Multi-target detection apparatus, detection method, and electronic device

Abstract

Embodiments of the present application provide a multi-target detection device, a detection method and an electronic device. The multi-target detection device comprises a processor, a transmitter and a receiver. The processor is configured to control the transmitter to transmit a first pulse, and control the receiver to receive a plurality of first echoes generated by reflection of the first pulse by a plurality of targets; obtain signal flight times corresponding to the plurality of targets respectively according to a time difference between transmission of the first pulse and reception of the plurality of first echoes; determine a time interval between two adjacent pulses in a plurality of second pulses according to the signal flight times corresponding to the plurality of targets; control the transmitter to transmit the plurality of second pulses according to the time interval, and control the receiver to receive a plurality of second echoes generated by reflection of each second pulse by the plurality of targets; and obtain vital signs of the plurality of targets according to transmission times of the plurality of second pulses, reception times of the plurality of second echoes corresponding to each second pulse, and the signal flight times corresponding to the plurality of targets.

Description

Technical Field

[0001] This application relates to the field of radar measurement technology, and in particular to a multi-target detection device, detection method and electronic equipment. Background Technology

[0002] Impulse Radio UltraWide Band (IR-UWB) is a new wireless transmission technology that uses extremely short pulses to carry bit information. IR-UWB transmits pulses, and a receiver receives the echoes reflected from the target's surface. The presence or movement of a target is detected by the time difference between the transmitted pulse and the echo generated by the pulse reflected from the target. One application of IR-UWB is to detect vital signs of a target by transmitting multiple pulses. However, when multiple targets are present, and the pulse repetition frequency (PRF) of the transmitted pulses is high, the echoes of pulses corresponding to different targets overlap, leading to inaccurate target identification and detection of vital signs. Summary of the Invention

[0003] This application provides a multi-target detection device, detection method, and electronic device, which solves the problem of the impact of echo overlap on the detection accuracy under multi-target conditions.

[0004] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0005] In a first aspect, a multi-target detection device is provided, comprising a processor, a transmitter, and a receiver; the processor is configured to: control the transmitter to transmit a first pulse, and control the receiver to receive multiple first echoes generated by the reflection of the first pulse by multiple targets; obtain the signal flight time corresponding to each of the multiple targets based on the time difference between the first pulse and the multiple first echoes; determine the time interval between two adjacent pulses in a plurality of second pulses based on the signal flight time corresponding to the multiple targets; control the transmitter to transmit multiple second pulses based on the time interval, and control the receiver to receive multiple second echoes generated by the reflection of each second pulse by multiple targets; and obtain the vital signs of multiple targets based on the transmission time of the multiple second pulses, the reception time of the multiple second echoes corresponding to each second pulse, and the signal flight time corresponding to the multiple targets.

[0006] This application embodiment detects multiple existing targets using a first pulse to determine the actual number of targets and the corresponding signal flight times. The signal flight time for one target is the time interval from when the transmitter emits a first pulse to when the receiver receives the first echo generated by the reflection of that first pulse from the target. The time interval between two adjacent second pulses is determined using the signal flight time for each target. By adjusting the time interval between the second pulses, the second echoes reflected by multiple targets from the emitted second pulses do not overlap when they reach the receiver. This allows for the separation of the second echo for each target, unaffected by interference from other targets, enabling accurate detection of vital signs for each target in multi-target application scenarios.

[0007] In one possible implementation, the time interval plus the signal flight time of the nearest target is greater than the signal flight time of the farthest target.

[0008] In this embodiment, a time interval is selected for each target's signal flight time. This time interval satisfies the following condition: the sum of the time interval and the signal flight time of the target closest to the multi-target detection device is greater than the signal flight time of the target farthest from the multi-target detection device. This ensures that in two adjacent second pulses, the second echo generated by the reflection of the target from the preceding second pulse arrives at the multi-target detection device before all second echoes generated by the reflection of the target from the following second pulse. This avoids the possibility of overlap between the second echoes of the preceding and following second pulses.

[0009] In one possible implementation, the processor is specifically configured to: for a second pulse and multiple corresponding second echoes belonging to the same detection period, add the transmission time of the second pulse to the signal flight time of the multiple targets respectively to obtain the expected reception time of the second echoes corresponding to the multiple targets respectively; and determine the second echoes corresponding to the multiple targets respectively based on the expected reception time and the reception time of the multiple second echoes; for a target, determine the distance change of a target in different detection periods based on the time difference between the second echo and the second pulse corresponding to different detection periods, and determine the vital signs of a target based on the distance change.

[0010] In this embodiment, the processor controls the transmitter to emit a first pulse, which arrives at the corresponding time point after the signal flight time for different targets. This time point is the expected reception time for each target. For a target, the receiver will receive the corresponding first echo at its expected reception time. The number of targets is detected by the received first echo. The distance to the target and the signal flight time for that target are determined based on the time difference between the time of emitting the first pulse and the time of receiving the corresponding first echo.

[0011] In one possible implementation, the processor is specifically used to: for a target, perform coherence integration on the time difference between the second echo and the second pulse corresponding to different detection cycles to obtain the vital signs of a target.

[0012] The embodiments of this application improve the signal-to-noise ratio in calculating vital sign signals through homology integration processing, thereby improving detection accuracy.

[0013] In one possible implementation, the processor is further configured to: if the distance change of a target is greater than a threshold, redetermine the signal flight time corresponding to each of the multiple targets.

[0014] This application embodiment detects the distance between the target and the multi-target detection device. When the distance changes, it may affect the detection accuracy. At the same time, the new distance may cause the second echoes of different targets to overlap. Therefore, it is necessary to redetermine the signal flight time corresponding to each of the multiple targets to ensure the detection accuracy.

[0015] In one possible implementation, the bandwidth of the first pulse is a first bandwidth; the bandwidth of the second pulse is a second bandwidth; the second bandwidth is less than or equal to the first bandwidth.

[0016] In this embodiment, a higher first bandwidth value results in higher accuracy in target detection, which is beneficial for accurately identifying each target. After identifying each target using the first pulse, the second bandwidth of the second pulse can be flexibly set.

