24GHz millimeter wave radar detection method and system for intelligent door lock

Abstract

The invention provides a 24GHz millimeter wave radar detection method and system for an intelligent door lock, and the method comprises the steps: continuously transmitting a detection signal at first power, and receiving and confirming an echo signal; whether the target object is a human body or a static object is distinguished according to the echo signal, and a first target distance between the intelligent door lock and the target object is calculated according to the echo signal in response to the fact that the target object is the human body; if the first target distance is smaller than or equal to the first distance threshold value, the detection signals are continuously transmitted at second power within the preset duration to determine a second target distance between the target object and the intelligent door lock; in response to the fact that the second target distance is smaller than or equal to a second distance threshold, determining whether the second target distance is larger than a third distance threshold, and if yes, sending a first interrupt signal to the intelligent door lock to start a video recording module; if not, a second interrupt signal is sent to the intelligent door lock to open the unlocking recognition module, accurate distance measurement and graded triggering are achieved, and the detection precision and the cruising ability of the intelligent door lock are improved.

Description

Technical Field

[0001] This application relates to the field of smart door lock detection, and in particular to a 24GHz millimeter-wave radar detection method and system for smart door locks. Background Technology

[0002] As the gateway and core component of smart homes, the accuracy and reliability of proximity detection in smart locks are crucial. Traditional solutions mainly rely on Bluetooth, Wi-Fi, or infrared sensors, which generally suffer from low detection accuracy, high power consumption, and susceptibility to environmental interference, making it difficult to meet the needs of high-level applications requiring precise distance measurement, such as graded trigger biometric identification or video recording. To improve performance, existing technologies have introduced radar solutions operating at 5.8GHz, which are based on the Doppler effect and can detect human movement. However, this technology has a fundamental limitation: it can only sense moving targets and their speed, and cannot obtain precise distance information for static targets (such as a user standing still in front of the door), resulting in a significantly reduced user experience in real-world scenarios.

[0003] Furthermore, existing 5.8GHz radar solutions face multiple challenges in practical implementation. First, their physical characteristics result in insufficient distance resolution; the minimum detection distance of typical solutions is usually around 1 meter, making it impossible to effectively distinguish subtle differences between close distances such as 0.5 meters and 1 meter, thus hindering the implementation of graded "proximity trigger" and "close proximity trigger" functions. Second, this solution uses a continuous wave radar mechanism, with power consumption generally exceeding 10mA. For battery-powered smart locks, this severely restricts their battery life, requiring frequent battery replacements and resulting in a poor user experience. Additionally, the 5.8GHz band overlaps with common Wi-Fi bands, leading to a false trigger rate as high as 15%-20% in environments with dense Wi-Fi coverage, and the reflection of electromagnetic waves by metal doors further exacerbates signal quality degradation. Finally, existing solutions are functionally limited, only achieving a general wake-up function based on "someone approaching," lacking multi-level triggering logic based on precise distance, and unable to support intelligent interactions such as "long-distance recording and close-range recognition." Summary of the Invention

[0004] The main objective of this application is to propose a 24GHz millimeter-wave radar detection method and system for smart door locks. It achieves accurate ranging through 24GHz millimeter-wave radar, significantly reduces power consumption by combining a dual-frequency detection mechanism, and realizes intelligent hierarchical triggering based on multi-level distance thresholds, which significantly improves detection accuracy, battery life and user experience.

[0005] To achieve the above objectives, a first aspect of this application proposes a 24GHz millimeter-wave radar detection method for smart door locks, comprising: It continuously transmits detection signals at the first power and receives and confirms the echo signals reflected by the detection signals when they encounter the target object; The system distinguishes between a human body and a stationary object based on the echo signal, and calculates the first target distance between the smart lock and the target object based on the echo signal if the target object is a human body. If the distance to the first target is less than or equal to a preset first distance threshold, then a detection signal is continuously emitted at a second power within a preset time period to continuously determine the second target distance between the target object and the smart door lock within the preset time period, and the second power is greater than the first power; In response to the second target distance being less than or equal to a preset second distance threshold, it is determined whether the second target distance is greater than a preset third distance threshold. If so, a first interrupt signal is sent to the smart lock to enable the smart lock to start the recording module to record the target object; if not, a second interrupt signal is sent to the smart lock to enable the smart lock to start the unlock recognition module. The second distance threshold is less than the first distance threshold and greater than the third distance threshold.

[0006] Furthermore, in some embodiments, the above method further includes: if the distance to the first target is greater than the first distance threshold, then continue to continuously transmit the detection signal at the first power for a preset time period to continuously determine the distance to the second target.

[0007] Furthermore, in some embodiments, the above method further includes: in response to the second target distance being greater than a second distance threshold, continuing to transmit a detection signal at a second power for a preset time period to continuously determine the second target distance.

[0008] Furthermore, in some embodiments, distinguishing the target object as a human body or a stationary object based on the echo signal includes: The amplitude of the echo signal is analyzed according to the timing of the received echo signal to obtain the amplitude values ​​corresponding to multiple time frames. When the amplitude value corresponding to each time frame within the preset frame length is detected to be greater than the preset amplitude threshold, the target object is determined to be a human body. Alternatively, when the amplitude value corresponding to a certain time frame within a preset frame length is detected to be less than or equal to the amplitude threshold, the target object is determined to be a stationary object.

