Intelligent screen turn-on and turn-off control method and system based on microwave radar

Abstract

The invention relates to the technical field of man-machine interaction, in particular to an intelligent screen turning-on and turning-off control method and system based on a microwave radar, which completely eradicates the risk of privacy disclosure and realizes high privacy protection through an identification mode of not collecting optical image information and only analyzing motion and vital signs through electromagnetic waves, and is not influenced by the environment, so that the intelligent screen turning-on and turning-off control method and system based on the microwave radar can be applied to intelligent screen turning-on and turning-off control. The system can stably work in severe environments such as all black and strong light, has super-strong environmental adaptability, and enables the judgment of screen opening to better conform to the real intention of a user by sensing the accurate postures of person existence, no person existence, approaching, departing, right facing or side facing, reduces false triggering to the greatest extent, improves the accuracy of system judgment, and improves the user experience. The instrument does not need to be kept in a bright state all the time in the operation process, when no person is in front of the instrument, the screen is automatically turned off at proper time, and when an operator comes to the front face of the instrument and prepares to operate the screen, screen display is automatically turned on, energy is saved, environment is protected, and the instrument is convenient to operate.

Description

Technical Field

[0001] This invention relates to the field of human-computer interaction technology, specifically to an intelligent screen-on and screen-off control method and system based on microwave radar. Background Technology

[0002] Currently, the existing screen-on and screen-off control technologies for displays in instruments, industrial control panels, and smart home central control screens suffer from problems such as privacy leakage risks, poor environmental adaptability, high power consumption, and inaccurate judgment. The specific screen-on and screen-off control technologies include the following methods:

[0003] (1) Manual control: Users can manually turn the screen on or off using physical buttons or a touch screen. This is the most direct method, but it is not smart or convenient enough. Users must perform active operations.

[0004] (2) Timed control: The system presets a time period of no operation, and the screen will automatically turn off after the time period is exceeded. Although it is simple to implement, it lacks awareness of the user's real state. For example, if the user is reading the screen content but does not perform any operation, the screen will also turn off incorrectly, affecting the user experience.

[0005] (3) Control based on infrared sensors or cameras: Although infrared sensors detect changes in infrared heat emitted by the human body to determine its presence, their detection range is limited, they cannot detect minute movements, are easily affected by ambient temperature interference, and cannot determine whether a person is facing the screen. Cameras (visual solutions) can determine whether a person's face or eyes are looking at the screen through image recognition algorithms. This method has high accuracy, but it involves user privacy issues, and the recognition rate will drop significantly in low light or when the user is wearing a mask. In addition, it is computationally complex and consumes a lot of power. Therefore, a smart screen opening and closing control method and system based on microwave radar is proposed. Summary of the Invention

[0006] To address the technical problems existing in the prior art, the present invention provides an intelligent screen-on and screen-off control method and system based on microwave radar.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method and system for intelligent screen opening and closing control based on microwave radar, wherein the intelligent screen opening and closing control method specifically includes the following steps:

[0008] S1, detects targets in the effective area in front of the display screen using a microwave radar sensor;

[0009] S2 processes radar echo signals and extracts target feature information from them;

[0010] S3, make a decision based on the feature information and according to the preset state machine model;

[0011] S4: When the decision result meets the preset trigger conditions for screen-on, control the display screen to turn on; when the decision result meets the preset trigger conditions for screen-off, control the display screen to turn off.

[0012] Preferably, in step S1, before detection, the system is initialized after being powered on, the display screen is in a screen-off state, the detection period is set, and the length of the detection period affects the response speed of the screen opening. The microwave radar sensor transmits microwave signals in low power mode according to the detection period and receives their echoes to perform preliminary presence detection.

[0013] Preferably, in step S2, when a target is initially detected within the effective area, the microwave radar sensor enters an active working mode, that is, it increases the microwave transmission frequency and shortens the microwave transmission cycle, enabling the sensor to more quickly perceive the location and micro-motion characteristics of a person, continuously transmit and receive signals, and processes the echo signal through the signal processing unit to extract the following characteristic information of the target:

[0014] Existence status: Determines whether there is a moving target within the valid area;

[0015] Motion information: including the target's distance, radial velocity, and direction of motion, and determining whether the direction of motion is approaching or moving away;

[0016] Micro-motion characteristics: Extract micro-motion signals of vital signs caused by breathing, heartbeat, etc., to determine whether they are vital signs;

[0017] Spatial location: The effective area is determined by the effective emission angle that the microwave radar sensor can detect through structural design. Only within the effective area can the microwave radar sensor detect the reflected waves of objects.