[0017] In one possible implementation, vital signs include at least one of heart rate and respiratory rate. Embodiments of this application can detect vital signs such as heart rate of a living being using the reflected second echo, and can be applied to various fields of living being detection.

[0018] Secondly, embodiments of this application also provide a multi-target detection method, the method comprising: transmitting a first pulse and receiving multiple first echoes generated by the reflection of the first pulse by multiple targets; obtaining the signal flight time corresponding to each of the multiple targets based on the time difference between the first pulse and the multiple first echoes; determining the time interval between two adjacent pulses in a plurality of second pulses based on the signal flight time corresponding to the multiple targets; transmitting multiple second pulses according to the time interval and receiving multiple second echoes generated by the reflection of each second pulse by multiple targets; and obtaining the vital signs of multiple targets based on the transmission time of the multiple second pulses, the reception time of the multiple second echoes corresponding to each second pulse, and the signal flight time corresponding to the multiple targets.

[0019] In one possible implementation, the time interval plus the signal flight time of the nearest target is greater than the signal flight time of the farthest target.

[0020] In one possible implementation, the method specifically includes: for a second pulse and multiple corresponding second echoes belonging to the same detection period, adding the transmission time of the second pulse to the signal flight time of the multiple targets respectively to obtain the expected reception time of the second echoes corresponding to the multiple targets respectively; and determining the second echoes corresponding to the multiple targets respectively based on the expected reception time and the reception time of the multiple second echoes; for a target, determining the distance change of a target in different detection periods based on the time difference between the second echo and the second pulse corresponding to different detection periods, and determining the vital signs of a target based on the distance change.

[0021] In one possible implementation, the method specifically includes: for a target, performing coherent integration on the time difference between the second echo and the second pulse corresponding to different detection cycles to obtain the target's vital signs.

[0022] In one possible implementation, the method further includes: if the distance change of a target is greater than a threshold, then redetermining the signal flight time corresponding to each of the multiple targets.

[0023] In one possible implementation, the bandwidth of the first pulse is a first bandwidth; the bandwidth of the second pulse is a second bandwidth; the second bandwidth is less than or equal to the first bandwidth.

[0024] In one possible implementation, vital signs include at least one of heart rate and respiratory rate.

[0025] Thirdly, embodiments of this application also provide an electronic device, which includes at least one of the multi-target detection devices described in the first aspect above; the multi-target detection device is used to calculate the vital signs of multiple targets.

[0026] Fourthly, embodiments of this application also provide a chip system. The chip system includes at least one processor and at least one interface circuit. The at least one processor and at least one interface circuit are interconnected via lines. The processor is used to support the chip system in implementing the various functions or steps in the above method embodiments, and the at least one interface circuit can be used to receive signals from other devices (e.g., memory) or to send signals to other devices (e.g., a communication interface). The chip system may include a chip and may also include other discrete devices.

[0027] Fifthly, embodiments of this application also provide a computer-readable storage medium including instructions that, when executed on the electronic device or chip system, cause the electronic device or chip system to perform the various functions or steps described in the second aspect.

[0028] In a sixth aspect, embodiments of this application also provide a computer program product including instructions that, when executed on the aforementioned electronic device or chip system, cause the electronic device or chip system to perform the various functions or steps described in the second aspect.

[0029] The technical effects of the second, third, fourth, fifth, and sixth aspects are the same as those of the preceding method embodiments. Attached Figure Description

[0030] Figure 1 A schematic diagram of a pulse provided for an embodiment of this application;

[0031] Figure 2 This is a schematic diagram of the structure of a multi-target detection device provided in an embodiment of this application;

[0032] Figure 3 A schematic diagram illustrating the transmission of a first pulse by a multi-target detection device according to an embodiment of this application;

[0033] Figure 4 A schematic diagram illustrating the emission of a second pulse by a multi-target detection device according to an embodiment of this application;

[0034] Figure 5 A schematic diagram of a signal frame transmitted by a multi-target detection device according to an embodiment of this application;

[0035] Figure 6 A schematic diagram of a single-pulse ranging frame provided in an embodiment of this application;

[0036] Figure 7 A schematic diagram of a multi-pulse detection frame provided in an embodiment of this application;

[0037] Figure 8A flowchart illustrating a multi-target detection method provided in an embodiment of this application;

[0038] Figure 9 A schematic flowchart illustrating another multi-target detection method provided in an embodiment of this application;

[0039] Figure 10 A schematic flowchart illustrating another multi-target detection method provided in an embodiment of this application;

[0040] Figure 11 This is a schematic diagram of the workflow of a multi-target detection device provided in an embodiment of this application;

[0041] Figure 12 A schematic diagram illustrating the relationship between pulse interval and signal flight time is provided for an embodiment of this application;

[0042] Figure 13 A schematic diagram illustrating a sub-signal separated from a set of second echoes, provided as an embodiment of this application;

[0043] Figure 14 This is a schematic diagram of a sub-signal obtained by performing homology integration on multiple sub-signals, as provided in an embodiment of this application.

[0044] Figure 15 This is a schematic diagram illustrating the detection of the respiratory rate of the first target using a 100MHz multi-pulse detection frame in an embodiment of this application.

[0045] Figure 16 This is a schematic diagram illustrating the detection of the heart rate of the first target using a 100MHz multi-pulse detection frame in an embodiment of this application.

[0046] Figure 17 This is a schematic diagram illustrating the detection of the respiratory rate of a second target using a 100MHz multi-pulse detection frame in an embodiment of this application.

[0047] Figure 18 This is a schematic diagram illustrating the detection of the heart rate of a second target using a 100MHz multi-pulse detection frame in an embodiment of this application.

[0048] Figure 19 This is a schematic diagram illustrating the detection and control of the respiratory rate of the first target using a single pulse in an embodiment of this application.

[0049] Figure 20 This is a schematic diagram illustrating the detection and comparison of the heart rate of the first target using a single pulse in an embodiment of this application.