[0009] Furthermore, in some embodiments, calculating the first target distance between the smart lock and the target object based on the echo signal includes: The peak value of the echo signal is determined based on the Fast Fourier Transform algorithm. Based on the peak values ​​of the spectrum, the propagation distance of the echo signal is calculated to obtain the first target distance.

[0010] Furthermore, in some embodiments, receiving and confirming the echo signal reflected by the detection signal upon encountering the target object includes: Receive the reflected signal from the target object when the detection signal encounters it; The reflected signal is amplified using low-noise amplification to obtain the amplified signal; The amplified signal and the probe signal are mixed to obtain the intermediate frequency signal; The intermediate frequency signal is filtered out by high frequency to obtain the echo signal.

[0011] To achieve the above objectives, a second aspect of this application proposes a 24GHz millimeter-wave radar detection system for smart door locks, comprising: The radar radio frequency front-end is used to continuously transmit detection signals at a first power and receive the echo signals reflected by the detection signals when they encounter the target object. The signal processing unit is used to distinguish whether the target object is a human body or a stationary object based on the echo signal, and in response to the target object being a human body, to calculate the first target distance between the smart door lock and the target object based on the echo signal. The detection control unit is used to control the radar radio frequency front end to continuously transmit detection signals at a second power within a preset time period if the distance to the first target is less than or equal to a preset first distance threshold, so that the signal processing unit can continuously determine the second target distance between the target object and the smart door lock within the preset time period, wherein the second power is greater than the first power. The detection control unit is also used to determine whether the distance to the second target is greater than a preset third distance threshold in response to the second target distance being less than or equal to a preset second distance threshold. If it is, the control unit sends a first interrupt signal to the smart lock to enable the smart lock to start the recording module to record the target object. If it is not, the control unit sends a second interrupt signal to the smart lock to enable the smart lock to start the unlocking recognition module. The second distance threshold is less than the first distance threshold and greater than the third distance threshold.

[0012] Furthermore, in some embodiments, the radar radio frequency front-end includes a signal modulator, a power divider, a power amplifier, a transmitting antenna, a receiving antenna, a low-noise amplifier, a mixer, and a low-pass filter. The signal modulator is connected to the power divider, the power divider is connected to the power amplifier and the low-pass filter respectively, the power amplifier is connected to the transmitting antenna, the receiving antenna is connected to the low-noise amplifier, the low-noise amplifier is connected to the mixer, and the mixer is connected to the low-pass filter. A signal modulator is used to generate a linear frequency modulated signal that produces a sawtooth wave. A power divider is used to distribute the power of the first power source to a linear frequency modulated signal; The power amplifier is used to amplify the linear frequency modulated signal after power distribution to obtain the detection signal; The transmitting antenna is used to transmit detection signals; The receiving antenna is used to receive the reflected signal of the probe signal when it encounters the target object; A low-noise amplifier is used to amplify the reflected signal with low noise to obtain the amplified signal. A mixer is used to mix the amplified signal and the probe signal to obtain an intermediate frequency signal; A low-pass filter is used to filter out high frequencies from an intermediate frequency signal to obtain an echo signal.

[0013] Furthermore, in some embodiments, the signal processing unit includes a high-speed analog-to-digital converter and a microcontroller, wherein the high-speed analog-to-digital converter is communicatively connected to the microcontroller and to a low-pass filter. A high-speed analog-to-digital converter is used to sample the echo signal output from a low-pass filter; The microcontroller is used to determine the spectral peak of the echo signal based on the Fast Fourier Transform algorithm, and to calculate the propagation distance of the echo signal based on the spectral peak to obtain the first target distance.

[0014] The embodiments of the first aspect of this application have the following beneficial effects: By employing a 24GHz millimeter-wave radar and combining it with an innovative dual-frequency detection mechanism, compared with the prior art, the 24GHz millimeter-wave radar achieves centimeter-level accurate ranging of static and dynamic targets by analyzing the phase and propagation time difference of the echo signal. This completely breaks through the fundamental limitation of traditional 5.8GHz Doppler radar, which can only detect moving targets and cannot sense stationary people, providing reliable distance sensing capabilities for smart door locks. Secondly, the innovative adaptive frequency conversion working mechanism reduces power consumption by operating at a lower first power during the monitoring phase, and only switches to a higher second power for intensive and precise measurement when the target enters the first distance threshold, achieving a balance between power consumption and performance. The optimal balance is achieved, significantly reducing the average power consumption of the system from over 10mA in traditional solutions to the milliamp level, thus improving battery life. In addition, the 24GHz operating frequency band effectively avoids interference with Wi-Fi frequency bands, significantly reducing the false trigger rate in complex environments. At the same time, its stronger penetration and resolution capabilities suppress multipath reflection problems caused by metal doors, improving system reliability. Finally, based on accurate distance calculation capabilities, multi-level intelligent triggering from "long-distance start recording" to "short-distance start unlock recognition" is realized by collaboratively determining the first, second, and third distance thresholds, constructing a seamless security and unlocking process, and upgrading the smart door lock from a single access tool to an intelligent terminal with scenario-based service capabilities. Attached Figure Description