[0018] Human posture: When the human body is facing the screen, the area receiving radar waves is large, and the signal reflecting radar waves is strong.

[0019] When the human body is positioned sideways to the screen, the area receiving radar waves is small, and the signal reflecting radar waves is weak.

[0020] Preferably, in step S3, the current conditions are determined based on the feature information extracted in step S2, and then a decision is made using a state machine model based on the determination result. The conditions for triggering screen-on and screen-off are as follows:

[0021] To trigger the screen-opening command, the following conditions must be met simultaneously:

[0022] A1, Confirmation that a moving target exists;

[0023] A2, the target is within the effective range;

[0024] A3, the target's direction of movement is toward the display screen;

[0025] To trigger the screen-off command, any one of the following conditions must be met:

[0026] B1, confirm that there is no moving target in the detection area, and continue for the first preset time T1;

[0027] B2, a moving target is detected, but its direction of movement is away from the display screen and beyond the effective distance range, and this continues for a second preset time T2;

[0028] B3, a moving target is detected, but the intensity of the micro-motion signal of the living organism is lower than the threshold and continues for a third preset time T3;

[0029] B4, a moving target is detected. When the relative distance to the screen changes within a small range, but the intensity of the received radar signal decreases significantly, it is assumed that the living being is facing the screen. Attention is diverted and this continues for a fourth preset time T4.

[0030] Preferably, in condition A1, when it is determined that a moving target exists, it is first determined that the microwave radar sensor detects microwave signals reflected back from different positions, and the position of the reflected microwaves is different each time.

[0031] Next, the intensity of vital signs micro-motion signals is collected: by transmitting electromagnetic waves at high speed, the changes in the low-frequency intensity of electromagnetic waves reflected by the human body are collected. When the frequency of human body reflection fluctuates slightly within a period of 1 to 5 seconds, it is determined to be a human breathing action.

[0032] A smart screen-on and screen-off control system based on microwave radar, the control system includes a microwave radar sensor module, a signal processing and analysis module, a main control decision module, and a display screen driver module. The microwave radar sensor module is connected to the signal processing and analysis module, the signal processing and analysis module is connected to the main control decision module, and the main control decision module is connected to the display screen driver module.

[0033] The microwave radar sensor module is used to transmit and receive radar signals, the signal processing and analysis module is used to extract target feature information from the radar signals, the main control decision module is used to execute a state machine model and generate control commands based on the feature information, and the display screen driver module is used to respond to the control commands to switch the display screen state.

[0034] Preferably, the microwave radar sensor module is a frequency-modulated continuous wave radar or a pulse Doppler radar, with an operating frequency of 24 GHz, 60 GHz, or 77 GHz.

[0035] Preferably, the signal processing and analysis module uses a Butterworth bandpass filter to filter the echo signal to eliminate noise interference, uses an operational amplifier to amplify the echo signal, and uses an analog-to-digital converter chip to convert the acquired echo analog signal into a digital signal. Finally, the strength of the acquired echo signal is converted into the magnitude of the signal value.

[0036] Preferably, the main control decision module converts the echo signal collected by the microwave radar sensor from an analog signal to a digital signal through an analog sampling circuit, and transmits the digital signal to the main control chip microcontroller for digital signal processing. The module converts the magnitude of the collected radar echo signal value into the existence state, motion information, micro-motion characteristics, spatial position, and human posture of the moving target. Then, the existence state, motion information, micro-motion characteristics, spatial position, and human posture information of the moving target are converted into electrical signals for opening or closing the screen, and transmitted to the display screen driver module through a cable.

