Occupation detection sensor based on TOF (Time of Flight) ranging technology

Abstract

The utility model discloses an occupancy detection sensor based on a TOF ranging technology. Comprising a 2.4 G low-power-consumption Bluetooth module, a battery circuit, a battery electric quantity detection circuit, an LDO power management circuit, a PIR infrared sensor circuit, a window comparator, an operational amplifier circuit, a TOF sensor circuit, a Flash memory circuit, an LED indicating lamp circuit, an anti-disassembly / power on-off key circuit, a Bluetooth gateway, a cloud server, a display and a mobile phone APP. According to the utility model, through combination of TOF distance measurement and PIR infrared sensing technologies, accurate detection and tracking of personnel or objects in a specific area are realized, a 2.4 G low-power-consumption Bluetooth chip and an ultra-low-power-consumption TOF sensor working mode are adopted, the service life of the system is prolonged, a user can check occupation information anytime and anywhere through a cloud server and a mobile phone APP, and the use experience of the user is improved. And remote monitoring and management are realized.

Description

Technical Field

[0001] This utility model belongs to the field of sensor technology, specifically relating to a occupancy detection sensor based on TOF ranging technology. Background Technology

[0002] In modern intelligent monitoring and automated control systems, accurate detection and tracking of people or objects occupying specific areas is crucial. Traditional occupancy detection technologies mostly rely on simple infrared or ultrasonic sensors. While these technologies are low-cost, they have significant limitations in ranging accuracy, environmental adaptability, and real-time performance. For example, infrared sensors are susceptible to ambient light, while ultrasonic sensors are prone to errors when encountering complex reflective surfaces.

[0003] In recent years, with the rapid development of optoelectronic and signal processing technologies, sensors based on Time-of-Flight (TOF) ranging technology have gradually emerged. TOF ranging technology calculates the distance between the target and the sensor by emitting a brief light pulse (usually infrared light or laser) and accurately measuring the time difference between the emission of the light pulse and its reflection from the target object. This technology, with its high precision, strong anti-interference capabilities, and wide measurement range, shows great potential in fields such as industrial automation, smart homes, and security monitoring.

[0004] In occupancy detection applications, Time-of-Flight (TOF) ranging technology can not only accurately determine whether a target exists within a pre-defined detection area, but also provide precise location information of the target. This is of great significance for optimizing space utilization and improving the efficiency of security monitoring. For example, in public places such as offices and conference rooms, TOF-based occupancy detection sensors can monitor seat usage in real time and automatically adjust the operating status of equipment such as lighting and air conditioning to achieve energy conservation and emission reduction. Meanwhile, in industrial scenarios such as warehouse management and production line monitoring, this technology can also effectively track material flow and personnel activity, improving production efficiency and management levels.

[0005] Furthermore, with the popularization of IoT technology, occupancy detection sensors based on TOF ranging technology can be easily connected to cloud management systems to achieve remote monitoring and data analysis, further expanding their application scenarios. Through smartphone apps or web interfaces, users can view the status of the detection area anytime, anywhere, receive abnormal alarms, and even make decisions based on data analysis results, greatly improving management efficiency and flexibility.

[0006] In conclusion, occupancy detection sensors based on Time-of-Flight (TOF) ranging technology are gradually becoming an important part of the field of intelligent monitoring and automation control due to their high precision, strong environmental adaptability, and good scalability, providing strong technical support for promoting the intelligent transformation of various industries. Utility Model Content

[0007] In view of this, the main objective of this utility model is to provide a occupancy detection sensor based on TOF ranging technology.

[0008] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0009] This utility model embodiment provides a occupancy detection sensor based on TOF ranging technology, including a 2.4G low-power Bluetooth module, a battery circuit, a battery power detection circuit, an LDO power management circuit, a PIR infrared sensor circuit, a window comparator, an operational amplifier circuit, a TOF sensor circuit, a Flash memory circuit, an LED indicator circuit, an anti-tamper / power on / off button circuit, a Bluetooth gateway, a cloud server, a display, and a mobile APP. The battery power is monitored in real time by the battery power detection circuit; the LDO power management circuit converts the battery voltage to a stable 3.3V power supply for the 2.4G low-power Bluetooth module; and the output signal of the anti-tamper / power on / off button circuit directly controls the 2.4G low-power Bluetooth module. The power-on / off state; the input signal of the LED indicator circuit comes from the 2.4G Low Energy Bluetooth module and is used to reflect the working status of the sensor; the TOF sensor circuit and Flash memory exchange data with the 2.4G Low Energy Bluetooth module through a communication protocol; the signal of the PIR infrared sensor circuit is processed by the operational amplifier circuit and window comparator, and is finally received and processed by the 2.4G Low Energy Bluetooth module; the 2.4G Low Energy Bluetooth module establishes a wireless connection with the cloud server through a Bluetooth gateway to realize data uploading and receiving; the data processed by the cloud server can be viewed on a display; the mobile APP communicates with the 2.4G Low Energy Bluetooth module and serves as the user interface for interacting with the sensor, capable of receiving and displaying sensor data.

[0010] In the above scheme, the battery circuit includes a battery, a first resistor, a twenty-eighth capacitor, and a 3.6V power output terminal. The positive terminal of the battery is connected to the first end of the first resistor, the second end of the first resistor is connected to the first end of the twenty-eighth capacitor and the 3.6V power output terminal, and the second end of the twenty-eighth capacitor is connected to the negative terminal of the battery.