[0015] Figure 1This is an optional flowchart of a 24GHz millimeter-wave radar detection method for smart door locks provided in an embodiment of this application; Figure 2 This is another optional flowchart of the 24GHz millimeter-wave radar detection method for smart door locks provided in the embodiments of this application; Figure 3 This is another optional flowchart of the 24GHz millimeter-wave radar detection method for smart door locks provided in the embodiments of this application; Figure 4 This is an optional flowchart provided in this application embodiment for distinguishing a target object as a human body or a stationary object based on the echo signal; Figure 5 This is an optional flowchart of receiving and confirming the echo signal reflected by the detection signal when it encounters a target object, provided in an embodiment of this application; Figure 6 This is an optional schematic diagram of the reflected signal provided in an embodiment of this application; Figure 7 This is an optional schematic diagram of an intermediate frequency signal obtained by mixing an amplified signal and a detection signal, provided in an embodiment of this application. Figure 8 This is an optional flowchart provided in an embodiment of this application for calculating the distance to the first target based on the echo signal; Figure 9 This is an optional schematic diagram of a 24GHz millimeter-wave radar detection system for smart door locks provided in an embodiment of this application; Figure 10 This is an optional schematic diagram of the radar radio frequency front-end provided in an embodiment of this application; Figure 11 This is a schematic diagram of the hardware structure of an electronic device provided in one embodiment of this application. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0017] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0018] It should also be noted that in the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If the terms "first" and "second" are used, they are only for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0020] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0021] Existing 5.8GHz radar solutions face multiple challenges in practical implementation. First, their physical characteristics result in insufficient distance resolution; typical solutions have a minimum detection distance of around 1 meter, failing to effectively distinguish subtle differences between close-range distances like 0.5 meters and 1 meter, making it difficult to implement graded "proximity trigger" and "close proximity trigger" functions. Second, this solution uses a continuous wave radar mechanism, with power consumption generally exceeding 10mA. For battery-powered smart locks, this severely restricts their battery life, requiring frequent battery replacements and resulting in a poor user experience. Furthermore, the 5.8GHz band overlaps with common Wi-Fi bands. In environments with dense Wi-Fi coverage, such as apartment buildings, the false trigger rate can reach 15%-20%, and the reflection of electromagnetic waves by metal doors further degrades signal quality. Finally, existing solutions are functionally limited, only achieving a general "someone is approaching" wake-up call, lacking multi-level triggering logic based on precise distance, and unable to support intelligent interactions such as "long-distance recording and close-range recognition."

[0022] It should be noted that the frequency of the reflected wave increases when the target approaches the 5.8GHz radar, and decreases when the target moves away from the 5.8GHz radar. The formula for the frequency shift is: .

[0023] in, For Doppler frequency shift, It is the relative velocity of the target. The wavelength (approximately 5.2 cm for 5.8 GHz radar) is measured. This is achieved through detection... This allows us to determine if an object is moving and to estimate its speed. The advantage of using 5.8GHz radar for detection is its simplicity and low cost, but its disadvantages include the inability to detect stationary individuals and the inability to obtain precise distances.

[0024] To address these issues, this application proposes a 24GHz millimeter-wave radar detection method for smart door locks. First, by employing a 24GHz millimeter-wave radar combined with an innovative dual-frequency detection mechanism, compared to existing technologies, the 24GHz millimeter-wave radar achieves centimeter-level accurate ranging of both static and dynamic targets by analyzing the phase and propagation time difference of the echo signal. This completely overcomes the fundamental limitation of traditional 5.8GHz Doppler radar, which can only detect moving targets and cannot sense stationary people, providing reliable distance sensing capabilities for smart door locks. Second, the innovative adaptive frequency conversion mechanism reduces power consumption by operating at a lower initial power during the monitoring phase, switching to a higher second power for intensive and precise measurement only when the target enters within the first distance threshold. This achieves an optimal balance between power consumption and performance, ensuring a smooth system operation. The average power consumption has been significantly reduced from over 10mA in traditional solutions to the milliamp level, improving battery life. In addition, the 24GHz operating frequency band effectively avoids interference with Wi-Fi bands, significantly reducing the false trigger rate in complex environments. At the same time, its stronger penetration and resolution capabilities suppress multipath reflection problems caused by metal doors, improving system reliability. Finally, based on accurate distance calculation capabilities, by collaboratively determining the first, second, and third distance thresholds, multi-level intelligent triggering from "long-distance start recording" to "short-distance start unlock recognition" is realized, constructing a seamless security and unlocking process, upgrading the smart door lock from a single access tool to an intelligent terminal with scenario-based service capabilities.

[0025] This application provides a 24GHz millimeter-wave radar detection method for smart door locks, which is applied to a 24GHz millimeter-wave radar detection system. The specific implementation details are illustrated in the following embodiments.

[0026] Firstly, referring to Figure 1 As shown, Figure 1 This is an optional flowchart of a 24GHz millimeter-wave radar detection method for smart door locks provided in the embodiments of this application. The method may include, but is not limited to, steps S101 to S102.

[0027] Step S101: Continuously transmit the detection signal at the first power, and receive and confirm the echo signal reflected by the detection signal when it encounters the target object.

[0028] Step S102: Based on the echo signal, distinguish whether the target object is a human body or a stationary object, and in response to the target object being a human body, calculate the first target distance between the smart door lock and the target object based on the echo signal.