[0037] Preferably, the display driver module receives instructions from the main control decision module and executes the on / off and screen-off operations of the display.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] 1. This invention employs a non-optical image information acquisition method for recognition. It uses a microwave radar sensor to collect information such as the human body's movement direction, spatial position, micro-motion characteristics, and whether it is facing the screen directly or sideways. This information is used to predict the likelihood of the human operating the screen, thereby enabling intelligent screen-on and screen-off operations. This process only analyzes motion and vital signs through electromagnetic waves, eliminating the risk of operator privacy leakage and achieving high privacy protection. It is also unaffected by ambient light, temperature, humidity, smoke, dust, etc., and can work stably in harsh environments such as complete darkness and strong light. It has excellent environmental adaptability and can be widely used in non-confidential equipment.

[0040] 2. In this invention, by sensing the precise posture of whether there is someone, no one, approaching, moving away, facing directly or to the side, the judgment of opening and closing the screen is more in line with the user's true intention, minimizing false triggers and improving the accuracy of the system's judgment. It also has a low-power monitoring mode, which only enters the full-function working state when a potential target is detected, resulting in low overall system power consumption. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the screen-on and screen-off control method of the present invention;

[0042] Figure 2 This is a schematic diagram of the effective sensing area of ​​the present invention;

[0043] Figure 3 This is a front view of the instrument of the present invention;

[0044] Figure 4 This is a schematic diagram of the system composition of the present invention. Detailed Implementation

[0045] The present invention will be further described below with reference to the accompanying drawings and embodiments, which illustrate the above and other technical features and advantages of the present invention. However, the following embodiments are merely preferred embodiments of the present invention and are not exhaustive.

[0046] Example 1:

[0047] like Figure 1-4 As shown, this invention provides a smart screen-on and screen-off control method and system based on microwave radar. The smart screen-on and screen-off control method specifically includes the following steps:

[0048] S1, detects targets in the effective area in front of the display screen using a microwave radar sensor;

[0049] S2 processes radar echo signals and extracts target feature information from them;

[0050] S3 makes decisions based on feature information and a preset state machine model;

[0051] S4: When the decision result meets the preset trigger conditions for screen-on, control the display screen to turn on; when the decision result meets the preset trigger conditions for screen-off, control the display screen to turn off.

[0052] In this embodiment, in step S1, before detection, the system is initialized after being powered on, the display screen is in a screen-off state, the detection period is set, and the length of the detection period affects the response speed of the screen opening. The microwave radar sensor transmits microwave signals in low power mode according to the detection period and receives their echoes to perform preliminary presence detection.

[0053] In this embodiment, in step S2, when a target is initially detected within the effective area, the microwave radar sensor enters an active working mode, that is, it increases the frequency of microwave transmission and shortens the microwave transmission period, enabling the sensor to more quickly perceive the position and micro-motion characteristics of a person, continuously transmit and receive signals, and processes the echo signal through the signal processing unit to extract the following characteristic information of the target:

[0054] Existence status: Determines whether there is a moving target within the valid area;

[0055] Motion information: including the target's distance, radial velocity, and direction of motion, and determining whether the direction of motion is approaching or moving away;

[0056] Micro-motion characteristics: Extract micro-motion signals of vital signs caused by breathing, heartbeat, etc., to determine whether they are vital signs;

[0057] Spatial location: The effective area is determined by the effective emission angle that the microwave radar sensor can detect through structural design. For example, within a 150° range in front of the instrument, microwave emission is not blocked or reflected. Only within the effective area can the microwave radar sensor detect the reflected wave from the object.

[0058] Human posture: When the human body is facing the screen, the area receiving radar waves is large, and the signal reflecting radar waves is strong.

[0059] When the human body is positioned sideways to the screen, the area receiving radar waves is small, and the signal reflecting radar waves is weak.

[0060] In this embodiment, in step S3, the current conditions are determined based on the feature information extracted in step S2, and then a decision is made through a state machine model based on the determination result. The conditions for triggering screen-on and screen-off are as follows:

[0061] To trigger the screen-opening command, the following conditions must be met simultaneously:

[0062] A1. Confirming the existence of a moving target: First, determine that the microwave radar sensor detects microwave signals reflected back from different locations, and the location of the reflected microwaves is different each time. Then, it is considered that a moving target exists.

