Low-power-consumption indoor induction intelligent zone control system

Abstract

The invention discloses a low-power-consumption indoor induction intelligent partition control system, which aims to solve the limitation of the existing induction system and comprises a sensor module, a control module, a communication module and an execution module. The sensor module is composed of a photosensitive sensor, a temperature sensor, a pyroelectric sensor and a 24G millimeter wave radar sensor, and is used for detecting environmental conditions and preliminarily detecting existence of a human body. When the environmental condition is good, the system does not start human body existence detection; otherwise, the pyroelectric sensor carries out preliminary detection firstly, once an organism is found, the millimeter wave radar is triggered to carry out accurate detection, and the control module converts a detection result into a control signal and transmits the control signal to the execution module through Bluetooth for controlling facilities such as illumination, a fan and an air conditioner. Through intelligent detection and fine partition control, the system is suitable for occasions where facility operation needs to be flexibly adjusted according to actual use conditions of different areas, and has the characteristics of energy conservation, environmental protection, low cost, easy deployment and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of smart home control systems, and in particular to a low-power indoor sensing smart partition control system. Background Art

[0002] As society pays more and more attention to energy conservation and emission reduction, improving energy efficiency has become an important topic in the field of smart home control. Especially in public spaces such as classrooms and offices, traditional control methods are difficult to accurately respond to changes in people's activities in different areas, resulting in widespread energy waste. The current existing presence sensing system has the following limitations: 1) High energy consumption, the system needs to run continuously to detect activities; 2) Insufficient detection accuracy. When the range of human activities is small, traditional sensors may not be able to accurately identify the presence of people, resulting in the lighting system, fans, and air conditioning lights remaining off when there are people; 3) Lack of refined zoning control, unable to adjust according to the actual use of different areas in the same occasion, increasing energy waste; 4) Easily affected by the external environment, false alarms occur when no one is around. Summary of the invention

[0003] The purpose of the present invention is to provide a low-power indoor sensing intelligent zoning control system, which realizes intelligent detection and zoning control of indoor human activities. It is particularly suitable for occasions where it is necessary to flexibly adjust the operation of facilities according to the actual usage of different areas, such as classrooms and offices, to achieve effective energy conservation from three aspects: system operation, regional energy saving, and unmanned power outage.

[0004] In order to achieve the above objectives, the technical solution adopted by the present invention is: a low-power indoor sensing intelligent zoning control system, including a sensor module, a control module, a communication module and an execution module. The control module converts the detection result of the sensor module into a control signal and transmits it to the execution module through the communication module to control the operation of indoor facilities. The sensor module is composed of a photosensitive sensor, a temperature sensor, a pyroelectric sensor and a 24G millimeter-wave radar sensor. The photosensitive sensor and the temperature sensor are used to detect the temperature and lighting conditions of the environment. The pyroelectric sensor is used to detect whether there are any living organisms entering the detection range and can distinguish between organisms and other objects. The millimeter-wave radar sensor performs more accurate detection to determine the position and activity of the human body.

[0005] Preferably, the sensor module is hierarchically controlled and divided into three levels. The first-level sensor is a photosensor and a temperature sensor, the second-level sensor is a pyroelectric sensor. The next-level sensor is started after the previous-level sensor meets the conditions, and the third-level sensor is a 24G millimeter-wave radar sensor.

[0006] Preferably, indoors, the 2Partitions are divided into zones, and a set of sensor modules are installed in each zone. The sensor modules are installed on the walls in the zone, and the millimeter-wave radar is tilted 30 to 60 degrees perpendicular to the ground.

[0007] Preferably, the millimeter wave radar sensor adopts a signal processing algorithm including direction of arrival (DOA) estimation, constant false alarm rate (CFAR) detection, a clustering algorithm (DBSCAN) and a state machine (SM).

[0008] Preferably, a distance-compensated adaptive signal-to-noise ratio (SNR) detection algorithm is used in the CFAR detection technology. Considering the characteristic that the signal strength is inversely proportional to the fourth power of the target distance, the expected power of the same target in different ranges can be calculated according to the signal attenuation law. The expected power formula can be expressed as:

[0009]

[0010] Where P1 is the power corresponding to the known target distance R1, and P2 is the expected power at the same target distance R2.