[0029] Step S103: If the distance to the first target is less than or equal to a preset first distance threshold, then a detection signal is continuously emitted at a second power within a preset time period to continuously determine the second target distance between the target object and the smart door lock within the preset time period.

[0030] Among them, the second power is greater than the first power; Step S104: In response to the second target distance being less than or equal to a preset second distance threshold, determine whether the second target distance is greater than a preset third distance threshold. If yes, send a first interrupt signal to the smart lock to enable the smart lock to start the recording module to record the target object; if no, send a second interrupt signal to the smart lock to enable the smart lock to start the unlock recognition module.

[0031] The second distance threshold is less than the first distance threshold and greater than the third distance threshold. In one possible embodiment, the first distance threshold is 3.3 meters, the second distance threshold is 3 meters, and the third distance threshold is 1.5 meters.

[0032] In one possible embodiment, the average current corresponding to the continuous transmission of the detection signal at the first power is 40 μA, and the average current corresponding to the continuous transmission of the detection signal at the first power is 130 μA.

[0033] In steps S101 to S104, firstly, the functional limitations of traditional detection technologies are fundamentally overcome, achieving a qualitative leap from "perceiving presence" to "precise ranging." This embodiment of the application, through the use of millimeter-wave radar technology, can accurately calculate the absolute distance between the target and the door lock by analyzing the phase and time difference of the echo signal, unaffected by the target's motion state. This capability completely solves the industry pain point that traditional 5.8GHz Doppler radar cannot detect stationary targets, enabling the door lock to accurately sense whether a user is approaching, has already stopped at the door, or is leaving, providing an irreplaceable data foundation for precise function triggering.

[0034] Secondly, this application's embodiments achieve high-precision continuous sensing with extremely low power consumption through an adaptive frequency conversion mechanism, perfectly resolving the conflict between battery life and performance. It's worth noting that this application does not operate continuously in a high-power mode, but rather employs an intelligent dual-frequency detection process: during the detection phase, it operates at a lower first power to minimize standby power consumption; only when a human target is confirmed to have entered the first warning zone (i.e., the area where the distance between the human and the smart lock is within a first distance threshold) does it switch to a higher second power for intensive scanning to obtain more accurate and real-time distance data. This "on-demand allocation of computing power" strategy significantly reduces the system's average power consumption to below milliamp level (below 200μA), which can significantly extend the battery life of battery-powered smart locks, greatly improving product usability and user experience.

[0035] Furthermore, the embodiments of this application significantly enhance the robustness and anti-interference capability of the system, ensuring reliability in complex real-world environments. The operating frequency band used by the millimeter-wave radar (such as 24GHz) is far lower than the congested Wi-Fi band, effectively avoiding electromagnetic interference from devices on the same frequency band and reducing the false trigger rate to a negligible level. At the same time, the strong penetration and resolution capabilities of 24GHz millimeter waves reduce the multipath reflection effects caused by environmental factors such as metal doors, further improving the signal-to-noise ratio and detection stability.

[0036] Finally, this application embodiment also constructs a multi-level intelligent triggering logic based on precise distance, greatly enriching the interactive functions and application scenarios of smart locks. By setting a collaborative judgment mechanism of "first distance threshold," "second distance threshold," and "third distance threshold," this application can achieve refined scene response. For example, when the target object is between 3 meters and 1.5 meters (i.e., the second and third distance thresholds), the smart lock can be woken up in advance and the recording function can be started to record the process of the target object approaching the smart lock; when the user approaches within 1.5 meters, a high-power face recognition module or palm vein recognition is activated for pre-alignment; finally, unlocking is performed after identity verification. This seamless automated process not only improves security and convenience but also upgrades the smart lock from a single security tool into a smart terminal with proactive service capabilities.

[0037] It should be noted that the unlocking and identification module of this application includes a palm vein recognition unit and a face recognition unit. The palm vein recognition unit can collect images of the palm veins of the target object through a near-infrared camera on the smart lock for biometric identification, while the face recognition unit can collect facial feature information of the target object through a near-infrared camera on the smart lock for biometric identification.

[0038] Reference Figure 2 As shown, Figure 2 This is another optional flowchart of the 24GHz millimeter-wave radar detection method for smart door locks provided in the embodiments of this application. The construction process may include, but is not limited to, steps S201 to S203.

[0039] Step S201: If the distance to the first target is greater than the first distance threshold, then continue to transmit the detection signal at the first power for a preset time to continuously determine the distance to the second target.

[0040] In one possible embodiment, after the millimeter-wave radar system completes the initial detection of the target, it enters a continuous monitoring phase. During this phase, the first target distance is calculated and compared with a preset first distance threshold (e.g., 3.3 meters). If the first target distance is determined to be greater than this threshold, it indicates that the target is still in a relatively distant area, and the system will maintain a low-power operation. Specifically, the control module instructs the radar front-end to continue transmitting detection signals at a preset first power level and maintain this transmission power unchanged for a subsequent preset duration (e.g., 10 seconds). During this continuous monitoring period, the system periodically collects echo signals and performs coherent accumulation processing to update the target's position information in real time, thereby continuously acquiring accurate second target distance data. This design effectively controls system power consumption while maintaining a low transmission power, ensuring the necessary detection range, and avoiding signal instability issues that may be caused by frequent power switching. Furthermore, continuous distance monitoring provides the system with criteria for judging the target's movement trend, reserving sufficient decision-making time for potentially triggered hierarchical response mechanisms, demonstrating the comprehensive optimization of power management, detection stability, and system response capabilities in this invention.