[0063] Next, the intensity of vital signs micro-motion signals is collected: by transmitting electromagnetic waves at high speed, the changes in the low-frequency intensity of electromagnetic waves reflected by the human body are collected. When the frequency of human body reflection fluctuates slightly within a period of 1 to 5 seconds, it is determined to be a human breathing action.

[0064] A2, the distance can be calculated by the time of microwave transmission and reflected wave reception, provided the target is within the effective range (e.g., 0.5 meters to 3 meters). Figure 2 (as shown)

[0065] A3, the target's movement direction is towards the display screen. By judging that the distance between the moving target and the microwave sensor is getting smaller and smaller, it is judged that it is approaching the screen;

[0066] To trigger the screen-off command, any one of the following conditions must be met:

[0067] B1, confirm that there is no moving target in the detection area, and continue for a first preset time T1 (e.g., 10 seconds).

[0068] B2, a moving target is detected, but its direction of movement is away from the display screen and beyond the effective distance range, and this continues for a second preset time T2 (e.g., 5 seconds).

[0069] B3, a moving target is detected, but the intensity of the micro-motion signal of the living being is below the threshold. For example, the user enters a stationary state and remains so for a third preset time T3 (e.g., 30 seconds).

[0070] Micromotion signals of living organisms are signals generated by the micro-movements of the human body caused by breathing, heartbeat, etc. when the human body is standing. The typical micromotion threshold range is 2~8mm.

[0071] B4. When a moving target is detected, if the relative distance to the screen changes within a small range, but the intensity of the received radar signal decreases significantly (i.e., the ratio of the reflected radar wave intensity in the previous state to that in the next state is between 1.2 and 1.6), it is assumed that the living being is facing the screen, and attention is diverted for a fourth preset time T4 (e.g., 20 seconds).

[0072] A smart screen-on and screen-off control system based on microwave radar. The control system includes a microwave radar sensor module, a signal processing and analysis module, a main control decision module, and a display screen driver module. The microwave radar sensor module is connected to the signal processing and analysis module, the signal processing and analysis module is connected to the main control decision module, and the main control decision module is connected to the display screen driver module.

[0073] The microwave radar sensor module is used to transmit and receive radar signals, the signal processing and analysis module is used to extract target feature information from radar signals, the main control decision module is used to execute the state machine model based on the feature information and generate control commands, and the display screen driver module is used to respond to control commands to switch the display screen state.

[0074] In this embodiment, the microwave radar sensor module is a frequency-modulated continuous wave radar or a pulse Doppler radar, with an operating frequency of 24 GHz, 60 GHz, or 77 GHz.

[0075] In this embodiment, the signal processing and analysis module uses a Butterworth bandpass filter to filter the echo signal to eliminate noise interference, uses an operational amplifier to amplify the echo signal, and uses an analog-to-digital converter chip to convert the acquired echo analog signal into a digital signal. Finally, the strength of the acquired echo signal is converted into the magnitude of the signal value.

[0076] In this embodiment, the main control decision module converts the echo signal collected by the microwave radar sensor from an analog signal to a digital signal through an analog sampling circuit, and transmits the digital signal to the main control chip microcontroller for digital signal processing. The module converts the magnitude of the collected radar echo signal into the existence state, motion information, micro-motion characteristics, spatial position, and human posture of the moving target. Then, the existence state, motion information, micro-motion characteristics, spatial position, and human posture information of the moving target are converted into electrical signals for opening or closing the screen, and transmitted to the display screen driver module through a cable to control the opening and closing of the screen.

[0077] Specifically, the analog-to-digital chip collects the echo signals from the microwave radar sensor array antenna. By collecting the strength and timing of the microwave signals collected by different antennas on the microwave sensor array antenna, the existence, operation information, micro-motion characteristics, and spatial position of an object are determined. When the microwave echo collected by the array antenna changes over time, a moving target is detected. When the echo signal collected by the array antenna increases or decreases over time, it is considered that the target is approaching or moving away from the microwave sensor. When the array antenna collects low-frequency, small-amplitude distance changes (2~8mm) with a change period in the range of 1~5 seconds, it is considered to be a micro-motion characteristic generated by human breathing.