[0050] Figure 21 This is a schematic diagram illustrating the detection and control of the respiratory rate of a second target using a single pulse in an embodiment of this application.

[0051] Figure 22 This is a schematic diagram illustrating the detection and comparison of the heart rate of a second target using a single pulse in an embodiment of this application.

[0052] Figure 23 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application;

[0053] Figure 24 This is a schematic diagram of a chip system provided in an embodiment of this application. Detailed Implementation

[0054] It should be noted that the terms "first" and "second" used in the embodiments of this application are only used to distinguish features of the same type and should not be construed as indicating relative importance, quantity, order, etc.

[0055] The terms "exemplary" or "for example" used in the embodiments of this application are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0056] The terms "coupling" and "connection" used in the embodiments of this application should be interpreted broadly. For example, they can refer to a physical direct connection or an indirect connection achieved through electronic devices, such as a connection achieved through resistors, inductors, capacitors or other electronic devices.

[0057] First, let's explain some basic concepts in this application:

[0058] A pulse typically refers to a brief, pulsating shock, often used in electronics. The main characteristics of a pulse include its waveform, pulse amplitude (PA), pulse width (PW), pulse bandwidth (PB), and pulse repetition frequency (PRF). Figure 1 The image shows one form of pulse. Within a complete signal cycle, a pulse, relative to a continuous signal, is a signal that occurs for a short period during the transmission cycle. During most of the transmission cycle, excluding the pulse, there is no signal. It's like a human pulse.

[0059] Impulse Radio Ultra-Wide Band (IR-UWB) is a new wireless transmission technology that uses extremely short pulses to carry bit information. IR-UWB works by transmitting pulses and receiving the echoes reflected from the target's surface. The presence or movement of the target is detected by the time difference between the transmitted pulse and the echo. However, because the power attenuation of an IR-UWB pulse is proportional to the square of the flight distance, the power of the received echo is approximately inversely proportional to the fourth power of the distance between the target and the receiver. This also means that the accuracy of IR-UWB detection is limited by a certain distance; as the target distance increases, the received signal power and signal-to-noise ratio decrease rapidly.

[0060] One application of IR-UWB is the detection of vital signs of a target by transmitting pulses. In IR-UWB pulse transmission, target features much smaller than the target size can be extracted from the echoes reflected back to the receiver from the transmitted pulses. These features are minute vibrations produced by the target during vital activities (such as chest rise and fall, pulse beats, etc.), which can be detected through the echoes reflected by the IR-UWB pulses, allowing the calculation of vital signs such as heart rate and respiratory rate. However, because these minute vibrations are typically on the millimeter scale, high detection accuracy is required. To improve the accuracy of vital sign detection, one approach is to transmit multiple pulses and then perform coherence integration on the multiple echoes generated by the target's transmission. This coherence integration improves the signal-to-noise ratio of the resulting echoes, thereby enhancing the accuracy of vital sign detection.

[0061] However, when multiple targets are present, each target will reflect multiple echoes from the emitted pulses. Echoes from different targets may overlap. This overlap not only interferes with target identification but also significantly affects the accuracy of target coherence integration, drastically reducing the precision of target identification and the detection of vital signs. This situation is particularly pronounced when the pulse repetition frequency (PRF) of the emitted pulses is high, and a high PRF is a major factor in improving detection accuracy.

[0062] Therefore, this application provides a multi-target detection device for emitting pulses and receiving echoes reflected from the pulses by targets. Based on the emission times of multiple pulses, the reception times of multiple echoes corresponding to each pulse, and the signal flight times corresponding to multiple targets, the vital signs of multiple targets are obtained. Figure 2 As shown, the multi-target detection device 1 includes a processor 10, a transmitter 11, and a receiver 12. Figure 3 As shown, the processor 10 is used to: control the transmitter 11 to transmit a first pulse 31, and control the receiver 12 to receive multiple first echoes 21 generated by the reflection of the first pulse 31 from multiple targets 2; obtain the signal flight time corresponding to each of the multiple targets 2 based on the time difference between transmitting the first pulse 31 and receiving the multiple first echoes 21; and determine the time interval between two adjacent pulses in the multiple second pulses 41 based on the signal flight time corresponding to the multiple targets 2. Figure 4 As shown, the processor 10 is also configured to: control the transmitter 11 to transmit multiple second pulses 41 according to the time interval, and control the receiver 12 to receive multiple second echoes 22 generated by the reflection of each second pulse 41 by multiple targets 2 respectively; and obtain the vital signs of multiple targets 2 according to the transmission time of the multiple second pulses 41, the reception time of the multiple second echoes 22 corresponding to each second pulse 41, and the signal flight time corresponding to the multiple targets 2.

[0063] This application embodiment detects multiple targets 2 using a first pulse 31 to determine the actual number of targets 2 and the corresponding signal flight times. The signal flight time for one target 2 is the time interval from when the transmitter 11 transmits a first pulse 31 until the receiver 12 receives the first echo 21 generated by the reflection of the first pulse 31 from the target 2. The time interval between two adjacent second pulses 41 is determined using the signal flight time for each target 2. By adjusting the time interval between the second pulses 41, the second echoes 22 reflected by multiple targets 2 from the transmitted second pulses 41 do not overlap when they reach the receiver 12. This allows for the separation of the second echo 22 from each target 2 without interference from other targets 2, enabling accurate detection of the vital signs of each target 2 in scenarios with multiple targets 2. It should be noted that... Figure 3 , Figure 4 In the diagram, the first pulse 31, the first echo 21, the second pulse 41, and the second echo 22 are represented by arrows. However, in practice, the different first pulses 31, the different first echoes 21, the different second pulses 41, and the different second echoes 22 are spaced-out pulses rather than continuous signals. Also, as in 2... Figure 3 , Figure 4 The distance between transmitter 11 and receiver 12 is for illustrative purposes only and does not represent the actual distance ratio. In reality, the distance difference between transmitter 11 and receiver 12 with respect to target 2 is negligible.

[0064] For example, multiple targets 2 can be different body parts or different organs of a living organism.

[0065] For example, the multiple targets 2 can be different body parts or organs of different living organisms.