[0041] Reference Figure 3 As shown, Figure 3 This is another optional flowchart of the 24GHz millimeter-wave radar detection method for smart door locks provided in the embodiments of this application. The process of this method may include, but is not limited to, step S301.

[0042] Step S301: In response to the second target distance being greater than the second distance threshold, the detection signal is continuously transmitted at the second power for a preset time period to continuously determine the second target distance.

[0043] In one possible embodiment, as the target object enters the first detection zone (i.e., the area where the distance between the human body and the smart lock is within a first distance threshold), after the system has completed close-range detection and confirmed that the target is a human body, if the second target distance calculated by the system is greater than a preset second distance threshold (e.g., 3 meters), it indicates that although the target has entered the monitoring range, it has not yet reached the distance to trigger a higher level of function. At this time, the control module will maintain the current enhanced detection mode and continue to transmit detection signals at a second power level for a preset duration (e.g., 5 seconds). During this continuous monitoring period, the radar front end operates at a higher power to ensure a sufficient signal-to-noise ratio, while the system updates the target's position information in real time through multiple sampling and dynamic target tracking algorithms, continuously acquiring accurate second target distance data. This design, by maintaining a moderate transmission power, ensures both the accuracy and stability of detection within the medium range and avoids the additional power consumption caused by using maximum power. Furthermore, continuous and accurate distance monitoring enables the system to accurately determine the target's movement trend—whether to continue approaching, maintain distance, or move away—providing a crucial decision-making basis for the precise activation of subsequent recording or unlocking / identification functions. This demonstrates the optimized balance of detection accuracy, power consumption control, and function triggering accuracy achieved in this application.

[0044] Furthermore, refer to Figure 4 As shown, Figure 4 This is an optional flowchart provided in the embodiments of this application for distinguishing a target object as a human body or a stationary object based on the echo signal. The method may include, but is not limited to, steps S401 to S403.

[0045] Step S401: Perform amplitude analysis on the echo signal according to the timing of the received echo signal to obtain the amplitude values ​​corresponding to multiple time frames; Step S402: When it is detected that the amplitude value corresponding to each time frame within the preset frame length is greater than the preset amplitude threshold, the target object is determined to be a human body. Step S403: Alternatively, when the amplitude value corresponding to a certain time frame within a preset frame length is detected to be less than or equal to the amplitude threshold, the target object is determined to be a stationary object.

[0046] In steps S401 to S403, firstly in step S401, the system performs amplitude analysis on the echo signal according to the timing of signal reception. Specifically, the system converts the continuous analog echo signal into a digital signal sequence in a fixed time window (e.g., 100 milliseconds). By performing envelope detection and amplitude quantization on the signal within each time unit, a series of amplitude values ​​arranged in chronological order are obtained, and these amplitude values ​​correspond to different time frames.

[0047] After obtaining the temporal amplitude data, the system enters the target recognition stage. According to step S402, when the system detects that the amplitude values ​​corresponding to all time frames within a preset frame length (e.g., 10 consecutive time frames, corresponding to a total duration of 1 second) are greater than a preset amplitude threshold, the target object is determined to be a human body. This criterion is based on the characteristics of human life activities—even a stationary standing human body will produce regular micro-Doppler effects from the respiratory movements of its chest cavity and the micro-vibrations of its skin, causing the echo signal amplitude to remain at a high level. Conversely, according to step S403, when the amplitude value is less than or equal to the amplitude threshold in any time frame within the preset frame length, it indicates that the echo signal lacks the continuity and regularity characteristic of vital signs, and the system determines the target object to be a stationary object (such as a package or suitcase placed in front of a door).

[0048] Therefore, this embodiment effectively distinguishes between human targets with life characteristics and stationary objects without life characteristics by combining time-series amplitude analysis with a continuous monitoring mechanism, significantly improving the accuracy and reliability of target identification and providing an accurate basis for subsequent distance calculation and function triggering.

[0049] Furthermore, refer to Figure 5 As shown, Figure 5 This is an optional flowchart of receiving and confirming the echo signal reflected by the detection signal when it encounters the target object, provided in the embodiments of this application. The method may include, but is not limited to, steps S501 to S504.

[0050] Step S501: Receive the reflection signal of the detection signal when it encounters the target object.

[0051] It should be noted that, referring to Figure 6 As shown, Figure 6 This is an optional schematic diagram of the reflected signal provided in an embodiment of this application. The detection signal in this embodiment is a sawtooth wave signal whose frequency varies linearly with time. The form of the transmitted signal is shown below:

[0052] Meanwhile, the reflected signal takes the following form:

[0053] in, The starting frequency, For frequency modulation bandwidth, One frequency modulation cycle This is the time delay caused by the signal traveling back at the speed of light after encountering the target. , Target distance, It is the speed of light.

[0054] Step S502: Perform low-noise amplification processing on the reflected signal to obtain the amplified signal.