[0078] Furthermore, the radar echo signal strength collected by antennas at different positions in the array antenna is different. When the echo signal collected by the left antenna is stronger than that of the right antenna, it means that the target is to the left of the microwave radar sensor, and vice versa. When the echo signal strength collected by the left and right antennas is equal, the equal threshold is that the difference in signal strength between the left and right antennas is within 5%, then the target is considered to be centered at the microwave radar sensor.

[0079] When the conditions for triggering the screen-on command are met simultaneously, the decision circuit generates a screen-on electrical signal; when any one of the conditions for triggering the screen-off command is met, the decision circuit generates a screen-off electrical signal.

[0080] In this embodiment, the display driver module receives instructions from the main control decision module and executes the on / off and screen-off operations of the display screen;

[0081] Specifically, the active decision-making module ultimately outputs a signal to turn the screen on or off. This signal is connected to the screen driver board via a cable from the decision-making module circuit. The decision-making module then uses a switch signal (high or low level signal) to notify the screen driver board to turn the screen on or off.

[0082] Example 2:

[0083] like Figure 3 As shown, taking an analytical instrument panel as an example, a 24GHz FMCW microwave radar sensor is installed below the instrument display screen. The control method is as follows:

[0084] Initial state: Control panel is in standby mode, screen is off, radar performs periodic scans at a frequency of 1Hz;

[0085] Screen opening process: An operator walks from a distance to the control panel. The radar first detects the presence of a living being 3 meters away and calculates that the radial velocity of the living being is positive (approaching). When the living being enters the effective area within 2 meters and its azimuth is directly facing the screen, the main control decision module immediately determines that the screen opening conditions are met and sends a screen opening command to the display screen, and the screen lights up.

[0086] Screen off process:

[0087] Scenario A: After the operator completes the operation and leaves, the radar detects that the direction of movement is away and starts timing after the operator walks out of the 2.5-meter range. After 5 seconds, it confirms that the user has left and triggers the screen to turn off.

[0088] Scenario B: If a moving target enters the effective area of ​​the instrument, but the microwave radar cannot detect the micro-motion signal of the moving target, the moving target is determined to be a non-living object, and the display screen will turn off after 30 seconds.

[0089] The above are merely preferred embodiments of the present invention and are illustrative in nature, not restrictive. Those skilled in the art will understand that many changes, modifications, and even equivalents can be made within the spirit and scope defined by the claims of the present invention, all of which will fall within the protection scope of the present invention.

Claims

1. A method for intelligent screen-on and screen-off control based on microwave radar, characterized in that, The intelligent screen-on and screen-off control method specifically includes the following steps: S1, detects targets in the effective area in front of the display screen using a microwave radar sensor; S2 processes radar echo signals and extracts target feature information from them; S3, make a decision based on the feature information and according to the preset state machine model; S4: When the decision result meets the preset trigger conditions for screen-on, control the display screen to turn on; when the decision result meets the preset trigger conditions for screen-off, control the display screen to turn off.

2. The intelligent screen-on and screen-off control method based on microwave radar as described in claim 1, characterized in that, In step S1, before detection, the system is initialized after being powered on, the display screen is in a screen-off state, the detection period is set, and the length of the detection period affects the response speed of the screen opening. The microwave radar sensor transmits microwave signals in low power mode according to the detection period and receives their echoes to perform preliminary presence detection.

3. The intelligent screen-on and screen-off control method based on microwave radar as described in claim 1, characterized in that, In step S2, when a target is initially detected within the effective area, the microwave radar sensor enters an active working mode, i.e., it increases the microwave transmission frequency and shortens the microwave transmission cycle, enabling the sensor to more quickly perceive the location and micro-motion characteristics of a person, continuously transmit and receive signals, and process the echo signals through the signal processing unit to extract the following characteristic information of the target: Existence status: Determines whether there is a moving target within the valid area; Motion information: including the target's distance, radial velocity, and direction of motion, and determining whether the direction of motion is approaching or moving away; Micro-motion characteristics: Extract micro-motion signals of vital signs caused by breathing, heartbeat, etc., to determine whether they are vital signs; Spatial location: The effective area is determined by the effective emission angle that the microwave radar sensor can detect through structural design. Only within the effective area can the microwave radar sensor detect the reflected waves of objects. Human posture: When the human body is facing the screen, the area receiving radar waves is large, and the signal reflecting radar waves is strong. When the human body is positioned sideways to the screen, the area receiving radar waves is small, and the signal reflecting radar waves is weak.