[0011] Preferably, the DBSCAN clustering algorithm is used to process the point cloud data after CFAR, and the point cloud is classified into different areas. For each area of ​​the same place, the clustered point cloud data is defined as N, and the preset threshold is T. When N>T, it is judged as someone, and when N≤T, it is judged as no one. Then, the SM technology is used to manage the state changes of each detected target.

[0012] Preferably, the millimeter wave radar antenna adopts a 2*2 unit design array with a maximum gain of 12.81dB. The antenna unit is fed by a 50Ω feeder, and its resonant operating point is 24.15GHz. The antenna units are connected by a T-type power divider, and the antenna is arranged in a counter-directional manner. The power divider performs unequal amplitude feeding, 180° phase compensation is performed on one side, and chamfering is performed in the T-type power divider to increase impedance matching.

[0013] Preferably, the communication module adopts an HC-05 Bluetooth module, and Bluetooth is used for wireless communication with the user's mobile device and controlling the opening and closing of public equipment.

[0014] Preferably, the execution module has a built-in Bluetooth switch, a central processing unit, a control module, a servo and a button battery, and is directly attached to the original switch at the place of use. The module can receive the control signal from the communication module and decode it through the internal central processing unit. Subsequently, the servo is driven by the internal control module to achieve the opening and closing control of the indoor facilities.

[0015] The technical effects of the present invention are:

[0016] The system realizes intelligent detection of human activities and efficient and refined control of facilities through multi-level detection mechanism and precise partition control. The main innovations are as follows: First, a compact antenna is designed to ensure the low cost and miniaturization of the system while meeting the requirements of high efficiency; in system design, light sensors and temperature sensors are used to preliminarily detect ambient light and temperature conditions. If the preset good conditions are met, the presence sensing system will not be turned on. If the conditions are not good, pyroelectric sensors are further used to distinguish living things from other objects. When the presence of living things is detected, low-power millimeter-wave radar is started for further detection to reduce power consumption. Then, in regional control, a variety of millimeter-wave radar processing technologies are integrated to finely partition and detect whether there are human activities in the room, reduce the impact of external temperature changes on the detection results, improve the accuracy of detection, and further save energy. At the same time, the communication module uses Bluetooth transmission to allow Bluetooth wireless communication with the user's mobile devices and external facilities for remote control and personalized settings; in particular, an easy-to-install switch with a built-in Bluetooth receiver is used. The switch can be directly attached to the original switch and receive control signals from the radar, thereby controlling lighting, fans, air conditioners and other facilities in partitions. This innovative solution realizes intelligent detection and zoning control of indoor human activities. It is particularly suitable for occasions such as classrooms and offices where facility operations need to be flexibly adjusted according to actual usage in different areas. It can effectively save energy from three aspects: system operation, regional energy saving, and unmanned power outages. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Shown is a schematic diagram of the system module structure of the present invention;

[0018] Figure 2 Shown is a schematic diagram of partition detection of the present invention;

[0019] Figure 3 Shown is a flow chart of the system detection of the present invention;

[0020] Figure 4 Shown is a schematic diagram of the circuit of the photosensor BH1750 of the present invention;

[0021] Figure 5 Shown is a circuit diagram of the temperature sensor DS18B20 of the present invention;

[0022] Figure 6 Shown is a hardware circuit diagram of a 24 GHz millimeter wave radar sensor of the present invention;

[0023] Figure 7 The EH plane radiation pattern of the 24 GHz millimeter wave radar antenna array of the present invention is shown;

[0024] Figure 8Shown is a graph of the 24 GHz millimeter wave radar antenna unit S11 (return loss) of the present invention;

[0025] Fig. 9 Shown is the 24 GHz millimeter wave radar antenna array S11 (return loss diagram) of the present invention;

[0026] Fig.10 The figure shows the detection flow chart of the millimeter wave radar algorithm of the present invention;

[0027] Fig.11 Shown is a distance compensation SNR threshold diagram of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the embodiments and drawings to clearly and completely describe the concept, specific structure and technical effects of the present invention, so as to fully understand the purpose, scheme and effect of the present invention. It should be noted that the embodiments and features in the embodiments of this application can be combined with each other without conflict, and the same reference numerals used in various places in the drawings indicate the same or similar parts.