[0055] Step S503: Mix the amplified signal and the detection signal to obtain the intermediate frequency signal.

[0056] Step S504: Perform high-frequency filtering on the intermediate frequency signal to obtain the echo signal.

[0057] Specifically, refer to Figure 7 As shown, Figure 7 This is an optional schematic diagram of an embodiment of the present application providing an intermediate frequency signal obtained by mixing an amplified signal and a probe signal. The amplified signal and the probe signal are multiplied in the system's mixer, and the high-frequency terms are filtered out by the system's mixer's low-pass filter to obtain a low-frequency echo signal. As shown below:

[0058] In steps S501 to S504, in this embodiment, after the system receives the reflected signal from the target object, it first enters the system's low-noise amplification unit. This unit uses a low-noise amplifier optimized for the 24GHz band to initially amplify the weak reflected signal, thereby effectively improving the system's signal-to-noise ratio. The signal after low-noise amplification enters the system's mixer unit for mixing with the detection signal. The mixer uses a balanced mixing structure to down-convert the 24GHz high-frequency echo signal to a suitable intermediate frequency signal for processing. This process simultaneously preserves the target object's distance and velocity information. Subsequently, the intermediate frequency signal enters the filtering unit, passing through a bandpass filter to effectively filter out high-order harmonic components and out-of-band noise interference generated during the mixing process, finally outputting a clean echo signal to the subsequent signal processing unit for further analysis and calculation. This embodiment, through optimized signal processing link design, achieves high-quality extraction of weak echo signals, laying a solid foundation for subsequent accurate target detection and distance measurement.

[0059] Furthermore, refer to Figure 8 As shown, Figure 8 This is an optional flowchart provided in the embodiments of this application for calculating the distance to the first target based on the echo signal. The method may include, but is not limited to, steps S601 to S603.

[0060] Step S601: Determine the peak value of the echo signal based on the Fast Fourier Transform algorithm.

[0061] Specifically, the peak value of the echo signal is obtained by performing a Fast Fourier Transform (FFT) on the echo signal. .

[0062] Step S602: Based on the peak value of the spectrum, calculate the propagation distance of the echo signal to obtain the first target distance.

[0063] Specifically, the peak spectral value Substituting the above In the middle, the distance to the first target is obtained. .

[0064] In steps S601 to S602, the echo signal is converted from the time domain to the frequency domain by executing the Fast Fourier Transform (FFT) algorithm. Then, a peak detection algorithm is used to find the spectral component with the largest amplitude in the spectrum, and the specific frequency position of the spectral peak is determined and recorded as the spectral peak. After obtaining the spectral peak frequency, the system calculates the distance according to the radar ranging principle, thus accurately calculating the distance to the first target. To improve measurement accuracy, this embodiment can also use a frequency domain interpolation algorithm. By performing quadratic curve fitting near the spectral peak, the frequency resolution is improved to a level far higher than the theoretical resolution of FFT, thereby achieving centimeter-level accurate ranging. This ranging method based on FFT spectrum analysis is not only computationally efficient and suitable for embedded system implementation, but also effectively suppresses noise interference through frequency domain processing, ensuring stable and reliable distance measurement results under different environmental conditions, providing an accurate data foundation for subsequent graded trigger judgment.

[0065] The second aspect of this application provides a 24GHz millimeter-wave radar detection system for smart door locks, referring to... Figure 9 As shown, Figure 9 This is an optional schematic diagram of a 24GHz millimeter-wave radar detection system 900 for smart door locks provided in an embodiment of this application. The 24GHz millimeter-wave radar detection system 900 includes: The radar radio frequency front-end 901 is used to continuously transmit detection signals at a first power and receive the echo signals reflected by the detection signals when they encounter a target object. The signal processing unit 902 is communicatively connected to the radar radio frequency front-end 901. The signal processing unit 902 is used to distinguish whether the target object is a human body or a stationary object based on the echo signal, and in response to the target object being a human body, to calculate the first target distance between the smart door lock and the target object based on the echo signal. The detection control unit 903 is communicatively connected to the signal processing unit 902. The detection control unit 903 is used to control the radar radio frequency front end to continuously transmit detection signals at a second power within a preset time period if the distance to the first target is less than or equal to a preset first distance threshold, so that the signal processing unit can continuously determine the second target distance between the target object and the smart door lock within the preset time period. The second power is greater than the first power. The detection control unit 903 is further configured to, in response to the second target distance being less than or equal to a preset second distance threshold, determine whether the second target distance is greater than a preset third distance threshold. If so, it sends a first interrupt signal to the smart lock to enable the smart lock to record video of the target object; if not, it sends a second interrupt signal to the smart lock to enable the smart lock to unlock the identification module. The second distance threshold is less than the first distance threshold and greater than the third distance threshold.