[0011] In the above scheme, the LDO power management circuit includes a nineteenth resistor, an eighteenth resistor, a twenty-sixth capacitor, a twenty-seventh capacitor, an LDO power management chip, and a 3.3V power output terminal. The first end of the nineteenth resistor is connected to the 3.6V power output terminal, the first end of the twenty-sixth capacitor, and the VIN terminal of the LDO power management chip. The second end of the nineteenth resistor is connected to the VDD terminal of the 2.4G low-power Bluetooth module, the VOUT terminal of the LDO power management chip, the first end of the eighteenth resistor, and the first end of the twenty-seventh capacitor. The second end of the eighteenth resistor is connected to the 3.3V power output terminal.

[0012] In the above scheme, the battery power detection circuit includes a sixth detection resistor, a seventh detection resistor, and a third detection capacitor. The first end of the sixth detection resistor is connected to the positive terminal of the battery. The second end of the sixth detection resistor is connected to the first end of the third detection capacitor, the first end of the seventh detection resistor, and the P0.31 / AIN7 terminal of the 2.4G low power Bluetooth module. The second end of the seventh detection resistor and the second end of the third detection capacitor are both grounded.

[0013] In the above scheme, the LED indicator circuit includes a first light-emitting diode and a twenty-first resistor. The positive terminal of the first light-emitting diode is connected to the second end of the nineteenth resistor, and the negative terminal of the first light-emitting diode is connected in series with the twenty-first resistor and then connected to the P0.17 terminal of the 2.4G low-power Bluetooth module.

[0014] In the above scheme, the anti-tamper / power switch button circuit includes a 24th resistor, a 39th capacitor, and a first switch. The first end of the 24th resistor is connected to the second end of the 19th resistor. The second end of the 24th resistor is connected to the P0.13 terminal of the 2.4G low power Bluetooth module, the first end of the first switch, and the first end of the 39th capacitor. The second end of the 39th capacitor is connected to the second end of the first switch and then grounded.

[0015] In the above scheme, the TOF sensor circuit includes a TOF sensor, a first resistor, a ninth resistor, a twenty-fourth capacitor, a twenty-sixth capacitor, a twenty-seventh capacitor, and a thirtieth capacitor. The first end of the first resistor is connected to the 3.3V power supply output terminal, the first end of the ninth resistor, the first end of the twenty-fourth capacitor, and the VDDC terminal of the TOF sensor, respectively. The second end of the first resistor is connected to the SDA terminal of the TOF sensor. The second end of the ninth resistor is connected to the SCL terminal of the TOF sensor. The second end of the twenty-fourth capacitor is connected to the GNDC terminal of the TOF sensor and then grounded. The first end of the twenty-sixth capacitor is connected to the 3.3V power supply output terminal and the VDD terminal of the TOF sensor. The second terminal of the 26th capacitor is connected to the GNDV terminal of the TOF sensor and then grounded. The first terminal of the 27th capacitor is connected to the first terminal of the 30th capacitor, the 3.3V power output terminal, and the VDD terminal of the TOF sensor. The second terminals of the 27th and 30th capacitors are both grounded. The SCL terminal of the TOF sensor is connected to the P0.11 terminal of the 2.4G Low Energy Bluetooth module through the Bluetooth motherboard connector. The SDA terminal of the TOF sensor is connected to the P0.12 terminal of the 2.4G Low Energy Bluetooth module through the Bluetooth motherboard connector. The EN terminal of the TOF sensor is connected to the P0.16 terminal of the 2.4G Low Energy Bluetooth module through the Bluetooth motherboard connector.

[0016] In the above scheme, the Flash memory circuit includes a memory chip, a thirtieth resistor, and a twenty-ninth capacitor. The first end of the thirtieth resistor is connected to the VCC terminal of the memory chip, the second end of the nineteenth resistor, and the first end of the twenty-ninth capacitor. The second end of the twenty-ninth capacitor is grounded. The second end of the thirtieth resistor is connected to the HOLD terminal of the memory chip. The CS terminal of the memory chip is connected to the P0.26 terminal of the 2.4G Low Energy Bluetooth module. The DO terminal of the memory chip is connected to the P0.25 terminal of the 2.4G Low Energy Bluetooth module. The CLK terminal of the memory chip is connected to the P0.27 terminal of the 2.4G Low Energy Bluetooth module. The DIO terminal of the memory chip is connected to the P0.28 terminal of the 2.4G Low Energy Bluetooth module.