[0029] The present invention provides a low-power indoor induction intelligent partition control system, including a sensor module, a control module, a communication module and an execution module. Figure 1 The sensor module consists of a photosensitive sensor, a temperature sensor, a pyroelectric sensor module and a millimeter wave radar sensor. Please refer to the installation location of the sensor module and the actuator module. Figure 2 , the sensor module is mounted on the wall sideways, and the millimeter-wave radar should be tilted 30 to 60 degrees perpendicular to the ground to achieve the best coverage. One millimeter-wave radar in this system can be used for an area of ​​about 15m 2 When the area to be detected exceeds this area, the coverage can be expanded by adding additional radar sensors.

[0030] Please refer to the system detection process of the present invention Figure 3 ,First, the same place is divided into multiple corresponding areas according to the ,distribution and number of the control facilities required, e.g. Figure 2 As shown in the figure, six partition scenes in the same place are demonstrated. The shaded part corresponds to the on state of lighting, air conditioning and other facilities when there are people. The partition can be flexibly adjusted according to the actual situation. The system uses light sensors and temperature sensors to perform preliminary detection of the surrounding environment. When the environmental conditions meet the preset conditions, that is, when the light is sufficient and the temperature is suitable, no further presence sensing detection is performed. Otherwise, a pyroelectric sensor is used to detect the use area first to distinguish between living things and other objects. When a living thing is detected, the millimeter-wave radar sensor is triggered to work. This can reduce the working time of the millimeter-wave radar, thereby further reducing the energy consumption of the system.

[0031] Specifically, the first step is to use a photosensitive sensor and a temperature sensor to detect the surrounding environment. The photosensitive sensor uses a BH1750 module, and its circuit diagram is as follows Figure 4 As shown, VCC is connected to the power supply, GND is connected to the ground, and the illumination data of BH1750 is read through the I2C protocol. The preset standard value is 50lx. The temperature sensor uses DS18B20. The circuit diagram is as follows Figure 5 As shown, VDD is connected to the power supply, DQ is connected to the control module to transmit data, and an external pull-up resistor is added. GND is grounded, and the temperature is preset to 26°C. When the light value is greater than the preset value and the temperature is lower than the preset value, it indicates that the environmental conditions are good, and other sensors are not further turned on at this time.

[0032] The second step is to turn on the pyroelectric sensor when the light value or temperature value does not meet the preset value. The pyroelectric sensor is W406Q PIR SENSOR. The VDD of the sensor needs to be connected to the ground with a 100NF capacitor. It detects the presence of organisms by detecting changes in infrared radiation. It is usually equipped with a Fresnel lens to help focus and help infrared radiation. When a living organism is detected, the control module transmits the high-level signal to the millimeter-wave radar sensor to trigger the radar.

[0033] The chip of the millimeter-wave radar sensor module is Skyrealy RC2412, the operating frequency is 24G, and it is equipped with a one-transmit-two-receive antenna. The present invention designs the antenna and hardware circuit. Please refer to the hardware circuit diagram of the millimeter-wave radar sensor module Figure 6 , Since the ROM of Skyrealy RC2412 is only 10K bytes, it cannot meet the needs of this project, so GD25WQ80E is selected as additional storage space. Considering the high processing cost of the high-frequency board, the radar sensor module only retains the most core components to ensure minimization. The remaining components are arranged in the lower low-frequency board. The radar sensor communicates with the low-frequency board through the serial port. Among them, the antenna array adopts a 2×2 unit design. Each antenna unit is fed by a 50Ω feeder and resonates at 24.15GHz. Please refer to the EH surface radiation pattern of the antenna array Figure 7 .

[0034] In order to achieve system miniaturization and improve integration, the antenna units are arranged in opposite directions and connected through a T-type power divider. The power divider design includes unequal amplitude feeding and a 180° phase compensation mechanism to ensure the consistency of the signal phase in the entire array. In addition, in order to improve impedance matching and further optimize performance, the T-type power divider is chamfered. The antenna array exhibits excellent matching characteristics in the frequency range of 23.88-24.45GHz, and the S11 parameter is less than -10dB in the entire bandwidth. The best matching state is achieved at 24.14GHz, with an S11 value as low as -22.34dB. Please refer to the unit S11 (return loss) diagram Figure 8 , please refer to the array S11 (return loss) diagram Fig. 9 This excellent matching performance ensures the efficient operation of the system within the specified frequency range. At the same time, the maximum gain of the antenna array reaches 12.81dB, which fully meets the needs of the system.