[0066] In some possible implementations, such as Figure 3 As shown, the processor 10 is used to: control the transmitter 11 to transmit a first pulse 31; and control the receiver 12 to receive the first echo 21 reflected by the target 2 from the first pulse 31. Based on the time difference between the time of transmitting the first pulse 31 and the time of receiving the first echo 21, the signal flight time corresponding to each target 2 is obtained.

[0067] In this embodiment, the relative distance between each target 2 and the multi-target detection device 1 is fixed when the target 2 is stationary. With a fixed flight speed of the first pulse 31 and a fixed distance between each target 2 and the multi-target detection device 1, the time it takes for the first echo 21 generated by the reflection of the first pulse 31 from the target 2 to reach the multi-target detection device 1 is fixed for each target 2; that is, the signal flight time for each target 2 is fixed. At this time, the processor 10 controls the transmitter 11 to transmit the first pulse 31, which arrives at the corresponding time point after the signal flight time corresponding to different targets 2. This time point is the expected reception time for each target 2. For each target 2, the receiver 12 receives the corresponding first echo 21 at its corresponding expected reception time. The number of targets 2 is detected by the received first echo 21. The distance to the target 2 and the signal flight time of that target 2 are determined based on the time difference between the time of transmitting the first pulse 31 and the time of receiving the corresponding first echo 21.

[0068] For example, such as Figure 5 As shown, the first pulse 31 and the second pulse 41 are transmitted in the form of a single-pulse ranging frame 3 and a multi-pulse detection frame 4, respectively. A single-pulse ranging frame 3 includes one first pulse 31. A multi-pulse detection frame 4 includes multiple second pulses 41. First, multiple single-pulse ranging frames 3 are transmitted via transmitter 11, and the signal flight time is determined by the first pulse 31 in the single-pulse ranging frame 3. Then, the number of second pulses 41 in a single multi-pulse detection frame 4 is determined based on the signal flight time, and multiple multi-pulse detection frames 4 are transmitted via transmitter 11. The vital signs of the target 2 are detected by the second echo 22 reflected back from the target 2 by the second pulses 41 in the multi-pulse detection frame 4.

[0069] The above are as follows Figure 2 The multi-pulse detection device 1 shown can be used to perform the following: Figure 8 The multi-pulse detection method shown includes steps S101-S103:

[0070] Step S101: The processor 10 controls the transmitter 11 to transmit a single-pulse ranging frame 3; the single-pulse ranging frame 3 includes a first pulse 31.

[0071] For example, processor 10 can control transmitter 11 to periodically transmit multiple single-pulse ranging frames 3. Figure 6 As shown, each single-pulse ranging frame 3 includes a first pulse 31. By transmitting multiple single-pulse ranging frames 3 to detect the distance to the target 2 and its signal flight time, the accuracy of detection can be improved.

[0072] For example, in practical applications, the bandwidth of the first pulse 31 is a first bandwidth, which can be as large as possible within the parameters of the transmitter 11. In this embodiment, since the target 2 is unknown when the first pulse 31 is transmitted, the larger the first bandwidth of the transmitted first pulse 31, the greater the resolution of the returned first echo 21 will be, thereby improving the accuracy of detecting the distance to the target 2 and its signal flight time.

[0073] Step S102: The processor 10 controls the receiver 12 to receive the first echo 21 reflected by the target 2 from the first pulse 31 in the single pulse ranging frame 3.

[0074] Step S103: The processor 10 determines the signal flight time corresponding to each target 2 based on the time difference between the time point of transmitting the first pulse 31 and the time point of receiving the first echo 21.

[0075] In some possible implementations, such as Figure 7 As shown, a single multipulse detection frame 4 includes multiple second pulses 41. The processor 10 is configured to: determine the time interval between two adjacent second pulses 41 in the multipulse detection frame 4 based on the signal flight time corresponding to all targets 2 before the transmitter 11 transmits the multipulse detection frame 4; control the transmitter 11 to transmit the multipulse detection frame 4 based on the determined time interval; and determine the second echo 22 of each target 2 with respect to the second pulse 41 based on the transmission time of each second pulse 41, the expected reception time of the second echo 22 corresponding to each target 2 (consistent with the expected reception time of the first echo 21), and the signal flight time corresponding to each target 2.

[0076] The above are as follows Figure 2 The multi-pulse detection device 1 shown can be used to perform the following: Figure 9 The multi-pulse detection method shown in steps S201-S203:

[0077] Step S201: Processor 10 determines the time interval between two adjacent second pulses 41 in the multi-pulse detection frame 4;

[0078] In some possible implementations, a detection cycle of the second pulse 41 is defined as the period from the transmission of one second pulse 41 to the transmission of the next second pulse 41. For the signal flight time of each target 2, a time interval is selected that satisfies the following condition: the sum of the time interval and the signal flight time of the target 2 closest to the multi-target detection device 1 is greater than the signal flight time of the target 2 farthest from the multi-target detection device 1.

[0079] For example, such as Figure 12 As shown in the figure, A represents the target 2 closest to the multi-target detection device 1; B represents the target 2 farthest from the multi-target detection device 1. t represents the signal flight time corresponding to the closest target 2, and T represents the signal flight time corresponding to the farthest target 2. H represents the time interval between two adjacent second pulses 41. When the sum of the time interval and the signal flight time t is greater than the signal flight time T, it can be guaranteed that in two adjacent second pulses 41, the second echo 22 generated by the reflection of the target 2 from the previous second pulse 41 arrives at the multi-target detection device 1 before all the second echoes 22 generated by the reflection of the target 2 from the subsequent second pulse 41. This avoids the possibility of overlap between the second echoes 22 of the previous second pulse 41 and the second echo 22 of the subsequent second pulse 41.

