed, that is, the internal structure of the device can be divided into different functional units to complete all or part of the functions described above. The specific working process of the system, device, and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0286] This application also provides a computer-readable storage medium storing instructions. When a computer executes these instructions, the computer performs each step of the method flow shown in the above-described method embodiments.

[0287] Embodiments of this application provide a computer program product containing instructions that, when executed on a computer, cause the computer to perform the fall detection method described in the above method embodiments.

[0288] The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), registers, hard disks, optical fibers, compact disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing, or any other form of computer-readable storage medium in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium may also be a component of the processor. The processor and the storage medium may reside in an application-specific integrated circuit (ASIC). In the embodiments of this application, the computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0289] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be covered within the scope of protection of this application.

Claims

1. A fall detection method, characterized in that, The method includes: The motion characteristics of a target object are acquired within each unit of time span across multiple consecutive time units. These motion characteristics include at least one of distance data, velocity data, Doppler signal data, and angle data. The distance data indicates the maximum change in motion distance. The velocity data indicates the maximum value of motion velocity and the velocity area change value, where the velocity area change value indicates the ratio of the target motion velocity to the multiple motion velocities, and the target motion velocity is greater than a first threshold. The Doppler signal data indicates the maximum value of the Doppler signal intensity. The angle data indicates the maximum change in motion angle. Based on a first judgment rule and the motion characteristics of the target object within each unit of time, a first state of the target object within each unit of time is determined, resulting in a first state sequence of the target object within multiple unit of time. The first judgment rule includes a first motion rule, a first stillness rule, and a first fall rule. The first state includes a fall state, a motion state, or a still state. The first state sequence includes the first states ordered by time. If the motion characteristics of the target object within each unit of time satisfy the first motion rule, the first state is determined to be a motion state. Alternatively, if the motion characteristics of the target object within each unit of time satisfy the first stillness rule, the first state is determined to be a still state. Alternatively, if the motion characteristics of the target object within each unit of time satisfy the first fall rule, the first state is determined to be a fall state. If the first state sequence matches any one of the multiple preset state sequences, it is determined that the target object has fallen.

2. The method according to claim 1, characterized in that, Each unit of time includes multiple frames. When the motion features include distance data, velocity data, Doppler signal data, and angle data, acquiring the motion features of the target object within each unit of time across multiple consecutive unit of time includes: The echo signal corresponding to each of the multiple frames is obtained by acquiring the echo signal corresponding to each of the multiple frames using radar equipment; the echo signal corresponding to each frame includes the signal reflected by the target object after the radar equipment sends multiple detection signals in each frame; Based on the echo signals corresponding to the multiple frames, the maximum and minimum motion distances of the target object in the multiple frames are determined respectively, and the difference between the maximum and minimum motion distances is determined as the distance data of the target object in each unit of time. Based on the echo signals corresponding to the multiple frames, the maximum value of the target object's motion speed and the value of the velocity area change in the multiple frames are determined respectively, and the maximum value of the motion speed and the value of the velocity area change are determined as the velocity data of the target object in each unit of time. Based on the echo signals corresponding to the multiple frames, the maximum value of the Doppler signal intensity of the target object in the multiple frames is determined, and the maximum value of the Doppler signal intensity is determined as the Doppler signal data of the target object in each unit of time. Based on the echo signals corresponding to the multiple frames, the maximum and minimum motion angles of the target object in the multiple frames are determined respectively, and the difference between the maximum and minimum motion angles is determined as the angle data of the target object in each unit of time.

3. The method according to claim 2, characterized in that, The method further includes: If the first state sequence is inconsistent with any of the plurality of preset state sequences, a second state of the target object within each unit of time is determined based on a second judgment rule and the motion characteristics of the target object within each unit of time, resulting in a second state sequence of the target object within the plurality of unit of time. The second judgment rule includes a second motion rule, a second stillness rule, and a second fall rule. The second state includes a fall state, a motion state, or a still state. The second state sequence includes the second states ordered by time. If the motion characteristics of the target object within each unit of time satisfy the second fall rule, the second state is determined to be the fall state. Alternatively, if the motion characteristics of the target object within each unit of time satisfy the second motion rule, the second state is determined to be the motion state. Alternatively, if the motion characteristics of the target object within each unit of time satisfy the second stillness rule, the second state is determined to be the still state. If the second state sequence matches the preset state sequence, it is determined that the target object has fallen.