[0017] In the above scheme, the window comparator includes a first operational amplifier, a third operational amplifier, a fourth operational amplifier, a thirty-seventh resistor, a thirty-sixth resistor, a seventh resistor, a twenty-eighth resistor, a thirty-fifth resistor, a second resistor, a thirty-second capacitor, a sixteenth capacitor, a fourth resistor, a third capacitor, a fifth resistor, and a thirteenth capacitor. The first terminal of the third operational amplifier is connected in series with the thirty-seventh resistor and then connected to the P0.05 terminal of the 2.4G Low Energy Bluetooth module. The first terminal of the fourth operational amplifier is connected in series with the thirty-sixth resistor and then connected to the P0.06 terminal of the 2.4G Low Energy Bluetooth module. The third terminal of the third operational amplifier is connected to the first terminal of the seventh resistor and the first terminal of the twenty-eighth resistor. The second terminal of the seventh resistor is connected to the second terminal of the nineteenth resistor. The second terminal of the twenty-eighth resistor is connected to the thirty-second resistor and the thirty-third resistor. The first terminal of the five resistors, the third terminal of the first operational amplifier, and the first terminal of the thirty-second capacitor are connected together. The second terminal of the thirty-second capacitor is grounded. The fourth terminal of the first operational amplifier is connected to the first terminal of the sixteenth capacitor and the second terminal of the nineteenth resistor. The second terminal of the sixteenth capacitor is grounded. The first terminal of the first operational amplifier is connected to the first terminal of the fourth resistor, the first terminal of the fifth resistor, and the first terminal of the thirteenth capacitor. The second terminal of the thirteenth capacitor is connected to the second terminal of the fifth resistor, the second terminal of the first operational amplifier, and the first terminal of the third capacitor. The second terminal of the fourth resistor is connected to the second terminal of the third operational amplifier and the third terminal of the fourth operational amplifier. The second terminal of the thirty-fifth resistor is connected to the first terminal of the second resistor and the second terminal of the fourth operational amplifier. The second terminal of the second resistor is grounded.

[0018] In the above scheme, the operational amplifier circuit includes a second operational amplifier, a sixth resistor, a sixth capacitor, an eleventh resistor, a twelfth resistor, an eighth resistor, a ninth capacitor, a thirty-fifth capacitor, a tenth resistor, an eighteenth capacitor, a thirty-sixth capacitor, a thirty-seventh capacitor, a first capacitor, a fourth capacitor, a fifth capacitor, and a third resistor. The first terminal of the sixth resistor is connected to the second terminal of the third capacitor. The second terminal of the sixth resistor is connected to the first terminal of the second operational amplifier, the first terminal of the eleventh resistor, and the first terminal of the sixth capacitor. The second terminal of the sixth capacitor is connected to the second terminal of the eleventh resistor, the third terminal of the second operational amplifier, the first terminal of the twelfth resistor, and the first terminal of the thirty-fifth capacitor. The second terminal of the twelfth resistor is connected to the ninth capacitor. The first end of the container is connected, the second end of the ninth capacitor is connected to the second end of the thirty-fifth capacitor and then grounded, the second end of the second operational amplifier is connected in series with the eighth resistor and then connected to the first end of the tenth resistor and the first end of the eighteenth capacitor, the second end of the tenth resistor is connected to the second end of the eighteenth capacitor and then grounded, the first end of the third resistor is connected to the second end of the nineteenth resistor, the first end of the fifth capacitor, the first end of the first capacitor and the first end of the fourth capacitor, the second end of the third resistor is connected to the first end of the thirty-sixth capacitor and the first end of the thirty-seventh capacitor, the second end of the thirty-seventh capacitor is connected to the second end of the thirty-sixth capacitor, the second end of the fifth capacitor, the second end of the first capacitor and the second end of the fourth capacitor and then grounded.

[0019] In the above scheme, the PIR infrared sensor circuit includes a PIR infrared sensor. The PIR_D terminal of the PIR infrared sensor is connected to the second terminal of the third resistor through a second connector, and the PIR_S terminal of the PIR infrared sensor is connected to the second terminal of the eighth resistor through a second connector.

[0020] Compared with existing technologies, this invention combines TOF ranging and PIR infrared sensing technologies to achieve accurate detection and tracking of people or objects in a specific area. It adopts a 2.4G low-power Bluetooth chip and an ultra-low-power TOF sensor working mode, which extends the service life of the system. Through a cloud server and a mobile APP, users can view occupancy information anytime and anywhere, and realize remote monitoring and management. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this invention, illustrate exemplary embodiments of the present invention and, together with their description, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings:

[0022] Figure 1 This is a structural block diagram of a occupancy detection sensor based on TOF ranging technology according to an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of the 2.4G low-power Bluetooth module described in an embodiment of this utility model;

[0024] Figure 3 This is a structural block diagram of the battery circuit and LDO power management circuit described in the embodiment of this utility model;

[0025] Figure 4 This is a schematic diagram of the battery power detection circuit described in an embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the LED indicator circuit described in an embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of the anti-tamper / power switch button circuit described in an embodiment of the present invention;

[0028] Figure 7 This is a schematic diagram of the TOF sensor circuit described in an embodiment of the present invention;

[0029] Figure 8 This is a schematic diagram of the Flash memory circuit described in an embodiment of the present invention;

[0030] Figure 9 This is a schematic diagram of the window comparator and operational amplifier circuit described in an embodiment of the present invention;

[0031] Figure 10 This is a schematic diagram of the PIR infrared sensor circuit described in an embodiment of the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0033] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0034] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element.