[0035] Step 3: When the millimeter wave radar sensor module is turned on, please refer to the algorithm flow Fig.10 First, a frequency modulated continuous wave signal is sent to collect the human body reflection signal in real time to obtain two ADC data, which contain the spatial position information of the target. By preprocessing this information, including 1DFFT and 2DFFT, deleting some invalid values ​​in 2DFFT, and then performing DOA estimation, a three-dimensional point cloud can be generated to determine the direction of the human body relative to the sensor. In order to maintain stable detection performance under complex backgrounds, CFAR detection technology is used, which can automatically adjust the detection threshold according to the background noise level to reduce the interference caused by background noise.

[0036] In order to meet the needs of intelligent zoning control, further improve detection accuracy and adapt to the needs of human presence sensing detection at different distances and angles, this radar algorithm uses the distance compensation adaptive signal-to-noise ratio (SNR) detection algorithm in the CFAR detection technology. Considering the characteristic that the signal strength is inversely proportional to the fourth power of the target distance, the expected power of the same target in different ranges can be calculated according to this signal attenuation law. In this way, even at different distances, the system can maintain relatively consistent detection performance, ensuring accuracy and reliability in the entire intelligent zoning control system. Its expected power formula can be expressed as:

[0037]

[0038] Where P1 is the power corresponding to the known target distance R1, and P2 is the expected power at the same target distance R2. Please refer to the distance compensation SNR threshold diagram Fig.11In this example, when R1 is set to 4m, P1 is 11dB, and the R2 range is set to [1,5]. For distances less than 1m, please refer to the data at 1m; for distances greater than 5m, please refer to the data at 5m.

[0039] In the fourth step, in order to distinguish individuals in different areas and reduce false detection, the DBSCAN clustering algorithm is used to process the point cloud data after CFAR and classify the point cloud into different areas. For each area of ​​the same place, the clustered point cloud data is defined as N, and the preset threshold is T. When N>T, it is judged as someone, and when N≤T, it is judged as no one; then, the SM technology is used to manage the state changes of each detected target, including entry, stay, exit and delay, which are represented by 00, 01, 10, and 11 respectively, to describe the activity status of the human body in each partition.

[0040] The control module is a storage unit connected to the sensor, with 1 and 0 representing the open and closed status of the facilities in each area. Under the default settings, when the radar sensor is entering, the control module uses Bluetooth to send a 1 instruction to the execution module, and the radar enters the 01 state; when a person leaves the detection area, the control module uses Bluetooth to send a 0 instruction to the execution module. The user can use Bluetooth to set the delay duration. Taking the delay setting of 1 minute as an example, when the radar detects that a person has left, it will enter the delay state. At this time, the facility will still remain on for 1 minute and then switch to the leaving state.

[0041] The control module is connected to the sensor module as a storage unit and is responsible for managing the on (1) and off (0) status of each detection area facility. By default, when the radar sensor detects that someone has entered the detection area, the control module uses Bluetooth to send a "1" command to the execution module, and the radar enters the "01" state (staying state). When the person leaves the detection area, the control module uses Bluetooth to send a "0" command to the execution module, and the radar enters the "10" state (leaving state).

[0042] Users can use Bluetooth communication to set the delay time D (in seconds) after leaving. Let t be the current time, t leave is the time when the person leaves. leave +D, the radar is in "11" state (delay state); when t≥t leave +D, the radar is in "10" state (leaving state). For example, when the delay is set to 1 minute, once the radar detects that a person has left, it will enter "11" state (delay state). During this period, the facility continues to remain on for 1 minute. After the delay is over, the radar state switches from "11" to "10" (leaving state), and the facility is closed.

[0043] The execution module is a Bluetooth receiving switch, which can be directly attached to the original switch, receives the signal from the control module, and decodes it, thereby controlling the opening and closing of indoor facilities (lighting, fans, air conditioning, etc.).