[0066] The aforementioned 24GHz millimeter-wave radar detection system 900 and 24GHz millimeter-wave radar detection method are based on the same inventive concept. By employing a 24GHz millimeter-wave radar and combining it with an innovative dual-frequency detection mechanism, compared to existing technologies, the 24GHz millimeter-wave radar achieves centimeter-level accurate ranging of both static and dynamic targets by analyzing the phase and propagation time difference of the echo signal. This completely breaks through the fundamental limitation of traditional 5.8GHz Doppler radar, which can only detect moving targets and cannot sense stationary people, providing reliable distance sensing capabilities for smart door locks. Secondly, the innovative adaptive frequency conversion working mechanism reduces power consumption by operating at a lower first power during the monitoring phase, switching to a higher second power for intensive and precise detection only when the target enters within the first distance threshold. The system achieves an optimal balance between power consumption and performance, significantly reducing the average power consumption from over 10mA in traditional solutions to the milliampere level, thus improving battery life. Furthermore, the 24GHz operating frequency band effectively avoids interference with Wi-Fi bands, significantly reducing the false trigger rate in complex environments. Its stronger penetration and resolution capabilities also suppress multipath reflection problems caused by metal doors, improving system reliability. Finally, based on precise distance calculation capabilities, and through collaborative determination of the first, second, and third distance thresholds, multi-level intelligent triggering from "long-distance recording activation" to "short-distance unlocking recognition" is achieved, constructing a seamless security and unlocking process. This upgrades the smart lock from a simple access tool to a smart terminal with scenario-based service capabilities.

[0067] In one possible embodiment, reference is made to... Figure 10 As shown, Figure 10 This is an optional schematic diagram of a radar RF front-end provided in an embodiment of this application. The radar RF front-end 901 includes a signal modulator, a power divider, a power amplifier, a transmitting antenna, a receiving antenna, a low-noise amplifier, a mixer, and a low-pass filter. The signal modulator is communicatively connected to the power divider, the power divider is communicatively connected to the power amplifier and the low-pass filter respectively, the power amplifier is communicatively connected to the transmitting antenna, the receiving antenna is communicatively connected to the low-noise amplifier, the low-noise amplifier is communicatively connected to the mixer, and the mixer is communicatively connected to the low-pass filter.

[0068] The system comprises: a signal modulator to generate a sawtooth-wave linear frequency modulated (LFM) signal; a power divider to distribute the power of the first power source to the LFM signal; a power amplifier to amplify the LFM signal after power distribution to obtain a detection signal; a transmitting antenna to transmit the detection signal; a receiving antenna to receive the reflection signal of the detection signal encountered by the target object; a low-noise amplifier to amplify the reflected signal to obtain an amplified signal; a mixer to mix the amplified signal and the detection signal to obtain an intermediate frequency (IF) signal; and a low-pass filter to filter out high frequencies from the IF signal to obtain an echo signal.

[0069] In one possible embodiment, the signal processing unit 902 includes a high-speed analog-to-digital converter and a microcontroller, wherein the high-speed analog-to-digital converter is communicatively connected to the microcontroller and the high-speed analog-to-digital converter is communicatively connected to a low-pass filter. The high-speed analog-to-digital converter is used to sample the echo signal output by the low-pass filter, and the microcontroller is used to determine the spectral peak of the echo signal based on the fast Fourier transform algorithm, and to solve the propagation distance of the echo signal based on the spectral peak to obtain the first target distance.

[0070] This application also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-described 24GHz millimeter-wave radar detection method for smart door locks. This electronic device can be any smart terminal, including mobile phones, tablets, and in-vehicle computers.

[0071] Please see Figure 11 , Figure 11 This is a schematic diagram of the hardware structure of an electronic device provided in one embodiment of this application. The electronic device includes: The processor 1101 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the 24GHz millimeter-wave radar detection method for smart door locks provided in the embodiments of this application. The memory 1102 can be implemented in the form of read-only memory (ROM), static storage device, dynamic storage device, or random access memory (RAM). The memory 1102 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 1102 and is called and executed by the processor 1101 to execute the 24GHz millimeter-wave radar detection method for smart door locks provided in the embodiments of this application. Input / output interface 1103 is used to implement information input and output; The communication interface 1104 is used to enable communication and interaction between this device and other devices. Communication can be achieved through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.). Bus 1105 transmits information between various components of the device (e.g., processor 1101, memory 1102, input / output interface 1103, and communication interface 1104); The processor 1101, memory 1102, input / output interface 1103 and communication interface 1104 are connected to each other within the device via bus 1105.

[0072] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, provides a 24GHz millimeter-wave radar detection method for smart door locks.

[0073] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0074] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0075] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0076] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0077] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0078] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0079] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0080] In the embodiments provided in this application, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the system embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0081] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0082] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0083] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-accessible storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0084] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A 24GHz millimeter wave radar detection method for a smart door lock, characterized in that, The method comprises the following steps: continuously emitting a probe signal at a first power, and receiving and confirming a reflected echo signal of the probe signal reflected by a target object; distinguishing whether the target object is a human body or a stationary object according to the reflected echo signal, and calculating a first target distance between the smart door lock and the target object according to the reflected echo signal in response to the target object being a human body; if the first target distance is less than or equal to a preset first distance threshold, continuously emitting a probe signal at a second power in a preset time period to continuously determine a second target distance between the target object and the smart door lock in the preset time period, the second power being greater than the first power; in response to the second target distance being less than or equal to a preset second distance threshold, determining whether the second target distance is greater than a preset third distance threshold, if yes, sending a first interrupt signal to the smart door lock to enable the smart door lock to start a video recording module to record a video of the target object, if no, sending a second interrupt signal to the smart door lock to enable the smart door lock to start an unlocking identification module; wherein the second distance threshold is less than the first distance threshold and greater than the third distance threshold.