[0035] like Figures 1-10As shown, Embodiment 1 of this utility model provides a occupancy detection sensor based on TOF ranging technology, including a 2.4G low-power Bluetooth module, a battery circuit, a battery power detection circuit, an LDO power management circuit, a PIR infrared sensor circuit, a window comparator, an operational amplifier circuit, a TOF sensor circuit, a Flash memory circuit, an LED indicator circuit, an anti-tamper / power on / off button circuit, a Bluetooth gateway, a cloud server, a display, and a mobile APP. The battery power is monitored in real time by the battery power detection circuit; the LDO power management circuit converts the battery voltage into a stable 3.3V power supply for the 2.4G low-power Bluetooth module; the output signal of the anti-tamper / power on / off button circuit directly controls the 2.4G low-power Bluetooth module. The power-on / off state; the input signal of the LED indicator circuit comes from the 2.4G Low Energy Bluetooth module and is used to reflect the working status of the sensor; the TOF sensor circuit and the Flash memory circuit exchange data with the 2.4G Low Energy Bluetooth module through a communication protocol; the signal of the PIR infrared sensor circuit is processed by the operational amplifier circuit and the window comparator, and is finally received and processed by the 2.4G Low Energy Bluetooth module; the 2.4G Low Energy Bluetooth module establishes a wireless connection with the cloud server through a Bluetooth gateway to realize data uploading and receiving; the data processed by the cloud server can be viewed on a display; the mobile APP communicates with the 2.4G Low Energy Bluetooth module and serves as the user interface for interacting with the sensor, capable of receiving and displaying sensor data.

[0036] like Figures 1-3 As shown, the battery circuit includes a battery, a first resistor R1, a twenty-eighth capacitor C28, and a 3.6V power output terminal 3V6. The positive terminal BAT+ of the battery is connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected to the first end of the twenty-eighth capacitor C28 and the 3.6V power output terminal 3V6, and the second end of the twenty-eighth capacitor C28 is connected to the negative terminal BAT- of the battery.

[0037] like Figures 1-3As shown, the LDO power management circuit includes a nineteenth resistor R19, an eighteenth resistor R18, a twenty-sixth capacitor C26, a twenty-seventh capacitor C27, an LDO power management chip U3, and a 3.3V power output terminal 3V3. The first end of the nineteenth resistor R19 is connected to the 3.6V power output terminal 3V6, the first end of the twenty-sixth capacitor C26, and the VIN terminal of the LDO power management chip U3. The second end of the nineteenth resistor R19 is connected to the VDD terminal of the 2.4G low-power Bluetooth module U2, the VOUT terminal of the LDO power management chip U3, the first end of the eighteenth resistor R18, and the first end of the twenty-seventh capacitor C27. The second end of the eighteenth resistor R18 is connected to the 3.3V power output terminal 3V3.

[0038] like Figures 1-4 As shown, the battery power detection circuit includes a sixth detection resistor SR6, a seventh detection resistor SR7, and a third detection capacitor SC3. The first end of the sixth detection resistor SR6 is connected to the positive terminal BAT+ of the battery. The second end of the sixth detection resistor SR6 is connected to the first end of the third detection capacitor SC3, the first end of the seventh detection resistor SR7, and the P0.31 / AIN7 terminal of the 2.4G low power Bluetooth module U2. The second end of the seventh detection resistor SR7 and the second end of the third detection capacitor SC3 are both grounded.

[0039] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the LED indicator circuit includes a first light-emitting diode D1 and a twenty-first resistor R21. The positive terminal of the first light-emitting diode D1 is connected to the second end of the nineteenth resistor R19, and the negative terminal of the first light-emitting diode D1 is connected to the P0.17 terminal of the 2.4G low-power Bluetooth module U2 after being connected in series with the twenty-first resistor R21.

[0040] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 6 As shown, the anti-tamper / power switch button circuit includes a 24th resistor R24, a 39th capacitor C39, and a first switch K1. The first end of the 24th resistor R24 ​​is connected to the second end of the 19th resistor R19. The second end of the 24th resistor R24 ​​is connected to the P0.13 terminal of the 2.4G low-power Bluetooth module U2, the first end of the first switch K1, and the first end of the 39th capacitor C39. The second end of the 39th capacitor C39 is connected to the second end of the first switch K1 and then grounded.

[0041] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 7 As shown, the TOF sensor circuit includes a TOF sensor U5, a first resistor R1, a ninth resistor R9, a twenty-fourth capacitor C24, a twenty-sixth capacitor C26, a twenty-seventh capacitor C27, and a thirtieth capacitor C30. The first terminal of the first resistor R1 is connected to the 3.3V power output terminal (3V3), the first terminal of the ninth resistor R9, the first terminal of the twenty-fourth capacitor R24, and the VDDC terminal of the TOF sensor U5. The second terminal of the first resistor R1 is connected to the SDA terminal of the TOF sensor U5. The second terminal of the ninth resistor R9 is connected to the SCL terminal of the TOF sensor U5. The second terminal of the twenty-fourth capacitor C24 is connected to the GNDC terminal of the TOF sensor U5 and then grounded. The first terminal of the twenty-sixth capacitor C26 is connected to the 3.3V power output terminal and the VDDC terminal of the TOF sensor U5. The VDDV terminal is connected, and the second terminal of the 26th capacitor C26 is connected to the GNDV terminal of the TOF sensor U5 and then grounded. The first terminal of the 27th capacitor C27 is connected to the first terminal of the 30th capacitor C30, the 3.3V power output terminal 3V3, and the VDD terminal of the TOF sensor U5, respectively. The second terminals of the 27th capacitor C27 and the 30th capacitor C30 are both grounded. The SCL terminal of the TOF sensor U5 is connected to the P0.11 terminal of the 2.4G Low Energy Bluetooth module U2 through the Bluetooth motherboard connector J1. The SDA terminal of the TOF sensor U5 is connected to the P0.12 terminal of the 2.4G Low Energy Bluetooth module U2 through the Bluetooth motherboard connector J1. The EN terminal of the TOF sensor U5 is connected to the P0.16 terminal of the 2.4G Low Energy Bluetooth module U5 through the Bluetooth motherboard connector J1.