[0080] In this embodiment, because there are multiple targets 2, the second echoes 22 generated by the second pulse 41 of a previous detection cycle with respect to different targets 2 may overlap with the second echoes 22 generated by the second pulse of a subsequent detection cycle with respect to different targets 2 at the time of arrival at the receiver 12. To avoid this problem, the selected time interval is such that the sum of the time interval and the signal flight time of the target 2 closest to the multi-target detection device 1 is greater than the signal flight time of the target 2 farthest from the multi-target detection device 1. This ensures that during flight, in two adjacent detection cycles, when the second echo 22 of the farthest target 2 corresponding to the second pulse 41 of the previous cycle arrives at the receiver 12, the second echo 22 of the closest target 2 corresponding to the second pulse 41 of the subsequent cycle has not yet arrived at the receiver 12, thus achieving no overlap of the second echoes 22 between multiple targets 2, thereby improving the detection accuracy.

[0081] For example, the number of second pulses 41 included in each multi-pulse detection frame 4 is determined by the pulse repetition frequency of the second pulses 41 and the frame length of the multi-pulse detection frame 4. Optionally, the frame length of the multi-pulse detection frame 4 can be set to 0.2 μs, 0.5 μs, etc.

[0082] Step S202: The processor 10 controls the transmitter 11 to transmit a multi-pulse detection frame 4, including the second pulse 41, at a determined time interval.

[0083] For example, for transmitter 11, the second pulse 41 has a pulse width, which represents the duration required for transmitter 11 to completely transmit a single second pulse 41. Therefore, for a detection cycle, the cycle duration is the reciprocal of the pulse repetition frequency of the second pulse 41 multiplied by a coefficient. For example, in the case of a cycle of 1 second, the cycle duration is inversely related to the pulse repetition frequency, and the coefficient is 1. The time interval between two adjacent second pulses 41 is calculated by subtracting the pulse width of the second pulse 41 from the cycle duration. Therefore, processor 10 can determine the time interval based on the signal flight time and add the pulse width of the second pulse 41 to obtain the required cycle duration of the second pulse 41. The pulse repetition frequency is calculated based on the cycle duration, and then transmitter 11 is controlled to transmit the second pulse 41 at this pulse repetition frequency.

[0084] In some possible implementations, fixed pulse repetition frequencies can be preset on the transmitter 11 by adjusting the parameters of the transmitter 11. These fixed pulse repetition frequencies each correspond to a fixed time interval. Based on the time interval determined in step S201, a pulse repetition frequency that satisfies the determined time interval is selected from the preset pulse repetition frequencies and used as the pulse repetition frequency for transmitting the second pulse 41. The selected pulse repetition frequency satisfies the following conditions: Condition 1: The fixed time interval corresponding to the pulse repetition frequency is greater than or equal to the time interval determined in step S201; Condition 2: The pulse repetition frequency is the pulse repetition frequency with the largest frequency value among the pulse repetition frequencies that satisfy Condition 1.

[0085] This embodiment of the application presets a certain gradient of pulse repetition frequencies by adjusting the parameters of the transmitter 11. These pulse repetition frequencies correspond to fixed time intervals. After the time interval is determined in step S201 based on factors such as signal flight time, it is only necessary to select the pulse repetition frequencies that satisfy conditions one and two from the preset pulse repetition frequencies. The reasons for setting conditions one and two are as follows: Regarding condition one, only when the selected time interval is greater than or equal to the determined time interval can it be ensured that when the second echo 22 of the farthest target 2 corresponding to the second pulse 41 of the previous cycle arrives at the receiver 12, the second echo 22 of the nearest target 2 corresponding to the second pulse 41 of the next cycle has not yet arrived at the receiver 12. Regarding condition two, the larger the frequency value of the pulse repetition frequency, the more second pulses 41 there are in a single multi-pulse detection frame 4, and the higher the detection accuracy will be. Therefore, it is necessary to select the pulse repetition frequency with the largest frequency value from the pulse repetition frequencies selected in condition one as the pulse repetition frequency when the transmitter 11 transmits the second pulse 41. This application embodiment reduces the problem that the transmitter 11 needs to adaptively adjust the corresponding pulse repetition frequency according to a determined time interval each time it is used by preset pulse repetition frequency, thereby reducing the difficulty of implementing the solution and improving the universality of the multi-target detection device 1 and its multi-target detection method.

[0086] For example, taking a multi-pulse detection frame 4 with a frame length of 0.2 μs, a pulse bandwidth of 1.50 GHz for the second pulse 41, and a pulse width of 0.67 ns for the second pulse 41, the following table shows the period duration of the second pulse 41, the time interval between two adjacent second pulses 41, the maximum distance difference between multiple targets 2, and the number of second pulses 41 in a single multi-pulse detection frame 4 when the pulse repetition frequency is 30 MHz, 45 MHz, 60 MHz, 75 MHz, and 100 MHz, respectively:

[0087] Table 1. Schematic diagram of corresponding parameters for different pulse repetition frequencies.

[0088] Period duration (ns) 33.33 22.22 16.67 13.33 10.00 Time interval (ns) 32.67 21.56 16.00 12.67 9.33 Distance difference (m) between the nearest and farthest targets 4.90 3.23 2.40 1.90 1.40 Second pulse count 6 9 12 15 20

[0089] As shown in Table 1, when the pulse repetition frequency is 30MHz, the corresponding period duration is 33.33ns. Subtracting the pulse width of the second pulse 41 (0.67ns), the time interval is 32.67ns. When the time interval determined in step S201 is less than 32.67ns, a pulse repetition frequency of 30MHz can satisfy the requirement of no overlap of the second echo 22. When 30MHz is selected, the time interval is 32.67ns. At this time, multiplying by the flight speed of the second pulse 41, the maximum allowable distance difference between the target 2 closest to the multi-target detection device 1 and the target 2 farthest from the multi-target detection device 1 can be obtained, that is, the distance difference between the distances of the closest target 2 and the farthest target 2 from the multi-target detection device 1, as shown in Table 1. This distance difference is 4.90m. Similarly, at pulse repetition frequencies of 45MHz, 60MHz, 75MHz and 100MHz, the corresponding time intervals are 21.56ns, 16.00ns, 12.67ns and 9.33ns, respectively, which also correspond to the maximum allowable distance difference between the nearest target 2 and the farthest target 2 of 3.23m, 2.40m, 1.90m and 1.40m, respectively.