[0044] Although the description of the present invention has been quite detailed and specifically describes several described embodiments, it is not intended to be limited to any of these details or embodiments or any particular embodiment, but should be regarded as providing a broad possible interpretation of these claims in view of the prior art by reference to the appended claims, thereby effectively covering the intended scope of the present invention. In addition, the above description of the present invention is based on the embodiments foreseeable by the inventor, and its purpose is to provide a useful description, and those non-substantial changes to the present invention that have not yet been foreseen may still represent equivalent changes to the present invention.

[0045] The above is only a preferred embodiment of the present invention. The present invention is not limited to the above implementation. As long as the technical effect of the present invention is achieved by the same means, it should belong to the protection scope of the present invention. Within the protection scope of the present invention, its technical scheme and / or implementation method can have various modifications and changes.

Claims

1. Low power consumption indoor induction intelligent partition control system, characterized by: It includes a sensor module, a control module, a communication module and an execution module. The control module converts the detection result of the sensor module into a control signal and transmits it to the execution module through the communication module to control the operation of indoor facilities. The sensor module is composed of a photosensitive sensor, a temperature sensor, a pyroelectric sensor and a 24G millimeter-wave radar sensor. The photosensitive sensor and the temperature sensor are used to detect the temperature and light conditions of the environment. The pyroelectric sensor is used to detect whether there are living things entering the detection range and can distinguish between living things and other objects. The millimeter-wave radar sensor performs more accurate detection to determine the position and activity of the human body.

2. The low-power indoor sensing intelligent partition control system according to claim 1 is characterized in that: The sensor module is controlled in three levels. The first-level sensor is a photosensitive sensor and a temperature sensor. The second-level sensor is a pyroelectric sensor. The next-level sensor is started after the previous-level sensor meets the conditions. The third-level sensor is a 24G millimeter-wave radar sensor.

3. The low-power indoor sensing intelligent partition control system according to claim 2 is characterized in that: Indoors according to 15m 2 Partitions are divided into zones, and a set of sensor modules are installed in each zone. The sensor modules are installed on the wall in the zone, and the millimeter-wave radar is tilted 30 to 60 degrees perpendicular to the ground.

4. The low-power indoor sensing intelligent partition control system according to claim 3 is characterized in that: The millimeter wave radar sensor adopts a signal processing algorithm including direction of arrival (DOA) estimation, constant false alarm rate (CFAR) detection, clustering algorithm (DBSCAN) and state machine (SM) 5. The low-power indoor sensing intelligent partition control system according to claim 4 is characterized in that: The CFAR detection technology uses a distance-compensated adaptive signal-to-noise ratio (SNR) detection algorithm. Considering the characteristic that the signal strength is inversely proportional to the fourth power of the target distance, the expected power of the same target in different ranges can be calculated according to this signal attenuation law. The expected power formula can be expressed as: Where P1 is the power corresponding to the known target distance R1, and P2 is the expected power at the same target distance R2.

6. The low-power indoor sensing intelligent partition control system according to claim 5 is characterized in that: The DBSCAN clustering algorithm is used to process the point cloud data after CFAR, and the point cloud is classified into different areas. For each area of ​​the same place, the clustered point cloud data is defined as N, and the preset threshold is T. When N>T, it is judged as someone, and when N≤T, it is judged as no one. Then, the SM technology is used to manage the state changes of each detected target.

7. The low-power indoor sensing intelligent partition control system according to claim 1 or 2, characterized in that: The millimeter-wave radar antenna adopts a 2*2 unit design array with a maximum gain of 12.81dB. The antenna unit is fed by a 50Ω feeder, and its resonant operating point is 24.15GHz. The antenna units are connected by a T-type power divider. The antenna is arranged in opposite directions, and the power divider is used for unequal amplitude feeding. 180° phase compensation is performed on one side, and the T-type power divider is chamfered to increase impedance matching.

8. The low-power indoor sensing intelligent partition control system according to claim 1 is characterized in that: The communication module adopts HC-05 Bluetooth module, and Bluetooth is used for wireless communication with the user's mobile device and controlling the opening and closing of public equipment.

9. The low-power indoor sensing intelligent partition control system according to claim 1 is characterized in that: The execution module has a built-in Bluetooth switch, a central processing unit, a control module, a servo and a button battery, and is directly attached to the original switch at the place of use. The module can receive the control signal from the communication module and decode it through the internal central processing unit. Subsequently, the servo is driven by the internal control module to achieve the opening and closing control of indoor facilities.

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