[0042] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 8As shown, the Flash memory circuit includes a memory chip U4, a thirtieth resistor R30, and a twenty-ninth capacitor C29. The first end of the thirtieth resistor R30 is connected to the VCC terminal of the memory chip U4, the second end of the nineteenth resistor R19, and the first end of the twenty-ninth capacitor C29. The second end of the twenty-ninth capacitor C29 is grounded. The second end of the thirtieth resistor R30 is connected to the HOLD terminal of the memory chip U4. The CS terminal of the memory chip U4 is connected to the P0.26 terminal of the 2.4G Low Energy Bluetooth module U2. The DO terminal of the memory chip U4 is connected to the P0.25 terminal of the 2.4G Low Energy Bluetooth module U2. The CLK terminal of the memory chip U4 is connected to the P0.27 terminal of the 2.4G Low Energy Bluetooth module U2. The DIO terminal of the memory chip U4 is connected to the P0.28 terminal of the 2.4G Low Energy Bluetooth module U2.

[0043] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 9As shown, the window comparator includes a first operational amplifier OP1, a third operational amplifier OP3, a fourth operational amplifier OP4, a thirty-seventh resistor R37, a thirty-sixth resistor R36, a seventh resistor R7, a twenty-eighth resistor R28, a thirty-fifth resistor R35, a second resistor R2, a thirty-second capacitor C32, a sixteenth capacitor C16, a fourth resistor R4, a third capacitor C3, a fifth resistor R5, and a thirteenth capacitor C13. The first terminal of the third operational amplifier OP3 is connected in series with the thirty-seventh resistor R37 and then connected to the P0.05 terminal of the 2.4G Low Energy Bluetooth module U2. The first terminal of the fourth operational amplifier OP4 is connected in series with the thirty-sixth resistor R36 and then connected to the P0.06 terminal of the 2.4G Low Energy Bluetooth module U2. The third terminal of the third operational amplifier OP3 is connected to the first terminal of the seventh resistor R7 and the first terminal of the twenty-eighth resistor R28. The second terminal of the seventh resistor R7 is connected to the second terminal of the nineteenth resistor R19. The second terminal of the twenty-eighth resistor R28 is connected to... The first terminal of the 35th resistor R35, the third terminal of the first operational amplifier OP1, and the first terminal of the 32nd capacitor C32 are connected. The second terminal of the 32nd capacitor C32 is grounded. The fourth terminal of the first operational amplifier OP1 is connected to the first terminal of the 16th capacitor C16 and the second terminal of the 19th resistor R19. The second terminal of the 16th capacitor C16 is grounded. The first terminal of the first operational amplifier OP1 is connected to the first terminal of the fourth resistor R4, the first terminal of the fifth resistor R5, and the first terminal of the 13th capacitor C13. The second terminal of the 13th capacitor C13 is connected to the second terminal of the fifth resistor R5, the second terminal of the first operational amplifier OP1, and the first terminal of the third capacitor C3. The second terminal of the fourth resistor R4 is connected to the second terminal of the third operational amplifier OP3 and the third terminal of the fourth operational amplifier OP4. The second terminal of the 35th resistor R35 is connected to the first terminal of the second resistor R2 and the second terminal of the fourth operational amplifier OP4. The second terminal of the second resistor R2 is grounded.

[0044] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 9As shown, the operational amplifier circuit includes a second operational amplifier OP2, a sixth resistor R6, a sixth capacitor C6, an eleventh resistor R11, a twelfth resistor R12, an eighth resistor R8, a ninth capacitor C9, a thirty-fifth capacitor C35, a tenth resistor R10, an eighteenth capacitor C18, a thirty-sixth capacitor C36, a thirty-seventh capacitor C37, a first capacitor C1, a fourth capacitor C4, a fifth capacitor C5, and a third resistor R3. The first terminal of the sixth resistor R6 is connected to the second terminal of the third capacitor C3. The second terminal of the sixth resistor R6 is connected to the first terminal of the second operational amplifier OP2, the first terminal of the eleventh resistor R11, and the first terminal of the sixth capacitor C6. The second terminal of the sixth capacitor C6 is connected to the second terminal of the eleventh resistor R11, the third terminal of the second operational amplifier OP2, the first terminal of the twelfth resistor R12, and the first terminal of the thirty-fifth capacitor C35. The twelfth resistor R12... The second terminal is connected to the first terminal of the ninth capacitor C9. The second terminal of the ninth capacitor C9 is connected to the second terminal of the thirty-fifth capacitor C35 and then grounded. The second terminal of the second operational amplifier OP2 is connected in series with the eighth resistor R8 and then connected to the first terminal of the tenth resistor R10 and the first terminal of the eighteenth capacitor C18. The second terminal of the tenth resistor R10 is connected to the second terminal of the eighteenth capacitor C18 and then grounded. The first terminal of the third resistor R3 is connected to the second terminal of the nineteenth resistor C19, the first terminal of the fifth capacitor C5, the first terminal of the first capacitor C1, and the first terminal of the fourth capacitor C4. The second terminal of the third resistor R3 is connected to the first terminal of the thirty-sixth capacitor C36 and the first terminal of the thirty-seventh capacitor C37. The second terminal of the thirty-seventh capacitor C37 is connected to the second terminal of the thirty-sixth capacitor C36, the second terminal of the fifth capacitor C5, the second terminal of the first capacitor C1, and the second terminal of the fourth capacitor C4 and then grounded.