4. The method according to any one of claims 1-3, characterized in that, The method further includes: If the target object remains stationary for a preset period of time after it is determined that it has fallen, an alarm message is generated; the alarm message is used to indicate that the target object has fallen.

5. A fall detection device, characterized in that, The device includes: an acquisition unit and a determination unit; The acquisition unit is used to acquire the motion characteristics of the target object within each unit of time span across multiple consecutive unit time spans. The motion characteristics include at least one of distance data, velocity data, Doppler signal data, and angle data. The distance data indicates the maximum change in motion distance. The velocity data indicates the maximum value of motion velocity and the velocity area change value. The velocity area change value indicates the ratio of the target motion velocity to the multiple motion velocities, where the target motion velocity is greater than a first threshold. The Doppler signal data indicates the maximum value of the Doppler signal intensity. The angle data indicates the maximum change in motion angle. The determining unit is configured to determine a first state of the target object within each unit of time based on a first judgment rule and the motion characteristics of the target object within each unit of time, thereby obtaining a first state sequence of the target object within multiple unit of time. The first judgment rule includes a first motion rule, a first stillness rule, and a first fall rule. The first state includes a fall state, a motion state, or a still state, and the first state sequence includes the first states ordered by time. If the motion characteristics of the target object within each unit of time satisfy the first motion rule, the first state is determined to be a motion state; or, if the motion characteristics of the target object within each unit of time satisfy the first stillness rule, the first state is determined to be a still state; or, if the motion characteristics of the target object within each unit of time satisfy the first fall rule, the first state is determined to be a fall state. The determining unit is further configured to determine that the target object has fallen if the first state sequence is consistent with any one of the multiple preset state sequences.

6. The apparatus according to claim 5, characterized in that, Each unit duration includes multiple frames. When the motion features include distance data, velocity data, Doppler signal data, and angle data, the acquisition unit is specifically used for: The echo signal corresponding to each of the multiple frames is obtained by acquiring the echo signal corresponding to each of the multiple frames using radar equipment; the echo signal corresponding to each frame includes the signal reflected by the target object after the radar equipment sends multiple detection signals in each frame; Based on the echo signals corresponding to the multiple frames, the maximum and minimum motion distances of the target object in the multiple frames are determined respectively, and the difference between the maximum and minimum motion distances is determined as the distance data of the target object in each unit of time. Based on the echo signals corresponding to the multiple frames, the maximum value of the target object's motion speed and the value of the velocity area change in the multiple frames are determined respectively, and the maximum value of the motion speed and the value of the velocity area change are determined as the velocity data of the target object in each unit of time. Based on the echo signals corresponding to the multiple frames, the maximum value of the Doppler signal intensity of the target object in the multiple frames is determined, and the maximum value of the Doppler signal intensity is determined as the Doppler signal data of the target object in each unit of time. Based on the echo signals corresponding to the multiple frames, the maximum and minimum motion angles of the target object in the multiple frames are determined respectively, and the difference between the maximum and minimum motion angles is determined as the angle data of the target object in each unit of time.

7. The apparatus according to claim 6, characterized in that, The determining unit is further configured to: If the first state sequence is inconsistent with any of the multiple preset state sequences, a second state of the target object within each unit of time is determined based on a second judgment rule and the motion characteristics of the target object within each unit of time, resulting in a second state sequence of the target object within the multiple unit of time. The second judgment rule includes a second motion rule, a second stillness rule, and a second fall rule. The second state includes a fall state, a motion state, or a still state. The second state sequence includes the second states ordered by time. If the motion characteristics of the target object within each unit of time satisfy the second fall rule, the second state is determined to be the fall state. Alternatively, if the motion characteristics of the target object within each unit of time satisfy the second motion rule, the second state is determined to be the motion state. Alternatively, if the motion characteristics of the target object within each unit of time satisfy the second stillness rule, the second state is determined to be the still state. If the second state sequence matches the preset state sequence, it is determined that the target object has fallen.

8. A radar device, characterized in that, include: One or more processors; One or more memory units; The one or more memories are used to store computer program code, which includes computer instructions. When the one or more processors execute the computer instructions, the radar device performs the fall detection method according to any one of claims 1 to 4.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes computer-executable instructions that, when executed on a computer, cause the computer to perform the fall detection method as described in any one of claims 1 to 4.

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