[0090] As shown in Table 1, the longer the period duration, the fewer second pulses 41 can be accommodated in a single multi-pulse detection frame 4. Taking the frame length of the multi-pulse detection frame 4 in Table 1 as 0.2 μs as an example, with a pulse repetition frequency of 30 MHz, the period duration is 33.33 ns. Therefore, a 0.2 μs multi-pulse detection frame 4 can accommodate 6 second pulses 41. Thus, when the time interval determined in step S201 is small, such as 15 ns, there are more pulse repetition frequencies available for the application. For example, the time intervals corresponding to 30 MHz, 45 MHz, and 60 MHz are all greater than the determined time interval of 15 ns. In this case, the pulse repetition frequency with the largest corresponding to these fixed time intervals is selected, namely 60 MHz. At 60 MHz, the number of second pulses 41 that can be accommodated in a single multi-pulse detection frame 4 is 12, which is more than in the cases of 45 MHz and 30 MHz. The more second pulses 41 in a single multi-pulse detection frame 4, the higher the detection accuracy will be.

[0091] In some possible implementations, the second bandwidth of the second pulse 41 may be equal to or less than the first bandwidth of the first pulse 31.

[0092] In this embodiment, when the first pulse 31 detects the target 2, since the target 2 is still unknown, a first bandwidth as high as possible is needed to improve the detection resolution. However, when the target 2 is known, the second bandwidth of the second pulse 41 can be adaptively adjusted according to the parameters of the actual multi-target detection device 1, increasing the flexibility and adaptability of the solution.

[0093] In some possible implementations, the processor 10 can calculate the distance between each target 2 and the multi-target detection device based on the signal flight time corresponding to each target 2 and the flight speed of the first pulse 31. Optionally, the processor 10 can also calculate the distance difference between the farthest target 2 and the nearest target 2 relative to the multi-target detection device 1 based on the calculated distance between each target 2 and the multi-target detection device 1. The processor 10 determines the pulse repetition frequency of the second pulse 41 in the multi-pulse detection frame 4 based on the calculated distance difference and controls the transmitter 11 to transmit the multi-pulse detection frame 4 at this pulse repetition frequency.

[0094] For example, as shown in Table 1, the time interval between two adjacent second pulses 41 has a unique numerical correspondence with the distance difference between the nearest target 2 and the farthest target 2. Using either the time interval or the distance difference as a reference factor is a calculation method that the processor 10 can choose. The corresponding pulse repetition frequency can be determined by the distance difference. The specific determination method is the same as the method described above for determining the pulse repetition frequency by time interval, and will not be repeated here.

[0095] In some possible implementations, the pulse repetition frequency is determined by adding a certain value to the time interval. Alternatively, the pulse repetition frequency can be determined by adding a certain value to the distance difference between the nearest and farthest targets.

[0096] For example, if the actual detected time interval in step S201 is 10 ns, as shown in Table 1, a pulse repetition frequency of 75 MHz can be selected without adding a certain value. Assuming this certain value is 5 ns, and in this embodiment where a certain value is required, the determined time interval is 15 ns, then 60 MHz should be selected. With 60 MHz selected, the time interval between the second pulses 41 will be greater than the interval between the second pulses 41 when 75 MHz is selected, thus making the distance between the second echoes 22 reflected from each target 2 by the second pulse 41 greater, further avoiding overlap of the second echoes 22 between different targets 2. The principle of adding a certain value to the distance difference between the nearest target 2 and the farthest target 2 to determine the pulse repetition frequency is the same, and therefore will not be elaborated further.

[0097] Step S203: The processor 10 controls the receiver 12 to receive the second echo 22.

[0098] In some possible implementations, the processor 10 is also configured to: for a target 2, determine the distance change of a target 2 in different detection cycles based on the time difference between the second echo 22 and the second pulse 41 corresponding to different detection cycles, and determine the vital signs of a target 2 based on the distance change.

[0099] The above are as follows Figure 2 The multi-pulse detection device 1 shown can be used to perform the following: Figure 10 The multi-pulse detection method shown in steps S301-S303 is as follows:

[0100] Step S301: Based on the period duration and time interval of the second pulse 41 and the signal flight time corresponding to each target 2, determine the time when all the second echoes 22 corresponding to each target 2 arrive at the multi-target detection device 1.

[0101] For example, given the period length and time interval of the second pulse 41, as well as the signal flight time of a certain target 2, the specific transmission time of each consecutive second pulse 41 can be determined by converting the time relationship, thereby determining the time point at which the second echo 22 reflected by each target 2 in different detection cycles arrives at the multi-pulse detection device 1, i.e., the expected arrival time.

[0102] Step S302: For each target 2, separate the sub-signal of the second echo 22 corresponding to the target 2 from the second echo 22 received by the receiver 12.

[0103] For example, after determining the expected arrival time of the second echo 22 corresponding to each target 2 in step S301, when the second echo 22 is actually received, it can be determined which target 2 the received second echo 22 specifically corresponds to based on the expected arrival time. Then, the second echo 22 corresponding to each target 2 is separated from all the received second echoes 22 and used as a sub-signal corresponding to each target 2.

[0104] Step S303: Calculate the vital signs corresponding to each target based on the separated sub-signals corresponding to each target 2.

[0105] For example, Figure 11The following is a schematic diagram of the workflow of the multi-target detection device 1 proposed in this application embodiment. As shown in the figure, the transmitter 11 first transmits a single-pulse ranging frame 3 including a first pulse 31. Then, the receiver 12 receives the first echo 21 generated by the reflection of the first pulse 31 by the target 2. The processor 10 determines the existing signal flight time based on the first echo 21, and determines the time interval between the second pulses 41 in the multi-pulse detection frame 4 based on the signal flight time. The transmitter 11 generates and transmits the multi-pulse detection frame 4 according to the determined time interval. Then, the receiver 12 receives the second echo 22 generated by the reflection of the second pulse 41 by the target 2 in the multi-pulse detection frame 4. The processor 10 separates the second echo 22 corresponding to each target 2 from the received second echo 22, and determines the vital signs of each target 2. At the same time, the processor 10 also determines whether the distance of the target 2 relative to the multi-target detection device 1 has changed based on the second echo. If it has changed, the single-pulse ranging frame 3 is retransmitted to detect the vital signs of the target 1 whose distance has changed.