[0045] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 9 and Figure 10 As shown, the PIR infrared sensor circuit includes a PIR infrared sensor PIR1. The PIR_D terminal of the PIR infrared sensor PIR1 is connected to the second terminal of the third resistor R3 through the second connector J2, and the PIR_S terminal of the PIR infrared sensor PIR1 is connected to the second terminal of the eighth resistor R8 through the second connector J2.

[0046] The working principle of this utility model is as follows:

[0047] like Figures 1-10As shown, this utility model is based on the integration of time-of-flight (TOF) ranging technology and passive infrared (PIR) sensing technology to achieve accurate detection and tracking of people or objects in a specific area.

[0048] PIR infrared sensing technology:

[0049] Working principle: A PIR infrared sensor is a non-contact device for detecting the presence of the human body. Its working principle is based on the pyroelectric effect, enabling it to capture changes in infrared radiation in the environment, especially the infrared radiation emitted by warm-blooded animals like humans. When a human enters the sensor's detection range, the temperature difference between the human body and the surrounding environment causes a change in the infrared radiation field, which in turn triggers a change in the sensor's electrical signal.

[0050] Signal processing: The sensor contains a pyroelectric element. When a change in infrared radiation is detected, the pyroelectric element generates a weak electrical signal change. This signal is then amplified and analyzed by the signal processor. Once the change exceeds a preset threshold, it is determined that there is human activity, thereby triggering the corresponding control action.

[0051] TOF ranging technology:

[0052] Working principle: Time-of-Flight (TOF) sensors calculate distance by emitting infrared light and measuring the time difference between its reflection and return from an object. When the light signal encounters a target object, part of the light is reflected back and then received by the sensor. By measuring the round-trip time difference of the light signal and considering that the speed of light is a constant, the distance between the target object and the sensor can be calculated.

[0053] Technical Classification: TOF sensors are mainly divided into dTOF (direct time-of-flight) sensors and iTOF (indirect time-of-flight) sensors. This invention uses a dTOF sensor, which features high precision and low power consumption.

[0054] Signal processing: The TOF sensor connects to the Bluetooth master controller via IC communication. The reflected light signal received by the sensor is processed by the internal circuitry, converted into a digital signal, and transmitted to the Bluetooth master controller for further processing and analysis.

[0055] When this invention is in use, after the system is powered on, it first performs initialization operations, including establishing a Bluetooth connection and calibrating sensors. This ensures that all modules are working properly and are ready to receive and process data.

[0056] PIR infrared sensing detection:

[0057] The PIR infrared sensor continuously monitors changes in infrared radiation in the surrounding environment. Once human activity is detected, the signal processing circuit is immediately triggered to amplify the analog signal and convert it into a digital signal.

[0058] After the digital signal is processed by the window comparator, it is compared with a preset threshold. If the signal exceeds the threshold, the human activity is deemed valid, and the TOF ranging function is triggered.

[0059] TOF ranging confirmed:

[0060] When the PIR infrared sensor detects human activity, the TOF sensor activates its ranging function. The sensor emits an infrared light pulse and measures the time difference between the emission of the light pulse and its reflection back from the target object.

[0061] The distance between the target object and the sensor is calculated based on the time difference and the speed of light constant. If the distance is within a preset range, the placeholder is confirmed to be valid.

[0062] Data upload and display:

[0063] The Bluetooth controller packages the detected position information and ranging results into a data packet. This data packet is then uploaded to a cloud server for storage and analysis via a smart Bluetooth gateway.

[0064] Users can view occupancy information and distance measurement results via a monitor or mobile app. This information can be used to monitor and manage the activity of people or objects within a specific area.

[0065] Interaction and Alarms:

[0066] Based on the occupancy detection results, the LED indicator displays the corresponding status. For example, when human activity is detected, the LED indicator may flash or remain constantly lit to indicate the occupancy status.

[0067] If the system is unauthorizedly disassembled or powered off, the tamper-proof switch and power on / off button will trigger alarm signals. These signals can be uploaded to the cloud server via Bluetooth module, notifying the user to take appropriate action.

[0068] In summary, this invention achieves precise detection and tracking of people or objects within a specific area by integrating PIR infrared sensing technology and TOF ranging technology. Furthermore, with the support of a Bluetooth module and cloud server, users can view occupancy information and ranging results anytime, anywhere, enabling remote monitoring and management.

[0069] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the scope of protection of the present utility model.