4. The intelligent screen-on and screen-off control method based on microwave radar as described in claim 1, characterized in that, In step S3, the current conditions are determined based on the feature information extracted in step S2, and then a decision is made using a state machine model based on the determination result. The conditions for triggering screen-on and screen-off are as follows: To trigger the screen-opening command, the following conditions must be met simultaneously: A1, Confirmation that a moving target exists; A2, the target is within the effective range; A3, the target's direction of movement is toward the display screen; To trigger the screen-off command, any one of the following conditions must be met: B1, confirm that there is no moving target in the detection area, and continue for the first preset time T1; B2, a moving target is detected, but its direction of movement is away from the display screen and beyond the effective distance range, and this continues for a second preset time T2; B3, a moving target is detected, but the intensity of the micro-motion signal of the living organism is lower than the threshold and continues for a third preset time T3; B4, a moving target is detected. When the relative distance to the screen changes within a small range, but the intensity of the received radar signal decreases significantly, it is assumed that the living being is facing the screen. Attention is diverted and this continues for a fourth preset time T4.

5. The intelligent screen-on and screen-off control method based on microwave radar as described in claim 4, characterized in that, In condition A1, when it is determined that a moving target exists, it is first determined that the microwave radar sensor detects microwave signals reflected back from different positions, and the position of the reflected microwaves is different each time. Next, the intensity of vital signs micro-motion signals is collected: by transmitting electromagnetic waves at high speed, the changes in the low-frequency intensity of electromagnetic waves reflected by the human body are collected. When the frequency of human body reflection fluctuates slightly within a period of 1 to 5 seconds, it is determined to be a human breathing action.

6. A control system for the intelligent screen-on and screen-off control method based on microwave radar according to any one of claims 1-5, characterized in that, The control system includes a microwave radar sensor module, a signal processing and analysis module, a main control decision module, and a display screen driver module. The microwave radar sensor module is connected to the signal processing and analysis module, the signal processing and analysis module is connected to the main control decision module, and the main control decision module is connected to the display screen driver module. The microwave radar sensor module is used to transmit and receive radar signals, the signal processing and analysis module is used to extract target feature information from the radar signals, the main control decision module is used to execute a state machine model and generate control commands based on the feature information, and the display screen driver module is used to respond to the control commands to switch the display screen state.

7. The intelligent screen-on and screen-off control system based on microwave radar as described in claim 6, characterized in that, The microwave radar sensor module is a frequency-modulated continuous wave radar or a pulse Doppler radar, with an operating frequency of 24 GHz, 60 GHz, or 77 GHz.

8. The intelligent screen-on and screen-off control system based on microwave radar as described in claim 6, characterized in that, The signal processing and analysis module uses a Butterworth bandpass filter to filter the echo signal to eliminate noise interference, uses an operational amplifier to amplify the echo signal, and uses an analog-to-digital converter chip to convert the acquired echo analog signal into a digital signal. Finally, the strength of the acquired echo signal is converted into the magnitude of the signal value.

9. The intelligent screen-on and screen-off control system based on microwave radar as described in claim 6, characterized in that, The main control decision module converts the echo signal collected by the microwave radar sensor from analog signal to digital signal through analog sampling circuit, and transmits the digital signal to the main control chip microcontroller for digital signal processing. The collected radar echo signal value is converted into the existence state, motion information, micro-motion characteristics, spatial position and human posture of the moving target. Then, the existence state, motion information, micro-motion characteristics, spatial position and human posture information of the moving target are converted into electrical signals for screen opening or screen closing, and transmitted to the display screen driver module through cable.

10. The intelligent screen-on and screen-off control system based on microwave radar as described in claim 6, characterized in that, The display driver module receives instructions from the main control decision module and executes the on / off and screen-off operations of the display.

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