[0106] In some possible implementations, for the second echo 22 of target 2, algorithms such as Chirp Z-Transform (CZT), Fast Fourier Transform (FFT), or Variational Modal Decomposition (VMD) can be used to extract features from the sub-signals of target 2, thereby obtaining the vital signs corresponding to target 2.

[0107] In some possible implementations, a certain number of second pulses 41 are used as a group of second pulses 41, and the sub-signals of target 2 are separated from the second echo 22 corresponding to this group of second pulses 41. Multiple groups of second pulses 41 are used to obtain multiple corresponding groups of sub-signals. For a single target 2, the obtained multiple groups of sub-signals are subjected to homology integration processing (also known as coherent integration processing) to obtain homology-integrated sub-signals. Feature extraction is performed on the homology-integrated sub-signals to obtain the vital signs corresponding to target 2.

[0108] For example, such as Figure 13 The image shows a waveform diagram of a set of sub-signals before homology integration processing. Figure 14 This diagram illustrates the sub-signals obtained after homology integration of multiple sub-signals. Homology integration improves the signal-to-noise ratio of the sub-signals, thereby increasing detection accuracy.

[0109] For example, the number of second pulses 41 in a set varies depending on the detected vital signs. Taking human respiratory rate as an example, the human respiratory rate per minute is typically in the range of [10, 30] breaths per minute. Therefore, the maximum time for one respiratory cycle (i.e., including one exhalation and one inhalation) might be 6 seconds (taking 10 breaths per minute as an example). When detecting respiratory rate, 2-3 respiratory cycles can be selected as a set of sub-signals for one detection, requiring a detection time of ten to twenty seconds to complete the detection of a set of sub-signals. Optionally, the respiratory rate can be measured using the second echo 22 within 20 seconds as a set of sub-signals. Similarly, if the human heart rate is used as the detected vital sign, since the heart rate is faster than the respiratory rate, the duration of a set of sub-signals can be appropriately reduced, for example, using the second echo 22 within 10 seconds as a set of sub-signals.

[0110] For example, the number of single-pulse ranging frames 3 or multi-pulse detection frames 4 transmitted per unit time can be adaptively adjusted according to the different vital signs detected. The number of single-pulse ranging frames 3 or multi-pulse detection frames 4 should not be too small, as too few frames are insufficient to detect continuous changes in target 2. Conversely, if the number of single-pulse ranging frames 3 or multi-pulse detection frames 4 is too high, it will increase unnecessary power consumption and the computational cost of processor 10. Therefore, the number of single-pulse ranging frames 3 or multi-pulse detection frames 4 should be as small as possible while still allowing for the detection of continuous changes in target 2. Taking human respiratory rate as an example, the number of single-pulse ranging frames 3 or multi-pulse detection frames 4 can be set in the range of 20-50 frames per second to satisfy the detection of continuous changes in chest cavity rise and fall. Optionally, the number of single-pulse ranging frames 3 or multi-pulse detection frames 4 can be set to 30 frames per second.

[0111] In some possible implementations, the processor 10 detects the distance between the target 2 and the multi-target detection device 1 based on the received second echo 22. If the distance changes or the amount of distance change is greater than a certain threshold, the processor 10 redetermines the signal flight distance and time interval corresponding to the target 2, and performs vital sign detection based on the redetermined time interval.

[0112] For example, the detection period for distance change can be one second, and the distance change of target 2 can be detected once every second. When the distance change is too large, that is, when there may be overlap of the second echo 22 corresponding to different targets 2 at the currently determined pulse repetition frequency, it is necessary to redetermine the signal flight distance, and then determine a new time interval or distance difference, so as to re-detect vital signs.

[0113] For example, consider two targets 2, where the distance difference between the closest target 2 and the farthest target 2 from the multi-target detection device 1 is 0.6 meters. The distance difference is determined to be 0.6 meters or the time interval to be 4 ns by transmitting a first pulse 31. A second pulse 41 can be transmitted using a pulse repetition frequency of 100 MHz. When the frame length of the multi-pulse detection frame 4 is 0.5 μs, using a pulse repetition frequency of 100 MHz to transmit the second pulse 41 yields... Figure 15 , Figure 16 , Figure 17 and Figure 18 A schematic diagram of the detection process. Among them, Figure 15 The results of respiratory rate detection for the first target, 2; Figure 16 The heart rate detection results for the first target, 2. Figure 17 The results of respiratory rate detection for the second target, 2; Figure 18 The heart rate detection results for the second target (2) are shown. A single pulse was used to detect both targets at a detection period of 0.5 μs, yielding the following results. Figure 19 , Figure 20 , Figure 21 and Figure 22 A schematic diagram of the detection process. Among them, Figure 19 The results of respiratory rate detection for the first target, 2; Figure 20 The heart rate detection results for the first target, 2. Figure 21 The results of respiratory rate detection for the second target, 2; Figure 22 The heart rate detection results for the second target (2) are shown. According to the comparison, using the 100MHz scheme in this embodiment, the accuracy rate of measurement for the two targets (2) out of a total of 84 data points is 83 / 84. The accuracy rate of the control group is 69 / 84. It can be seen that using the multi-target detection device 1 and multi-target detection method provided in this embodiment can greatly improve the measurement accuracy.

[0114] like Figure 23 As shown, this application embodiment also provides an electronic device 5, which includes at least one of the above-described multi-target detection devices 1; the multi-target detection device 1 is used to calculate the vital signs of multiple targets.

[0115] For example, electronic device 5 can be a smartwatch, mobile phone, tablet computer, or other similar device.

[0116] For example, electronic device 5 can be a dedicated vital sign detection device.