Claims

1. A occupancy detection sensor based on TOF ranging technology, characterized in that, The system includes a 2.4G Low Energy Bluetooth module, a battery circuit, a battery level detection circuit, an LDO power management circuit, a PIR infrared sensor circuit, a window comparator, an operational amplifier circuit, a TOF sensor circuit, a Flash memory circuit, an LED indicator circuit, a tamper-proof / power on / off button circuit, a Bluetooth gateway, a cloud server, a display, and a mobile app. The battery level is monitored in real-time by the battery level detection circuit. The LDO power management circuit converts the battery voltage to a stable 3.3V power supply for the 2.4G Low Energy Bluetooth module. The output signal of the tamper-proof / power on / off button circuit directly controls the power on / off state of the 2.4G Low Energy Bluetooth module. The LED indicator circuit... The input signal comes from a 2.4G Low Energy Bluetooth module and is used to reflect the sensor's operating status. Both the TOF sensor circuit and the Flash memory circuit exchange data with the 2.4G Low Energy Bluetooth module via a communication protocol. The signal from the PIR infrared sensor circuit is processed by an operational amplifier circuit and a window comparator before being received and processed by the 2.4G Low Energy Bluetooth module. The 2.4G Low Energy Bluetooth module establishes a wireless connection with the cloud server through a Bluetooth gateway to upload and receive data. The data processed by the cloud server can be viewed on a display. The mobile app communicates with the 2.4G Low Energy Bluetooth module, serving as the user interface for interacting with the sensor, and can receive and display sensor data.

2. The occupancy detection sensor based on TOF ranging technology according to claim 1, characterized in that, The battery circuit includes a battery, a first resistor, a twenty-eighth capacitor, and a 3.6V power output terminal. The positive terminal of the battery is connected to the first end of the first resistor, the second end of the first resistor is connected to the first end of the twenty-eighth capacitor and the 3.6V power output terminal, and the second end of the twenty-eighth capacitor is connected to the negative terminal of the battery. The LDO power management circuit includes a nineteenth resistor, an eighteenth resistor, a twenty-sixth capacitor, a twenty-seventh capacitor, an LDO power management chip, and a 3.3V power output terminal. The first end of the nineteenth resistor is connected to the 3.6V power output terminal, the first end of the twenty-sixth capacitor, and the VIN terminal of the LDO power management chip. The second end of the nineteenth resistor is connected to the VDD terminal of the 2.4G low-power Bluetooth module, the VOUT terminal of the LDO power management chip, the first end of the eighteenth resistor, and the first end of the twenty-seventh capacitor. The second end of the eighteenth resistor is connected to the 3.3V power output terminal. The battery power detection circuit includes a sixth detection resistor, a seventh detection resistor, and a third detection capacitor. The first end of the sixth detection resistor is connected to the positive terminal of the battery. The second end of the sixth detection resistor is connected to the first end of the third detection capacitor, the first end of the seventh detection resistor, and the P0.31 / AIN7 terminal of the 2.4G low power Bluetooth module. The second end of the seventh detection resistor and the second end of the third detection capacitor are both grounded.

3. The occupancy detection sensor based on TOF ranging technology according to claim 2, characterized in that, The LED indicator circuit includes a first light-emitting diode and a twenty-first resistor. The positive terminal of the first light-emitting diode is connected to the second end of the nineteenth resistor, and the negative terminal of the first light-emitting diode is connected in series with the twenty-first resistor and then connected to the P0.17 terminal of the 2.4G low-power Bluetooth module.

4. The occupancy detection sensor based on TOF ranging technology according to claim 3, characterized in that, The anti-tamper / power switch button circuit includes a 24th resistor, a 39th capacitor, and a first switch. The first end of the 24th resistor is connected to the second end of the 19th resistor. The second end of the 24th resistor is connected to the P0.13 terminal of the 2.4G low-power Bluetooth module, the first end of the first switch, and the first end of the 39th capacitor. The second end of the 39th capacitor is connected to the second end of the first switch and then grounded.

5. The occupancy detection sensor based on TOF ranging technology according to claim 4, characterized in that, The TOF sensor circuit includes a TOF sensor, a first resistor, a ninth resistor, a twenty-fourth capacitor, a twenty-sixth capacitor, a twenty-seventh capacitor, and a thirtieth capacitor. The first end of the first resistor is connected to the 3.3V power output terminal, the first end of the ninth resistor, the first end of the twenty-fourth capacitor, and the VDDC terminal of the TOF sensor. The second end of the first resistor is connected to the SDA terminal of the TOF sensor. The second end of the ninth resistor is connected to the SCL terminal of the TOF sensor. The second end of the twenty-fourth capacitor is connected to the GNDC terminal of the TOF sensor and then grounded. The first end of the twenty-sixth capacitor is connected to the 3.3V power output terminal and the VDDV terminal of the TOF sensor. The second terminal of the 26th capacitor is connected to the GNDV terminal of the TOF sensor and then grounded. The first terminal of the 27th capacitor is connected to the first terminal of the 30th capacitor, the 3.3V power output terminal, and the VDD terminal of the TOF sensor. The second terminals of both the 27th and 30th capacitors are grounded. The SCL terminal of the TOF sensor is connected to the P0.11 terminal of the 2.4G Low Energy Bluetooth module through the Bluetooth motherboard connector. The SDA terminal of the TOF sensor is connected to the P0.12 terminal of the 2.4G Low Energy Bluetooth module through the Bluetooth motherboard connector. The EN terminal of the TOF sensor is connected to the P0.16 terminal of the 2.4G Low Energy Bluetooth module through the Bluetooth motherboard connector.