2. The 24 GHz millimeter-wave radar detection method of claim 1, wherein, The method further comprises the following steps: if the first target distance is greater than the first distance threshold, continuously emitting a probe signal at the first power in the preset time period to continuously determine the second target distance.

3. The 24 GHz millimeter-wave radar detection method of claim 2, wherein, The method further comprises the following steps: in response to the second target distance being greater than the second distance threshold, continuously emitting a probe signal at the second power in the preset time period to continuously determine the second target distance.

4. The 24 GHz millimeter-wave radar detection method of claim 1, wherein, The distinguishing whether the target object is a human body or a stationary object according to the reflected echo signal comprises the following steps: performing amplitude analysis on the reflected echo signal according to the time sequence of receiving the reflected echo signal to obtain amplitude values corresponding to a plurality of time frames; when it is detected that the amplitude values corresponding to each time frame within a preset frame length are all greater than a preset amplitude threshold, determining that the target object is a human body; or, when it is detected that the amplitude value corresponding to a certain time frame within a preset frame length is less than or equal to the amplitude threshold, determining that the target object is a stationary object.

5. The 24 GHz millimeter-wave radar detection method of claim 1, wherein, The calculating the first target distance between the smart door lock and the target object according to the reflected echo signal comprises the following steps: determining a frequency spectrum peak value of the reflected echo signal based on a fast Fourier transform algorithm; solving the propagation distance of the reflected echo signal according to the frequency spectrum peak value to obtain the first target distance.

6. The 24 GHz millimeter-wave radar detection method of claim 1, wherein, The receiving and confirming the reflected echo signal of the probe signal reflected by the target object comprises the following steps: receiving a reflected signal of the probe signal encountering the target object; performing low-noise amplification processing on the reflected signal to obtain an amplified signal; performing mixing processing on the amplified signal and the probe signal to obtain an intermediate frequency signal; performing high-frequency filtering on the intermediate frequency signal to obtain the reflected echo signal.

7. A 24 GHz millimeter wave radar detection system for a smart door lock, characterized by, The method comprises the following steps: a radar radio frequency front end for continuously emitting a probe signal at a first power, and receiving a reflected echo signal of the probe signal reflected by a target object; The signal processing unit is configured to distinguish whether the target object is a human body or a stationary object according to the echo signal, and in response to the target object being a human body, calculate a first target distance between the smart door lock and the target object according to the echo signal; The detection control unit is configured to, if the first target distance is less than or equal to a preset first distance threshold, control the radar radio frequency front end to continuously emit a detection signal at a second power for a preset time length to enable the signal processing unit to continuously determine a second target distance between the target object and the smart door lock within the preset time length, the second power being greater than the first power; The detection control unit is further configured to, in response to the second target distance being less than or equal to a preset second distance threshold, determine whether the second target distance is greater than a preset third distance threshold, and if yes, send a first interrupt signal to the smart door lock to enable the smart door lock to start a video recording module to record a video of the target object, and if no, send a second interrupt signal to the smart door lock to enable the smart door lock to start an unlocking identification module; wherein the second distance threshold is less than the first distance threshold and greater than the third distance threshold.

8. The 24 GHz millimeter-wave radar detection system of claim 7, wherein, The radar radio frequency front end comprises a signal modulator, a power divider, a power amplifier, a transmitting antenna, a receiving antenna, a low-noise amplifier, a mixer, and a low-pass filter, The signal modulator is in communication connection with the power divider, the power divider is in communication connection with the power amplifier and the low-pass filter respectively, the power amplifier is in communication connection with the transmitting antenna, the receiving antenna is in communication connection with the low-noise amplifier, the low-noise amplifier is in communication connection with the mixer, and the mixer is in communication connection with the low-pass filter; The signal modulator is configured to generate a sawtooth wave linear frequency modulation signal; The power divider is configured to allocate power of the first power to the linear frequency modulation signal; The power amplifier is configured to amplify the linear frequency modulation signal after power allocation to obtain the detection signal; The transmitting antenna is configured to emit the detection signal; The receiving antenna is configured to receive a reflection signal of the detection signal encountering a target object; The low-noise amplifier is configured to perform low-noise amplification processing on the reflection signal to obtain an amplified signal; The mixer is configured to perform mixing processing on the amplified signal and the detection signal to obtain an intermediate frequency signal; The low-pass filter is configured to filter out high frequencies of the intermediate frequency signal to obtain the echo signal.

9. The 24 GHz millimeter-wave radar detection system of claim 8, wherein, The signal processing unit comprises a high-speed analog-to-digital converter and a microcontroller, the high-speed analog-to-digital converter is in communication connection with the microcontroller, and the high-speed analog-to-digital converter is in communication connection with the low-pass filter; The high-speed analog-to-digital converter is configured to sample the echo signal output by the low-pass filter; The microcontroller is configured to determine a frequency spectrum peak value of the echo signal based on a fast Fourier transform algorithm, and calculate a propagation distance of the echo signal according to the frequency spectrum peak value to obtain the first target distance.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a processor executable program, and the processor executable program is used for realizing the 24GHz millimeter wave radar detection system for the intelligent door lock according to any one of claims 1 to 6 when executed by the processor.

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