[0117] like Figure 24As shown, this application embodiment also provides a chip system 6. The chip system 6 includes at least one processor 61 and at least one interface circuit 62. The at least one processor 61 and at least one interface circuit 62 are interconnected via lines. The processor 61 is used to support the chip system in implementing the various functions or steps in the above method embodiments, and the at least one interface circuit 62 can be used to receive signals from other devices (e.g., memory) or to send signals to other devices (e.g., a communication interface). The chip system 6 may include a chip and may also include other discrete devices.

[0118] This application also provides a computer-readable storage medium including instructions that, when executed on the electronic device 5 or chip system 6, cause the electronic device 5 or chip system 6 to perform various functions or steps in the method embodiments described above, such as executing... Figure 8 , Figure 9 and Figure 10 The method shown.

[0119] This application also provides a computer program product including instructions. When the instructions are executed on the aforementioned electronic device 5 or chip system 6, the electronic device 5 or chip system 6 causes the electronic device 5 or chip system 6 to perform the various functions or steps in the above method embodiments, such as executing... Figure 8 , Figure 9 and Figure 10 The method shown.

[0120] The technical effects of electronic devices, chip systems, computer-readable storage media, and computer program products are the same as those in the preceding method embodiments.

[0121] The processor involved in the embodiments of this application can be a chip. For example, it can be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD), or other integrated chips.

[0122] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0123] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software 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.

[0124] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and modules described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0125] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or modules may be electrical, mechanical, or other forms.

[0126] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located on one device or distributed across multiple devices. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0127] In addition, the functional modules in the various embodiments of this application can be integrated into one device, or each module can exist physically separately, or two or more modules can be integrated into one device.

[0128] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software programs, implementation can be, in whole or in part, in the form of a computer program product. This computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device containing one or more servers, data centers, etc., that can be integrated with the medium. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state drives (SSDs)).

[0129] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A multi-target detection device, characterized in that, Includes a processor, a transmitter, and a receiver; the processor is used for: The transmitter is controlled to transmit a first pulse, and the receiver is controlled to receive multiple first echoes generated by the reflection of the first pulse by multiple targets. Based on the time difference between the first pulse and the plurality of first echoes, the signal flight time corresponding to each of the plurality of targets is obtained; The time interval between two adjacent pulses in the plurality of second pulses is determined based on the signal flight time corresponding to the plurality of targets; The transmitter is controlled to transmit the plurality of second pulses according to the time interval, and the receiver is controlled to receive the plurality of second echoes generated by the reflection of each second pulse by the plurality of targets. For the second pulse and the corresponding plurality of second echoes belonging to the same detection period, the transmission time of the second pulse is added to the signal flight time corresponding to the plurality of targets respectively to obtain the expected reception time of the second echo corresponding to the plurality of targets respectively; And based on the expected reception time and the reception time of the plurality of second echoes, determine the second echoes corresponding to the plurality of targets respectively; For a target, the distance change of the target in different detection cycles is determined based on the time difference between the second echo and the second pulse corresponding to different detection cycles, and the vital signs of the target are determined based on the distance change.

2. The apparatus according to claim 1, characterized in that, The time interval plus the signal flight time of the nearest target is greater than the signal flight time of the farthest target.

3. The apparatus according to claim 1, characterized in that, The processor is specifically used for: For a target, the time difference between the second echo and the second pulse corresponding to different detection cycles is processed by homology integration to obtain the vital signs of the target.

4. The apparatus according to any one of claims 1-3, characterized in that, The processor is also used for: If the distance change of a target is greater than a threshold, the signal flight time corresponding to each of the multiple targets is re-determined.

5. The apparatus according to any one of claims 1-3, characterized in that, The bandwidth of the first pulse is a first bandwidth; the bandwidth of the second pulse is a second bandwidth; the second bandwidth is less than or equal to the first bandwidth.

6. The apparatus according to any one of claims 1-3, characterized in that, The vital signs include at least one of heart rate and respiratory rate.

7. A multi-target detection method, characterized in that, The method includes: Transmit a first pulse and receive multiple first echoes generated by the reflection of the first pulse by multiple targets; Based on the time difference between the first pulse and the plurality of first echoes, the signal flight time corresponding to each of the plurality of targets is obtained; The time interval between two adjacent pulses in the plurality of second pulses is determined based on the signal flight time corresponding to the plurality of targets; The plurality of second pulses are transmitted according to the time interval, and the plurality of second echoes generated by the reflection of each second pulse by the plurality of targets are received; For the second pulse and the corresponding plurality of second echoes belonging to the same detection period, the transmission time of the second pulse is added to the signal flight time corresponding to the plurality of targets respectively to obtain the expected reception time of the second echo corresponding to the plurality of targets respectively; and the second echo corresponding to the plurality of targets is determined according to the expected reception time and the reception time of the plurality of second echoes respectively. For a target, the distance change of the target in different detection cycles is determined based on the time difference between the second echo and the second pulse corresponding to different detection cycles, and the vital signs of the target are determined based on the distance change.

8. The method according to claim 7, characterized in that, The time interval plus the signal flight time of the nearest target is greater than the signal flight time of the farthest target.

9. The method according to claim 7, characterized in that, The method specifically includes: For a target, the vital signs of the target are obtained by performing coherent integration on the time difference between the second echo and the second pulse corresponding to different detection periods.

10. The method according to any one of claims 7-9, characterized in that, The method further includes: If the distance change of a target is greater than a threshold, the signal flight time corresponding to each of the multiple targets is re-determined.

11. The method according to any one of claims 7-9, characterized in that, The bandwidth of the first pulse is a first bandwidth; the bandwidth of the second pulse is a second bandwidth; the second bandwidth is less than or equal to the first bandwidth.

12. The method according to any one of claims 7-9, characterized in that, The vital signs include at least one of heart rate and respiratory rate.

13. An electronic device, characterized in that, Includes the multi-target detection device as described in any one of claims 1-6; the multi-target detection device is used to calculate the vital signs of multiple targets.

14. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes instructions that, when executed on the electronic device of claim 13, cause the electronic device to perform the method of any one of claims 7-12.

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