6. The occupancy detection sensor based on TOF ranging technology according to claim 5, characterized in that, The Flash memory circuit includes a memory chip, a thirtieth resistor, and a twenty-ninth capacitor. The first end of the thirtieth resistor is connected to the VCC terminal of the memory chip, the second end of the nineteenth resistor, and the first end of the twenty-ninth capacitor. The second end of the twenty-ninth capacitor is grounded. The second end of the thirtieth resistor is connected to the HOLD terminal of the memory chip. The CS terminal of the memory chip is connected to the P0.26 terminal of the 2.4G Low Energy Bluetooth module. The DO terminal of the memory chip is connected to the P0.25 terminal of the 2.4G Low Energy Bluetooth module. The CLK terminal of the memory chip is connected to the P0.27 terminal of the 2.4G Low Energy Bluetooth module. The DIO terminal of the memory chip is connected to the P0.28 terminal of the 2.4G Low Energy Bluetooth module.

7. The occupancy detection sensor based on TOF ranging technology according to claim 6, characterized in that, The window comparator includes a first operational amplifier, a third operational amplifier, a fourth operational amplifier, a thirty-seventh resistor, a thirty-sixth resistor, a seventh resistor, a twenty-eighth resistor, a thirty-fifth resistor, a second resistor, a thirty-second capacitor, a sixteenth capacitor, a fourth resistor, a third capacitor, a fifth resistor, and a thirteenth capacitor. The first terminal of the third operational amplifier is connected in series with the thirty-seventh resistor and then connected to the P0.05 terminal of the 2.4G Low Energy Bluetooth module. The first terminal of the fourth operational amplifier is connected in series with the thirty-sixth resistor and then connected to the P0.06 terminal of the 2.4G Low Energy Bluetooth module. The third terminal of the third operational amplifier is connected to the first terminal of the seventh resistor and the first terminal of the twenty-eighth resistor. The second terminal of the seventh resistor is connected to the second terminal of the nineteenth resistor. The second terminal of the twenty-eighth resistor is connected to the third terminal of the thirty-fifth resistor. The first terminal of the first operational amplifier, the third terminal of the first operational amplifier, and the first terminal of the thirty-second capacitor are connected together. The second terminal of the thirty-second capacitor is grounded. The fourth terminal of the first operational amplifier is connected to the first terminal of the sixteenth capacitor and the second terminal of the nineteenth resistor. The second terminal of the sixteenth capacitor is grounded. The first terminal of the first operational amplifier is connected to the first terminal of the fourth resistor, the first terminal of the fifth resistor, and the first terminal of the thirteenth capacitor. The second terminal of the thirteenth capacitor is connected to the second terminal of the fifth resistor, the second terminal of the first operational amplifier, and the first terminal of the third capacitor. The second terminal of the fourth resistor is connected to the second terminal of the third operational amplifier and the third terminal of the fourth operational amplifier. The second terminal of the thirty-fifth resistor is connected to the first terminal of the second resistor and the second terminal of the fourth operational amplifier. The second terminal of the second resistor is grounded.

8. The occupancy detection sensor based on TOF ranging technology according to claim 7, characterized in that, The operational amplifier circuit includes a second operational amplifier, a sixth resistor, a sixth capacitor, an eleventh resistor, a twelfth resistor, an eighth resistor, a ninth capacitor, a thirty-fifth capacitor, a tenth resistor, an eighteenth capacitor, a thirty-sixth capacitor, a thirty-seventh capacitor, a first capacitor, a fourth capacitor, a fifth capacitor, and a third resistor. The first terminal of the sixth resistor is connected to the second terminal of the third capacitor. The second terminal of the sixth resistor is connected to the first terminal of the second operational amplifier, the first terminal of the eleventh resistor, and the first terminal of the sixth capacitor. The second terminal of the sixth capacitor is connected to the second terminal of the eleventh resistor, the third terminal of the second operational amplifier, the first terminal of the twelfth resistor, and the first terminal of the thirty-fifth capacitor. The second terminal of the twelfth resistor is connected to the ninth capacitor. The first terminal is connected, the second terminal of the ninth capacitor is connected to the second terminal of the thirty-fifth capacitor and then grounded, the second terminal of the second operational amplifier is connected in series with the eighth resistor and then connected to the first terminal of the tenth resistor and the first terminal of the eighteenth capacitor, the second terminal of the tenth resistor is connected to the second terminal of the eighteenth capacitor and then grounded, the first terminal of the third resistor is connected to the second terminal of the nineteenth resistor, the first terminal of the fifth capacitor, the first terminal of the first capacitor and the first terminal of the fourth capacitor, the second terminal of the third resistor is connected to the first terminal of the thirty-sixth capacitor and the first terminal of the thirty-seventh capacitor, the second terminal of the thirty-seventh capacitor is connected to the second terminal of the thirty-sixth capacitor, the second terminal of the fifth capacitor, the second terminal of the first capacitor and the second terminal of the fourth capacitor and then grounded.

9. The occupancy detection sensor based on TOF ranging technology according to claim 8, characterized in that, The PIR infrared sensor circuit includes a PIR infrared sensor. The PIR_D terminal of the PIR infrared sensor is connected to the second terminal of a third resistor through a second connector, and the PIR_S terminal of the PIR infrared sensor is connected to the second terminal of an eighth resistor through a second connector.

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